Sudden cardiac death: investigation of the classical risk factors in a community-based hypertrophic cardiomyopathy cohort.

INTRODUCTION

The identification of high-risk patients in hypertrophic cardiomyopathy (HCM) is still a challenge. The classical clinical risk factors for sudden death have been reported by studies coming from referral HCM cohorts. So far, other studies of community-based HCM populations have not managed to identify risk factors for sudden cardiac death. The aim of the present study was to determine the clinical course of the disease in a community-based HCM population, as well as to identify the clinical factors of sudden death in such a population.

METHODS

Three hundred four (304) consecutive HCM patients (202 males, age 48 ± 18.5 years) from 280 different families were assessed. Referral was based on disease diagnosis, irrespective of clinical status or treatment needs. All patients were examined clinically, echocardiographically, by 24h ambulatory electrocardiographic monitoring, and by cardiopulmonary exercise testing at regular intervals, for a period of 56.4 ± 29.9 months.

RESULTS

Most patients (n=264/304, 87.2%) were in New York Heart Association functional class I or II. The disease was familial in 60.5%. At initial examination, maximum left ventricular wall thickness was 19 ± 4.4 mm and a left ventricular outflow gradient >30 mmHg was present in 30.9% patients. The annual sudden death mortality was 1.2%. Familial sudden death, non-sustained ventricular tachycardia, severe left ventricular hypertrophy >30 mm, and young age were predictors of sudden cardiac death.

CONCLUSIONS

In this community-based HCM population, the risk factors for sudden death were similar to those found in referral cohorts.