Primary prevention of sudden cardiovascular death in hypertensive patients. Mortality results from the MAPHY Study

In a randomized primary prevention trial including 3,234 men with mild to moderate uncomplicated hypertension, the effect of the beta-blocker metoprolol or a thiazide diuretic as an initial antihypertensive therapy was compared regarding the risk of sudden cardiovascular death during a follow-up ranging from 2.3 to 10.8 years (median of 4.2 years). Only men aged 40 to 64 years were included in the study. The randomization of patients into the metoprolol (n = 1,609) or diuretic group (n = 1,625) was performed after stratification for age, smoking habits, serum cholesterol, and systolic blood pressure. At baseline the two treatment groups were well matched. Metoprolol was given in a mean dose of 174 mg daily and the mean dose of thiazide diuretic was either 46 mg hydrochlorothiazide daily or 4.4 mg bendroflumethiazide daily. Identical blood pressure control was achieved using the fixed therapeutic schedule. Total and cardiovascular mortality were significantly lower for metoprolol than for diuretics, owing to fewer deaths from coronary heart disease and stroke. Of the cardiovascular deaths, 78% were classified as sudden cardiovascular deaths (occurred within 24 h after the onset of symptoms). There were significantly fewer sudden cardiovascular deaths in the metoprolol group compared to the diuretic group (32 v 45, P = .017). The present results suggest that initial antihypertensive therapy with metoprolol is associated with a lesser incidence of sudden cardiovascular deaths than initial diuretic treatment in uncomplicated hypertension.