Study Of Blood Pressure Pattern And Prognosis In Hemodialysis Population

Objective:The thrice weekly hemodialysis(HD)treatment in ESRD patients brought them a unique pattern of blood pressure(BP)behavior.This tidal-like feature makes the BP management a great challenge in HD population.Peridialysis BP was most widely used in clinical practice and current guidelines on BP management in HD population were largely based on peridialysis BP.However,the association between peridialysis BP levels and death risks was controversial and the quantitative features of such association were unknown.Dialysis unit BP pattern captured the tidal-feature of BP behavior in HD population and showed superiority in prognostic evaluation and interdialytic BP burden assessment.However previous studies mainly focused on the recurrent BP pattern within a session(intradialysis BP change),the clinical value of the weekly pattern of dialysis unit BP was unknown.The objectives of our study were:1.To summarize the quantitative associations between peridialysis BP levels and all-cause mortality risks and to determine the effect of various confounding factors,especially the cardiovascular(CV)confounders;2.To explore the clinical value of weekly dialysis unit BP pattern in prognostic evaluation and interdialytic BP burden assessment.Method:1.We searched all of the cohort studies(published before March 18,2017 in PubMed and Embase databases)on the associations between peridialysis BP levels and all-cause mortality risk,and conducted a dose-response meta analysis of included studies.2.We performed a prospective cohort study in adult ESRD patients on thrice weekly hemodialysis.The slope and the change of the postdialysis SBP in the course of week(post-SBP slope and post-SBP change)were used to characterize the weekly pattern of dialysis unit BP and served as the exposure variable.Outcomes included all-cause mortality,cardiovascular mortality and first cardiovascular event.We also measured the home BP in our cohort.Results:1.A total of 229,688 prevalent HD patients from 8 studies were included.Significant non-linear associations were noted between peridialytic BP levels and all-cause mortality risk.Significant increased risk of death was found in four peridialysis BP ranges,that is,low levels of predialysis SBP(<135mmHg,140 mmHg as the reference),two extremes of predialysis DBP(<55 and >95mmHg,90 mmHg as the reference),high levels of postdialysis SBP(>180mmHg,130 mmHg as the reference),and low levels of postdialysis DBP(<75mmHg,80 mmHg as the reference).Threshold effect was determined in the associations between peridialysis BP and all-cause mortality risk,and potential BP thresholds were identified(149mmHg for predialysis SBP,79 mmHg for predialysis DBP,147 mmHg for postdialysis SBP and 76 mmHg for postdialysis DBP).CV confounders,volume overload and dialysis vintage had significant impact on the associations between peridialytic BP levels and all-cause mortality risk.2.129 subjects were followed over a median of 36 months.For most subjects(61%),the weekly pattern of postdialysis SBP presented a decreasing trend(post-SBP slope﹤0)with postdialysis SBP significantly higher at the first compared with the second and third session of the week.Higher post-SBP slope(≥0.185)was independently associated with increased risk of all-cause mortality,cardiovascular mortality and first cardiovascular event.Results were similar for increased post-SBP change(postdialysis SBP at the third session﹣postdialysis SBP at the first session ≥-3).HD patients with a higher post-SBP slope or an increased post-SBP change also had significant increased interdialytic BP burden measured by home SBP on both dialysis days and non-dialysis days.Conclusions:1.Significant non-linear associations were found between peridialytic BP levels and all-cause mortality risk.Peridialysis BP ranges with increased death risk and the peridialysis BP thresholds could help clinicians identify high risk HD patients.The interpretation of such associations should be made on the basis of the CV condition,the volume status and the vintage of the specific HD subgroup.2.The weekly pattern of dialysis unit BP had its unique clinical value.Post-SBP slope and post-SBP change might be promising dialysis BP markers for prognostic evaluation and interdialytic BP burden assessment.