Drug treatment trials in hypertension: a review

Thirteen controlled clinical trials (11 randomized) reporting morbidity and mortality results during 1960-1982 are summarized. Given the diverse design features, results are presented both for individual trials and for several combinations of similar studies, to provide more stable estimates of effects. Two of three trials in severe hypertension, while lacking enough events to evaluate effect on mortality, found significant reductions in "hypertensive" events, with the overall estimate being an 80% reduction. Similarly, combining six trials in less severe hypertension with untreated controls showed a 54% reduction in such events. The favorable trend in all-causes mortality from these trial results, whether viewed separately or in combination, was not significant. However, the findings from a large randomized trial with community controls, the Hypertension Detection and Follow-up Program, indicated significant reduction of all-causes mortality, the magnitude of which was consistent with the other trials. Outcomes of hypertensive participants in the Multiple Risk Factor Intervention Trial raised questions about mortality benefits in certain subgroups. These and other issues about patient benefit are further addressed with trial data and reference to the 1984 Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. We note also 1) that evidence for reduction of coronary heart disease death or nonfatal myocardial infarction with antihypertensive drug treatment is weak, perhaps due to inadequate power to detect such a difference, and that data are limited regarding effects on quality of life. Nevertheless, the overall trial results provide strong support for drug treatment of severe hypertension, and for most individuals with less severe hypertension, when nonpharmacologic treatment will not suffice.