Device complications in adult congenital heart disease Robert M. Hayward, MD,* Thomas A. Dewland, MD,* Brian Moyers, MD,* Eric Vittinghoff, PhD,† Ronn E. Tanel, MD, FHRS,‡ Gregory M. Marcus, MD, MAS, FHRS,* Zian H. Tseng, MD, MAS, FHRS* From the *Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, University of California, San Francisco, California, †Department of Biostatistics, University of California, San Francisco, California, and ‡Division of Pediatric Cardiology, Department of Pediatrics, University of California, San Francisco, California. BACKGROUND Pacemakers and implantable cardioverterdefibrillators (ICDs) are increasingly implanted in adults with congenital heart disease (CHD), but little is known about implant-related complications and mortality. OBJECTIVE The purpose of this study was to compare pacemaker and ICD implantation complication rates between adults with and those without CHD using a comprehensive, statewide database. METHODS We used the Healthcare Cost and Utilization Project database to identify initial transvenous pacemaker and ICD implantations and implant-related complications in California hospitals from January 1, 2005, to December 31, 2011. We calculated relative risks of implant-related complications by comparing those with and those without CHD using Poisson regression with robust standard errors, adjusting for age and medical comorbidities. RESULTS We identified 105,852 patients undergoing pacemaker implantation, 1465 with noncomplex CHD and 66 with complex CHD. CHD was not associated with increased risk of pacemaker implant-related complications: adjusted risk ratio (aRR) 0.92, 95% confidence interval (CI) 0.74–1.14, P ¼ .45. We identified 32,948 patients undergoing ICD implantation, 815 with noncomplex CHD
Introduction More than 1 million adults are living with congenital heart disease (CHD) in the United States, and this group now outnumbers children with CHD.1,2 As patients with CHD live to adulthood, arrhythmias are an increasing cause of morbidity and mortality,3,4 and both pacemaker and implantable cardioverter-defibrillator (ICD) implantations are increasingly performed in this population.5 The 2 published studies of ICD placement in the CHD population, including This work was supported in part by NIH/NHLBI 5R01 HL102090 to Dr. Tseng. Dr. Tseng has received minor honoraria from Biotronik. Dr. Marcus receives research support from Medtronic. Dr. Dewland and Dr. Hayward have received educational travel grants from Medtronic and Boston Scientific. Address reprint requests and correspondence: Dr. Zian H. Tseng, Cardiac Electrophysiology Section, University of California–San Francisco, 500 Parnassus Ave, Box 1354, San Francisco, CA 94143-1354. E-mail address: [email protected].
1547-5271/$-see front matter B 2015 Heart Rhythm Society. All rights reserved.
and 87 with complex CHD. Patients with CHD had increased risk of ICD implant-related complications: aRR 1.36, 95% CI 1.05–1.76, P ¼ .02. Patients with complex CHD had greater increased risk of ICD implant-related complications: aRR 2.14, 95% CI 1.16–3.95, P ¼ .02. In patients receiving devices, CHD was associated with a trend toward lower 30-day in-hospital mortality after pacemaker (P ¼ .07) and ICD (P ¼ .19) implantation. CONCLUSION Among adult patients undergoing device implantation in California, CHD was associated with increased risk of ICD implant-related complications, but not pacemaker implant-related complications or higher 30-day in-hospital mortality. KEYWORDS Congenital heart disease; Pacemaker; Implantable cardioverter-defibrillator ABBREVIATIONS ACHD ¼ adult congenital heart disease; aRR ¼ adjusted risk ratio; CHD ¼ congenital heart disease; CI ¼ confidence interval; HCUP ¼ Health Care Cost and Utilization Project; ICD ¼ implantable cardioverter-defibrillator; NCDR ¼ National Cardiovascular Data Registry (Heart Rhythm 2015;12:338–344) I 2015 Heart Rhythm Society. All rights reserved.
children, have suggested a particularly high acute complication rate,6,7 but whether this is true for adults outside of the tertiary referral center setting is unknown. Risk factors for device complications have been reported in the general population,8–10 but it is not known if the same risk factors apply to patients with adult congenital heart disease (ACHD). The Health Care Cost and Utilization Project (HCUP) is a group of databases sponsored by the Agency for Healthcare Research and Quality. HCUP has already been used to study ACHD hospitalizations in the United States5,11 and procedural complications from electrophysiologic procedures.12,13 Together, HCUP’s California State Inpatient Database, State Ambulatory Surgery Database, and State Emergency Department Database captured more than 110 million hospitalbased health care encounters between 2005 and 2011. We leveraged this comprehensive, statewide database to query http://dx.doi.org/10.1016/j.hrthm.2014.10.038
Hayward et al
Device Complications in ACHD
for acute complication rates of pacemaker and ICD implantation in those with and those without CHD. This study aims to define these complication risks and to compare them to risks in patients without CHD undergoing pacemaker and ICD implantation with the hypothesis that these risks are higher in CHD patients.
Methods Patients at least 18 years of age with a procedure code for a new pacemaker (ICD-9-CM codes 37.80, 37.81, 37.82, or 37.83) or ICD (ICD-9-CM code 37.94) implantation were identified from HCUP’s State Inpatient Database, State Ambulatory Surgery Database, and State Emergency Department Database for California between January 1, 2005, and December 31, 2011. Because of possible differences in coronary sinus anatomy, patients receiving biventricular devices were excluded. Patients with a history of heart transplantation or ventricular assist device also were excluded. Patients undergoing cardiothoracic surgery on the same admission as the device implantation procedure were excluded because determination of the procedural complications specific to device implant is limited in the setting of multiple procedures. Nontransvenous ICDs were referred to as epicardial devices for clarity even though the shocking coil often does not contact the epicardium. The full details of the ICD-9 codes applied in this analysis, including departures from classifications used by others, are given in the Online Supplemental Appendix. As classified by others previously, CHD diagnoses including “complex” CHD were defined by ICD-9 codes or current procedural terminology (CPT) codes.14–16 If a CHD diagnosis code was present for any encounter during the study period, the patient was assigned that diagnosis for all visits. Patients with both complex and noncomplex CHD diagnoses were assigned to the complex CHD group. Medical comorbidities were classified based on ICD-9 diagnosis codes for coronary artery disease, congestive heart failure, cerebrovascular disease, chronic kidney disease, lung disease, hypertension, and diabetes.12 Patients were identified as having the comorbidity of interest if the diagnosis code was recorded for any health care encounter between January 1, 2005, and the admission date for the device implantation procedure. To include only prevalent rather than new incident comorbidities, a diagnosis was required to be “present on admission” if the comorbidity was first recorded at the admission for the device implant procedure. Procedural complications were identified based on definitions adapted from the National Quality Forum developed for the Centers for Medicare and Medicaid Services.17 These definitions have been used previously.18 We modified these definitions by adding diagnosis and procedure codes relevant to pacemakers and revised some definitions to better fit with the definitions of these complications in clinical practice. According to National Quality Forum definitions, procedural
339 complications measured at 30 days included pneumothorax or hemothorax requiring a chest tube, hematoma requiring blood transfusion or evacuation, cardiac tamponade, and mortality. Complications measured at 90 days included mechanical complications (diagnostic codes specific to cardiac devices, including mechanical breakdown, displacement, leakage, mechanical obstruction, perforation, or protrusion) requiring device revision, device-related infection, and additional device implantation. Because the HCUP database contains only de-identified patient identification numbers, deaths outside of the hospital could not be captured, limiting mortality data to deaths occurring in a California hospital. The primary outcome was any complication within the time period specified by the National Quality Forum definition for that complication (30 or 90 days). The secondary outcome was death in a California hospital within 30 days.
