Prognostic determinants of hypertrophic cardiomyopathy--the results of the Shiga Cardiomyopathy Study.

Previous studies have reported that patients with hypertrophic cardiomyopathy (HCM) are prone to sudden death. In this study, we retrospectively assessed the prognosis and any influencing factors in 83 patients (66 male, 17 female) with HCM. Twenty-two patients were obstructive, 40 were non-obstructive, 18 were apical HCM and 3 were unclassified. Four of the 83 cases progressed to left ventricular dilatation and dysfunction during the follow-up period. The mean age was 51.2 years (range 16 to 73) and the mean duration of follow-up was 6.7 years (range 0.3 to 15.1). The 5- and 10-year survival rates were 98% and 89%, respectively. Five patients dies; 3 from cardiac events (two sudden deaths and one due to congestive heart failure) and 2 from malignant diseases. The lack of a family history of sudden death and the amplitude of the S wave in lead V1 (less than 2.0 mV) were associated with a favorable prognosis. None of the patients who were diagnosed before age 50 died, but this observation was not statistically significant. None of the patients with apical HCM died, but the classification of HCM was not significantly associated with the prognosis. None of the patients without medication died and medical treatment did not influence the prognosis. Sex, family history of HCM, the patient's symptoms and physical signs, NYHA classification of cardiovascular disability, thickness of the septum and the posterior wall of the left ventricle, dimension of the left atrium, and the left and right ventricles in echocardiogram, amplitude of the R wave in lead V5, the depth of the negative T wave and atrial fibrillation did not influence the prognosis.