A DOUBLE-BLIND, PLACEBO-CONTROLLED CROSSOVER TRIAL OF NADOLOL AND VERAPAMIL IN MILD AND MODERATELY SYMPTOMATIC HYPERTROPHIC CARDIOMYOPATHY

Objectives. The aim of this study was to determine whether therapy wit h a beta-adrenergic or calcium channel blocking agent can improve the functional capacity and quality of life of patients with mild or moder ately symptomatic hypertrophic cardiomyopathy. Background. Both beta-b lockers and calcium channel blockers may alleviate symptoms in hypertr ophic cardiomyopathy, but previous studies have been performed in hosp italized patients or have been open studies without control subjects. Methods. A randomized, double-blind crossover trial of nadolol, verapa mil and placebo, administered for periods of 4 weeks each, was perform ed in 18 patients with mild or moderately symptomatic hypertrophic car diomyopathy (10 men, 8 women; mean age +/- SD 39 +/- 17 years). A deta iled symptom assessment, bicycle exercise testing, echocardiography an d Holter monitoring were performed in each period. Results. Two patien ts withdrew from the study owing to symptomatic sinus bradycardia duri ng nadolol therapy. Neither drug improved maximal oxygen consumption ( placebo 26 +/- 8, verapamil 23 +/- 6, nadolol 21 +/- 7 ml/kg per min; p = 0.1). Peak exercise work load was reduced by -10 W in 13 patients (81%) during nadolol therapy and in 4 patients (25%) during verapamil therapy (p = 0.005, nadolol vs. verapamil). Despite the effects on exe rcise capacity, 13 patients (81%) preferred drug treatment (8 verapami l, 5 nadolol) over placebo (p = 0.001). Verapamil improved reported pe rformance at work compared with nadolol (p = 0.01) and tended to impro ve other measures of health-related behavior and symptoms compared wit h nadolol and placebo. Conclusions. In patients with mild or moderatel y symptomatic hypertrophic cardiomyopathy, exercise capacity was not i mproved by nadolol or verapamil, and individuals were more often impai red by nadolol than with verapamil. Nevertheless, many patients derive d symptomatic benefit from drug therapy, especially with verapamil.