Statistical analysis Continuous variables are presented as mean ⫾ SD and categorical variables as percentages. Unadjusted complication rates were compared using the Fisher exact test. Because of the higher complication rates of epicardial pacemakers and ICDs, these were excluded from the main analysis and analyzed separately. We assessed the effects of CHD on any complication and 30-day in-hospital mortality using multivariate Poisson regression with robust standard errors; beginning with an a priori set of predictors, backward selection was used to remove covariates with P o.1 in adjusted analysis. Because no inpatient deaths occurred in the group with complex CHD, patients with complex and noncomplex CHD were analyzed together for evaluation of 30-day mortality. Two-tailed P o.05 was considered significant. Because of HCUP publication requirements, cell sizes less than 10 are not reported, although the exact number is used in analyses. Statistical analyses were performed using Stata/SE 13.1 (StataCorp, College Station, TX). Patient information was anonymized before analysis, and certification to use this de-identified HCUP data was obtained from the University of California, San Francisco Committee on Human Research.
Results Patients From a total of 110,805,877 hospital-based encounters in calendar years 2005–2011, we identified 377 California hospitals with at least 1 device implantation procedure and 138,800 patients undergoing pacemaker or ICD implantation; 2433 of these patients had a diagnosis of CHD (Table 1). The majority of the CHD diagnoses were noncomplex; 153 patients had complex CHD (Table 2). Atrial septal defect was the most common congenital defect overall. Of the complex congenital defects, tetralogy of Fallot and transposition of the great arteries were the most common. We identified 105,852 patients undergoing pacemaker implantation, 1465 with noncomplex CHD and 66 with
340
Heart Rhythm, Vol 12, No 2, February 2015
Table 1
Baseline characteristics of pacemaker and ICD implantations
Variable
Non-CHD PPM implantations (n ¼ 104,321)
CHD PPM implantations (n ¼ 1531)
77.1 ⫾ 11.1 49.1 56.6 43.4 20.1 26.1 30.4 89.4 40.0 82543 (79.2) 88362 (84.7)
66.3 ⫾ 17.9 49.7 52.6 49.1 19.9 18.4 28.9 79.0 32.4 1028 (67.1) 1298 (84.8)
750 (0.7) 8436 (8.1) 26935 (25.8) 68200 (65.4)
13 (0.9) 87 (5.7) 332 (21.7) 1099 (71.8)
Age Female (%) Coronary artery disease (%) Congestive heart failure (%) Cerebrovascular disease (%) Chronic kidney disease (%) Lung disease (%) Hypertension (%) Diabetes (%) Unplanned admission Dual-chamber pacemaker Hospital volume Lowest quartile Second quartile Third quartile Highest quartile
P value* o.00005 .63 .003 o.00005 .83 o.00005 .24 o.00005 o.00005 o.00005 .93 o.0005
Non-CHD ICD implantations (n ¼ 32,046)
CHD ICD implantations (n ¼ 902)
P value*
65.3 ⫾ 13.5 26.5 82.1 85.7 14.7 27.9 37.0 86.1 47.4 20391 (63.7)
53.2 ⫾ 17.6 33.9 58.1 69.3 14.8 19.8 30.9 66.2 29.1 577 (64.0)
o.00005 o.00005 o.00005 o.00005 .90 o.00005 .0005 o.00005 o.00005 .86
145 (0.5) 1404 (4.4) 6686 (20.9) 23811 (74.3)
o10‡ 54 (6.0) 170 (18.9) 670 (74.3)
†
.02
Values are given as mean ⫾ SD or number (percent of total). CHD ¼ congenital heart disease; ICD ¼ implantable cardioverter-defibrillator; PPM ¼ permanent pacemaker. * Two-sample t test with unequal variances, χ2 for categorical variables. † Limitations of ICD-9 coding prevented determination of single- vs dual-chamber ICDs. ‡ Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses.
complex CHD. Patients with CHD were younger (mean age 44.1 ⫾ 20.0 years for complex CHD and 67.3 ⫾ 17.2 years for noncomplex CHD) and had a lower prevalence of Table 2
Type of congenital heart disease PPM ICD implantations implantations
No CHD Complex CHD Tetralogy of Fallot Transposition complex Endocardial cushion defect Univentricular heart Truncus arteriosus Hypoplastic left heart syndrome Noncomplex CHD Atrial septal defect Ventricular septal defect Patent ductus arteriosus Aortic coarctation Ebstein anomaly Unspecified defect of septal closure Anomalies of the pulmonary artery Congenital valve disease Anomalies of great veins Other specified cardiac anomalies
104,321 66* 16 27 16 o10† o10† o10† 1465* 641 93 32 24 13 o10†
32,046 87* 51 37 o10† 0 o10† 0 815* 240 45 17 16 o10† o10†
23
22
383 64 397
111 32 473
CHD ¼ congenital heart disease; ICD ¼ implantable cardioverterdefibrillator; PPM ¼ permanent pacemaker. * Some subjects have multiple CHD defects classified. † Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses.
coronary artery disease and kidney disease but had a higher prevalence of heart failure than patients without CHD (Table 1). In total, 32,948 patients undergoing ICD implantation were identified, 815 with noncomplex CHD and 87 with complex CHD. Patients with CHD were younger (mean age 39.3 ⫾ 12.5 years for complex CHD and 54.7 ⫾ 17.4 years for noncomplex CHD) and had fewer other medical comorbidities, including a lower prevalence of heart failure (Table 1).
Pacemakers In patients undergoing pacemaker implantation, complications occurred in 6.5% of patients without CHD, 6.4% of patients with noncomplex CHD, and 7.6% of patients with complex CHD (P ¼ .84, Fisher exact test; Table 3). Inhospital mortality within 30 days occurred in 2.0% of pacemaker recipients without CHD and 1.2% of patients with CHD (P ¼ .03). After multivariate analysis, CHD was not associated with increased risk of pacemaker implant-related complications (adjusted risk ratio [aRR] 0.92, 95% confidence interval [CI] 0.74–1.14, P ¼ .45). When complex and noncomplex CHD were analyzed separately, neither was associated with increased risk of pacemaker implant-related complications (aRR 0.92 for noncomplex CHD, 95% CI 0.74–1.14, P ¼ .45; aRR 0.94 for complex CHD, 95% CI 0.36–2.46, P ¼ .91; Figure 1). CHD was associated with a trend toward lower 30-day in-hospital mortality after pacemaker implantation (aRR 0.62, 95% CI 0.37–1.03, P ¼ .07).
Hayward et al Table 3
Device Complications in ACHD
341
Pacemaker procedural complication rates
Outcome Any complication Pneumothorax Hematoma Tamponade Mechanical complications§ Device infection Repeat procedure Mortality
Patients without CHD (n ¼ 104,21)
Noncomplex CHD (n ¼ 1465)
Complex CHD (n ¼ 66)
Unadjusted P value‡
6786 (6.5) 1071 (1.0) 321 (0.3) 512 (0.5) 1997 (1.9)
93 (6.4) 10 (0.7) o10* 13 (0.9) 22 (1.5)
o10* o10* 0 (0.0) 0 (0.0) o10*
.84 .30 .37 .11 .49
695 (0.7) 955 (0.9) 2040 (2.0)
20 (1.4) 14 (1.0) 18 (1.2)
o10*,† o10* 0 (0.0)
.001 .16 .09
Values are given as number (%). CHD ¼ congenital heart disease. * Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses. † Complication rate not reported but higher than in the noncomplex CHD group. ‡ P values calculated by Fisher exact test. § Mechanical complications are diagnostic codes specific to cardiac devices (including mechanical breakdown, displacement, leakage, mechanical obstruction, perforation, or protrusion) requiring device revision.
