Coronary artery disease can be prevented by antihypertensive therapy: experiences from the MAPHY Study.

The present randomized primary prevention study in hypertensive men aged 40-64 years (n = 3,234) was aimed at investigating whether metoprolol given as initial treatment would prevent coronary artery disease (CAD) better than thiazide diuretics. Two hundred fifty-five patients had a definite CAD event during the 15,730 patient-years of follow-up; 25% of these events were fatal, and 38% were definite acute myocardial infarctions. The incidence of CAD was significantly lower during follow-up in patients randomized to metoprolol than in patients randomized to diuretics: 111 vs. 144 cases (p = 0.001). Stroke mortality was significantly lower in the metoprolol group than in the diuretic group, but the overall stroke incidence was similar in the two treatment groups. A majority of events occurred among smokers in both treatment groups although only one-third of patients were smokers at baseline. Blood pressure (BP) control was similar in the two treatment groups; therefore, the difference between the groups in CAD events is mediated via mechanisms other than the BP-reducing effect of metoprolol.