Background: In the event of infection, erosion, or failure, fibrosis of a defibrillation lead can make extraction difficult. In the ENDOTAK RELIANCE G defibrillation lead, coils are covered with expanded polytetrafluoroethylene (ePTFE) to prevent tissue ingrowth.
Objective: The objective of the REFLEx Study was to evaluate if RELIANCE G defibrillation leads with ePTFE-covered coils are as good as comparative defibrillation leads with respect to electrical performance and termination of spontaneous tachyarrhythmias.
Methods: Patients were randomized to type of defibrillation lead--Guidant RELIANCE G lead or a non-ePTFE-covered lead of choice. Electrical performance success was defined as meeting all minimum standards in the respective manufacturer's manual for amplitude, threshold, and impedance. A noninferiority margin of 5% was prespecified.
Results: Electrical performance success at 12 months was 93.0% (280/301) for RELIANCE G and 94.5% (291/308) for comparative leads. The performance success rate for RELIANCE G did not differ significantly from study comparative (P = 0.04, noninferiority). For spontaneous episodes, first shock conversion success rate was 90% for RELIANCE G and 95% for study comparative (P = 0.89, noninferiority). Implant conversion testing was successful in 96.7% (524/542) of RELIANCE G patients and 94.3% (512/543) of comparative patients (chi-square P-value = 0.0784). About 55% (609/1115) of patients completed follow-up through month 12.
Conclusion: Data from the REFLEx study indicate that ePTFE-covered leads are not inferior to comparative leads with respect to electrical performance and implant conversion testing. We cannot conclude that the first shock conversion efficacy of ePTFE covered leads was statistically noninferior to comparative leads.