Introduction: The Medtronic SelectSecureTM pacing lead (MSS) has hypothesized advantages compared to conventional transvenous pacing leads (CPL) of similar design (bipolar pacing, thin lead diameter, and steroid-eluting). Data regarding long-term performance of these devices is limited. Our purpose was to determine whether differences in electrical function and complications exist between these PL in a large data set of pediatric and congenital patients.
Methods: A multicenter historical longitudinal cohort study was performed comparing MSS and CPL performance over a 72-month follow-up (FU). Each center (10) provided data for a MSS and a CPL, on patients matched for age, implanted cardiac pacing chamber, time period of implantation, and presence of heart disease. Data = mean ± SE.
Results: The cohort consisted of 139 subjects in each study group (MSS vs. CPL) with a mean age of 14.3 ± 0.5 vs. 14.1 ± 0.5 years, p=NS. Of the CPL, 121 were other Medtronic PL. No differences were observed in gender, racial group, presence of congenital or electrical heart disease or pacing indication. The median FU by group was similar (58 vs. 57 mo, p=NS). Atrial and ventricular capture thresholds were stable throughout FU and higher in the MSS group, ––––p < 0.001. At last follow-up: atrial: 0.75 ± 0.4 vs. 0.6 ± 0.4 V, ventricular: 1.0 ± 0.4 vs. 0.75 ± 0.4 V. Atrial sensing threshold was stable in the MSS, but trended downward in the CPL group, p = 0.03. Ventricular sensing was the opposite, trending downward in the MSS group, p = 0.15. Energy to pace increased during FU in a parallel fashion in both groups, remaining higher in the MSS group, ––––p < 0.001. At last follow-up: atrial: 0.62 ± 0.06 vs. 0.46 ± 0.06 mJ, ventricular: 1.1 ± 0.08 vs. 0.68 ± 0.08 mJ. Implant complication rates were similar; lead dislodgement occurred more often in the MSS group (7 vs. 2). Long-term PL survival was high in both groups, FU failure rate = 2 per 100 person-months. PL fracture occurred in 2 patients for each group.
Conclusions: The MSS and CPL groups had similar PL survival and complications rates. Survival of MSS and CPL is high with a low fracture rate. The MSS had acceptable electrical function compared to CPL, but did show higher capture thresholds and increased energy to pace over time, possibly reducing battery longevity.