Survival and Clinical Behavior of Hypertrophic Cardiomyopathy in a Latin American Cohort in Contrast to Cohorts from the Developed World

BACKGROUND Hypertrophic cardiomyopathy (HCM) is the most common hereditary heart disease with diverse phenotipyc, genetic expession and clinical presentations. The evolution of patients with HCM in Latin America has not been properly described being the frequency, the long-term prognosis as well as the predominant phenotypic expression still unknown. The aim of this study was to determine the survival rate of HCM patients having different phenotypes in a Mexican cohort of patients. METHODS Clinical and echocardiographic data obtained from 77 Mexican patients with recently diagnosed HCM were analyzed. The follow-up was of 12.5 years. RESULTS 96.1% of patients were in functional class I/II according to the New York Heart Association, 2.6% in class III and 1.3% in class IV. Only 3.9% of them went to surgery for myectomy. During the follow-up, 17 patients (22%) died: 4/9 (44%) had apical HCM, 5/20 (25%) had obstructive septal asymmetric HCM, 6/35 (17%) had nonobstructive septal asymmetric HCM and 2/3 (15%) had concentric HCM. The survival rate was worse for patients with apical HCM, followed by those with obstructive and nonobstructive septal asymmetric HCM and patients showing concentric HCM had the best survival rates. There is significant difference in survival rates which declined in 65% in a 9 years-period. Log rank test showed significant differences (p < 0.002). CONCLUSION The survival rate of patients with HCM was worse in those with apical variety. The majority of patients received medical treatment. The indication for myectomy was below that observed in other international centers.