Isolated systolic hypertension : prognostic information provided by pulse pressure

Abstract

Increased arterial stiffness results in increased characteristic impedance of the aorta and increased pulse wave velocity, which increases systolic and pulse pressures. An association between increased pulse pressure and adverse cardiovascular events has been found in normotensive and hypertensive patient populations. Increased pulse pressure has also been associated with thickening of the carotid intima and media. However, the relationship between pulse pressure and stroke has not previously been evaluated. In this study, we examined the hypothesis that pulse pressure is an independent predictor of stroke in elderly patients with systolic hypertension entered in the Systolic Hypertension in the Elderly Program. Differences in baseline characteristics were examined by tertiles of pulse pressure. The independent prognostic value of pulse pressure and mean arterial pressure for predicting either stroke or total mortality was assessed with Cox proportional hazards models that included pulse pressure, mean arterial pressure, and other variables that were significant on univariate analysis. This analysis demonstrated an 11% increase in stroke risk and a 16% increase in risk of all-cause mortality for each 10-mm Hg increase in pulse pressure. Each 10-mm Hg increase in mean arterial pressure was independently associated with a 20% increase in the risk of stroke and a 14% increase in the risk of all-cause mortality. These data provide strong evidence of an association of increased conduit vessel stiffness, as indicated by increased pulse pressure, with stroke and total mortality, independent of the effects of mean arterial pressure, in elderly patients with isolated systolic hypertension.