19. Visit-to-visit Systolic Blood Pressure Variability Independent of Mean Systolic Blood Pressure is Associated with Various Cardiovascular Events and Mortality: A Systematic Review and Meta-analysis

Background: The association between visit-to-visit systolic blood pressure variability (SBPV) and cardiovascular outcomes after being adjusted with mean systolic blood pressure (SBP) is questionable. Objective: To systematically review studies quantifying the associations of visit-to-visit SBPV adjusted to mean SBP with cardiovascular outcomes. Method: A systematic search in PubMed, Scopus, and Science Direct was conducted on 27 November 2022. We included studies evaluating the association of various SBPV parameters with cardiovascular outcomes. Only clinical trials and cohort studies were included. We included all patients with available data on visit-to-visit SBPV and cardiovascular outcomes. Hemodialysis patients were excluded due to inter-hemodialysis BPV. Different parameters of SBPV (standard deviation, coefficient of variation, variation in mean) were extracted and analyzed as standardized hazard ratios, a log-hazard ratio for each unit of SBPV divided by its standard deviation. Generic inverse variance using random effect meta-analysis was performed to estimate pooled standardized hazard ratio. The QUIPS tool for prognostic study was used for risk of bias assessment. Result: A total of 9,944,254 subjects from 43 studies (21 trials and 22 cohorts) were included in meta-analysis. Increased visit-to-visit SBPV was associated with a risk of all-cause mortality (HR 1.21, CI95%[1.16–1.25]), cardiovascular mortality (HR 1.1, CI95%[1.07–1.14]) cardiovascular events (HR 1.1, CI95%[1.07–1.13]), myocardial infarction (HR1.13, CI95%[1.07–1.19]) and stroke (HR 1.22, CI95%[1.16–1.29]). After sensitivity analysis for studies adjusted to mean SBP, SBPV is still significantly associated with all mentioned cardiovascular outcomes. Conclusion: Systolic blood pressure variability, independent of mean SBP, is associated with all-cause mortality, cardiovascular death, cardiovascular events, myocardial infarction, and stroke. PROSPERO registration number CRD42023389113