Pediatr Cardiol (2014) 35:550–555 DOI 10.1007/s00246-013-0822-1
ORIGINAL ARTICLE
Risk Factors and Prognosis of Atrioventricular Block After Atrial Septum Defect Closure Using the Amplatzer Device Yibin Wang • Yimin Hua • Li Li • Xiaoqin Wang Lina Qiao • Xiaoqing Shi • Jiping Hua • Yi Qu • Dezhi Mu
•
Received: 2 July 2013 / Accepted: 3 October 2013 / Published online: 30 October 2013 Ó Springer Science+Business Media New York 2013
Abstract Amplatzer septal occluder (ASO)-induced complications have been observed. However, little attention is paid to the atrioventricular block (AVB) induced by atrial septum defect (ASD) closure using the Amplatzer device. This study aimed to analyze the risk factors and prognosis of AVB after catheter closure and to reduce the incidence of adverse events. In this study, 706 ASD patients who received closure in our division were investigated retrospectively for the relationship between AVB and factors such as age, size of the ASD (Dd), diameter of the occluder (Do), diameter of the septum (Ds), Do/Dd ratio, and Do/Ds ratio. Data distribution was evaluated with the Kolmogorov–Smirnov normality test. The Wilcoxon rank sum test was used to compare non-normal distribution data. A p value lower than 0.05 was considered significant. Of the 706 patients, six had experienced the development of AVB, giving an incidence of 0.85 %. The risk factors included younger age, larger size of the ASD, larger size of the device, and the Do/Ds ratio (C0.45). The milder AVB is, the better the prognosis. An AVB of III° and an unchanged electrocardiogram (ECG) within 3 days after the procedure are poor prognostic indicators. More attention should be paid to AVB induced by ASD closure. Younger age, size of the ASD, size of the device, and a Do/ Ds ratio of 0.45 or higher are the risk factors associated with AVB after closure. A timely retrieval of the device should be considered for a good prognosis.
Keywords device
ASD Closure AVB Amplatzer
Transcatheter closure of ostium secundum atrial septal defects (ASDs) has been widely accepted and is becoming one of the standard treatments for this malformation since the report of King and Mills [10] in 1974. Among these devices, the Amplatzer septal occluder (ASO; AGA Medical Corp., Golden Valley, MN, USA) is used most often [7, 11]. However, in recent years, ASO-induced complications have been observed such as pericardial effusion, perforation/device erosion, thrombus and thromboembolic events, device embolization/malposition, and arrhythmia [5, 6, 15]. For adult patients, most reported occluder-induced arrhythmias are atrial tachycardia, atrial flutter, and atrial fibrillation, whereas few atrioventricular blocks (AVBs) are reported because AVB occurs only occasionally in adults and usually is transient, with a good prognosis [14]. For ASO-induced AVB in children, especially in infant patients, no studies with large samples have been reported. In this study, we analyzed the incidence, risk factors, and prognosis of AVB associated with ASD closure using the ASO in our hospital.
Materials and Methods Patients Y. Wang Y. Hua L. Li X. Wang L. Qiao X. Shi J. Hua Y. Qu D. Mu (&) Division of Pediatric Cardiology, West China Second University Hospital, Sichuan University, Szechuan, China e-mail: [email protected]
123
From 1 March 2002 to 28 February 2013, the ASDs of 706 patients (467 males and 239 females) were closed successfully using the ASO or a modified ASO (made in China) in our division. All these patients were included in
Pediatr Cardiol (2014) 35:550–555
551
Table 1 Data of the patients who had closure of atrial septal defects with the Amplatzer septal occluder (ASO) (n = 706)
Table 2 Patients with AVB 1
2
3
4
5
6
Median (P25, P75)
Range Age (years)
5.3
3.2
3.1
2.3
3.2
3.5
Age (years)
4.6 (3.30, 7.89)
2–18
Gender
F
F
F
M
F
M
15
14
14
11
15
15
Dd (mm)
12.35 (8, 16)
4–31
Weight (kg)
Do (mm)
16 (12, 22)
6–36
Rs (mm)
6
9
10
9
6
7
Ds (mm)
44 (39, 50)
32–69
Ri (mm)
9
8
8
11
9
7
Dd/Do ratio
0.72 (0.63, 0.83)
0.22–1.00
Rsv (mm)
5
11
9
5
8
9
Do/Ds ratio
0.38 (0.28, 0.45)
0.15–0.65
Riv (mm)
7
7
8
10
5
6
P25 the first quartile, P75 the third quartile, Dd diameter of atrial septal defect, Do diameter of occluder, Ds diameter of atrial septum
Ra (mm)
2
1
0
2
4
2
Rp (mm)
5
8
10
0
3
8
Dd (mm)
21
14
15
19
19
20
Ds (mm) Do (mm)
40 26
40 18
41 22
38 24
43 22
41 24
Dd/Do
0.81
0.78
0.68
0.86
0.86
0.83
Do/Ds
0.65
0.45
0.54
0.63
0.51
0.59
this study. Of the 706 patients, 53 patients had ASD closure with the ASO, and the remaining 653 patients had closure using the modified ASO (ratio, *1:12). All Amplatzer devices were used before 2005. The ages of the patients ranged from 2 to 18 years (median 4.6 years; P25: 3.30 years; P75: 7.89 years). Three of the patients had distant defects, and their multiple ASDs were closed using two devices. The remaining patients had their defects closed using a single device (Table 1). Written informed consent was obtained from all the patients and/or their guardians. The study was approved by the Ethics Committee of Sichuan University. Before the closing procedure, every patient received a routine 12-lead electrocardiogram (ECG), chest X-ray, and a transthoracic echocardiogram (TTE). Consecutive ECG monitoring was performed for the patients during the procedure and then 3 days after the procedure. The patients with AVB were further evaluated with a 12-lead ECG daily in the first week, weekly in the first month, and monthly thereafter. A 24-h ambulatory ECG was performed for the last follow-up evaluation of the patients. Procedure Protocol Before the procedure, TTE was performed for all the patients to evaluate the type, number, position, size, surrounding rims, and largest diameter of the ASDs (subcostal double-atrium view). Unfractionated heparin (100 U/kg/ dose) was administered intravenously via an arm after establishment of a femoral access and before the procedure. Right heart catheterization was performed in all cases to measure pulmonary pressure. Standard technical delivery of the device over a guidewire through the defect was performed, as previously described [11]. The size of device selected for use was determined by the size and rim length of the ASD. If all the rims of the ASD were sufficient, the size of device was 2–4 mm larger than the size of the ASD. If one of rims was not long enough, the size of device was 4–6 mm larger than the size of the ASD.
