Prolonged Effect of Postoperative Infectious Complications on Survival After Cardiac Surgery Michael P. Robich, MD, Joseph F. Sabik, III, MD, Penny L. Houghtaling, MS, Marta Kelava, MD, Steven Gordon, MD, Eugene H. Blackstone, MD, and Colleen G. Koch, MD, MS Departments of Thoracic and Cardiovascular Surgery and Cardiothoracic Anesthesia, Heart and Vascular Institute; Department of Quantitative Health Sciences, Research Institute; and Department of Infectious Disease, Medicine Institute, Cleveland Clinic, Cleveland, Ohio
Background. Whether patients having infections after cardiac surgery are at a survival disadvantage after hospital discharge is unclear. Our objectives were (1) to identify characteristics of such patients and (2) to determine whether this complication is associated with increased mortality beyond hospital discharge. Methods. In all, 30,414 patients were discharged after isolated coronary artery bypass grafting, valve, ascending aorta repair, or combined procedures from January 2000 to January 2011. Surgical site infection, septicemia, pneumonia, and urinary tract infection occurred in 1,868 patients (6.1%). Propensity matching was used to account for differences in perioperative characteristics and postoperative in-hospital events between these patients and those not having postoperative infections, to give 1,593 propensity-matched pairs. Time-related mortality and instantaneous risk were compared. Results. Surgical site infection occurred in 122 patients (0.40%), sternal wound infection in 263 (0.86%), septicemia
in 656 (2.2%), urinary tract infection in 853 (2.8%), and pneumonia in 513 (1.7%). Infections were associated with older age, female sex, larger body mass index, and multiple comorbidities. Among 1,593 propensity-matched pairs, postdischarge survival at 6 months and at 1, 5, and 10 years, respectively, was 89%, 86%, 67%, and 45% for patients without infections, and 86%, 83%, 63%, and 43% (p [ 0.008) for patients with infections. Survival differences resulted from a higher, but gradually declining, early instantaneous risk during the first year after surgery. Elevated risk was of shorter duration for surgical site infections than for other infections. Conclusions. Postoperative infection is associated with a high-risk patient profile, and risk of death is elevated early after hospital discharge. Reasons for this prolonged effect are unclear.
P
Patients and Methods
ostoperative complications after noncardiac surgery are associated with decreased survival beyond the standard inhospital or 30-day postoperative recovery phase [1, 2], and in both surgical and nonsurgical hospital settings, infectious complications in particular have been associated with reduced long-term survival after initial treatment [3–8]. In the cardiac surgical setting, infectious complications are known to increase resource utilization and inhospital mortality [9, 10], but there are limited data about whether patients who have and recover from postoperative infections are at a survival disadvantage after hospital discharge. Our objectives were (1) to identify characteristics of patients having postoperative infections who survive to discharge to propensity match patients with and without infections, and (2) to determine whether postoperative infectious complications are associated with increased mortality beyond hospital discharge, accounting for these differing characteristics.
Accepted for publication Dec 5, 2014. Address correspondence to Dr Koch, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, 600 N Wolfe St, Blalock 1415, Baltimore, MD 21287; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
(Ann Thorac Surg 2015;-:-–-) Ó 2015 by The Society of Thoracic Surgeons
Patients From January 2000 to January 2011, 32,707 isolated coronary artery bypass graft, isolated valve operations, ascending aorta repair, or combined procedures were performed at Cleveland Clinic on 32,146 patients. Only the first operation for a given patient was included in this study. Because this investigation focused on survival after hospital discharge, 667 patients who died in the hospital and 1,065 without postdischarge follow-up information were excluded, leaving 30,414 patients as the study population.
Dr Sabik discloses financial relationships with Abbott Laboratories and Medtronic.
