Failure to reduce cholesterol as explanation for the limited efficacy of antihypertensive treatment in the reduction of CHD. Examination of the evidence from six hypertension intervention trials.

Over the past 6 years, major hypertension intervention studies in Europe, Australia, and the USA have shown disappointing results in the prevention of coronary heart disease (CHD) in spite of adequate treatment and good compliance. Recently, it has become increasingly clear that hypertensives with or without treatment display higher cholesterol levels than normotensive persons. The present review examines cholesterol levels in six intervention studies, none of which offered dietary or drug therapy for hypercholesterolemic patients. The Oslo study and the British MRC Trial reported very high average cholesterol levels and both showed no protection from CHD through intensive therapy in comparison to control patients. The Australian and the American MRFIT studies produced evidence for reduced coronary mortality among hypertensives with low in contrast to those with high cholesterol levels. The European Working Party showed indirectly that patients with marked reduction in blood pressure and cholesterol had a significantly lower cardiac mortality compared to placebo-treated patients. The IPPPSH study found that increasing cholesterol levels in hypertensives under beta blocker or diuretic therapy increased the risk of myocardial infarction. Failure to reduce cholesterol in hypertensive patients apparently is a major reason for the limited efficacy of antihypertensive treatment in the reduction of CHD.