ICDs
Epicardial devices
In patients undergoing ICD implantation, complications occurred in 6.0% of those without CHD, 7.4% of those with noncomplex CHD, and 11.5% of those with complex CHD (P ¼ .03, Fisher exact test; Table 4). In-hospital mortality within 30 days occurred in 1.4% of ICD recipients without CHD and 0.6% of patients with CHD (P ¼ .02). After multivariable adjustment for potential confounders, CHD was associated with increased risk of implant-related complications (aRR 1.36, 95% CI 1.05–1.76, P ¼ .02). When noncomplex and complex CHD were considered separately, noncomplex CHD was associated with a trend toward increased risk for implant-related complications, whereas complex CHD was associated with a significantly increased risk (aRR 1.28, 95% CI 0.97–1.69, P ¼ .08 for noncomplex CHD; aRR 2.14, 95% CI 1.16–3.95, P ¼ .02 for complex CHD; Figure 2). After multivariable adjustment, CHD was not associated with 30-day in-hospital mortality (aRR 0.53, 95% CI 0.20–1.39, P ¼ .19).
We found a total of 470 epicardial pacemakers (426 in patients without CHD, 24 in patients with noncomplex CHD, and 20 in patients with patients with complex CHD) and 205 epicardial ICDs (191 in patients without CHD, 12 in patients with noncomplex CHD, and 2 in patients with patients with complex CHD). CHD was not associated with increased risk of implant-related complications in univariate analysis of patients undergoing epicardial pacemaker (P ¼ .66, Fisher exact test) or ICD placement (P ¼ .22, Fisher exact test). When epicardial procedures were included with transvenous devices in multivariate analysis, results for implant-related complications and 30-day inpatient mortality in patients with CHD were unchanged (data not shown).
Discussion In this analysis of pacemaker and ICD implantations in a large, comprehensive statewide database for the 7-year period 2005–2011, CHD was associated with higher risk
Figure 1 Adjusted relative risks and 95% confidence intervals for pacemaker implant-related complications. CHD ¼ congenital heart disease; CI ¼ confidence interval; RR ¼ relative risk.
342 Table 4
Heart Rhythm, Vol 12, No 2, February 2015 ICD procedural complication rates
Outcome Any complication Pneumothorax Hematoma Tamponade Mechanical complications§ Device infection Repeat procedure Mortality
Patients without CHD (n ¼ 32,046)
Noncomplex CHD (n ¼ 815)
Complex CHD (n ¼ 87)
Unadjusted P value‡
1913 (6.0) 149 (0.5) 163 (0.5) 107 (0.3) 540 (1.7)
60 (7.4) o10* o10* o10* 22 (2.7)
10 (11.5) 0 (0.0) 0 (0.0) 0 (0.0) o10*,†
.03 .86 .64 .13 .01
345 (1.1) 357 (1.1) 459 (1.4)
11 (1.4) 16 (2.0) o10*
o10*,† o10*,† 0 (0.0)
.02 .003 .09
Values are given as number (%). CHD ¼ congenital heart disease; ICD ¼ implantable cardioverter-defibrillator. * Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses. † Complication rate not reported but higher than in the noncomplex CHD group. ‡ P values calculated by Fisher exact test. § Mechanical complications are diagnostic codes specific to cardiac devices (including mechanical breakdown, displacement, leakage, mechanical obstruction, perforation, or protrusion) requiring device revision.
of implant-related complications for ICDs but not for pacemakers. After adjustment for potential confounders, patients with noncomplex CHD demonstrated a trend toward higher risk of an ICD procedural complication, whereas patients with complex CHD had a significant 2-fold higher risk compared to those without CHD undergoing ICD implantation. The 30-day in-hospital mortality after pacemaker or ICD implantation was similar for those with and those without CHD, although we observed a trend toward lower mortality in the CHD groups. Because of the small number of deaths observed, a moderate-sized effect cannot be excluded. This analysis is based on a CHD population 5-fold larger than prior reports,7 although our analysis excluded children and included pacemakers as well as a much larger proportion of patients with noncomplex CHD. This study also captured procedures from a broad range of hospitals, providing real-world data beyond the experience of a few specialized referral centers.7,19 Increased rates of ICD-related complications in CHD were mainly due to higher rates of mechanical complications (which includes mechanical breakdown, displacement,
leakage, obstruction, perforation, and protrusion), device infections, and repeat procedures. Rates of tamponade were not increased in patients with CHD, suggesting that the increase in mechanical complications probably is due to lead displacement or obstruction. Scarring from prior surgeries, either in the myocardium, the pericardium, or the mediastinum, may prevent lead perforation and tamponade in these patients. Possible explanations for increased rates of mechanical complications in patients with CHD include abnormal venous anatomy, abnormal hemodynamics, intracardiac shunting, and abnormal chamber size and morphology. Epicardial devices were more common in the group with CHD, and these devices were associated with higher rates of complications. However, we observed higher rates of complications for CHD patients undergoing any ICD implantation even after adjusting for epicardial devices or when only transvenous ICDs were considered. ICD complication rates in this analysis were higher than those reported in a recent study of Medicare beneficiaries by Peterson and colleagues18 as well as a study using outcomes from the National Cardiovascular Data Registry (NCDR) by
Figure 2 Adjusted relative risks and 95% confidence intervals for implantable cardioverter-defibrillator implant-related complications. CHD ¼ congenital heart disease; CI ¼ confidence interval; RR ¼ relative risk.
Hayward et al
Device Complications in ACHD
Hsu and colleagues.9 Compared to the Medicare study, patients in the current study were younger but did not have additional comorbidities to account for higher complication rates. The NCDR study only recorded in-hospital complications and would have missed complications presenting at subsequent hospitalizations. The major limitations of NCDR and Medicare registry data are that outcomes are limited by compliance with reporting to the NCDR registry and, Medicare patients are restricted to those older than 65 years. In contrast, HCUP captures 495% of statewide outcomes for all adults during the study period. In this analysis, ICD complications in patients with complex CHD were similar to the acute complication rates reported in 2 studies of ICD implantations in children and patients with CHD.6,7 In these studies, the leading complications were pocket infections, hematomas, and lead dislodgment. The most common complications in our analysis were mechanical complications, repeat procedures, and device infections. No hematomas were identified in the complex CHD group in our analysis; this may be due to our stricter definition for clinically significant hematoma, which required evacuation or blood transfusion. There are several potential explanations for our observation that complications were more common among CHD patients receiving ICDs than pacemakers. ICD implantation can be technically more challenging in CHD patients. The generally larger diameter of ICD leads compared to pacemaker leads could have resulted in increased difficulty with stable lead placement for ICDs, accounting for the higher observed mechanical complication rate. Mechanical complications included both lead displacement and mechanical obstruction. In patients with abnormal hemodynamics due to impaired ventricular function, stable lead placement can be more difficult to achieve, especially with larger diameter leads, and obstruction of venous structures or baffles could also be more common with larger-diameter leads. Dislodgment may also occur during defibrillation threshold testing. Although we observed higher complication rates in CHD patients undergoing ICD implantation, our results suggest that these patients are not at increased risk for acute mortality. This may be because among patients undergoing ICD implantation, we found that those with CHD were generally younger and had fewer traditional medical comorbidities. In patients with CHD, the main medical issue is often profound alterations in cardiac anatomy and hemodynamics as opposed to multiple medical comorbidities such as coronary artery disease or chronic kidney disease. However, the trend toward lower inpatient mortality remained even after adjusting for medical comorbidities. Therefore, patients with CHD may also have more attentive intraoperative and postoperative care because of their complex disease.