The Appendix can be viewed in the online version of this article [http://dx.doi.org/10.1016/j.athoracsur.2014. 12.037] on http://www.annalsthoracicsurgery.org.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.12.037
2
ROBICH ET AL POSTOPERATIVE INFECTIONS AND SURVIVAL
Ann Thorac Surg 2015;-:-–-
Table 1. Characteristics, Cardiac Surgery, and Postoperative Outcomes of Patients With and Patients Without Postoperative Infectious Complications No Infection (n ¼ 28,546) Variable Demographics Age, years Female Race Black White Other Body surface area, m2 Clinical presentation New York Heart Association functional class I II III IV Emergency surgery Hospital transfer Hospital admission before date of surgery or transfer Cardiac comorbidity Myocardial infarction Left ventricular ejection fraction, % Atrial fibrillation or flutter Complete heart block or pacer Preoperative ventricular arrhythmia Heart failure Endocarditis Prior cardiac surgery Number of cardiac operations 0 1 2 3 Noncardiac comorbidity Peripheral arterial disease Hypertension Pharmacologically treated diabetes Insulin treated Not insulin treated Chronic obstructive pulmonary disease Preoperative immunosuppressive therapy Smoking Preoperative renal dialysis Prior stroke Preoperative laboratory values Bilirubin, g $ dL1 Glomerular filtration rate Blood urea nitrogen, g $ dL1 Hematocrit, % Surgical procedure Surgical invasiveness Full incision
n
a
No. (%)
Infection (n ¼ 1,868) na
No. (%)
p Value
28,546 28,546
64 13 9,105 (32)
1,868 1,868
68 12 860 (46)
Background. Whether patients having infections after cardiac surgery are at a survival disadvantage after hospital discharge is unclear. Our objectives were (1) to identify characteristics of such patients and (2) to determine whether this complication is associated with increased mortality beyond hospital discharge. Methods. In all, 30,414 patients were discharged after isolated coronary artery bypass grafting, valve, ascending aorta repair, or combined procedures from January 2000 to January 2011. Surgical site infection, septicemia, pneumonia, and urinary tract infection occurred in 1,868 patients (6.1%). Propensity matching was used to account for differences in perioperative characteristics and postoperative in-hospital events between these patients and those not having postoperative infections, to give 1,593 propensity-matched pairs. Time-related mortality and instantaneous risk were compared. Results. Surgical site infection occurred in 122 patients (0.40%), sternal wound infection in 263 (0.86%), septicemia
in 656 (2.2%), urinary tract infection in 853 (2.8%), and pneumonia in 513 (1.7%). Infections were associated with older age, female sex, larger body mass index, and multiple comorbidities. Among 1,593 propensity-matched pairs, postdischarge survival at 6 months and at 1, 5, and 10 years, respectively, was 89%, 86%, 67%, and 45% for patients without infections, and 86%, 83%, 63%, and 43% (p [ 0.008) for patients with infections. Survival differences resulted from a higher, but gradually declining, early instantaneous risk during the first year after surgery. Elevated risk was of shorter duration for surgical site infections than for other infections. Conclusions. Postoperative infection is associated with a high-risk patient profile, and risk of death is elevated early after hospital discharge. Reasons for this prolonged effect are unclear.
P
Patients and Methods
ostoperative complications after noncardiac surgery are associated with decreased survival beyond the standard inhospital or 30-day postoperative recovery phase [1, 2], and in both surgical and nonsurgical hospital settings, infectious complications in particular have been associated with reduced long-term survival after initial treatment [3–8]. In the cardiac surgical setting, infectious complications are known to increase resource utilization and inhospital mortality [9, 10], but there are limited data about whether patients who have and recover from postoperative infections are at a survival disadvantage after hospital discharge. Our objectives were (1) to identify characteristics of patients having postoperative infections who survive to discharge to propensity match patients with and without infections, and (2) to determine whether postoperative infectious complications are associated with increased mortality beyond hospital discharge, accounting for these differing characteristics.
Accepted for publication Dec 5, 2014. Address correspondence to Dr Koch, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, 600 N Wolfe St, Blalock 1415, Baltimore, MD 21287; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
(Ann Thorac Surg 2015;-:-–-) Ó 2015 by The Society of Thoracic Surgeons
Patients From January 2000 to January 2011, 32,707 isolated coronary artery bypass graft, isolated valve operations, ascending aorta repair, or combined procedures were performed at Cleveland Clinic on 32,146 patients. Only the first operation for a given patient was included in this study. Because this investigation focused on survival after hospital discharge, 667 patients who died in the hospital and 1,065 without postdischarge follow-up information were excluded, leaving 30,414 patients as the study population.
Dr Sabik discloses financial relationships with Abbott Laboratories and Medtronic.
The Appendix can be viewed in the online version of this article [http://dx.doi.org/10.1016/j.athoracsur.2014. 12.037] on http://www.annalsthoracicsurgery.org.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.12.037
2
ROBICH ET AL POSTOPERATIVE INFECTIONS AND SURVIVAL
Ann Thorac Surg 2015;-:-–-
Table 1. Characteristics, Cardiac Surgery, and Postoperative Outcomes of Patients With and Patients Without Postoperative Infectious Complications No Infection (n ¼ 28,546) Variable Demographics Age, years Female Race Black White Other Body surface area, m2 Clinical presentation New York Heart Association functional class I II III IV Emergency surgery Hospital transfer Hospital admission before date of surgery or transfer Cardiac comorbidity Myocardial infarction Left ventricular ejection fraction, % Atrial fibrillation or flutter Complete heart block or pacer Preoperative ventricular arrhythmia Heart failure Endocarditis Prior cardiac surgery Number of cardiac operations 0 1 2 3 Noncardiac comorbidity Peripheral arterial disease Hypertension Pharmacologically treated diabetes Insulin treated Not insulin treated Chronic obstructive pulmonary disease Preoperative immunosuppressive therapy Smoking Preoperative renal dialysis Prior stroke Preoperative laboratory values Bilirubin, g $ dL1 Glomerular filtration rate Blood urea nitrogen, g $ dL1 Hematocrit, % Surgical procedure Surgical invasiveness Full incision
n
a
No. (%)
Infection (n ¼ 1,868) na
No. (%)
p Value
28,546 28,546
64 13 9,105 (32)
1,868 1,868
68 12 860 (46)
