| Literature DB >> 20690018 |
Brian J Lichtenstein1, David P Bichell, Dana M Connolly, John J Lamberti, Suzanne M Shepard, Stephen P Seslar.
Abstract
Permanent cardiac pacing in pediatric patients presents challenges related to small patient size, complex anatomy, electrophysiologic abnormalities, and limited access to cardiac chambers. Epicardial pacing currently remains the conventional technique for infants and patients with complex congenital heart disease. Pacemaker lead failure is the major source of failure for such epicardial systems. The authors hypothesized that a retrocostal surgical approach would reduce the rate of lead failure due to fracture compared with the more traditional subrectus and subxiphoid approaches. To evaluate this hypothesis, a retrospective chart review analyzed patients with epicardial pacemaker systems implanted or followed at Rady Children's Hospital San Diego between January 1980 and May 2007. The study cohort consisted of 219 patients and a total of 620 leads with epicardial pacemakers. Among these patients, 84% had structural congenital heart disease, and 45% were younger than 3 years at time of the first implantation. The estimated lead survival was 93% at 2 years and 83% at 5 years. The majority of leads failed due to pacing problems (54%), followed by lead fracture (31%) and sensing problems (14%). When lead failure was adjusted for length of follow-up period, no significant differences in the rates of failure by pocket location were found.Entities:
Mesh:
Year: 2010 PMID: 20690018 PMCID: PMC2948166 DOI: 10.1007/s00246-010-9754-1
Source DB: PubMed Journal: Pediatr Cardiol ISSN: 0172-0643 Impact factor: 1.655
Fig. 1Chest radiographs demonstrating pocket locations. The typical sites of epicardial pacemaker implantation are demonstrated from left to right: retrocostal, subxiphoid, and subrectus. Notably, the retrocostal location keeps all hardware within an intrathoracic location, whereas the subrectus and subxiphoid pacemaker pockets require that the pacemaker leads traverse the abdominal musculature
Patient demographics
| Variable | Subrectus | Subxyphoid | Retrocostal | Total |
|
|---|---|---|---|---|---|
|
| 99 | 24 | 96 | 219 | – |
| Demographic data (at first implant)a | |||||
| Female (%) | 49% | 58% | 46% | 49% | 0.541 |
| Median age: years (range) | 3.08 (0–30.04) | 6.59 (0–37.84) | 4.27 (0–39.51) | 3.62 | 0.140 |
| Median follow-up period: years (range) | 5.32 (0.02–22.75) | 3.53 (0.02–14.61) | 2.77 (0.04–14.40) | 3.69 | <0.001 |
| Median weight: kg (range) | 11.9 (2.0–95.4) | 18.1 (2.5–64.1) | 15.9 (2.0–87.5) | 14.0 | 0.168 |
| Median height: cm (range) | 86 (33–173) | 104.5 (37–177) | 99 (43–179) | 96 | 0.188 |
| Median body surface area: m2 (range) | 0.527 (0.15–2.03) | 0.732 (0.17–1.75) | 0.658 (0.15–1.98) | 0.611 | 0.204 |
| Median no. of prior surgeries: | 2 (0–6) | 1 (0–7) | 2 (0–11) | 2 | 0.114 |
| Principal cardiac diagnosis: | 0.397 | ||||
| Congenital structural heart disease | 85 (85.9) | 19 (79.2) | 79 (82.3) | 183 (83.6) | – |
| Cardiomyopathy | 3 (3.3) | 0 (0) | 3 (3.1) | 6 (27.4) | – |
| No structural heart disease | 8 (8.1) | 5 (20.8) | 14 (17.7) | 27 (12.3) | – |
| Unknown | 3 (3.3) | 0 (0) | 0 (0) | 3 (1.6) | – |
| Indication for device placement ( | 0.266 | ||||
| Arrhythmia, nonspecific (cardiac) | 1 | 0 | 1 | 2 | |