343 deaths occurring in the complex CHD group. Even when the complex and noncomplex CHD groups were combined, the number of CHD deaths was small, and a moderate-sized effect of CHD on 30-day in-hospital mortality after pacemaker or ICD implantation cannot be excluded. In addition, the number of patients with individual complex congenital defects was small; thus, a full analysis of each individual lesion was not possible. In addition, because of the nature of the HCUP database, we were only able to capture deaths within a California hospital, so any deaths occurring out-ofhospital and any out-of-state deaths would not have been captured. These would be expected to be primarily out-ofhospital sudden deaths because nonsudden deaths are likely to be preceded by rehospitalization. Patients are generally monitored in the hospital after device implantation and death after device implantation is rare, so the number of deaths missed by this analysis is likely to be small. Next, the imperfect sensitivity and specificity of ICD-9 codes is well known.20 However, if bias occurred in the classification of CHD, we would expect this to be the same for those with and those without device complications (nondifferential misclassification), and this would tend to bias the measures of association toward the null. ICD-9 codes also did not allow for determination of the indication for device implantation or single- vs dual-chamber ICDs, which is a known risk factor for device-related complications.8,18 Because very few devices were implanted in CHD patients at low-volume centers, the complication rates of these procedures at such centers are not known. Many patients with CHD undergo device placement at the time of cardiac surgery; these patients were excluded from our analyses because outcomes may have been influenced by the open heart surgeries rather than CHD diagnosis itself. Finally, we cannot exclude unmeasured confounding. Patients without CHD undergoing initial pacemaker implantation were substantially older than those with CHD (mean age 77 years vs 65 years) and thus may have had additional unmeasured comorbidities that could not be accounted for using this administrative dataset.
Conclusion In this analysis of adults undergoing pacemaker and ICD implantations in a large, comprehensive statewide database, CHD was associated with increased risk of ICD implantrelated complications but not with pacemaker implantrelated complications or increased 30-day in-hospital mortality.
Appendix Supplementary data Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1016/j.hrthm. 2014.10.038.
Study limitations This study has several limitations. Despite capturing more than 138,000 device implantation procedures, the number of complications in the group with CHD was small, with no
References 1. Hoffman JI, Kaplan S, Liberthson RR. Prevalence of congenital heart disease. Am Heart J 2004;147:425–439.
344
Heart Rhythm, Vol 12, No 2, February 2015
2. Warnes CA, Liberthson R, Danielson GK, Dore A, Harris L, Hoffman JI, Somerville J, Williams RG, Webb GD. Task force 1: the changing profile of congenital heart disease in adult life. J Am Coll Cardiol 2001;37:1170–1175. 3. Oechslin EN, Harrison DA, Connelly MS, Webb GD, Siu SC. Mode of death in adults with congenital heart disease. Am J Cardiol 2000;86:1111–1116. 4. Pillutla P, Shetty KD, Foster E. Mortality associated with adult congenital heart disease: trends in the US population from 1979 to 2005. Am Heart J 2009;158: 874–879. 5. Opotowsky AR, Siddiqi OK, Webb GD. Trends in hospitalizations for adults with congenital heart disease in the U.S. J Am Coll Cardiol 2009;54:460–467. 6. Alexander ME, Cecchin F, Walsh EP, Triedman JK, Bevilacqua LM, Berul CI. Implications of implantable cardioverter defibrillator therapy in congenital heart disease and pediatrics. J Cardiovasc Electrophysiol 2004;15:72–76. 7. Berul CI, Van Hare GF, Kertesz NJ, Dubin AM, Cecchin F, Collins KK, Cannon BC, Alexander ME, Triedman JK, Walsh EP, Friedman RA. Results of a multicenter retrospective implantable cardioverter-defibrillator registry of pediatric and congenital heart disease patients. J Am Coll Cardiol 2008;51: 1685–1691. 8. Dewland TA, Pellegrini CN, Wang Y, Marcus GM, Keung E, Varosy PD. Dualchamber implantable cardioverter-defibrillator selection is associated with increased complication rates and mortality among patients enrolled in the NCDR implantable cardioverter-defibrillator registry. J Am Coll Cardiol 2011;58: 1007–1013. 9. Hsu JC, Varosy PD, Bao H, Wang Y, Curtis JP, Marcus GM. Low body mass index but not obesity is associated with in-hospital adverse events and mortality among implantable cardioverter-defibrillator recipients: insights from the National Cardiovascular Data Registry. J Am Heart Assoc 2012;1:e003863. 10. Parsonnet V, Bernstein AD, Lindsay B. Pacemaker-implantation complication rates: an analysis of some contributing factors. J Am Coll Cardiol 1989;13: 917–921.
11. Gurvitz MZ, Inkelas M, Lee M, Stout K, Escarce J, Chang RK. Changes in hospitalization patterns among patients with congenital heart disease during the transition from adolescence to adulthood. J Am Coll Cardiol 2007;49:875–882. 12. Shah RU, Freeman JV, Shilane D, Wang PJ, Go AS, Hlatky MA. Procedural complications, rehospitalizations, and repeat procedures after catheter ablation for atrial fibrillation. J Am Coll Cardiol 2012;59:143–149. 13. Zhan C, Baine WB, Sedrakyan A, Steiner C. Cardiac device implantation in the United States from 1997 through 2004: a population-based analysis. J Gen Intern Med 2008;23(Suppl 1):13–19. 14. Mackie AS, Ionescu-Ittu R, Pilote L, Rahme E, Marelli AJ. Hospital readmissions in children with congenital heart disease: a population-based study. Am Heart J 2008;155:577–584. 15. Mackie AS, Pilote L, Ionescu-Ittu R, Rahme E, Marelli AJ. Health care resource utilization in adults with congenital heart disease. Am J Cardiol 2007;99:839–843. 16. Marelli AJ, Mackie AS, Ionescu-Ittu R, Rahme E, Pilote L. Congenital heart disease in the general population: changing prevalence and age distribution. Circulation 2007;115:163–172. 17. National Voluntary Standards for Patient Outcomes: A Consensus Report. National Quality Forum 2011;2011:A1–A6. 18. Peterson PN, Varosy PD, Heidenreich PA, Wang Y, Dewland TA, Curtis JP, Go AS, Greenlee RT, Magid DJ, Normand SL, Masoudi FA. Association of singlevs dual-chamber ICDs with mortality, readmissions, and complications among patients receiving an ICD for primary prevention. JAMA 2013;309:2025–2034. 19. Stephenson EA, Batra AS, Knilans TK, et al. A multicenter experience with novel implantable cardioverter defibrillator configurations in the pediatric and congenital heart disease population. J Cardiovasc Electrophysiol 2006;17:41–46. 20. Humphries KH, Rankin JM, Carere RG, Buller CE, Kiely FM, Spinelli JJ. Comorbidity data in outcomes research: are clinical data derived from administrative databases a reliable alternative to chart review? J Clin Epidemiol 2000;53: 343–349.