F female, M male, Rs superior rim, Ri atrioventricular valve rim, Rsv superior vena cava rim, Riv inferior vena cava rim, Ra aortic rim, Rp posterior rim, Dd diameter of atrial septal defect, Ds diameter of atrial septum, Do diameter of occluder
A sizing balloon (AGA Medical Corp.) was used to measure the diameter of the defect in 62 patients in its early stage, and the remaining 644 patients were measured using TTE. The ASO was delivered by an appropriate delivery system and deployed when a satisfactory device position was confirmed by TTE and fluoroscopy, a position in which the device would not influence the motion of the atrioventricular valves or blood flow of the inferior and superior vena cava. Statistical Analysis Because the variables in this study such as age, size of the ASD, size of the device, largest diameter of the atrial septum, Dd/Do ratio, and Do/Ds ratio were positive skewness distribution, the data is expressed as the median value (P25, P75) and range. Data distribution was evaluated with the Kolmogorov–Smirnov normality test. The Wilcoxon rank sum test was used to compare data between subgroups. A p value lower than 0.05 was considered significant. Statistical analyses were performed with SPSS 17.0 for Windows (SPSS. Inc., Chicago, IL, USA).
Results In six of the 706 patients, AVB had developed after ASD closure with ASO, giving an incidence of 0.85 %. No AVB was found in patients who had ASD closure with the ASO (AGA Medical Corp., Golden Valley, MN, USA) or in the
123
552
Pediatr Cardiol (2014) 35:550–555
Table 3 Variables between subgroups Patients with AVB (n = 6)
Patients without AVB (n = 700)
z Value
p Value
Age (years)
3.2 (2.9, 3.95)
4.9 (3.3, 7.9)
-2.190
0.028a
Dd (mm)
16.5 (14.75, 20.5)
12 (8, 16)
-0.213
0.009a
Do (mm)
20 (21, 24.5)
16 (12, 22)
-2.717
0.007a
Ds (mm)
41.5 (39.5, 41.5)
44 (39, 50)
-1.564
0.118
Dd/Do
0.82 (0.76, 0.86)
0.72 (0.63, 0.83)
-1.709
0.088
Do/Ds
0.48 (0.50, 0.64)
0.36 (0.31, 0.42)
-3.463
0.001a
Dd diameter of atrial septal defect, Do diameter of occluder, Ds diameter of atrial septum a Statistically significant
patients whose defect diameter was measured using a sizing balloon. The general data and measurements of the defects for the patients with AVB are listed in Table 2.
Table 4 Comparison of ECGs before and after closure
Risk Factors Associated With AVB As shown in Table 2, all the rims of ASD were sufficient except for the aortic rim. The variables are shown in Table 3. Among these variables, the differences in age, size of the ASD, size of the device, and Do/Ds ratio between the two subgroups are significant. The ages of all the patients with AVB were 5.3 years or younger. Moreover, it was noted that the patients with serious AVB (above II° AVB) were younger than 3.5 years. The most important factor was the Do/Ds ratio (p = 0.001). All the AVBs were developed in patients with a Do/Ds ratio of 0.45 or higher. No AVB was developed in patients with a Do/Ds ratio lower than 0.45. Prognosis of AVB All AVBs occurred within 24 h after ASD closure (Table 4). The types of AVB in the early stage included I°, II°, advanced and III° AVB. Among these cases, the patient with I° AVB recovered shortly (in about 2 weeks) and had a good prognosis. The patients with III° AVB had a poor prognosis. The ECG of one of two patient with III° AVB recovered after retrieval of the device immediately during procedure. Another patient had the device retrieved surgically. However, the ECG did not recover completely during a follow-up period of 14 months. This result differed from that of previous reports, suggesting that the AVB induced by closure of ASD using ASO is transient and has a good prognosis [2, 9, 14].
