THE AUSTRALIAN THERAPEUTIC TRIAL IN MILD HYPERTENSION: Report by the Management Committee

Abstract

The Australian National Blood Pressure Study was a controlled therapeutic trial of antihypertensive drug treatment in 3427 men and women with mild hypertension. Subjects, who were aged 30 to 69 years, were free of clinical evidence of cardiovascular disease and, after randomisation, were given either active or placebo tablets at special clinics for an average of 4 years. The results showed a significant reduction in mortality in the actively treated group, mainly due to a reduction by two-thirds in deaths from cardiovascular disease. There was also a significant reduction in the incidence of non-fatal trial end-points. There were fewer cerebrovascular events in the actively treated group, but there was little overall difference in ischæmic heart disease events. There were fewer deaths from ischæmic heart disease in the active group, but the number was small and the difference just short of significance. Trial end-point rates correlated well with blood-pressure levels throughout the trial irrespective of treatment regimens. The occurrence of trial end-points overall was low, reflecting the mild degree of hypertension and the absence of pre-existing cardiovascular disease.