CLINICAL PERSPECTIVES The population of adults with congenital heart disease (CHD) is growing rapidly, and pacemakers and implantable cardioverter-defibrillators (ICDs) are increasingly implanted in this group. However, data regarding device procedural complication rates in this population are sparse. This article analyzes risk of device implantation in adult patients with CHD compared to those without CHD in a large statewide database capturing events for nearly all hospitalizations and procedures over a 7-year period, representing the largest series of CHD patients ever reported. CHD was associated with increased risk of ICD implant-related complications but not pacemaker implant-related complications or increased 30-day in-hospital mortality. These real-world data go beyond the experience of specialized referral centers and may be used by clinicians in planning procedures and discussions with patients about the risks and benefits of device implantation.
Introduction More than 1 million adults are living with congenital heart disease (CHD) in the United States, and this group now outnumbers children with CHD.1,2 As patients with CHD live to adulthood, arrhythmias are an increasing cause of morbidity and mortality,3,4 and both pacemaker and implantable cardioverter-defibrillator (ICD) implantations are increasingly performed in this population.5 The 2 published studies of ICD placement in the CHD population, including This work was supported in part by NIH/NHLBI 5R01 HL102090 to Dr. Tseng. Dr. Tseng has received minor honoraria from Biotronik. Dr. Marcus receives research support from Medtronic. Dr. Dewland and Dr. Hayward have received educational travel grants from Medtronic and Boston Scientific. Address reprint requests and correspondence: Dr. Zian H. Tseng, Cardiac Electrophysiology Section, University of California–San Francisco, 500 Parnassus Ave, Box 1354, San Francisco, CA 94143-1354. E-mail address: [email protected].
1547-5271/$-see front matter B 2015 Heart Rhythm Society. All rights reserved.
and 87 with complex CHD. Patients with CHD had increased risk of ICD implant-related complications: aRR 1.36, 95% CI 1.05–1.76, P ¼ .02. Patients with complex CHD had greater increased risk of ICD implant-related complications: aRR 2.14, 95% CI 1.16–3.95, P ¼ .02. In patients receiving devices, CHD was associated with a trend toward lower 30-day in-hospital mortality after pacemaker (P ¼ .07) and ICD (P ¼ .19) implantation. CONCLUSION Among adult patients undergoing device implantation in California, CHD was associated with increased risk of ICD implant-related complications, but not pacemaker implant-related complications or higher 30-day in-hospital mortality. KEYWORDS Congenital heart disease; Pacemaker; Implantable cardioverter-defibrillator ABBREVIATIONS ACHD ¼ adult congenital heart disease; aRR ¼ adjusted risk ratio; CHD ¼ congenital heart disease; CI ¼ confidence interval; HCUP ¼ Health Care Cost and Utilization Project; ICD ¼ implantable cardioverter-defibrillator; NCDR ¼ National Cardiovascular Data Registry (Heart Rhythm 2015;12:338–344) I 2015 Heart Rhythm Society. All rights reserved.
children, have suggested a particularly high acute complication rate,6,7 but whether this is true for adults outside of the tertiary referral center setting is unknown. Risk factors for device complications have been reported in the general population,8–10 but it is not known if the same risk factors apply to patients with adult congenital heart disease (ACHD). The Health Care Cost and Utilization Project (HCUP) is a group of databases sponsored by the Agency for Healthcare Research and Quality. HCUP has already been used to study ACHD hospitalizations in the United States5,11 and procedural complications from electrophysiologic procedures.12,13 Together, HCUP’s California State Inpatient Database, State Ambulatory Surgery Database, and State Emergency Department Database captured more than 110 million hospitalbased health care encounters between 2005 and 2011. We leveraged this comprehensive, statewide database to query http://dx.doi.org/10.1016/j.hrthm.2014.10.038
Hayward et al
Device Complications in ACHD
for acute complication rates of pacemaker and ICD implantation in those with and those without CHD. This study aims to define these complication risks and to compare them to risks in patients without CHD undergoing pacemaker and ICD implantation with the hypothesis that these risks are higher in CHD patients.
Methods Patients at least 18 years of age with a procedure code for a new pacemaker (ICD-9-CM codes 37.80, 37.81, 37.82, or 37.83) or ICD (ICD-9-CM code 37.94) implantation were identified from HCUP’s State Inpatient Database, State Ambulatory Surgery Database, and State Emergency Department Database for California between January 1, 2005, and December 31, 2011. Because of possible differences in coronary sinus anatomy, patients receiving biventricular devices were excluded. Patients with a history of heart transplantation or ventricular assist device also were excluded. Patients undergoing cardiothoracic surgery on the same admission as the device implantation procedure were excluded because determination of the procedural complications specific to device implant is limited in the setting of multiple procedures. Nontransvenous ICDs were referred to as epicardial devices for clarity even though the shocking coil often does not contact the epicardium. The full details of the ICD-9 codes applied in this analysis, including departures from classifications used by others, are given in the Online Supplemental Appendix. As classified by others previously, CHD diagnoses including “complex” CHD were defined by ICD-9 codes or current procedural terminology (CPT) codes.14–16 If a CHD diagnosis code was present for any encounter during the study period, the patient was assigned that diagnosis for all visits. Patients with both complex and noncomplex CHD diagnoses were assigned to the complex CHD group. Medical comorbidities were classified based on ICD-9 diagnosis codes for coronary artery disease, congestive heart failure, cerebrovascular disease, chronic kidney disease, lung disease, hypertension, and diabetes.12 Patients were identified as having the comorbidity of interest if the diagnosis code was recorded for any health care encounter between January 1, 2005, and the admission date for the device implantation procedure. To include only prevalent rather than new incident comorbidities, a diagnosis was required to be “present on admission” if the comorbidity was first recorded at the admission for the device implant procedure. Procedural complications were identified based on definitions adapted from the National Quality Forum developed for the Centers for Medicare and Medicaid Services.17 These definitions have been used previously.18 We modified these definitions by adding diagnosis and procedure codes relevant to pacemakers and revised some definitions to better fit with the definitions of these complications in clinical practice. According to National Quality Forum definitions, procedural
339 complications measured at 30 days included pneumothorax or hemothorax requiring a chest tube, hematoma requiring blood transfusion or evacuation, cardiac tamponade, and mortality. Complications measured at 90 days included mechanical complications (diagnostic codes specific to cardiac devices, including mechanical breakdown, displacement, leakage, mechanical obstruction, perforation, or protrusion) requiring device revision, device-related infection, and additional device implantation. Because the HCUP database contains only de-identified patient identification numbers, deaths outside of the hospital could not be captured, limiting mortality data to deaths occurring in a California hospital. The primary outcome was any complication within the time period specified by the National Quality Forum definition for that complication (30 or 90 days). The secondary outcome was death in a California hospital within 30 days.
Statistical analysis Continuous variables are presented as mean ⫾ SD and categorical variables as percentages. Unadjusted complication rates were compared using the Fisher exact test. Because of the higher complication rates of epicardial pacemakers and ICDs, these were excluded from the main analysis and analyzed separately. We assessed the effects of CHD on any complication and 30-day in-hospital mortality using multivariate Poisson regression with robust standard errors; beginning with an a priori set of predictors, backward selection was used to remove covariates with P o.1 in adjusted analysis. Because no inpatient deaths occurred in the group with complex CHD, patients with complex and noncomplex CHD were analyzed together for evaluation of 30-day mortality. Two-tailed P o.05 was considered significant. Because of HCUP publication requirements, cell sizes less than 10 are not reported, although the exact number is used in analyses. Statistical analyses were performed using Stata/SE 13.1 (StataCorp, College Station, TX). Patient information was anonymized before analysis, and certification to use this de-identified HCUP data was obtained from the University of California, San Francisco Committee on Human Research.
