Increased vascular compliance/decreased cardiovascular risk: what the studies tell us.

Increasing arterial stiffness and decreasing arterial compliance are now thought to occur at the beginning of the hypertension disease process. Decreased arterial compliance is associated with isolated systolic blood pressure elevations. Many clinical trials of isolated systolic hypertension provide indirect evidence that improving compliance lowers the risk of cardiovascular disease. The Systolic Hypertension in the Elderly Program showed that antihypertensive therapy in older patients with isolated systolic hypertension lowers systolic blood pressure and narrows pulse pressure without unduly lowering diastolic blood pressure. Treatment over 5 years significantly reduced the incidence of stroke, nonfatal myocardial infarction and coronary death, all cardiovascular events, and all-cause mortality. The Systolic Hypertension in Europe and Systolic Hypertension in China trials showed similar effects on pulse pressure and on clinical end points. The Heart Outcomes Prevention Evaluation was a primary prevention study of the effect of an angiotensin-converting enzyme (ACE) inhibitor in subjects who were not necessarily hypertensive but were at risk for cardiovascular events. With minimal lowering of blood pressure, ramipril therapy provided significant risk reduction in all major end points--overall mortality, stroke, myocardial infarction, and cardiovascular death. ACE inhibitors restore endothelial cell balance to improve arterial compliance, thus they can provide benefits beyond lowering blood pressure.