Abstract 13443: Clinical Outcomes Following Primary Prevention Implantable Cardioverter Defibrillator (ICD) Implantation Among Older Patients With Hypertrophic Cardiomyopathy (HCM)

Abstract

Introduction: The clinical benefit of primary prevention ICDs among older patients (age > 65) with HCM is unclear. This analysis examined procedural complications and post-discharge outcomes among older patients with HCM following initial placement of a primary prevention ICD. Methods: The NCDR ICD Registry was queried to identify patients with HCM who received a primary prevention ICD between 2010-2016. Procedure-related adverse event rates were examined. Direct identifiers were used to link patients > 65 years to CMS claims data. Cox proportional hazard models were used to assess clinical factors associated with post-discharge mortality and hospitalization for cardiac arrest/ventricular arrhythmia (VA). Kaplan Meier curves were generated to depict 5-year outcomes. Results: Of 5571 patients with HCM who were included, 1511 (27.1%) were > 65 years old. Compared with patients < 65 years of age, older patients with HCM were more likely to experience a procedure-related event (2.3% vs 1.5%, p=0.038) and procedure-related death (0.3% vs 0.1%, p=0.024). The variables most strongly associated with post-discharge mortality were older age (aHR 1.8, 95% CI 1.47-2.21), NYHA class (III/IV vs I/II aHR 2.17, 95% CI 1.57-2.98), and LVEF (LVEF < 35% vs >50% aHR 2.34, 95% CI 1.58-3.48; LVEF 36-50% vs >50% aHR 2.98, 95% CI 2.02-4.4). For the endpoint of hospitalization for cardiac arrest/VA, history of NSVT at the time of device implantation (aHR 2.38, 95% CI 1.62-3.51) and NYHA class (NYHA class III/IV vs I/II aHR 1.84, 95% CI 1.22-2.78) were the strongest predictors. The event-free survival rates are shown ( Figure). Conclusions: Procedure-related complication and mortality rates were low, but they occurred more frequently among older patients. Further prospective investigation should focus on whether clinical factors, such as NYHA class and history of NSVT, may be useful in identifying older patients with HCM who are most likely to benefit from a primary prevention ICD.