Results Patients From a total of 110,805,877 hospital-based encounters in calendar years 2005–2011, we identified 377 California hospitals with at least 1 device implantation procedure and 138,800 patients undergoing pacemaker or ICD implantation; 2433 of these patients had a diagnosis of CHD (Table 1). The majority of the CHD diagnoses were noncomplex; 153 patients had complex CHD (Table 2). Atrial septal defect was the most common congenital defect overall. Of the complex congenital defects, tetralogy of Fallot and transposition of the great arteries were the most common. We identified 105,852 patients undergoing pacemaker implantation, 1465 with noncomplex CHD and 66 with
340
Heart Rhythm, Vol 12, No 2, February 2015
Table 1
Baseline characteristics of pacemaker and ICD implantations
Variable
Non-CHD PPM implantations (n ¼ 104,321)
CHD PPM implantations (n ¼ 1531)
77.1 ⫾ 11.1 49.1 56.6 43.4 20.1 26.1 30.4 89.4 40.0 82543 (79.2) 88362 (84.7)
66.3 ⫾ 17.9 49.7 52.6 49.1 19.9 18.4 28.9 79.0 32.4 1028 (67.1) 1298 (84.8)
750 (0.7) 8436 (8.1) 26935 (25.8) 68200 (65.4)
13 (0.9) 87 (5.7) 332 (21.7) 1099 (71.8)
Age Female (%) Coronary artery disease (%) Congestive heart failure (%) Cerebrovascular disease (%) Chronic kidney disease (%) Lung disease (%) Hypertension (%) Diabetes (%) Unplanned admission Dual-chamber pacemaker Hospital volume Lowest quartile Second quartile Third quartile Highest quartile
P value* o.00005 .63 .003 o.00005 .83 o.00005 .24 o.00005 o.00005 o.00005 .93 o.0005
Non-CHD ICD implantations (n ¼ 32,046)
CHD ICD implantations (n ¼ 902)
P value*
65.3 ⫾ 13.5 26.5 82.1 85.7 14.7 27.9 37.0 86.1 47.4 20391 (63.7)
53.2 ⫾ 17.6 33.9 58.1 69.3 14.8 19.8 30.9 66.2 29.1 577 (64.0)
o.00005 o.00005 o.00005 o.00005 .90 o.00005 .0005 o.00005 o.00005 .86
145 (0.5) 1404 (4.4) 6686 (20.9) 23811 (74.3)
o10‡ 54 (6.0) 170 (18.9) 670 (74.3)
†
.02
Values are given as mean ⫾ SD or number (percent of total). CHD ¼ congenital heart disease; ICD ¼ implantable cardioverter-defibrillator; PPM ¼ permanent pacemaker. * Two-sample t test with unequal variances, χ2 for categorical variables. † Limitations of ICD-9 coding prevented determination of single- vs dual-chamber ICDs. ‡ Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses.
complex CHD. Patients with CHD were younger (mean age 44.1 ⫾ 20.0 years for complex CHD and 67.3 ⫾ 17.2 years for noncomplex CHD) and had a lower prevalence of Table 2
Type of congenital heart disease PPM ICD implantations implantations
No CHD Complex CHD Tetralogy of Fallot Transposition complex Endocardial cushion defect Univentricular heart Truncus arteriosus Hypoplastic left heart syndrome Noncomplex CHD Atrial septal defect Ventricular septal defect Patent ductus arteriosus Aortic coarctation Ebstein anomaly Unspecified defect of septal closure Anomalies of the pulmonary artery Congenital valve disease Anomalies of great veins Other specified cardiac anomalies
104,321 66* 16 27 16 o10† o10† o10† 1465* 641 93 32 24 13 o10†
32,046 87* 51 37 o10† 0 o10† 0 815* 240 45 17 16 o10† o10†
23
22
383 64 397
111 32 473
CHD ¼ congenital heart disease; ICD ¼ implantable cardioverterdefibrillator; PPM ¼ permanent pacemaker. * Some subjects have multiple CHD defects classified. † Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses.
coronary artery disease and kidney disease but had a higher prevalence of heart failure than patients without CHD (Table 1). In total, 32,948 patients undergoing ICD implantation were identified, 815 with noncomplex CHD and 87 with complex CHD. Patients with CHD were younger (mean age 39.3 ⫾ 12.5 years for complex CHD and 54.7 ⫾ 17.4 years for noncomplex CHD) and had fewer other medical comorbidities, including a lower prevalence of heart failure (Table 1).
Pacemakers In patients undergoing pacemaker implantation, complications occurred in 6.5% of patients without CHD, 6.4% of patients with noncomplex CHD, and 7.6% of patients with complex CHD (P ¼ .84, Fisher exact test; Table 3). Inhospital mortality within 30 days occurred in 2.0% of pacemaker recipients without CHD and 1.2% of patients with CHD (P ¼ .03). After multivariate analysis, CHD was not associated with increased risk of pacemaker implant-related complications (adjusted risk ratio [aRR] 0.92, 95% confidence interval [CI] 0.74–1.14, P ¼ .45). When complex and noncomplex CHD were analyzed separately, neither was associated with increased risk of pacemaker implant-related complications (aRR 0.92 for noncomplex CHD, 95% CI 0.74–1.14, P ¼ .45; aRR 0.94 for complex CHD, 95% CI 0.36–2.46, P ¼ .91; Figure 1). CHD was associated with a trend toward lower 30-day in-hospital mortality after pacemaker implantation (aRR 0.62, 95% CI 0.37–1.03, P ¼ .07).
Hayward et al Table 3
Device Complications in ACHD
341
Pacemaker procedural complication rates
Outcome Any complication Pneumothorax Hematoma Tamponade Mechanical complications§ Device infection Repeat procedure Mortality
Patients without CHD (n ¼ 104,21)
Noncomplex CHD (n ¼ 1465)
Complex CHD (n ¼ 66)
Unadjusted P value‡
6786 (6.5) 1071 (1.0) 321 (0.3) 512 (0.5) 1997 (1.9)
93 (6.4) 10 (0.7) o10* 13 (0.9) 22 (1.5)
o10* o10* 0 (0.0) 0 (0.0) o10*
.84 .30 .37 .11 .49
695 (0.7) 955 (0.9) 2040 (2.0)
20 (1.4) 14 (1.0) 18 (1.2)
o10*,† o10* 0 (0.0)
.001 .16 .09
Values are given as number (%). CHD ¼ congenital heart disease. * Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses. † Complication rate not reported but higher than in the noncomplex CHD group. ‡ P values calculated by Fisher exact test. § Mechanical complications are diagnostic codes specific to cardiac devices (including mechanical breakdown, displacement, leakage, mechanical obstruction, perforation, or protrusion) requiring device revision.