Discussion Compared with the perimembranous ventricular septal defect (PMVSD), the structure around ASD is less
123
Before closure
AVB type after closure
Time initially (h)
1
S, IRBB
I°
18
2
S, IRBB
II° Itype
1
3 4
S S, IRBB
I° ? II°, 2:1 conduction Advanced AVB
9 24
5
S, IRBB
III°
8
6
S, IRBB
III°
Instantly after device deployment
AVB atrioventricular block, S sinus rhythm, IRBB incomplete right bundle block
complicated. Consequently, transcatheter closure of ostium secundum ASDs has been widely accepted worldwide. Most physicians think closing ASD with ASO is effective and safe, with few complications. Moreover, less attention is given to AVB induced by closure of ASD with ASO than to AVB induced by closure of a PMVSD with the device. However, some complications after closure with ASO have been reported in recent years, such as pericardial effusion, perforation/device erosion, thrombus and thromboembolic events, device embolization/malposition, and arrhythmia [5, 6, 15]. Some cases of AVB induced by closure of ASD with ASO also have been reported occasionally [2–4, 8, 9, 12–14]. According to previous reports, the majority of AVBs have occurred in children after closure of ASD with ASO. Age, size of the ASD, and size of the occluder are perhaps the risk factors associated with AVB. To date, the mechanism is unclear. Some authors think the right disc of the device compresses and stimulates the atrioventricular node (AVN) located in Koch’s triangle anteinferiorly and results in the abnormality of conduction. The stretching effect of the device on the AVN is another potential mechanism. Gupta et al. [8] reported a case in which a III° AVB developed after closure of ASD with ASO. The device was retrieved surgically. In the operating room, the device was
Pediatr Cardiol (2014) 35:550–555
found to be well positioned. However, due to a deficient inferior rim of the defect, the ASO was impinging against the AVN. Of the six cases in the current study, only one (case 5) involved a retrieved device and a surgically repaired ASD. This case involved a 3.2-year-old boy, and the diameter of the ASD was 19 mm (Table 2). When the atrium was opened, the surgeon found that the atrial septum was covered fully and that the AVN was impinged by the device. This finding supported the speculation that the compression of the device on the AVN could result in the occurrence of AVB. In case 6, a III° AVB occurred instantly after deployment of the device. But the ECG recovered shortly after retrieval of the device through the delivery system. A III° AVB occurred again after another deployment. Closure with the device was given up after three tries. This phenomenon also indirectly suggests a compressing and stretching effect of the device on the AVN. The surgeon suggests that surgical repair of ASD is safer than closure with ASO in the case of younger and large ASD patients in terms of complications (including AVB and erosion of heart) and mortality. The study by Suda et al. [14] suggested that a device size of 19 mm or larger, a device/height ratio greater than 0.18 mm/cm, and a Qp:Qs greater than 2.8 are the risk factors. In our retrospective study, we found that the younger the age (B5.3 years) and the larger the Do/Ds ratio (C0.45), the more likely the development of AVB will be. The size of the device and the size of the ASD are other risk factors. Because the atrial septum diameter increases with age, the younger the age, the smaller the diameter will be. In younger children, if a large device is chosen based on a large ASD size, the Do/Ds ratio increases, and the AVN is prone to compression by the device, which may result in the occurrence of AVB. In the current study, a traditional sizing balloon (AGA Medical Corp.) was used to measure the diameter of the defect in 62 patients in the early stage. No AVB was found in these patients. However, we thought the inflated balloon would lacerate the atrial septum and overstretch the defect in younger children. Since then, we have measured the diameter of the defect using TTE and have chosen a device 4 to 6 mm larger than the defect. All AVBs have occurred in the patients measured via TTE. We therefore speculate that this measurement resulted in oversizing of the ASO, which caused AVB. Currently, most intervention lists recommend the stop-flow method as the measurement in every patient to avoid overstretching of the defect and oversizing of the ASO [1]. All six patients who experienced AVB had a deficient aortic rim (0–4 mm, as shown in Table 2). Two of the patients had a deficient posterior rim (0–3 mm), and the
553 Table 5 Prognosis and follow-up Prognosis
Follow-up (months)
1
Steroid therapy, ECG recovered 2 weeks later
12, S
2
Steroid therapy, ECG recovered 22 h later
8, S
3
Steroid therapy, I° ? II° 12 h later and 2:1 conduction, I° ? II° IItype 38 h later and more conduction; I° AVB 80 h later
16, I° AVB
4
Steroid therapy, more conduction after 36 h, I° AVB 48 h later, II° IItype occasionally; ECG recovered 70 h later
72, S
5
Steroid therapy, III° AVB persisted. retrieved device and repaired ASD surgically 168 h later; ECG changed to I° AVB instantly when heart rebeated; 2 weeks later ambulatory ECG shown I° AVB, II° II AVB occasionally Retrieved device through deliver system ECG recovered instantly; III° AVB occurred again after another deployment; gave up closure with device after three tries
14 I° AVB
6
3, S, IRBB
ECG electrocardiogram, S sinus rhythm, AVB atrioventricular block, IRBB incomplete right bundle block
remaining rims were sufficient. This finding differs from that of previous reports, which speculated that the AVB was associated with a deficient posterior-inferior rim. We think this is the case because we deliberately chose a larger device for secure implantation when the aortic rim or posterior rim was deficient. As a result, the Do/Ds ratio further increased, and the AVN was more prone to be compressed, especially in young children who have thinner and softer ASD rims. For example, the aortic rim was 0 mm in case 3. To prevent malpositioning of the device, we deliberately chose an occluder that had a diameter 7 mm larger than the diameter of the defect so that both discs of the device could slightly embrace the aortic root. However, this choice was not standard practice and resulted in a Do/Ds ratio of 0.54 (C0.45), with I° ? II° AVB occurring 9 h after the procedure. The AVB advanced the II° AVB with 2:1 conduction 12 h later (Table 5). The I° AVB was unchanged during the follow-up evaluation 16 months later. The oversized device in this case not only resulted in AVB, which at this writing has not recovered completely, but also likely will result in erosion of the aorta in the future [6]. Further follow-up assessment is needed, and an oversized device should be avoided. In the study of Suda et al. [14], a device/height ratio greater than 0.18 mm/cm was a risk factor. However, we think because the height indicates the largest diameter of the atrial septum to some extent, it is more reliable to measure the diameter of the atrial septum directly. We therefore suggest that the Do/Ds ratio is a risk factor more
123
554
valuable for prediction of AVB occurrence than the device/ height ratio. According to the experience obtained from this research, we suggest that younger patients (age \3 years) with a large ASD and deficient rims should be repaired surgically. Since 1 March 2013, ASDs in 31 cases have been closed with modified ASO in our department. No AVB occurred in these patients. In this study, the prognosis of AVB also differed from those reported previously. Suda et al. [14] and Ho et al. [9] reported patients who experienced transient and reversible AVB after closure of ASD with ASO. They think the prognosis for such patients is good. But Nehgme et al. [12] reported the case of a 6-year-old girl who presented with progression of AVB from II° AVB to symptomatic complete heart block requiring permanent pacemaker implantation 4 years after ASD closure with ASO. Gupta et al. [8] reported a patient who experienced III° AVB after closure, with the medication having no effect on the AVB. The ECG recovered after retrieval of the device surgically 72 h later. For six cases in the current study, if the degree of AVB was mild and ECG changed favorably within 72 h after closure, the prognosis was good. The patients with III° AVB and unchanged ECG within 72 h after closure had a poor prognosis. In two cases, the device had to be retrieved either by surgery or by sheath. To date, the optimal time for retrieving the device still is unknown. More studies need to be conducted. In our study, we observed that the patient whose device was retrieved immediately when III° AVB occurred during the procedure was able to recover instantly and had good prognosis. The patient with III° AVB and unchanged ECG within the first 72 h had a poor prognosis. The later the device is retrieved, the poorer the prognosis will be. We speculate that the prognosis depends on the degree of compression on the AVN. The stretching effect of the device or stimulation of the right disc of the device to the AVN results in edema and inflammation of the AVN. This is the reason why the steroid was used for all the patients who experienced AVB after closure. In this situation, perhaps the AVB is mild and the ECG is changed. The AVB ameliorates gradually when the heart adapts to the situation and is treated with steroids and nonsteroid antiinflammatory agents. If the device compresses directly on the AVN and results in ischemia, necrosis, and fibrosis of the AVN, the AVB is serious, progressive, and unrecovered even after retrieval of the device, especially when the device is retrieved at a later time. This study had the following limitations. Because the follow-up periods were short, the long-term prognosis of AVB induced by closure of ASD with ASO needs to be studied further. The sample in this study was small, and
123
Pediatr Cardiol (2014) 35:550–555
future studies with larger samples in multiple centers are needed to test our results.
