Abstract 16551: Pathways of Prognosis and Effective Treatment Interventions in Hypertrophic Cardiomyopathy
Background: Hypertrophic cardiomyopathy (HCM) is a genetic heart disease with diverse clinical course, including extended periods of stability and possibly normal longevity, but also major complications for which there are now effective therapeutic options. The proportion of patients with sudden death (SD), heart failure progression, or atrial fibrillation/stroke within established cohorts and likelihood that patients incur multiple disease pathways during their clinical course is unknown.
Methods: We studied 1893 consecutive HCM patients (40 ± 19 years) from the Minneapolis Heart Institute/Tufts Medical Center, over average follow-up of 10.7 years, and identified 3 hallmark endpoints and disease complication pathways: (1) SD or an appropriate ICD intervention for VT/VF; (2) progression of heart failure to NYHA class III/IV refractory to drugs; (3) ≥1 episode or persistent atrial fibrillation (AF).
Results: Of 1893 patients, 953 (50%) survived without reaching any endpoint or requiring major interventions, and were in NYHA class I/II at follow-up. Another 680 patients (36%) progressed along 1 major adverse disease pathway, most commonly progressive heart failure (n=376) due to outflow obstruction or diastolic dysfunction, or AF (n=233), or SD events (n=71). Only 237 patients (13%) experienced 2 major complication pathways, most commonly AF or progressive heart failure unrelated to AF (n=198); and 23 patients (1%) incurred all 3 adverse pathways. Of the 1893 patients, 70 (3%) died of HCM, with 5-year and 10-year survival, 98% and 94%, and 1693 patients (89%) were in class I/II at follow-up. HCM mortality was: 1 adverse disease pathway: 7%, 2 pathways: 8%, 3 pathways: 26% (p=0.002 for 3 pathways).
Conclusion: In this referral-based HCM population, almost 90% of patients had a benign clinical course or reached one major end-point associated with effective management options. Evolution along 2 or 3 disease pathways was uncommon (14%), but also amenable to treatment, although mortality was highest in patients with 3 complications. With contemporary management strategies, HCM has become a treatable disease with low overall mortality (0.5%/year).
Author Disclosures: B. Maron: None. E.J. Rowin: None. S.A. Casey: None. M.S. Maron: None.
- © 2015 by American Heart Association, Inc.