Clinical course of hypertrophic cardiomyopathy in a non selected population. the Experience of the Italian Multicenter Cardiomyopathy Study
Cecchi, F.; Olivotto, I.; Lazzeroni, E.; Chiriatti, G.; Sachero, A.; Beretta, L.; Giagnoni, E.; Renosto, G.; Montereggi, A.; Baldassarre, S.; Castelli, G.; Ciaccheri, M.
Giornale Italiano di Cardiologia 27(11): 1133-1143
1997
ISSN/ISBN: 0046-5968 PMID: 9463057 Document Number: 474894
Most of the information available on the clinical course and prognosis of hypertrophic cardiomyopathy (HCM) is based on data generated from international referral centres and as a result, it constitutes a potentially biased perspective of the disease process in this complex and diverse condition. A multicentric study was therefore set up with the aim of providing information on unselected patient populations with HCM. The study group comprised 330 patients from 5 non-referral hospitals (mean age 42 +/- 16 years, M/F 226/104, 74-22%-obstructive, 299-91%-in NYHA class I-II) who were followed up regularly for 9.5 +/- 5.6 years. The vast majority of patients (n = 272, 82%) remained asymptomatic or mildly symptomatic during the follow-up period, whereas the remaining patients (n = 58, 18%) experienced clinical deterioration or died. Of the 18 patients (5%) who died of cardiovascular causes related to hypertrophic cardiomyopathy, 14 had progressive congestive heart failure and only 4 died suddenly. The annual mortality rate for cardiovascular disease was 0.57%, while the mortality rate due to sudden cardiac death was only 0.1%. The cumulative survival rate was 98, 95 and 93%, at 5, 10 and 15 years of follow-up respectively. Atrial fibrillation proved to be a relatively common (n = 81, 24%) and particularly unfavourable clinical feature, with higher mortality rate for cardiovascular causes related to hypertrophic cardiomyopathy. Syncope occurred in 47 patients (14%) but did not appear to have prognostic significance. In an unselected population, hypertrophic cardiomyopathy had a relatively benign prognosis that was inconsistent with its prior characterization as a generally progressive disorder, based primarily on the experience of selected referral institutions. Sudden unexpected cardiac death was distinctly uncommon, although a sizable proportion of patients, particularly the subset prone to atrial fibrillation, did experience clinical deterioration.