Blood Pressure Variability and Prognosis in Hemodialysis Patients: A Systematic Review and Meta-Analysis

Abstract

Background: The prognostic value of blood pressure variability (BPV) in patients receiving hemodialysis is inconclusive. In this study, we aimed to assess the association between BPV and clinical outcomes in the hemodialysis population.

Methods: Pubmed/Medline, EMBASE, Ovid, the Cochrane Library, and the Web of Science databases were searched for relevant articles published until April 1, 2020. Studies on the association between BPV and prognosis in patients receiving hemodialysis were included.

Results: A total of 14 studies (37,976 patients) were included in the analysis. In patients receiving hemodialysis, systolic BPV was associated with higher all-cause (hazard ratio [HR]: 1.13; 95% confidence interval [CI]: 1.07-1.19; p < 0.001) and cardiovascular (HR: 1.16; 95% CI: 1.10-1.22; p < 0.001) mortality. In the stratified analysis of systolic BPV, interdialytic systolic BPV, rather than 44-h ambulatory systolic BPV or intradialytic systolic BPV, was identified to be related to both all-cause (HR: 1.11; 95% CI: 1.05-1.17; p = 0.001) and cardiovascular (HR: 1.14; 95% CI: 1.06-1.22; p < 0.001) mortality. Among the different BPV metrics, the coefficient of variation of systolic blood pressure was a predictor of both all-cause (p = 0.01) and cardiovascular (p = 0.002) mortality. Although diastolic BPV was associated with all-cause mortality (HR: 1.09; 95% CI: 1.01-1.17; p = 0.02) in patients receiving hemodialysis, it failed to predict cardiovascular mortality (HR: 0.86; 95% CI: 0.52-1.42; p = 0.56).

Conclusions: This meta-analysis revealed that, in patients receiving hemodialysis, interdialytic systolic BPV was associated with both increased all-cause and cardiovascular mortality. Furthermore, the coefficient of variation of systolic blood pressure was identified as a potentially promising metric of BPV in predicting all-cause and cardiovascular mortality. The use of 44-h ambulatory systolic BPV, intradialytic systolic BPV, and metrics of diastolic BPV in the prognosis of the hemodialysis population require further investigation (PROSPERO registry number: CRD42019139215).

Keywords: Blood pressure variability; Cardiovascular; Hemodialysis; Mortality; Prognosis.

Fig. 1

PRISMA flow chart of study selection. BPV, blood pressure variability.

Fig. 2

a Meta-analysis of all-cause mortality in a random-effects model. b Meta-analysis of all-cause mortality by type of BPV in a random-effects model. c Meta-analysis of all-cause mortality by BPV metrics in a random-effects model. AR, absolute residual; ARIR, average residual-intercept ratio; ARV, average real variability; BPV, blood pressure variability; CV, coefficient of variation; HR, hazard ratio; CI, confidence interval; PC, pressure change; SD, standard deviation; VIM, variation independent of mean.

Fig. 3

a Meta-analysis of cardiovascular mortality in a random-effects model. b Meta-analysis of cardiovascular mortality by type of BPV in a random-effects model. c Meta-analysis of cardiovascular mortality by BPV metrics in a random-effects model. AR, absolute residual; ARV, average real variability; BPV, blood pressure variability; CV, coefficient of variation; HR, hazard ratio; CI, confidence interval; PC, pressure change; SD, standard deviation; VIM, variation independent of mean.

Fig. 4

a Begg's funnel plot for all-cause mortality. b Trim and fill method-adjusted Begg's funnel plot for all-cause mortality. c Begg's funnel plot for cardiovascular mortality.