Decreased coronary heart disease in hypertensive smokers. Mortality results from the MAPHY study

Abstract

The present primary prevention study aimed at investigating whether metoprolol given as initial antihypertensive treatment would lower cardiovascular complications of high blood pressure to a greater extent than thiazide diuretics. Patients were randomized to metoprolol (n = 1,609, 8,110 patient-years) or a thiazide diuretic (n = 1,625, 8,070 patient-years). At randomization, 535 patients in the metoprolol group and 524 patients in the diuretic group were classified as smokers. Blood pressure control during follow-up was equally effective regardless of smoking habits at randomization. Cardiovascular and coronary heart disease mortality was three to four times higher in smokers than in nonsmokers, underlining the importance of smoking as a risk factor. Total and cardiovascular mortality were significantly lower for the metoprolol group than for the thiazide diuretic group in the whole study population (p = 0.028 and p = 0.012), as well as in smokers (p = 0.013 and p = 0.016). Coronary heart disease mortality was significantly lower for patients on metoprolol than for patients on diuretics in the whole study population (p = 0.048) as well as in smokers (p = 0.021). The results suggest that initial antihypertensive therapy with metoprolol is associated with a lesser incidence of total, cardiovascular, and coronary heart disease mortality as compared with initial diuretic treatment, both in the whole study population and in smokers. The favorable effect of metoprolol must be mediated via mechanisms other than the blood pressure-lowering effect of metoprolol because equal blood pressure control was achieved with both types of medication, irrespective of smoking habits at randomization.