Predialysis blood pressure and mortality risk in a national sample of maintenance hemodialysis patients

The role of predialysis blood pressure (BP) as a risk factor for the high m ortality in chronic hemodialysis (HD) patients has remained controversial. The objective of the current study was to further explore in a national ran dom sample of 4,499 US hemodialysis patients any relationship of systolic o r diastolic and predialysis or postdialysis BP with mortality, while consid ering subgroups of patients and controlling for other patient characteristi cs and comorbidities. The main finding of this study is the association of a low predialysis systolic BP with an elevated adjusted mortality risk (rel ative mortality risk [RR] = 1.86 for systolic BP < 110, P < 0.0001). No ass ociation with an elevated mortality risk could be observed for predialysis systolic hypertension (RR = 0.98 to 0.99, not significant [NS]), except for an elevated risk of cerebrovascular deaths. Postdialysis systolic BP was a ssociated with an elevated mortality risk both for low and high BP levels a s compared with midrange BP, Further evaluation of the elevated mortality r isk associated with low predialysis systolic BP indicated similar patterns for both diabetic and nondiabetic subgroups and for patients with and witho ut congestive heart failure (CHF) or coronary artery disease, although it w as more pronounced among those with CHF. The level of predialysis fluid exc ess did not modify these results substantially, The findings from this hist orical prospective national study do not argue against the treatment of hyp ertension and suggest greater attention to postdialysis hypertension. The s trikingly elevated mortality risk with low predialysis systolic BP suggests that low predialysis BP needs to be viewed with great concern and avoided where possible. (C) 1999 by the National Kidney Foundation, Inc.