Nonsurgical septal reduction therapy for hypertrophic obstructive cardiomyopathy: One-year follow-up

OBJECTIVE The objective of this study is to evaluate the one-year outcome o f the first 50 patients who underwent nonsurgical septal reduction for symp tomatic hypertrophic obstructive cardiomyopathy at our institution. BACKGROUND Left ventricular outflow tract obstruction is an important deter minant of clinical symptoms in patients with hypertrophic obstructive cardi omyopathy. Nonsurgical septal reduction is a new therapy that has been show n to result in left ventricular outflow tract gradient reduction and resolu tion of symptoms immediately after the procedure and on midterm follow-up. METHODS Fifty patients with hypertrophic obstructive cardiomyopathy who und erwent nonsurgical sep;al reduction at our institution and completed 1-year follow-up are described. Complete history, physical examination, two-dimen sional echocardiography with Doppler and exercise treadmill. testing have b een analyzed. RESULTS The mean age of the study group was 53 +/- 17 years. All patients h ad refractory symptoms before enrollment. Ninety-four percent had class III or IV New York Heart Association class symptoms at baseline compared to no ne at 1 year (p < 0.001). The exercise duration increased by 136 s at 1 yea r (p < 0.021). Only 20% of patients were either receiving beta-blockers or calcium-channel blockers on follow-up. The resting left ventricular outflow tract gradient decreased from 74 +/- 23 mm Hg to 6 +/- 18 mm Hg (p < 0.01) and from 84 +/- 28 mm Hg to 30 +/- 33 mm Hg (p < 0.01) in patients with do butamine-provoked gradient at one year. These changes are associated with d ecreased septal thickness and preserved systolic function. CONCLUSION Nonsurgical septal reduction therapy is an effective therapy for symptomatic patients with hypertrophic obstructive cardiomyopathy with per sistence of the favorable outcome up to one year after the procedure. (C) 2 000 by the American College of Cardiology.