Conclusion More attention should be paid to AVB induced by closure of ASD with ASO. Younger age, size of the ASD, size of the device, and a Do/Ds ratio of 0.45 or higher are the risk factors associated with AVB after closure. The AVB after closure should be followed up for the long term; the mechanism of the AVB should be studied further with a larger number of patients; and the relationship between the device and the anatomic structure around the ASD should be investigated. Acknowledgments This work was supported by the National Science Foundation of China (No. 31171020 to Dezhi Mu; Nos. 81172174 and 81270724 to Yi Qu) and a grant of the Clinical Discipline Program (neonatology) from the Ministry of Health of China (1311200003303).
References 1. Carlson KM, Justino H, O’Brien RE, Dimas VV, Leonard GT Jr, Pignatelli RH et al (2005) Transcatheter atrial septal defect closure: modified balloon sizing technique to avoid overstretching the defect and oversizing the Amplatzer septal occluder. Catheter Cardiovasc Interv 66:390–396 2. Celiker A, Ozkutlu S, Karakurt C, Karagoz T (2005) Cardiac dysrhythmias after transcatheter closure of ASD with Amplatzer device. Turk J Pediatr 47:323–326 3. Chessa M, Carminati M, Butera G, Bini RM, Drago M, Rosti L, Giamberti A, Pome G, Bossone E, Frigiola A (2002) Early and late complications associated with transcatheter occlusion of secundum atrial septal defect. J Am Coll Cardiol 39:1061–1065 4. Dalvi B, Pinto R, Gupta A (2008) Device closure of large atrial septal defects requiring devices [ or = 20 mm in small children weighing \20 kg. Catheter Cardiovasc Interv 71:679–686 5. Delaney JW, Li JS, Rhodes JF (2007) Major complications associated with transcatheter atrial septal occluder implantation: a review of the medical literature and the manufacturer and user facility device experience (MAUDE) database. Congenit Heart Dis 2:256–264 6. Diab K, Kenny D, Hijazi ZM (2012) Erosions, erosions, and erosions! device closure of atrial septal defects: how safe is safe? Catheter Cardiovasc Interv 80:168–174 7. DiBardino DJ, McElhinney DB, Kaza AK, Mayer JE Jr (2009) Analysis of the US food and drug administration manufacturer and user facility device experience database for adverse events involving Amplatzer septal occluder devices and comparison with the society of thoracic surgery congenital cardiac surgery database. J Thorac Cardiovasc Surg 137:1334–1341 8. Gupta U, Al-anani SJ, Polimenakos AC (2011) Timing for successful surgical management of heart block after placement of an Amplatzer occlusion device for secundum atrial septal defect repair. J Thorac Cardiovasc Surg 141:1319–1321 9. Ho T-Y, Tsai M-C, Lee P-C, Lu J-H, Liang C-M, Laura Meng C-C, Hwang B (2005) Amplatzer septal occluder-induced arrhythmias. J Med Sci 25:105–108
Pediatr Cardiol (2014) 35:550–555 10. King TD, Mills NL (1974) Nonoperative closure of atrial septal defects. Surgery 75:383–388 11. Masura J, Gavora P, Formanek A, Hijazi ZM (1997) Transcatheter closure of secundum atrial septal defects using the new selfcentering Amplatzer septal occluder: initial human experience. Cathet Cardiovasc Diagn 42:388–393 12. Nehgme RA, Huddleston AR, Cheatham JP (2009) Progression to late complete atrioventricular block following Amplatzer device closure of atrial septal defect in a child. Pediatr Cardiol 30:367–370
555 13. Sadiq M, Kazmi T, Rehman AU, Latif F, Hyder N, Qureshi SA (2012) Device closure of atrial septal defect: medium-term outcome with special reference to complications. Cardiol Young 22:71–78 14. Suda K, Raboisson MJ, Piette E, Dahdah NS, Miro J (2004) Reversible atrioventricular block associated with closure of atrial septal defects using the Amplatzer device. J Am Coll Cardiol 43:1677–1682 15. Ueda H, Yanagi S, Nakamura H, Ueno K, Gatayama R, Asou T, Yasui S (2012) Device closure of atrial septal defect: immediate and midterm results. Circ J 76:1229–1234
123
ORIGINAL ARTICLE
Risk Factors and Prognosis of Atrioventricular Block After Atrial Septum Defect Closure Using the Amplatzer Device Yibin Wang • Yimin Hua • Li Li • Xiaoqin Wang Lina Qiao • Xiaoqing Shi • Jiping Hua • Yi Qu • Dezhi Mu
•
Received: 2 July 2013 / Accepted: 3 October 2013 / Published online: 30 October 2013 Ó Springer Science+Business Media New York 2013
Abstract Amplatzer septal occluder (ASO)-induced complications have been observed. However, little attention is paid to the atrioventricular block (AVB) induced by atrial septum defect (ASD) closure using the Amplatzer device. This study aimed to analyze the risk factors and prognosis of AVB after catheter closure and to reduce the incidence of adverse events. In this study, 706 ASD patients who received closure in our division were investigated retrospectively for the relationship between AVB and factors such as age, size of the ASD (Dd), diameter of the occluder (Do), diameter of the septum (Ds), Do/Dd ratio, and Do/Ds ratio. Data distribution was evaluated with the Kolmogorov–Smirnov normality test. The Wilcoxon rank sum test was used to compare non-normal distribution data. A p value lower than 0.05 was considered significant. Of the 706 patients, six had experienced the development of AVB, giving an incidence of 0.85 %. The risk factors included younger age, larger size of the ASD, larger size of the device, and the Do/Ds ratio (C0.45). The milder AVB is, the better the prognosis. An AVB of III° and an unchanged electrocardiogram (ECG) within 3 days after the procedure are poor prognostic indicators. More attention should be paid to AVB induced by ASD closure. Younger age, size of the ASD, size of the device, and a Do/ Ds ratio of 0.45 or higher are the risk factors associated with AVB after closure. A timely retrieval of the device should be considered for a good prognosis.
