Safety and efficacy of transvenous high-voltage implantable cardioverter-defibrillator leads in high-risk hypertrophic cardiomyopathy patients

BACKGROUND The implantable cardioverter-defibrillator (ICD) prevents sudden cardiac death in high-risk patients with hypertrophic cardiomyopathy (HCM). However, recently concerns have been raised regarding the performance of transvenous high-voltage ICD Leads (HVL) in this population. OBJECTIVE The purpose of this retrospective, multicenter study was to assess the safety and efficacy of HVL in high-risk HCM patients. METHODS The study population consisted of HCM patients who received HVL ICDs and were subsequently followed at seven centers in the United States. Kaplan-Meier survival rates were calculated for HVL and patients. HVL failure was a malfunction caused by a noniatrogenic defect. RESULTS Between 1992 and 2007, 324 HCM patients (mean age 47 +/- 16 years) received 343 HVL from three major manufacturers. The average HVL implant duration was 3.3 +/- 2.8 years. Overall, the HVL failure rate was 1.4%/year. However, two models (Sprint Fidelis and Transvene, Medtronic, Inc.) accounted for 60% of HVL failures. Survival probabilities for HVL and patients at 10 years were 93% and 91%, respectively. No deaths or serious injuries were reported, although inappropriate shocks occurred in 12% of cases. CONCLUSIONS This multicenter experience shows that HVLs are safe and effective in high-risk HCM patients. However, differences in failure rates were found between lead models.