Treatment of high blood pressure--the effect on coronary morbidity and mortality.

Established drugs used in the treatment of hypertension have reduced stroke but have had disappointingly little impact on coronary artery disease and its complications. This could be due to inadequate falls in blood pressure (or excessive falls). It is possible that the role of blood pressure in ischaemic heart disease has been over-estimated compared to other risk factors. Alternatively, the drugs used previously may have adversely affected other factors. Mortality in treated hypertensives remains higher than normotensives but so does their blood pressure. The blood pressure on treatment is a much better predictor of outcome than initial blood pressure. This suggests that improved blood pressure control may be desirable. In our hospital-based hypertension clinic many patients have more than one risk factor. In spite of intensive efforts between 1980 and 1988, smoking habits changed little and serum cholesterol and random blood glucose actually rose. Cholesterol is high in our population of hypertensive patients and the mean (+/- SD) rose from 6.4 +/- 1.3 to 6.6 +/- 1.3 (n = 127; P less than 0.01). These observations highlight the importance of a multiple risk factor approach. The benefits of alternative drugs which can lower total cholesterol and/or low-density lipoprotein (LDL) and/or raise high-density lipoprotein (HDL) deserve study in this population. A final possibility is that the widely observed association between hypertension and ischaemic heart disease is not causal (or is weak compared to other risk factors). If a common underlying mechanism caused both atheroma and hypertension then reduction of blood pressure would not be expected to reverse atheroma and its complications. At present this possibility cannot be excluded.