The Natural (and Unnatural( History of Hypertrophic Obstructive Cardiomyopathy

A MULTICENTER STUDY

SHAH, PRAVIN M. M.D.
ADELMAN, ALLAN G. M.D.
WIGLE, E. DOUGLAS M.D.
GOBEL, FREDARICK L. M.D.
BURCHELL, HOWARD B. M.D.
HARDARSON, T. M.D.
CURIEL, R. M.D.
de la CALZADA, C. M.D.
OAKLEY, CELIA M. M.D.
GOODWIN, JOHN F. M.D.

University of Rochester School of Medicine and Dentistry, Rochester, New York; Toronto General Hospital, University of Toronto, Ontario, Canada; the University of Minnesota, Minneapolis, Minnesota; and the Royal Postgraduate Medical School London, England (SHAH)(ADELMAN)(WIGLE)(GOBEL)(BURCHELL)(CURIEL)(de la CALZADA)(OAKLEY)(GOODWIN)
University of Rochester School of Medicine and Dentistry Rochester, New York Toronto General Hospital, University of Toronto Ontario, Canada University of Minnesota Minneapolis, Minnesota Royal Postgraduate Medical School London, England (HARDARSON)

Circulation Research 35(2):p II-195, August 1974.

The records of 190 patients have been reviewed in a multicenter cooperative study to evaluate the course of hypertrophic obstructive cardiomyopathy. The criteria for inclusion in the study were: (a) demonstration of left ventricular-aortic pressure difference in systole either at rest or on provocation; and (b) minimum follow-up period of one year. The 190 patients were followed for 981 patient-years (average, 5.2 years per patient).

The significant findings include: (1) older patients tended to be more symptomatic, with outstanding exceptions; (2) sudden death was the most common cause of demise, accounting for 26 deaths of a total of 49; (3) patients who successfully underwent ventriculomyotomy had a lower incidence of sudden death, suggesting some protection against this complication; (4) no correlation was found between age, sex, length of follow-up, or severity of presenting symptoms and the occurrence of sudden death; (5) the vast majority (83%) of the surviving patients remained clinically stable or were improved over the relatively short follow-up period in this study; (6) surgery in the form of ventriculomyotomy often provided lasting clinical and hemodynamic improvement, although the operative mortality was high (26% overall); (7) clinical response to propranolol was variable; (8) development of a clinical picture dominated by congestive heart failure with loss of outflow obstruction was extremely rare; and (9) excluding surgical and unrelated deaths, the overage attrition rate from this disorder was 3.4% per year.