Results of MRC (UK) trial of drug therapy for mild hypertension.

The main aim of the trial was to determine whether drug treatment of mild hypertension (phase V diastolic pressure 90-109 mm Hg) reduced the rates of stroke, of death due to hypertension, and of coronary events, in men and women aged 35-64 years. A total of 17,354 patients was recruited, and 85,572 patient-years of observation accrued. Patients were randomly allocated at entry to take bendrofluazide or placebo, or propranolol or placebo. The stroke rate was reduced with treatment (60 strokes, vs 109 in the placebo groups), being 1.4 and 2.6 per 1,000 patient-years of observation, respectively (p less than 0.01), but overall rates of coronary events were not different (222 with treatment and 234 with placebos). The incidence of all cardiovascular events was reduced with treatment (286 events, vs 352 with placebos; p less than 0.05). For rates of mortality from all causes, treatment made no difference. Several post hoc analyses of subgroup results were performed. The all-cause mortality was reduced in men on treatment (157 deaths, vs 181 in placebo groups) but increased in women on treatment (91 deaths, vs 72 with placebos); this difference between the sexes was significant (p = 0.05). The reduction in stroke rate was greater with bendrofluazide than with propranolol (p = 0.002). The rate of strokes was reduced in both smokers and non-smokers taking bendrofluazide, but only in non-smokers taking propranolol; this difference between the drugs was significant (p = 0.03). The coronary-event rate was not reduced by bendrofluazide, whatever the smoking habit, nor in smokers taking propranolol, but it was reduced in non-smokers taking propranolol. (ABSTRACT TRUNCATED AT 250 WORDS)