Keywords device
ASD Closure AVB Amplatzer
Transcatheter closure of ostium secundum atrial septal defects (ASDs) has been widely accepted and is becoming one of the standard treatments for this malformation since the report of King and Mills [10] in 1974. Among these devices, the Amplatzer septal occluder (ASO; AGA Medical Corp., Golden Valley, MN, USA) is used most often [7, 11]. However, in recent years, ASO-induced complications have been observed such as pericardial effusion, perforation/device erosion, thrombus and thromboembolic events, device embolization/malposition, and arrhythmia [5, 6, 15]. For adult patients, most reported occluder-induced arrhythmias are atrial tachycardia, atrial flutter, and atrial fibrillation, whereas few atrioventricular blocks (AVBs) are reported because AVB occurs only occasionally in adults and usually is transient, with a good prognosis [14]. For ASO-induced AVB in children, especially in infant patients, no studies with large samples have been reported. In this study, we analyzed the incidence, risk factors, and prognosis of AVB associated with ASD closure using the ASO in our hospital.
Materials and Methods Patients Y. Wang Y. Hua L. Li X. Wang L. Qiao X. Shi J. Hua Y. Qu D. Mu (&) Division of Pediatric Cardiology, West China Second University Hospital, Sichuan University, Szechuan, China e-mail: [email protected]
123
From 1 March 2002 to 28 February 2013, the ASDs of 706 patients (467 males and 239 females) were closed successfully using the ASO or a modified ASO (made in China) in our division. All these patients were included in
Pediatr Cardiol (2014) 35:550–555
551
Table 1 Data of the patients who had closure of atrial septal defects with the Amplatzer septal occluder (ASO) (n = 706)
Table 2 Patients with AVB 1
2
3
4
5
6
Median (P25, P75)
Range Age (years)
5.3
3.2
3.1
2.3
3.2
3.5
Age (years)
4.6 (3.30, 7.89)
2–18
Gender
F
F
F
M
F
M
15
14
14
11
15
15
Dd (mm)
12.35 (8, 16)
4–31
Weight (kg)
Do (mm)
16 (12, 22)
6–36
Rs (mm)
6
9
10
9
6
7
Ds (mm)
44 (39, 50)
32–69
Ri (mm)
9
8
8
11
9
7
Dd/Do ratio
0.72 (0.63, 0.83)
0.22–1.00
Rsv (mm)
5
11
9
5
8
9
Do/Ds ratio
0.38 (0.28, 0.45)
0.15–0.65
Riv (mm)
7
7
8
10
5
6
P25 the first quartile, P75 the third quartile, Dd diameter of atrial septal defect, Do diameter of occluder, Ds diameter of atrial septum
Ra (mm)
2
1
0
2
4
2
Rp (mm)
5
8
10
0
3
8
Dd (mm)
21
14
15
19
19
20
Ds (mm) Do (mm)
40 26
40 18
41 22
38 24
43 22
41 24
Dd/Do
0.81
0.78
0.68
0.86
0.86
0.83
Do/Ds
0.65
0.45
0.54
0.63
0.51
0.59
this study. Of the 706 patients, 53 patients had ASD closure with the ASO, and the remaining 653 patients had closure using the modified ASO (ratio, *1:12). All Amplatzer devices were used before 2005. The ages of the patients ranged from 2 to 18 years (median 4.6 years; P25: 3.30 years; P75: 7.89 years). Three of the patients had distant defects, and their multiple ASDs were closed using two devices. The remaining patients had their defects closed using a single device (Table 1). Written informed consent was obtained from all the patients and/or their guardians. The study was approved by the Ethics Committee of Sichuan University. Before the closing procedure, every patient received a routine 12-lead electrocardiogram (ECG), chest X-ray, and a transthoracic echocardiogram (TTE). Consecutive ECG monitoring was performed for the patients during the procedure and then 3 days after the procedure. The patients with AVB were further evaluated with a 12-lead ECG daily in the first week, weekly in the first month, and monthly thereafter. A 24-h ambulatory ECG was performed for the last follow-up evaluation of the patients. Procedure Protocol Before the procedure, TTE was performed for all the patients to evaluate the type, number, position, size, surrounding rims, and largest diameter of the ASDs (subcostal double-atrium view). Unfractionated heparin (100 U/kg/ dose) was administered intravenously via an arm after establishment of a femoral access and before the procedure. Right heart catheterization was performed in all cases to measure pulmonary pressure. Standard technical delivery of the device over a guidewire through the defect was performed, as previously described [11]. The size of device selected for use was determined by the size and rim length of the ASD. If all the rims of the ASD were sufficient, the size of device was 2–4 mm larger than the size of the ASD. If one of rims was not long enough, the size of device was 4–6 mm larger than the size of the ASD.
