HYPERTROPHIC CARDIOMYOPATHY IN TUSCANY - CLINICAL COURSE AND OUTCOME IN AN UNSELECTED REGIONAL POPULATION

Objectives. Our aim was to study a population of patients with hypertr ophic cardiomyopathy from the well defined geographic region of Tuscan y in central Italy, a group virtually free of selective referral bias and therefore probably closely representative of the true patient popu lation with this disease. Background. Most available information on cl inical course, natural history and prognosis of hypertrophic cardiomyo pathy is based on data generated from tertiary referral centers and th erefore constitutes a potentially biased perspective of the disease pr ocess in this complex and diverse condition. Methods. The study group comprised 202 patients aged 1 to 74 years (mean +/- SD 41 +/- 17) at i nitial diagnosis and followed up for 1 to 30 years (mean 10 +/- 5). Re sults. Largely with the use of single or multiple drug therapy, the va st majority of patients (n = 154 [76%]) were asymptomatic or mildly sy mptomatic and in stable or improved condition over the period of follo w-up, whereas the remaining patients (n = 48 [24%]) experienced deteri oration, had substantial functional impairment or died. Of the 13 pati ents (6%) who died of cardiovascular causes related to hypertrophic ca rdiomyopathy, 11 had progressive congestive heart failure (including 6 in the end-stage phase) and only 2 died suddenly. The annual mortalit y rate for cardiovascular disease was 0.6% and that due to sudden card iac death was only 0.1%; the cumulative survival rate was 97%, 95% and 92%, respectively, at 5, 10 and 15 years of follow-up. Atrial fibrill ation proved to be a relatively common (n = 57 [28%]) and particularly unfavorable clinical feature, with premature death occurring in 9 of the 57 patients. The cumulative survival rate after 15 years was 76% f or patients with atrial fibrillation versus 97% for patients with sinu s rhythm. Syncope occurred in 33 patients (16%) but did not appear to be of prognostic significance. Conclusions. In an unselected regional population, hypertrophic cardiomyopathy had a relatively benign progno sis inconsistent with its prior characterization as a generally progre ssive 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 p rone to atrial fibrillation), did experience clinical deterioration.