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

Interdialytic blood pressure variability and all-cause mortality in patients undergoing maintenance hemodialysis: a multicenter study using DialysisNet

BACKGROUND/AIMS

In this study, we aimed to analyze all-cause mortality according to interdialytic blood pressure variability (BPV) in patients undergoing hemodialysis.

METHODS

Data on predialysis blood pressure (BP) and clinical information were extracted from four dialysis units through the DialysisNet system, which enables efficient hemodialysis management using common data elements. Interdialytic BPV was evaluated as the coefficient of variation (CV) of predialysis BP at each dialysis session over a 12-month period. The CV of systolic BP (SBP) and diastolic BP (DBP) was divided into tertiles. The primary outcome was all-cause mortality according to the CV of predialysis SBP, which was analyzed using Cox regression analysis.

RESULTS

The data of 357 patients undergoing hemodialysis were analyzed. Compared with the first SBP CV tertile, the third tertile showed significantly increased all-cause mortality after adjustment (hazard ratio [HR], 2.11; 95% confidence interval [CI] 1.04-4.24). Compared with the first DBP CV tertile, the third tertile showed significantly increased mortality in univariable analysis (HR, 2.18; 95% CI 1.10-4.30) but not in multivariable analysis (HR, 1.88; 95% CI 0.89-3.95).

CONCLUSIONS

Increased interdialytic BPV in patients undergoing hemodialysis is associated with all-cause mortality. This was more prominent in SBP than in DBP. Particular attention should be paid to large BPVs in older adults, women, and patients with a relatively longer dialysis vintage.

Prognostic Significance of Visit-to-Visit Ultrafiltration Volume Variability in Hemodialysis Patients

Introduction: Patients on chronic hemodialysis (HD) have significantly higher mortality compared with the general population. Cardiovascular (CV) disease is the primary reason for death in these patients. Suboptimal extracellular fluid management increases the CV risk of HD patients. We aimed to study the effect of visit-to-visit ultrafiltration volume (UV) variability on CV events and mortality in chronic HD patients. Patients and Methods: In our study, 173 chronic HD patients were included (median age: 63 ± 13 years; 53% men). Ultrafiltration volume (UV) variability was analyzed retrospectively for 24 months. The standard deviation (SD) and coefficient of variation (CV) were calculated using the indices of UV variability. CV is the SD divided by the mean. The obtained parameters were SD and CV of the UV: UVSD and UVCV. UV data during the observation period were recorded and used to calculate UV variability. Routine transthoracal echocardiography was performed. Results: Patients were divided into groups based on the median of UVSD, low-UVSD (<568 mL) and high-UVSD (≥568 mL) group; and also based on the median of UVCV, low- (<0.29) and high-UVCV (≥0.29) group. All-cause mortality was significantly higher in the high compared to the low-UVSD (21/84 vs. 9/89; p < 0.001) group. Similarly, mortality was higher in the high-UVCV group compared to the low-UVCV group (18/78 vs. 12/95; p = 0.005) after 24 months. Major adverse CV event (MACE) rates were also significantly higher in the high- compared to the low-UVSD group (20/84 vs. 8/89; p < 0.001). Similarly, the MACE rate was significantly higher in the high-UVCV group compared to the low-UVCV group (15/78 vs. 13/95; p = 0.029) after 24 months. There was no significant difference between the groups in CV mortality. UVSD correlated with parathormone (PTH) level (r = 0.416; p = 0.015), and UVCV with total cholesterol (r = 0.419; p = 0.015). Left ventricular end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD) were higher in the high-UVCV group compared to the low-UVCV group (49.95 vs. 52.08; p = 0.013 and 32.19 vs. 34.13; p = 0.034). Conclusions: According to our results, high UVSD and UVCD are associated with increased all-cause mortality and MACE rates but not CV mortality in chronic HD patients. Cardiovascular changes caused by increased UF volume variability during HD may contribute to higher CV morbidity and mortality in these patients.

Association between oral microbial nitrate metabolism and poor prognosis in acute ischemic stroke patients with a history of hypertension

Background

Oral microbes mediate the production of nitric oxide (NO) through the denitrification pathway. This study aimed to investigate the association between oral microbial nitrate metabolism and prognosis in acute ischemic stroke (AIS) patients.

Methods

This prospective, observational, single-center cohort study included 124 AIS patients admitted within 24 hours of symptom onset, with 24-hour ambulatory blood pressure data. Oral swabs were collected within 24 hours. Hypertensive AIS patients were stratified by the coefficient of variation (CV) of 24-hour systolic blood pressure. Microbial composition was analyzed using LEfSe and PICRUSt2 for bacterial and functional pathway identification.

Results

Significant differences in oral microbiota composition were observed between hypertensive AIS patients with varying CVs. Lower CV groups showed enrichment of nitrate-reducing bacteria and "Denitrification, nitrate => nitrogen" pathways. The TAX score of oral nitrate-reducing bacteria, derived from LASSO modeling, independently correlated with 90-day modified Rankin Scale scores, serving as an independent risk factor for poor prognosis. Mediation analyses suggested indirect that the TAX score not only directly influences outcomes but also indirectly affects them by modulating 24-hour systolic blood pressure CV.

Conclusions

AIS patients with comorbid hypertension and higher systolic blood pressure CV exhibited reduced oral nitrate-reducing bacteria, potentially worsening outcomes.

Interdialytic home systolic blood pressure variability increases all-cause mortality in hemodialysis patients

BACKGROUND

The association between Interdialytic home blood pressure variability (BPV) and the prognosis of patients undergoing maintenance hemodialysis (MHD) largely unknown.

HYPOTHESIS

We proposed the hypothesis that interdialytic home BPV exert effect on cardiac and all-cause mortality among individuals undergoing MHD.

METHODS

A total of 158 patients receiving MHD at the hemodialysis unit of Wuhan Fourth Hospital between December 2019 and August 2020 were included in this prospective cohort study. Patients were divided into tertiles according to the systolic BPV (SBPV), and the primary endpoints were cardiac and all-cause death. Kaplan-Meier analysis was used to assess the relationship between long-term survival and interdialytic home SBPV. In addition, Cox proportional hazards regression models were used to identify risk factors contributing to poor prognosis.

RESULTS

The risk of cardiac death and all-cause death was gradually increased in patients according to tertiles of SBPV (3.5% vs. 14.8% vs. 19.2%, p for trend = .021; and 11.5% vs. 27.8% vs. 44.2%, p for trend <.001). The Cox regression analysis revealed that compared to Tertile 1, the hazard ratios for all-cause mortality in Tertile 2 and Tertile 3 were 3.13 (p = .026) and 3.24 (p = .021), respectively, after adjustment for a series of covariates.

CONCLUSIONS

The findings revealed a positive correlation between increased interdialytic home SBPV and elevated mortality risk in patients with MHD.