ICDs
Epicardial devices
In patients undergoing ICD implantation, complications occurred in 6.0% of those without CHD, 7.4% of those with noncomplex CHD, and 11.5% of those with complex CHD (P ¼ .03, Fisher exact test; Table 4). In-hospital mortality within 30 days occurred in 1.4% of ICD recipients without CHD and 0.6% of patients with CHD (P ¼ .02). After multivariable adjustment for potential confounders, CHD was associated with increased risk of implant-related complications (aRR 1.36, 95% CI 1.05–1.76, P ¼ .02). When noncomplex and complex CHD were considered separately, noncomplex CHD was associated with a trend toward increased risk for implant-related complications, whereas complex CHD was associated with a significantly increased risk (aRR 1.28, 95% CI 0.97–1.69, P ¼ .08 for noncomplex CHD; aRR 2.14, 95% CI 1.16–3.95, P ¼ .02 for complex CHD; Figure 2). After multivariable adjustment, CHD was not associated with 30-day in-hospital mortality (aRR 0.53, 95% CI 0.20–1.39, P ¼ .19).
We found a total of 470 epicardial pacemakers (426 in patients without CHD, 24 in patients with noncomplex CHD, and 20 in patients with patients with complex CHD) and 205 epicardial ICDs (191 in patients without CHD, 12 in patients with noncomplex CHD, and 2 in patients with patients with complex CHD). CHD was not associated with increased risk of implant-related complications in univariate analysis of patients undergoing epicardial pacemaker (P ¼ .66, Fisher exact test) or ICD placement (P ¼ .22, Fisher exact test). When epicardial procedures were included with transvenous devices in multivariate analysis, results for implant-related complications and 30-day inpatient mortality in patients with CHD were unchanged (data not shown).
Discussion In this analysis of pacemaker and ICD implantations in a large, comprehensive statewide database for the 7-year period 2005–2011, CHD was associated with higher risk
Figure 1 Adjusted relative risks and 95% confidence intervals for pacemaker implant-related complications. CHD ¼ congenital heart disease; CI ¼ confidence interval; RR ¼ relative risk.
342 Table 4
Heart Rhythm, Vol 12, No 2, February 2015 ICD procedural complication rates
Outcome Any complication Pneumothorax Hematoma Tamponade Mechanical complications§ Device infection Repeat procedure Mortality
Patients without CHD (n ¼ 32,046)
Noncomplex CHD (n ¼ 815)
Complex CHD (n ¼ 87)
Unadjusted P value‡
1913 (6.0) 149 (0.5) 163 (0.5) 107 (0.3) 540 (1.7)
60 (7.4) o10* o10* o10* 22 (2.7)
10 (11.5) 0 (0.0) 0 (0.0) 0 (0.0) o10*,†
.03 .86 .64 .13 .01
345 (1.1) 357 (1.1) 459 (1.4)
11 (1.4) 16 (2.0) o10*
o10*,† o10*,† 0 (0.0)
.02 .003 .09
Values are given as number (%). CHD ¼ congenital heart disease; ICD ¼ implantable cardioverter-defibrillator. * Health Care Cost and Utilization Project policy prohibits reporting cell frequencies o10, although the exact number was used for analyses. † Complication rate not reported but higher than in the noncomplex CHD group. ‡ P values calculated by Fisher exact test. § Mechanical complications are diagnostic codes specific to cardiac devices (including mechanical breakdown, displacement, leakage, mechanical obstruction, perforation, or protrusion) requiring device revision.
of implant-related complications for ICDs but not for pacemakers. After adjustment for potential confounders, patients with noncomplex CHD demonstrated a trend toward higher risk of an ICD procedural complication, whereas patients with complex CHD had a significant 2-fold higher risk compared to those without CHD undergoing ICD implantation. The 30-day in-hospital mortality after pacemaker or ICD implantation was similar for those with and those without CHD, although we observed a trend toward lower mortality in the CHD groups. Because of the small number of deaths observed, a moderate-sized effect cannot be excluded. This analysis is based on a CHD population 5-fold larger than prior reports,7 although our analysis excluded children and included pacemakers as well as a much larger proportion of patients with noncomplex CHD. This study also captured procedures from a broad range of hospitals, providing real-world data beyond the experience of a few specialized referral centers.7,19 Increased rates of ICD-related complications in CHD were mainly due to higher rates of mechanical complications (which includes mechanical breakdown, displacement,
leakage, obstruction, perforation, and protrusion), device infections, and repeat procedures. Rates of tamponade were not increased in patients with CHD, suggesting that the increase in mechanical complications probably is due to lead displacement or obstruction. Scarring from prior surgeries, either in the myocardium, the pericardium, or the mediastinum, may prevent lead perforation and tamponade in these patients. Possible explanations for increased rates of mechanical complications in patients with CHD include abnormal venous anatomy, abnormal hemodynamics, intracardiac shunting, and abnormal chamber size and morphology. Epicardial devices were more common in the group with CHD, and these devices were associated with higher rates of complications. However, we observed higher rates of complications for CHD patients undergoing any ICD implantation even after adjusting for epicardial devices or when only transvenous ICDs were considered. ICD complication rates in this analysis were higher than those reported in a recent study of Medicare beneficiaries by Peterson and colleagues18 as well as a study using outcomes from the National Cardiovascular Data Registry (NCDR) by
Figure 2 Adjusted relative risks and 95% confidence intervals for implantable cardioverter-defibrillator implant-related complications. CHD ¼ congenital heart disease; CI ¼ confidence interval; RR ¼ relative risk.
Hayward et al
Device Complications in ACHD
Hsu and colleagues.9 Compared to the Medicare study, patients in the current study were younger but did not have additional comorbidities to account for higher complication rates. The NCDR study only recorded in-hospital complications and would have missed complications presenting at subsequent hospitalizations. The major limitations of NCDR and Medicare registry data are that outcomes are limited by compliance with reporting to the NCDR registry and, Medicare patients are restricted to those older than 65 years. In contrast, HCUP captures 495% of statewide outcomes for all adults during the study period. In this analysis, ICD complications in patients with complex CHD were similar to the acute complication rates reported in 2 studies of ICD implantations in children and patients with CHD.6,7 In these studies, the leading complications were pocket infections, hematomas, and lead dislodgment. The most common complications in our analysis were mechanical complications, repeat procedures, and device infections. No hematomas were identified in the complex CHD group in our analysis; this may be due to our stricter definition for clinically significant hematoma, which required evacuation or blood transfusion. There are several potential explanations for our observation that complications were more common among CHD patients receiving ICDs than pacemakers. ICD implantation can be technically more challenging in CHD patients. The generally larger diameter of ICD leads compared to pacemaker leads could have resulted in increased difficulty with stable lead placement for ICDs, accounting for the higher observed mechanical complication rate. Mechanical complications included both lead displacement and mechanical obstruction. In patients with abnormal hemodynamics due to impaired ventricular function, stable lead placement can be more difficult to achieve, especially with larger diameter leads, and obstruction of venous structures or baffles could also be more common with larger-diameter leads. Dislodgment may also occur during defibrillation threshold testing. Although we observed higher complication rates in CHD patients undergoing ICD implantation, our results suggest that these patients are not at increased risk for acute mortality. This may be because among patients undergoing ICD implantation, we found that those with CHD were generally younger and had fewer traditional medical comorbidities. In patients with CHD, the main medical issue is often profound alterations in cardiac anatomy and hemodynamics as opposed to multiple medical comorbidities such as coronary artery disease or chronic kidney disease. However, the trend toward lower inpatient mortality remained even after adjusting for medical comorbidities. Therefore, patients with CHD may also have more attentive intraoperative and postoperative care because of their complex disease.