F female, M male, Rs superior rim, Ri atrioventricular valve rim, Rsv superior vena cava rim, Riv inferior vena cava rim, Ra aortic rim, Rp posterior rim, Dd diameter of atrial septal defect, Ds diameter of atrial septum, Do diameter of occluder
A sizing balloon (AGA Medical Corp.) was used to measure the diameter of the defect in 62 patients in its early stage, and the remaining 644 patients were measured using TTE. The ASO was delivered by an appropriate delivery system and deployed when a satisfactory device position was confirmed by TTE and fluoroscopy, a position in which the device would not influence the motion of the atrioventricular valves or blood flow of the inferior and superior vena cava. Statistical Analysis Because the variables in this study such as age, size of the ASD, size of the device, largest diameter of the atrial septum, Dd/Do ratio, and Do/Ds ratio were positive skewness distribution, the data is expressed as the median value (P25, P75) and range. Data distribution was evaluated with the Kolmogorov–Smirnov normality test. The Wilcoxon rank sum test was used to compare data between subgroups. A p value lower than 0.05 was considered significant. Statistical analyses were performed with SPSS 17.0 for Windows (SPSS. Inc., Chicago, IL, USA).
Results In six of the 706 patients, AVB had developed after ASD closure with ASO, giving an incidence of 0.85 %. No AVB was found in patients who had ASD closure with the ASO (AGA Medical Corp., Golden Valley, MN, USA) or in the
123
552
Pediatr Cardiol (2014) 35:550–555
Table 3 Variables between subgroups Patients with AVB (n = 6)
Patients without AVB (n = 700)
z Value
p Value
Age (years)
3.2 (2.9, 3.95)
4.9 (3.3, 7.9)
-2.190
0.028a
Dd (mm)
16.5 (14.75, 20.5)
12 (8, 16)
-0.213
0.009a
Do (mm)
20 (21, 24.5)
16 (12, 22)
-2.717
0.007a
Ds (mm)
41.5 (39.5, 41.5)
44 (39, 50)
-1.564
0.118
Dd/Do
0.82 (0.76, 0.86)
0.72 (0.63, 0.83)
-1.709
0.088
Do/Ds
0.48 (0.50, 0.64)
0.36 (0.31, 0.42)
-3.463
0.001a
Dd diameter of atrial septal defect, Do diameter of occluder, Ds diameter of atrial septum a Statistically significant
patients whose defect diameter was measured using a sizing balloon. The general data and measurements of the defects for the patients with AVB are listed in Table 2.
Table 4 Comparison of ECGs before and after closure
Risk Factors Associated With AVB As shown in Table 2, all the rims of ASD were sufficient except for the aortic rim. The variables are shown in Table 3. Among these variables, the differences in age, size of the ASD, size of the device, and Do/Ds ratio between the two subgroups are significant. The ages of all the patients with AVB were 5.3 years or younger. Moreover, it was noted that the patients with serious AVB (above II° AVB) were younger than 3.5 years. The most important factor was the Do/Ds ratio (p = 0.001). All the AVBs were developed in patients with a Do/Ds ratio of 0.45 or higher. No AVB was developed in patients with a Do/Ds ratio lower than 0.45. Prognosis of AVB All AVBs occurred within 24 h after ASD closure (Table 4). The types of AVB in the early stage included I°, II°, advanced and III° AVB. Among these cases, the patient with I° AVB recovered shortly (in about 2 weeks) and had a good prognosis. The patients with III° AVB had a poor prognosis. The ECG of one of two patient with III° AVB recovered after retrieval of the device immediately during procedure. Another patient had the device retrieved surgically. However, the ECG did not recover completely during a follow-up period of 14 months. This result differed from that of previous reports, suggesting that the AVB induced by closure of ASD using ASO is transient and has a good prognosis [2, 9, 14].
