Characteristics of visit-to-visit blood pressure variability in hemodialysis patients

Intra-dialytic blood pressure variability is a greater predictor of cardiovascular events in hemodialysis patients

BACKGROUND

Short-term and long-term blood pressure variability (BPV) in hemodialysis (HD) population are risk factors of cardiovascular diseases (CVD) and all-cause mortality. There is no full consensus on the best BPV metric. We compared the prognostic role of intra-dialytic and visit-to-visit BPV metrics for CVD morbidity and all-cause mortality in HD patients.

METHODS

A retrospective cohort of 120 patients on HD was followed up for 44 months. Systolic blood pressure (SBP) and baseline characteristics were collected for 3 months. We calculated intra-dialytic and visit-to-visit BPV metrics, including standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), average real variability (ARV) and residual. The primary outcomes were CVD events and all-cause mortality.

RESULTS

In Cox regression analysis, both intra-dialytic and visit-to-visit BPV metrics were associated with increased CVD events (intra-dialytic CV: HR 1.70, 95% CI 1.28-2.27, p < 0.01; visit-to-visit CV: HR 1.55, 95% CI 1.12-2.16, p < 0.01), but not associated with increased all-cause mortality (intra-dialytic CV: HR 1.32, 95% CI 0.99-1.76, p = 0.06; visit-to-visit CV: HR 1.22, 95% CI 0.91-1.63, p = 0.18). Overall, intra-dialytic BPV showed greater prognostic ability than visit-to-visit BPV for both CVD event (AUC of intra-dialytic BPV and visit-to-visit BPV metrics respectively: SD 0.686, 0.606; CV 0.672, 0.425; VIM 0.677, 0.581; ARV 0.684, 0.618; residual 0.652, 0.586) and all-cause mortality (SD 0.671, 0.608; CV 0.662, 0.575; VIM 0.669, 0.581; ARV 0.529, 0.588; residual 0.651, 0.602).

CONCLUSION

Compared to visit-to-visit BPV, intra-dialytic BPV is a greater predictor of CVD event in HD patients. No obvious priority was found among various BPV metrics.

The association of long-term blood pressure variability with hemodialysis access thrombosis

Background

Blood pressure variability (BPV) is an important risk factor for cardiovascular events in hemodialysis patients. We sought to determine the impact of BPV on hemodialysis access thrombosis.

Methods

We enrolled 1,011 prevalent hemodialysis patients from 12 hemodialysis centers since January 2018 and followed them until December 2020. Predialysis blood pressure (BP) was assessed at 12-week intervals. The coefficient of variation derived from 36 consecutive BP measurements was used as the metric for variability. The primary outcome was incident hemodialysis access thrombosis. Linear regression models were used to assess factors associated with BPV at baseline. Kaplan-Meier curves of the time until vascular access events were drawn and log-rank tests were calculated. Cox proportional hazards models were performed to assess the association of BPV with incident vascular access events.

Results

The average coefficient of variance for systolic BPV was 10.9%. BPV was associated with age, body mass index, mean BP, diabetes, coronary and peripheral artery disease, history of access dysfunction, graft access, intradialytic hypotension, and use of antihypertensive medications. There were 194 access thrombosis events and 451 access stenosis events during a median follow-up period of 30 months. After adjustment of potential confounding factors, BPV was associated with increased risk of access thrombosis [hazard ratio = 1.27, 95% confidence interval (CI), 1.18–1.44, per 1 standard deviation increase in BPV]. The patients in the highest BPV quartile had 2.45 times the risk of thrombosis (CI, 1.62–3.70). The association was independent of average BP, intradialytic hypotension, and comorbidities. Similar trends of association were found in the subgroups analyzed. Comparative analysis using a time-varying variable model and different metrics of BPV showed consistent results.

Conclusion

Our findings underscored the impact of BP fluctuation on vascular access thrombosis.

Association between gestational visit-to-visit blood pressure variability and adverse neonatal outcomes

The authors aimed to explore the association between visit‐to‐visit blood pressure variability (BPV) in pregnant women and adverse neonatal outcomes. The study included 52 891 pregnant women. BPV was calculated as standard deviation (SD) and coefficient of variation (CV) of systolic blood pressure (SBP) or diastolic blood pressure (DBP). All participants were divided into four groups by the quartiles of BPV. When comparing the highest quartiles to the lowest quartiles of DBP SD in all participants, the fully adjusted ORs were 1.19 (95% CI 1.11–1.27, p for trend < .001) for fetal distress, 1.32 (95% CI 1.14–1.54, p for trend < .001) for small for gestational age, 1.32 (95% CI 1.06–1.63, p for trend = .003) for 1‐min Apgar score ≤ 7. When comparing the highest quartiles to the lowest quartiles of DBP CV, ORs were 1.22 (95% CI 1.14–1.30, p for trend < .001) for fetal distress, 1.38 (95% CI 1.17–1.61, p for trend < .001) for small for gestational age, 1.43 (95% CI 1.14–1.79, p for trend < .001) for 1‐min Apgar score ≤ 7. ORs for preterm birth and 5‐min Apgar score ≤ 7 were not statistically significant. However, in participants with gestational hypertension or preeclampsia, ORs for preterm birth were 2.80 (95% CI 1.99–3.94, p for trend < .001) in DBP SD and 3.25 (95% CI 2.24–4.72, p for trend < .001) in DBP CV when extreme quartiles were compared. In conclusion, higher visit‐to‐visit BPV was associated with adverse neonatal outcomes.

