Visit-to-visit blood pressure variability is a risk factor for all-cause mortality and cardiovascular disease: a systematic review and meta-analysis

Objective: Clinical cohort studies have reported that visit-to-visit variability (VVV) of blood pressure (BP) is associated with cardiovascular disease (CVD) or mortality. However, the results were not consistent in all studies. The current study is, therefore, aimed to conduct a systematic review and meta-analysis to determine the association between VVV of BP and CVD and all-cause mortality. Method: PubMed and EMBASE were searched through 18 May 2014, using the following terms: VVV, BP, CVD, coronary heart disease (CHD), myocardial ischemia, stroke, and mortality. Overall, 84 records were identified, and 23 publications were enrolled into the current study. Data were extracted from selected publications, and meta-analysis was performed using a random effect model. Result: VVV of SBP was significantly associated with outcomes of all-cause mortality with the relative risk (RR) and 95% confidence interval (CI) 1.14 (1.09, 1.18), CVD incidence (RR = 1.12, 95% CI: 1.05, 1.09), CVD mortality (RR = 1.18, 95% CI: 1.09, 1.28), CHD incidence (RR = 1.12, 95% CI: 1.06, 1.19), and stroke incidence (RR = 1.34, 95% CI: 1.11, 1.61). Conclusion: In summary, among the wide heterogenetic population, modest associations between VVV of SBP and all-cause mortality, CVD incidence, CVD mortality, CHD incidence, and stroke incidence were found. Findings of the current study suggested that standardized approaches of monitoring VVV in the high-risk population, including patients with cardiac infarction, diabetes, stroke, and patients with chronic kidney disease or in dialysis, are necessary in designing a prospective clinical study on the association of VVV and patients' prognosis.