Blood pressure variability and its utility in acute disease and critical illness: a systematic review.

BACKGROUND: Blood pressure variability (BPV) reflects the function of the autonomic nervous system (ANS). This systematic review and meta-analysis aim to evaluate the relationship between BPV and outcomes in acute disease and critical illness. METHODS: A systematic search was conducted across PubMed and Google Scholar. Data were extracted from included studies and analysed using Stata 15. The Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality Methods Guide were used to assess the risk of bias in the included studies. Subgroup analysis and sensitivity analysis were conducted to explore heterogeneity across studies. RESULTS: The systematic review yielded 38 articles, 13 of which (comprising 21,475 participants) were included in the meta-analysis. Meta-analysis revealed that per a 1-unit increase in BPV, the total OR (95% CI) value for non-mortality outcomes was 1.06 (1.04, 1.07), OR (95% CI) of standard deviation of systolic blood pressure variability (SBPV SD), coefficient of variation of SBPV (SBPV CV), successive variation of SBPV (SBPV SV), and SD of diastolic blood pressure variability (DBPV SD) were 1.04 (1.04, 1.09), 1.06 (1.02, 1.09), 1.04 (1.02, 1.07), and 1.17 (1.06, 1.28), respectively. SBPV SD was correlated with non-mortality outcomes (OR 1.06, 95% CI 1.04-1.09), with ORs 1.09 (95% CI 1.05-1.13) in the serious infection cohorts and 1.05 (95% CI 1.03-1.08) in the stroke cohort. CONCLUSIONS: The evidence suggests a modest correlation between BPV and non-mortality outcomes in acute disease and critical illness. At the same time, BPV requires further validation as a potential predictive tool in emergency and intensive care settings. Certain BPV metrics, such as SBPV SD, appear more applicable to specific conditions, including stroke and severe infection. Further research is needed to determine whether modulating BPV translates into clinical benefits. TRIAL REGISTRATION: This study was registered on PROSPERO (International Prospective Register of Systematic Reviews) with the registration number CRD42024593808 in Autumn 2024.