| Atrial fibrillation | 0 | 0 | 1 | 1 | |
| Atrial flutter | 4 | 1 | 4 | 9 | |
| Bradycardia (sinus) | 3 | 1 | 3 | 7 | |
| Functional disturbances after cardiac surgery | 0 | 0 | 1 | 1 | |
| Heart block 1° | 1 | 0 | 1 | 2 | |
| Heart block 2° type 1 Wenckebach | 0 | 2 | 4 | 6 | |
| Heart block 2° type 2 Mobitz | 4 | 2 | 5 | 11 | |
| Heart block 3° (acquired) | 38 | 10 | 25 | 73 | |
| Heart block 3° congenital | 7 | 1 | 15 | 23 | |
| Junctional rhythm | 0 | 0 | 8 | 8 | |
| Junctional tachycardia | 0 | 0 | 1 | 1 | |
| Left bundle branch block | 0 | 0 | 1 | 1 | |
| Multifocal atrial tachycardia | 0 | 0 | 1 | 1 | |
| Sinus node dysfunction | 38 | 7 | 24 | 69 | |
| Syncope | 1 | 0 | 0 | 1 | |
| Unknown | 1 | 0 | 1 | 2 | |
| Ventricular tachycardia | 1 | 1 | |||
| Total | 99 | 24 | 96 | 219 | |
| Lead failureb | 62 (62) | 7 (29) | 26 (27) | 95 (43) | <0.001 |
Each patient is counted once in this analysis using first implantation information. Patients may have had more than one lead and more than one pocket location. The p values were derived from Kruskal–Wallis tests for demographic data. Categorical data for principal cardiac diagnosis and indication for device placement were assessed with Pearson chi-square
aFor continuous variables, median (range) is reported. For categorical variables the count (n) is listed as well as the percentage within that pocket location subgroup (%)
bNo. of patients who experienced one or more lead failures during the study period
Lead characteristics by pocket location
| Variable | Subrectus | Subxyphoid | Retrocostal | Total |
|
|---|---|---|---|---|---|
|
|
|
| |||
|
| 284 | 62 | 274 | 620 | – |
| Manufacturer: | <0.001 | ||||
| Medtronic | 205 (72.2) | 57 (91.9) | 180 (65.7) | 442 (71.3) | – |
| Guidant (CPI) | 15 (5.3) | 1 (1.6) | 86 (31.4) | 102 (16.5) | – |
| St. Jude Medical | 0 (0) | 0 (0) | 0 (0) | 0 (0) | – |
| Intermedics | 37 (13.0) | 2 (3.2) | 1 (0.4) | 40 (6.5) | – |
| Unknown | 27 (9.5) | 7 (11.3) | 2 (0.7) | 36 (5.8) | – |
| Steroid-eluting: | <0.001 | ||||
| Steroid-eluting | 91(32.0) | 47 (75.8) | 206 (75.2) | 344 (55.5) | – |
| Non–steroid-eluting | 166 (58.5) | 13 (21.0) | 61 (22.2) | 240 (38.7) | – |
| Unknown | 27 (9.5) | 2 (3.2) | 7 (2.6) | 36 (5.8) | – |
| Polarity: | <0.001 | ||||
| Bipolar | 46 (16.2) | 16 (25.8) | 172 (62.8) | 234 (37.7) | – |
| Unipolar | 211 (74.3) | 44 (71.0) | 95 (34.7) | 350 (56.5) | – |
| Unknown | 27 (9.5) | 2 (3.2) | 7 (2.6) | 36 (5.8) | – |
| Insulation material: | <0.001 | ||||
| Silicone | 181 (63.7) | 59 (95.2) | 247 (90.1) | 480 (77.4) | – |
| Polyurethane | 16 (5.6) | 1 (1.6) | 17 (6.2) | 34 (5.5) | – |
| Unknown | 27 (9.5) | 2 (3.2) | 7 (2.6) | 36 (5.8) | – |
| Fixation mechanism: | <0.001 | ||||
| Screw-in | 132 (46.5) | 11 (17.7) | 206 (75.2) | 349 (56.3) | – |
| Sew-on | 68 (23.9) | 43 (69.4) | 58 (21.2) | 169 (27.3) | – |
| Stab-in | 57 (20.0) | 6 (9.7) | 3 (1.1) | 66 (10.7) | – |
| Unknown | 27 (9.5) | 2 (3.2) | 7 (2.6) | 36 (5.8) | – |
Each lead is used as the unit of analysis. Patients may have more than one lead. If the pocket location is changed and a functioning lead is left in situ, the lead is censured at the time of pocket change. Due to the study’s constraints, with access limited to only our in-house medical records, we were unable to obtain every variable for every lead in our study. Analyses were conducted with unknowns as missing values, which did not change the p values in our chi-square tests. Categorical data for the variables were assessed with Pearson chi-square. Lead fracture grouping includes proven lead fracture, suspected lead fracture, and lead impedance
