Low Risk of Hypertrophic Cardiomyopathy With Contemporary Management Strategies Implemented in Non-Referral Regional Community-Based Practices

Abstract

Major advances in diagnosis and treatment have emerged for hypertrophic cardiomyopathy (HCM), largely in major tertiary referral centers dedicated to this disease. Whether these therapeutic benefits are confined to patients in such highly selected cohorts, or can be implemented effectively in independent regional or community-based populations is not generally appreciated. We assessed management and clinical outcomes in a non-referral HCM center (n = 214 patients) in Eastern Pennsylvania. Over a 6.0 ± 3.2-year follow-up, the HCM-related mortality rate was 0.1% per year attributed to a single disease-related death, in a 49-year-old man with end-stage heart failure, ineligible for heart transplant. Fifteen patients (7%) with prophylactically placed implantable cardioverter-defibrillators (ICDs) experienced appropriate therapy terminating life-threatening ventricular tachyarrhythmias. In 23 other patients (11%; 5%/year), heart failure due to left ventricular outflow obstruction was reversed by surgical septal myectomy (n = 20) or percutaneous alcohol septal ablation (n = 3). This regional HCM cohort was similar to a comparison tertiary center referral population in terms of HCM-mortality: 0.1%/year vs 0.3%/year (p = 0.3) and ICD therapy (31% vs 16% of primary prevention implants), although more frequently with uncomplicated benign clinical course (62% vs 46%; p <0.01). In conclusion, effective contemporary HCM management strategies and outcomes in referral-based HCM centers can be successfully replicated in regional and/or non-referral settings. Therefore, HCM is now a highly treatable disease compatible with normal longevity when assessed in a variety of clinical venues not limited to tertiary centers.