[Predictors of cardiovascular mortality and morbidity in hypertension]

Blood pressure is a summation of a steady component, mean blood pressure, and a pulsatile component, pulse pressure, the latter a function of the stiffness of large arteries. Target organ damage remains a major issue in the management of hypertension. More recent evidence points to the reduction of systolic blood pressure as an important aspect of protecting the hypertensive subject from the risk of cardiovascular events, but it is not the only factor. Antihypertensive drugs which achieve similar reductions in blood pressure show differences in the degree of cardiovascular protection offered. Differences between agents may depend upon the exact mechanism by which they reduce blood pressure, for instance their effect on central or peripheral pulse pressure. Pulse pressure differs significantly between the centre and the periphery, and it is former to which the heart is subjected. It is found that central but not peripheral pulse pressure is a predictor of all-cause mortality in end-stage renal disease. A major determinant of aortic pulse pressure is arterial wall stiffness which determines how much energy is absorbed by the large arteries. Three epidemiological studies show that arterial stiffness is itself an independent predictor of the risk of all-cause mortality, cardiovascular mortality, coronary events and stroke in hypertensive subjects. Pulse pressure and arterial stiffness are therefore important targets for antihypertensive agents, which need to demonstrate efficacy not only against elevated blood pressure in brachial arteries but also on large artery stiffness in order to achieve target organ protection. Major evidence of the efficacy of antihypertensive agents in these components of blood pressure has come from a study which found that low-dose perindopril/indapamide but not atenolol reduced central pulse pressure and arterial stiffness.