Abstract 13294: Evidence for Reduced Mortality in an Adult Cohort With Hypertrophic Cardiomyopathy
Background: Hypertrophic cardiomyopathy (HCM) has traditionally been regarded as a high risk disease, and the most common cause of sudden cardiac death (SCD) in the young. However, the overall mortality benefit attributable to contemporary treatment interventions in adults with HCM, including the implantable cardioverter-defibrillator (ICD), is not fully appreciated.
Methods and Results: We studied 785 consecutive HCM patients presenting to the 2 participating centers at 30-59 years of age, and followed for 7.5±5.5 years; 70% were men. Over follow-up, there were 71 deaths (9.0%), including 32 HCM-related (44%): advanced heart failure or operative complication (n=17), SCD (n=14), and embolic stroke (n=1). Each of the 14 SCD occurred either prior to the ICD era (n=8), were in patients who declined ICD (n=5), or had no conventional risk factors dictating prophylactic implant (n=1). An additional 45 patients who survived despite HCM-related events requiring life- preserving therapy: appropriate ICD interventions (n= 27), heart transplantation (n= 14), and resuscitated cardiac arrests (n=4). Notably, HCM-related mortality was 0.54% per year, 2.4-fold less than the event rate when combining HCM mortality with appropriately prevented life-threatening HCM-related events (1.3% per year; p<0.001), i.e, appropriate ICD discharges and transplantation for advanced heart failure. A significant decrease in HCM-related mortality was evident in those patients initially evaluated after year 2000 (post-ICD era) in comparison to those assessed before year 2000 (0.29% vs 0.82% per year, p=0.016). Furthermore, mortality due to HCM was less, but did not differ significantly from the overall expected mortality risk in an age-matched general U.S. population (0.54% vs 0.88% per year; p=0.32).
Conclusions: In the modern era of HCM management, disease-related mortality has been reduced significantly, largely due to prevention of SCD with the ICD, underscoring that HCM can now be regarded as a treatable disease. The most common cause of mortality in HCM is now advanced heart failure in the absence of obstruction. HCM-related mortality rate is currently less, although not significantly different, from the risk for all-causes of death expected in the general population.
- © 2013 by American Heart Association, Inc.