The Australian Therapeutic Trial in Mild Hypertension

Abstract

In the Australian Therapeutic Trial in Mild Hypertension treated patients had significantly lower cardiovascular mortality and a significantly lower incidence of cerebrovascular complications than patients given placebos. There was, however, no difference in the incidence of nonfatal myocardial infarction or other new manifestations of ischaemic heart disease. Although the evidence of benefit from treatment was clear-cut, the number of cardiovascular complications in the control group was small. This was due to several factors. Patients admitted to the trial had no preceding evidence of cardiovascular complications, the blood pressure fell spontaneously to below 95 mm Hg in almost half the control group, and patients whose blood pressures rose to levels above 110 mm Hg were given treatment, but remained in the placebo group for analysis. In both treated and placebo groups, trial end-points occurred more frequently in persons whose average diastolic blood pressure during the study remained raised. Ischaemic heart disease and many cases of stroke are due to atherosclerotic arterial disease. This appears not to be favourably influenced by antihypertensive drug therapy.