Prognosis of Hypertrophic Cardiomyopathy

INTRODUCTION Background: The actual prognosis of hypertrophic cardiomyopathy, a disorder previously thought of to be notorious for an increased risk of untimely death is poorly defined. Objective: The present study describes the findings of patients with Hypertrophic Cardiomyopathy followed for more than nineteen years in a large clinic population. Materials and Methods: A clinic population of 113 patients with Hypertrophic Cardiomyopathy was prospectively studied to assess cardiac mortality in the overall groups and in selected subgroups commonly thought to be at high risk for sudden death. Diagnosis of hypertrophic cardiomyopathy was based on the presence of left ventricular hypertrophy without a known cause. Left ventricular hypertrophy was determined by echocardiography. Results: During follow-up there were 11 cardiac and 2 non cardiac deaths. The annual cardiac mortality was 1% (95% confidence interval 0.2-1.8%). Relative risk for cardiac death was not significantly different in the presence of young age (< 30 years), family history for Hypertrophic Cardiomyopathy (HCM) and sudden death, history for syncope or previous cardiac arrest or both, ventricular tachyeardia on 24-hour, holter monitoring or operation for refractory symptoms and outflowtract obstruction. Conclusion: HCM has a relatively benign prognosis (1% cardiac annual mortality) that is 2-4 times less than previously thought. These findings might have important consequences for risk assessment in individual patients. Echocardiography is obligatory to determine the presence, and extent of myocardial hypertrophy. In addition, the technique allows differentiation between Hypertrophic Cardiomyopathy and Athlete’s Heart. Hypertrophic cardiomyopathy is a primary cardiac disease often genetically transmitted with a diverse clinical and morphologic expression and characterized by unexplained left ventricular hypertrophy1. Most studies in the past are based on populations from large tertiary referral centers of highly selected patients. These studies have reported a severe prognosis with annual mortality due to sudden cardiac death of 2-4%2~. Recent studies however have suggested a more benign prognosis4’L The latter findings have important implications for treatment strategies and risk stratification for premature cardiac death. In the present study we describe our findings in a large clinic population of Hypertrophic Cardiomyopathy (HCM) and show that prognosis is significantly more benign than previously thought. In addition we give some clues which can be found by echocardiography to differentiate between Hypertrophic Cardiomyopathy and Athlete’s Heart. Materials and Methods