Prognostic significance of day-by-day in-hospital blood pressure variability in COVID-19 patients with hypertension

Hypertension is the most common comorbidity in patients with coronavirus disease 2019 (COVID-19) and increases in-hospital mortality. Day-by-day blood pressure (BP) variability (BPV) is associated with clinical outcomes in hypertensive patients. However, little information is available on the association of BPV with the outcomes of COVID-19 patients with hypertension. This study aimed to demonstrate whether day-by-day in-hospital BPV had prognostic significance in these patients. The authors included 702 COVID-19 patients with hypertension from Huoshenshan Hospital (Wuhan, China), who underwent valid in-hospital BP measurements on at least seven consecutive days. Day-by-day BPV was assessed by standard deviation (SD), coefficient of variation (CV), and variation independent of mean (VIM). Overall, patients with severe COVID-19 and non-survivors had higher BPV than moderate cases and survivors, respectively. Additionally, higher BPV was correlated with greater age and higher levels of C-reactive protein, procalcitonin, high-sensitive cardiac troponin I, and B-type natriuretic peptide. In multivariable Cox regression, SD of systolic BP (SBP) was predictive of mortality [hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.05-1.30] as well as acute respiratory distress syndrome (ARDS) (HR 1.09, 95% CI 1.01-1.16). Similar trends were observed for CV and VIM of SBP, but not indices of diastolic BP variability. The authors demonstrated that day-by-day in-hospital SBP variability can independently predict mortality and ARDS in COVID-19 patients with hypertension. And high BPV might be correlated with severe inflammation and myocardial injury. Further studies are needed to clarify whether early reduction of BPV will improve the prognosis of these patients.

Intradialytic BP variability is associated with cardiovascular mortality and hospitalization in HD patients

INTRODUCTION

Studies showed that pre-dialysis BP variability (BPV) was an independent risk factor of cardiovascular disease (CVD) among HD patients, but which is limited on how intradialytic BPV affects prognosis.

METHODS

In this study, we designed a retrospective cohort study to examine the association between intradialytic BPV and CVD outcomes in HD patients. A total of 202 patients who underwent HD in our center were included, and all intradialytic BP measurements of November 2017 were obtained from the database. Patients were divided into four groups according to variability independent of the mean (VIM) interquartile.

RESULTS

The mean age was 62.1 ± 14.3 years, 60.9% were male, and median VIM was 14.75 (12.60-18.59). Multiple-regression analyses showed patients age, dialysis vintage, serum albumin, and the percentage of intradialytic weight gain as significant predictors of VIM (all p values were <0.05). Kaplan-Meier survival curves showed that CVD mortality was greater in patients with higher VIM (p = 0.05), whereas all-cause mortality had no significant difference between the four groups overall (p = 0.149). Furthermore, multivariate regression analyses demonstrated that VIM (HR = 1.091, p < 0.004) and age (HR = 1.059, p = 0.003) were significant independent predictors for CVD death. Logistic-regression models revealed that higher VIM groups were more likely to have CVD-related hospitalization (OR = 1.085, p = 0.030), whereas the association between VIM and all-cause hospitalization was not statistically significant (OR = 1.015, p = 0.669).

CONCLUSIONS

This retrospective study suggested that higher intradialytic BPV was associated with increasing age, longer dialysis vintage, lower albumin, and greater ultrafiltration; intradialytic BPV could be an effective predictor for CVD mortality and hospitalization in the HD population.

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

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).

Blood Pressure Variability and Outcomes in End-Stage Renal Disease Patients on Dialysis: A Systematic Review and Meta-Analysis

Objective: Previous studies have suggested that blood pressure variability (BPV) is associated with an increased risk of mortality and cardiovascular events in patients on dialysis. However, the results are inconsistent. A comprehensive literature review was conducted to analyze the association between BPV and outcomes in patients on dialysis. Methods: Articles in Embase, Medline, and Web of Science from the date of inception through January 1, 2020, were identified. The outcomes were all-cause and cardiovascular mortality and cardiovascular events. The risk of bias was assessed using the Newcastle-Ottawa scale tool. Random effects models were used to pool the overall effect sizes. Two reviewers extracted the data independently. Meta-regression and subgroup analyses were performed to explore potential heterogeneity. Results: Fifteen eligible studies were included, and all enrolled hemodialysis recipients only. The overall risk of bias for the included studies was low. A 1-SD increase in systolic BPV was associated with higher risks of all-cause mortality (HR = 1.18; 95% CI 1.11–1.26, I2 = 53.8%), cardiovascular mortality (HR = 1.23; 95% CI 1.10–1.37, I2 = 57.2%), and cardiovascular events (HR = 1.27; 95% CI 1.07–1.51, I2 = 69.3%). Likewise, a 1-SD increase in diastolic BPV was associated with higher HR for all-cause and cardiovascular mortality (HR = 1.14; 95% CI 1.05–1.23, I2 = 0.0%, and HR = 1.14; 95% CI 0.94–1.38, I2 = 0.0%, respectively). Conclusions: A greater BPV is associated with higher risks of cardiovascular and mortality outcomes in patients on hemodialysis. Further research is required to determine whether BPV may be useful either as a marker enabling individualized treatment of cardiovascular risk or as a treatment target in its own right.