Discussion Compared with the perimembranous ventricular septal defect (PMVSD), the structure around ASD is less
123
Before closure
AVB type after closure
Time initially (h)
1
S, IRBB
I°
18
2
S, IRBB
II° Itype
1
3 4
S S, IRBB
I° ? II°, 2:1 conduction Advanced AVB
9 24
5
S, IRBB
III°
8
6
S, IRBB
III°
Instantly after device deployment
AVB atrioventricular block, S sinus rhythm, IRBB incomplete right bundle block
complicated. Consequently, transcatheter closure of ostium secundum ASDs has been widely accepted worldwide. Most physicians think closing ASD with ASO is effective and safe, with few complications. Moreover, less attention is given to AVB induced by closure of ASD with ASO than to AVB induced by closure of a PMVSD with the device. However, some complications after closure with ASO have been reported in recent years, such as pericardial effusion, perforation/device erosion, thrombus and thromboembolic events, device embolization/malposition, and arrhythmia [5, 6, 15]. Some cases of AVB induced by closure of ASD with ASO also have been reported occasionally [2–4, 8, 9, 12–14]. According to previous reports, the majority of AVBs have occurred in children after closure of ASD with ASO. Age, size of the ASD, and size of the occluder are perhaps the risk factors associated with AVB. To date, the mechanism is unclear. Some authors think the right disc of the device compresses and stimulates the atrioventricular node (AVN) located in Koch’s triangle anteinferiorly and results in the abnormality of conduction. The stretching effect of the device on the AVN is another potential mechanism. Gupta et al. [8] reported a case in which a III° AVB developed after closure of ASD with ASO. The device was retrieved surgically. In the operating room, the device was
Pediatr Cardiol (2014) 35:550–555
found to be well positioned. However, due to a deficient inferior rim of the defect, the ASO was impinging against the AVN. Of the six cases in the current study, only one (case 5) involved a retrieved device and a surgically repaired ASD. This case involved a 3.2-year-old boy, and the diameter of the ASD was 19 mm (Table 2). When the atrium was opened, the surgeon found that the atrial septum was covered fully and that the AVN was impinged by the device. This finding supported the speculation that the compression of the device on the AVN could result in the occurrence of AVB. In case 6, a III° AVB occurred instantly after deployment of the device. But the ECG recovered shortly after retrieval of the device through the delivery system. A III° AVB occurred again after another deployment. Closure with the device was given up after three tries. This phenomenon also indirectly suggests a compressing and stretching effect of the device on the AVN. The surgeon suggests that surgical repair of ASD is safer than closure with ASO in the case of younger and large ASD patients in terms of complications (including AVB and erosion of heart) and mortality. The study by Suda et al. [14] suggested that a device size of 19 mm or larger, a device/height ratio greater than 0.18 mm/cm, and a Qp:Qs greater than 2.8 are the risk factors. In our retrospective study, we found that the younger the age (B5.3 years) and the larger the Do/Ds ratio (C0.45), the more likely the development of AVB will be. The size of the device and the size of the ASD are other risk factors. Because the atrial septum diameter increases with age, the younger the age, the smaller the diameter will be. In younger children, if a large device is chosen based on a large ASD size, the Do/Ds ratio increases, and the AVN is prone to compression by the device, which may result in the occurrence of AVB. In the current study, a traditional sizing balloon (AGA Medical Corp.) was used to measure the diameter of the defect in 62 patients in the early stage. No AVB was found in these patients. However, we thought the inflated balloon would lacerate the atrial septum and overstretch the defect in younger children. Since then, we have measured the diameter of the defect using TTE and have chosen a device 4 to 6 mm larger than the defect. All AVBs have occurred in the patients measured via TTE. We therefore speculate that this measurement resulted in oversizing of the ASO, which caused AVB. Currently, most intervention lists recommend the stop-flow method as the measurement in every patient to avoid overstretching of the defect and oversizing of the ASO [1]. All six patients who experienced AVB had a deficient aortic rim (0–4 mm, as shown in Table 2). Two of the patients had a deficient posterior rim (0–3 mm), and the
553 Table 5 Prognosis and follow-up Prognosis
Follow-up (months)
1
Steroid therapy, ECG recovered 2 weeks later
12, S
2
Steroid therapy, ECG recovered 22 h later
8, S
3
Steroid therapy, I° ? II° 12 h later and 2:1 conduction, I° ? II° IItype 38 h later and more conduction; I° AVB 80 h later
16, I° AVB
4
Steroid therapy, more conduction after 36 h, I° AVB 48 h later, II° IItype occasionally; ECG recovered 70 h later
72, S
5
Steroid therapy, III° AVB persisted. retrieved device and repaired ASD surgically 168 h later; ECG changed to I° AVB instantly when heart rebeated; 2 weeks later ambulatory ECG shown I° AVB, II° II AVB occasionally Retrieved device through deliver system ECG recovered instantly; III° AVB occurred again after another deployment; gave up closure with device after three tries
14 I° AVB
6
3, S, IRBB
ECG electrocardiogram, S sinus rhythm, AVB atrioventricular block, IRBB incomplete right bundle block
remaining rims were sufficient. This finding differs from that of previous reports, which speculated that the AVB was associated with a deficient posterior-inferior rim. We think this is the case because we deliberately chose a larger device for secure implantation when the aortic rim or posterior rim was deficient. As a result, the Do/Ds ratio further increased, and the AVN was more prone to be compressed, especially in young children who have thinner and softer ASD rims. For example, the aortic rim was 0 mm in case 3. To prevent malpositioning of the device, we deliberately chose an occluder that had a diameter 7 mm larger than the diameter of the defect so that both discs of the device could slightly embrace the aortic root. However, this choice was not standard practice and resulted in a Do/Ds ratio of 0.54 (C0.45), with I° ? II° AVB occurring 9 h after the procedure. The AVB advanced the II° AVB with 2:1 conduction 12 h later (Table 5). The I° AVB was unchanged during the follow-up evaluation 16 months later. The oversized device in this case not only resulted in AVB, which at this writing has not recovered completely, but also likely will result in erosion of the aorta in the future [6]. Further follow-up assessment is needed, and an oversized device should be avoided. In the study of Suda et al. [14], a device/height ratio greater than 0.18 mm/cm was a risk factor. However, we think because the height indicates the largest diameter of the atrial septum to some extent, it is more reliable to measure the diameter of the atrial septum directly. We therefore suggest that the Do/Ds ratio is a risk factor more
123
554
valuable for prediction of AVB occurrence than the device/ height ratio. According to the experience obtained from this research, we suggest that younger patients (age \3 years) with a large ASD and deficient rims should be repaired surgically. Since 1 March 2013, ASDs in 31 cases have been closed with modified ASO in our department. No AVB occurred in these patients. In this study, the prognosis of AVB also differed from those reported previously. Suda et al. [14] and Ho et al. [9] reported patients who experienced transient and reversible AVB after closure of ASD with ASO. They think the prognosis for such patients is good. But Nehgme et al. [12] reported the case of a 6-year-old girl who presented with progression of AVB from II° AVB to symptomatic complete heart block requiring permanent pacemaker implantation 4 years after ASD closure with ASO. Gupta et al. [8] reported a patient who experienced III° AVB after closure, with the medication having no effect on the AVB. The ECG recovered after retrieval of the device surgically 72 h later. For six cases in the current study, if the degree of AVB was mild and ECG changed favorably within 72 h after closure, the prognosis was good. The patients with III° AVB and unchanged ECG within 72 h after closure had a poor prognosis. In two cases, the device had to be retrieved either by surgery or by sheath. To date, the optimal time for retrieving the device still is unknown. More studies need to be conducted. In our study, we observed that the patient whose device was retrieved immediately when III° AVB occurred during the procedure was able to recover instantly and had good prognosis. The patient with III° AVB and unchanged ECG within the first 72 h had a poor prognosis. The later the device is retrieved, the poorer the prognosis will be. We speculate that the prognosis depends on the degree of compression on the AVN. The stretching effect of the device or stimulation of the right disc of the device to the AVN results in edema and inflammation of the AVN. This is the reason why the steroid was used for all the patients who experienced AVB after closure. In this situation, perhaps the AVB is mild and the ECG is changed. The AVB ameliorates gradually when the heart adapts to the situation and is treated with steroids and nonsteroid antiinflammatory agents. If the device compresses directly on the AVN and results in ischemia, necrosis, and fibrosis of the AVN, the AVB is serious, progressive, and unrecovered even after retrieval of the device, especially when the device is retrieved at a later time. This study had the following limitations. Because the follow-up periods were short, the long-term prognosis of AVB induced by closure of ASD with ASO needs to be studied further. The sample in this study was small, and
123
Pediatr Cardiol (2014) 35:550–555
future studies with larger samples in multiple centers are needed to test our results.
