Abstract
Background
Blood pressure variability (BPV) is an independent risk factor for cardiovascular events and death in general population. Hemodialysis patients have higher BPV and higher vascular events than general population. However, the impact of BPV on vascular events of hemodialysis patients is not clear.
Purpose
To determine the association of BPV with vascular outcomes in patients on maintenance hemodialysis.
Method
In this prospective multi-center study, we enrolled 927 maintenance hemodialysis patients from Jan, 2017 to Dec, 2017. We used the coefficient of variation (CV) and the variance independent of mean (VIM) of predialysis systolic blood pressure (SBP) derived from the first 3 months (36 dialysis sessions) after enrollment as the metrics of BPV. Patients were prospectively followed at 3-month interval. Outcomes included death, systemic vascular thrombosis (nonfatal myocardial infarction, ischemic stroke, and acute limb ischemia), and dialysis vascular access thrombosis.
Results
In all, 707 subjects with at least 20 measurements were included in the analysis. Patients' mean age was 66 years and 50% of patients were male. Baseline factors associated higher BPV included diabetes, high co-morbidity scores, low albumin, high systolic and diastolic blood pressure. The mean pre-dialysis SBP CV was 10.9% and VIM was 28.9%. The median follow-up duration was 2.5 years, during which 103 deaths, 81 systemic vascular thrombosis, and 155 dialysis access thrombosis occurred. In unadjusted model, we found that the highest BPV tertile had a 52% increased risk of vascular thrombosis than the lowest BPV tertile (HR=1.52, 95% CI 1.23–1.86, P<0.001). After multivariable adjustment (including age, diabetes, co-morbidity score, albumin, baseline systolic and diastolic BP), this association remained statistically significant (HR=1.47, 95% CI=1.18–1.84, P=0.001). Systolic BPV was associated with either systemic vascular thrombosis (HR=1.44, 95% CI=1.08–1.93, P=0.01) or dialysis vascular access thrombosis (HR=1.55, 95% CI=1.16–1.82, P=0.001).
Conclusion
In the cohort of patients on maintenance hemodialysis, high pre-dialysis systolic BPV was associated a higher risk of vascular thrombosis events, both for systemic vascular thrombosis and dialysis vascular access thrombosis.
Funding Acknowledgement
Type of funding source: Public hospital(s). Main funding source(s): National Taiwan University Hsinchu Branch
Interdialytic blood pressure variability and the risk of stroke in maintenance hemodialysis patients
