Long-term outcome of patients with hypertrophic cardiomyopathy successfully resuscitated after cardiac arrest.

This study describes the long-term outcome of 33 patients with hypertrophic cardiomyopathy who experienced a cardiac arrest but were successfully resuscitated. Cardiac arrest occurred at ages 9 to 62 years (mean 32); five patients survived multiple (two or three) arrests. A variety of treatments were administered; 18 patients with left ventricular outflow tract obstruction underwent ventricular septal myotomy-myectomy or mitral valve replacement and also received drug therapy; 15 patients received medical therapy alone. To date, 22 (67%) of the 33 patients have survived after the initial cardiac arrest for periods of 17 months to 22 years (mean 7 years); 12 patients have survived for greater than or equal to 5 and 6 for greater than or equal to 10 years. Of the 22 survivors, 16 have remained asymptomatic or only mildly symptomatic over the period of follow-up; 6 others have become severely symptomatic with heart failure, including 3 with evidence of left ventricular wall thinning and cavity enlargement. Eight patients ultimately died of natural cardiac causes (suddenly or of progressive heart failure) 7 months to 8.4 years (mean 4 years) after their initial cardiac arrest. Actuarial patient survival was 97 +/- 3%, 74 +/- 9% and 61 +/- 11% after 1, 5 and 10 years, respectively. Event-free rate (defined as actuarial survival without recurrent cardiac arrest of death) was 83 +/- 7%, 65 +/- 9% and 53 +/- 11%, respectively. For this group of patients with hypertrophic cardiomyopathy who were treated in a nonsystematic fashion with a variety of therapeutic strategies, the long-term outcome after surviving a cardiac arrest was variable.(ABSTRACT TRUNCATED AT 250 WORDS)