Sex Differences in Clinical Outcomes for Obstructive Hypertrophic Cardiomyopathy in the United States

Introduction: Differences to clinical presentation of HCM-related outcomes in female patients with oHCM among the general US population are unknown. We utilized a large, commercial medical and pharmacy claims database to evaluate sex differences in demographic and clinical characteristics, treatments, and outcomes for patients with diagnosed oHCM Methods: This retrospective observational study queried the MarketScan database to identify patients with ≥1 claim with an oHCM ICD-10 code (I42.1) from 2016 - 2018. Student's t‐test were used to compare continuous patient characteristics and chi‐square tests were used to compare categorical patient characteristics and HCM-related clinical outcomes between men and women with diagnosed oHCM. Kaplan-Meier analysis was used to analyze time to HCM-related event, with comparisons between sex using a log‐rank test. Results: Among 9.306 patients with oHCM, the majority were male (60.5%, p<0.0001) and women were of comparable age to men (50±15 vs. 49±15 years, p<0.0001). Women were less likely to be prescribed beta blockers (42.7% vs. 45.2%, p=0.0171) and undergo an implantable cardioverter-defibrillator (1.7% vs. 2.6%, p=0.005). Alcohol septal ablation (ASA) and septal myectomy (SM) were performed slightly more frequently in women (ASA: 0.08% vs. 0.05%, p=0.60; SM: 0.35% vs. 0.18%, p=0.096). Women were less likely to have atrial fibrillation (6.7% vs. 9.9%, p<0.0001). Rates of heart failure were slightly greater in females (8.8% vs. 8.5%, p=0.615) but sudden cardiac death was lower (0.16% vs. 0.28%, p=0.2386). Conclusion: Women were less likely to be prescribed beta blockers and undergo implantable cardioverter-defibrillator and heart transplant. While the magnitude of these sex differences in most cases was marginal, they warrant greater attention. Lower rates of treatments for women may represent a missed opportunity to improve women’s health and quality of life.