Hypertension and survival in hemodialysis patients.

Abstract

Hypertension is clearly an independent risk factor for cardiovascular (CV) events and death in the general population, but the relationship between blood pressure (BP) and survival in dialysis patients is less clear. In dialysis populations at lower risk of CV events, BP is directly related to survival, while in those with high risk, it has been difficult to show such an effect. The effects of cardiac disease complicate the relationship between BP and outcome. Retrospective studies of large cohorts, with high prevalence of CV disease, have shown a U-shaped relationship between both systolic and diastolic BP and outcome. These findings probably reflect a high prevalence of cardiac failure and thus high mortality associated with low BP (i.e., a so-called reverse causation). Pulse pressure (high systolic BP and low diastolic BP) predicts outcome in hypertensive dialysis patients. Whether this reflects advanced vessel wall disease or is an independent etiologically significant risk factor is unclear. However, the current uncertainties as to the exact relationship between BP and outcome in dialysis patients do not warrant complacency regarding the prevention and treatment of hypertension.