343 deaths occurring in the complex CHD group. Even when the complex and noncomplex CHD groups were combined, the number of CHD deaths was small, and a moderate-sized effect of CHD on 30-day in-hospital mortality after pacemaker or ICD implantation cannot be excluded. In addition, the number of patients with individual complex congenital defects was small; thus, a full analysis of each individual lesion was not possible. In addition, because of the nature of the HCUP database, we were only able to capture deaths within a California hospital, so any deaths occurring out-ofhospital and any out-of-state deaths would not have been captured. These would be expected to be primarily out-ofhospital sudden deaths because nonsudden deaths are likely to be preceded by rehospitalization. Patients are generally monitored in the hospital after device implantation and death after device implantation is rare, so the number of deaths missed by this analysis is likely to be small. Next, the imperfect sensitivity and specificity of ICD-9 codes is well known.20 However, if bias occurred in the classification of CHD, we would expect this to be the same for those with and those without device complications (nondifferential misclassification), and this would tend to bias the measures of association toward the null. ICD-9 codes also did not allow for determination of the indication for device implantation or single- vs dual-chamber ICDs, which is a known risk factor for device-related complications.8,18 Because very few devices were implanted in CHD patients at low-volume centers, the complication rates of these procedures at such centers are not known. Many patients with CHD undergo device placement at the time of cardiac surgery; these patients were excluded from our analyses because outcomes may have been influenced by the open heart surgeries rather than CHD diagnosis itself. Finally, we cannot exclude unmeasured confounding. Patients without CHD undergoing initial pacemaker implantation were substantially older than those with CHD (mean age 77 years vs 65 years) and thus may have had additional unmeasured comorbidities that could not be accounted for using this administrative dataset.
Conclusion In this analysis of adults undergoing pacemaker and ICD implantations in a large, comprehensive statewide database, CHD was associated with increased risk of ICD implantrelated complications but not with pacemaker implantrelated complications or increased 30-day in-hospital mortality.
Appendix Supplementary data Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1016/j.hrthm. 2014.10.038.
Study limitations This study has several limitations. Despite capturing more than 138,000 device implantation procedures, the number of complications in the group with CHD was small, with no
References 1. Hoffman JI, Kaplan S, Liberthson RR. Prevalence of congenital heart disease. Am Heart J 2004;147:425–439.
344
Heart Rhythm, Vol 12, No 2, February 2015
2. Warnes CA, Liberthson R, Danielson GK, Dore A, Harris L, Hoffman JI, Somerville J, Williams RG, Webb GD. Task force 1: the changing profile of congenital heart disease in adult life. J Am Coll Cardiol 2001;37:1170–1175. 3. Oechslin EN, Harrison DA, Connelly MS, Webb GD, Siu SC. Mode of death in adults with congenital heart disease. Am J Cardiol 2000;86:1111–1116. 4. Pillutla P, Shetty KD, Foster E. Mortality associated with adult congenital heart disease: trends in the US population from 1979 to 2005. Am Heart J 2009;158: 874–879. 5. Opotowsky AR, Siddiqi OK, Webb GD. Trends in hospitalizations for adults with congenital heart disease in the U.S. J Am Coll Cardiol 2009;54:460–467. 6. Alexander ME, Cecchin F, Walsh EP, Triedman JK, Bevilacqua LM, Berul CI. Implications of implantable cardioverter defibrillator therapy in congenital heart disease and pediatrics. J Cardiovasc Electrophysiol 2004;15:72–76. 7. Berul CI, Van Hare GF, Kertesz NJ, Dubin AM, Cecchin F, Collins KK, Cannon BC, Alexander ME, Triedman JK, Walsh EP, Friedman RA. Results of a multicenter retrospective implantable cardioverter-defibrillator registry of pediatric and congenital heart disease patients. J Am Coll Cardiol 2008;51: 1685–1691. 8. Dewland TA, Pellegrini CN, Wang Y, Marcus GM, Keung E, Varosy PD. Dualchamber implantable cardioverter-defibrillator selection is associated with increased complication rates and mortality among patients enrolled in the NCDR implantable cardioverter-defibrillator registry. J Am Coll Cardiol 2011;58: 1007–1013. 9. Hsu JC, Varosy PD, Bao H, Wang Y, Curtis JP, Marcus GM. Low body mass index but not obesity is associated with in-hospital adverse events and mortality among implantable cardioverter-defibrillator recipients: insights from the National Cardiovascular Data Registry. J Am Heart Assoc 2012;1:e003863. 10. Parsonnet V, Bernstein AD, Lindsay B. Pacemaker-implantation complication rates: an analysis of some contributing factors. J Am Coll Cardiol 1989;13: 917–921.
11. Gurvitz MZ, Inkelas M, Lee M, Stout K, Escarce J, Chang RK. Changes in hospitalization patterns among patients with congenital heart disease during the transition from adolescence to adulthood. J Am Coll Cardiol 2007;49:875–882. 12. Shah RU, Freeman JV, Shilane D, Wang PJ, Go AS, Hlatky MA. Procedural complications, rehospitalizations, and repeat procedures after catheter ablation for atrial fibrillation. J Am Coll Cardiol 2012;59:143–149. 13. Zhan C, Baine WB, Sedrakyan A, Steiner C. Cardiac device implantation in the United States from 1997 through 2004: a population-based analysis. J Gen Intern Med 2008;23(Suppl 1):13–19. 14. Mackie AS, Ionescu-Ittu R, Pilote L, Rahme E, Marelli AJ. Hospital readmissions in children with congenital heart disease: a population-based study. Am Heart J 2008;155:577–584. 15. Mackie AS, Pilote L, Ionescu-Ittu R, Rahme E, Marelli AJ. Health care resource utilization in adults with congenital heart disease. Am J Cardiol 2007;99:839–843. 16. Marelli AJ, Mackie AS, Ionescu-Ittu R, Rahme E, Pilote L. Congenital heart disease in the general population: changing prevalence and age distribution. Circulation 2007;115:163–172. 17. National Voluntary Standards for Patient Outcomes: A Consensus Report. National Quality Forum 2011;2011:A1–A6. 18. Peterson PN, Varosy PD, Heidenreich PA, Wang Y, Dewland TA, Curtis JP, Go AS, Greenlee RT, Magid DJ, Normand SL, Masoudi FA. Association of singlevs dual-chamber ICDs with mortality, readmissions, and complications among patients receiving an ICD for primary prevention. JAMA 2013;309:2025–2034. 19. Stephenson EA, Batra AS, Knilans TK, et al. A multicenter experience with novel implantable cardioverter defibrillator configurations in the pediatric and congenital heart disease population. J Cardiovasc Electrophysiol 2006;17:41–46. 20. Humphries KH, Rankin JM, Carere RG, Buller CE, Kiely FM, Spinelli JJ. Comorbidity data in outcomes research: are clinical data derived from administrative databases a reliable alternative to chart review? J Clin Epidemiol 2000;53: 343–349.
CLINICAL PERSPECTIVES The population of adults with congenital heart disease (CHD) is growing rapidly, and pacemakers and implantable cardioverter-defibrillators (ICDs) are increasingly implanted in this group. However, data regarding device procedural complication rates in this population are sparse. This article analyzes risk of device implantation in adult patients with CHD compared to those without CHD in a large statewide database capturing events for nearly all hospitalizations and procedures over a 7-year period, representing the largest series of CHD patients ever reported. CHD was associated with increased risk of ICD implant-related complications but not pacemaker implant-related complications or increased 30-day in-hospital mortality. These real-world data go beyond the experience of specialized referral centers and may be used by clinicians in planning procedures and discussions with patients about the risks and benefits of device implantation.
