Experiences from hypertension trials. Impact of other risk factors

Abstract

It is well documented that elevated blood pressure is an independent and major risk factor for cardiovascular disease (CVD). In controlled trials it has been shown that single factor treatment of arterial hypertension reduces CVD morbidity but seems to have little, if any, effect on coronary heart disease (CHD). The risk for development of CVD and CHD is multifactorial and varies considerably according to the total risk factor profile in the total and the hypertensive population. In both the untreated and treated hypertensive subject the risk for suffering a CVD complication can vary up to 15- to 20-fold at a given blood pressure, according to the absence or presence of other risk factors such as smoking, elevated serum cholesterol, glucose intolerance and various manifestations of end-organ involvement. The prognostic impact of risk factors other than elevated blood pressure has been documented in both controlled treatment trials of hypertension and long term observational studies of treated hypertensive patient series. Treated hypertensives who smoke have 2 to 3 times higher total mortality. CVD mortality, CVD morbidity and CHD morbidity rates compared with their non-smoking counterparts. Similarly, treated hypertensives with various symptoms or signs of cardiac, cerebral or renal involvement have a doubled to tripled CVD mortality and CVD and CHD morbidity risk compared with patients without end-organ involvement. Elevated serum cholesterol levels have been found to independently increase the risk for CVD and CHD morbidity in some treated hypertensive series, whereas the results are not in full agreement with regard to mortality. Experiences from interventional and observational hypertension studies indicate that the potential beneficial effects of antihypertensive treatment seem to be highly dependent both on the patient's initial risk factor profile and on changes in this profile during follow-up. Treatment has little or no effect on morbidity and mortality in hypercholesterolaemic (and smoking) hypertensive subjects. Failure to reduce elevated serum cholesterol levels may be an important explanation for the failure of the controlled hypertension treatment trials to show a reduction of CHD morbidity.(ABSTRACT TRUNCATED AT 400 WORDS)