The association of interdialytic blood pressure variability with cardiovascular events and all-cause mortality in haemodialysis patients

Abstract Background Long-term pre-dialysis blood pressure variability (BPV) in haemodialysis patients is associated with increased cardiovascular risk. The association of the main haemodynamic culprit in dialysis, that is, short-term BPV, with outcomes has not been investigated. We examine the prognostic role of short-term BPV for mortality and cardiovascular events in this population. Methods A total of 227 haemodialysis patients underwent 44-h ambulatory monitoring during a standard interval and were followed-up for 30.17 ± 17.70 months. We calculated SD, weighted SD (wSD), coefficient of variation (CV) and average real variability (ARV) of BP with validated formulas. The primary endpoint was first occurrence of all-cause death, non-fatal myocardial infarction or non-fatal stroke. Secondary endpoints were: (i) all-cause mortality, (ii) cardiovascular mortality and (iii) a combination of cardiovascular events. Results Cumulative freedom from the primary endpoint was similar for quartiles of pre-dialysis and 44-h systolic BP (SBP), but was progressively longer for increasing quartiles of 44-h SBP-SD (P = 0.014), wSD (P = 0.007), CV (P = 0.031) and ARV (83.9, 71.9, 70.2 and 43.9% for quartiles 1–4; P