LONG-TERM FOLLOW-UP OF MEDICAL VERSUS SURGICAL THERAPY FOR HYPERTROPHIC CARDIOMYOPATHY - A RETROSPECTIVE STUDY

In a retrospective analysis 139 patients with hypertrophic cardiomyopathy were followed up for 8.9 years (range 1 to 28 years). Patients were divided into two groups: Group 1 consisted of 60 patients with medical therapy and Group 2 of 79 patients with surgical therapy (septal myectomy). Groups 1 and 2 were subdivided according to the medical treatment. Group 1a received propranolol, 160 mg/day (n = 20); Group 1b verapamil, 360 mg/day (n = 18); and Group 1c, no therapy (n = 22). Group 2a received verapamil, 120 to 360 mg/day, after septal myectomy (n = 17) and Group 2b had no medical therapy after surgery (n = 62). In Group 1, 19 patients died (annual mortality rate 3.6%) and in Group 2, 17 patients died (mortality rate 2.4%, p = NS). Of the patients who died, approximately one half to two thirds in both Groups 1 and 2 died suddenly and the other one half to one third died because of congestive heart failure. The 10 year cumulative survival rate was 67% in Group 1, significantly smaller than that in Group 2 (84%, p < 0.05). In the subgroups, the 10 year survival rate was 67% in Group 1a, 80% in 1b (p < 0.05 versus 1a) and 65% in 1c (p < 0.05 versus 1b). The 10 year survival rate was 100% in Group 2a (p < 0.05 versus 1a, 1b, 1c) and 78% in Group 2b (p < 0.05 versus 2a). It is concluded that cumulative survival rate is significantly better in surgically than in medically treated patients. However, the survival rate among medically treated patients was better in those treated with verapamil than in those treated with propranolol or in untreated patients. The 10 year survival rate was similar in the medically treated patients receiving verapamil (80%) and the entire surgically treated group (84%, p = NS). The most favorable outcome was observed in surgically treated patients receiving long-term therapy with verapamil, probably as a result of the reduction of systolic pressure overload by septal myectomy and improvement in left ventricular diastolic function mediated by verapamil.