a% indicates the percentage of leads within that implantation location subgroup
Fig. 2Kaplan–Meyer survival curve for epicardial pacemaker leads by pocket location. Cumulative lead longevity, defined as freedom from lead failure for any reason, does not differ between retrocostal, subrectus, and subxiphoid pacemaker pocket locations (p = 0.491, Mantel-Cox)
Lead failure by pocket location
| Variable | Subrectus | Subxyphoid | Retrocostal | Total |
|
|---|---|---|---|---|---|
|
|
|
| |||
|
| 284 | 62 | 274 | 620 | – |
| Lead failure | 116 (40.8) | 10 (16.1) | 47 (17.2) | 173 (27.9) | 0.002 |
| Cause of lead failurea | – | – | – | – | 0.194 |
| Lead fracture | 38 (32.8) | 3 (30) | 12 (25.5) | 53 (30.6) | – |
| Pacing problems (NOS) | 62 (53.5) | 7 (70) | 24 (51.1) | 93 (15.0) | – |
| Sensing problems (NOS) | 13 (11.2) | 0 (0) | 11 (23.4) | 24 (13.9) | – |
| Unknown | 3 (2.6) | 0 (0) | 0 (0) | 3 (1.7) | – |
| No lead failure | 168 (59.2) | 52 (83.9) | 227 (82.9) | 447 (72.1) | – |
aThe cause of lead failure is not shown to be statistically different when stratified by lead failure versus nonfailure (p = 0.194, Pearson chi-square). See Fig. 3 for graphic representation
Fig. 3Bar graph showing the cause of lead failure by pocket location expressed as the proportion of total lead failures. When lead failure is stratified by cause, groups do show statistical differences based on their epicardial pacemaker pocket location (retrocostal vs subrectus vs subxiphoid; p = 0.194, Pearson chi-square)
Risk factors for lead failure (univariate analysis)
| Variable | HR |
| Lower CI | Upper CI |
|---|---|---|---|---|
| Patient variablesa | ||||
| Pocket location (retrocostal) | 1.06 | 0.807 | 0.66 | 1.71 |
| No. of prior surgeries >2 | 1.47 | 0.067 | 0.97 | 2.24 |
| Age at first implant <12 years | 0.93 | 0.778 | 0.55 | 1.56 |
| Congenital heart disease | 1.67 | 0.146 | 0.84 | 3.32 |
| Linear growth rate ≥15 cm/year | 0.82 | 0.391 | 0.52 | 1.29 |
| Height at first implant ≤70 cm | 1.41 | 0.146 | 0.89 | 2.25 |
| Weight at first implant ≤8 kg | 1.31 | 0.256 | 0.82 | 2.07 |
| Age at first implant ≥18 years | 1.03 | 0.944 | 0.45 | 2.39 |
| Age at first implant 12–18 years | 1.20 | 0.533 | 0.68 | 2.13 |
| Lead variablesb | ||||
| Pocket location (retrocostal) | 1.014 | 0.938 | 0.71 | 1.44 |
| Lead manufacturer: Medtronic | 0.740 | 0.062 | 0.54 | 1.02 |
| Steroid-eluting | 0.833 | 0.307 | 0.59 | 1.18 |
| Insulation material: silicone | 1.02 | 0.908 | 0.73 | 1.41 |
| Fixation mechanism: sew-on | 1.02 | 0.889 | 0.69 | 1.51 |
| Polarity: bipolar | 0.870 | 0.498 | 0.58 | 1.31 |
HR hazard ratio, CI confidence interval
aEach patient is counted once, modeled on time to first lead failure. Some patients experienced more than one lead failure
bEach lead is counted as a unique entity in this analysis
Fig. 4Kaplan–Meyer survival curve for epicardial pacemaker leads by (non)steroid elution. For all leads for all pacemaker pocket locations, comparison of steroid-eluting leads with non–steroid-eluting leads shows no significant difference in lead longevity (p = 0.244, Mantel-Cox)