Conclusion More attention should be paid to AVB induced by closure of ASD with ASO. Younger age, size of the ASD, size of the device, and a Do/Ds ratio of 0.45 or higher are the risk factors associated with AVB after closure. The AVB after closure should be followed up for the long term; the mechanism of the AVB should be studied further with a larger number of patients; and the relationship between the device and the anatomic structure around the ASD should be investigated. Acknowledgments This work was supported by the National Science Foundation of China (No. 31171020 to Dezhi Mu; Nos. 81172174 and 81270724 to Yi Qu) and a grant of the Clinical Discipline Program (neonatology) from the Ministry of Health of China (1311200003303).
References 1. Carlson KM, Justino H, O’Brien RE, Dimas VV, Leonard GT Jr, Pignatelli RH et al (2005) Transcatheter atrial septal defect closure: modified balloon sizing technique to avoid overstretching the defect and oversizing the Amplatzer septal occluder. Catheter Cardiovasc Interv 66:390–396 2. Celiker A, Ozkutlu S, Karakurt C, Karagoz T (2005) Cardiac dysrhythmias after transcatheter closure of ASD with Amplatzer device. Turk J Pediatr 47:323–326 3. Chessa M, Carminati M, Butera G, Bini RM, Drago M, Rosti L, Giamberti A, Pome G, Bossone E, Frigiola A (2002) Early and late complications associated with transcatheter occlusion of secundum atrial septal defect. J Am Coll Cardiol 39:1061–1065 4. Dalvi B, Pinto R, Gupta A (2008) Device closure of large atrial septal defects requiring devices [ or = 20 mm in small children weighing \20 kg. Catheter Cardiovasc Interv 71:679–686 5. Delaney JW, Li JS, Rhodes JF (2007) Major complications associated with transcatheter atrial septal occluder implantation: a review of the medical literature and the manufacturer and user facility device experience (MAUDE) database. Congenit Heart Dis 2:256–264 6. Diab K, Kenny D, Hijazi ZM (2012) Erosions, erosions, and erosions! device closure of atrial septal defects: how safe is safe? Catheter Cardiovasc Interv 80:168–174 7. DiBardino DJ, McElhinney DB, Kaza AK, Mayer JE Jr (2009) Analysis of the US food and drug administration manufacturer and user facility device experience database for adverse events involving Amplatzer septal occluder devices and comparison with the society of thoracic surgery congenital cardiac surgery database. J Thorac Cardiovasc Surg 137:1334–1341 8. Gupta U, Al-anani SJ, Polimenakos AC (2011) Timing for successful surgical management of heart block after placement of an Amplatzer occlusion device for secundum atrial septal defect repair. J Thorac Cardiovasc Surg 141:1319–1321 9. Ho T-Y, Tsai M-C, Lee P-C, Lu J-H, Liang C-M, Laura Meng C-C, Hwang B (2005) Amplatzer septal occluder-induced arrhythmias. J Med Sci 25:105–108
Pediatr Cardiol (2014) 35:550–555 10. King TD, Mills NL (1974) Nonoperative closure of atrial septal defects. Surgery 75:383–388 11. Masura J, Gavora P, Formanek A, Hijazi ZM (1997) Transcatheter closure of secundum atrial septal defects using the new selfcentering Amplatzer septal occluder: initial human experience. Cathet Cardiovasc Diagn 42:388–393 12. Nehgme RA, Huddleston AR, Cheatham JP (2009) Progression to late complete atrioventricular block following Amplatzer device closure of atrial septal defect in a child. Pediatr Cardiol 30:367–370
555 13. Sadiq M, Kazmi T, Rehman AU, Latif F, Hyder N, Qureshi SA (2012) Device closure of atrial septal defect: medium-term outcome with special reference to complications. Cardiol Young 22:71–78 14. Suda K, Raboisson MJ, Piette E, Dahdah NS, Miro J (2004) Reversible atrioventricular block associated with closure of atrial septal defects using the Amplatzer device. J Am Coll Cardiol 43:1677–1682 15. Ueda H, Yanagi S, Nakamura H, Ueno K, Gatayama R, Asou T, Yasui S (2012) Device closure of atrial septal defect: immediate and midterm results. Circ J 76:1229–1234
123
![[Atrioventricular block after transcatheter atrial septal defect closure using the Amplatzer septal occluder(®)].](/assets/img/hold.png)
