Abstract 2740: 24-hour Ambulatory Blood Pressure and Cardiovascular Disease: A Systematic Review and Meta-Analysis
Background Ambulatory blood pressure (BP) may be a better predictor of cardiovascular events than conventional office BP, and provide incremental prognostic information. To address this issue, we systematically assessed the evidence regarding the association between noninvasive 24-hour systolic BP and incident cardiovascular events.
Data sources and study selection We searched PubMed, EMBASE and the Cochrane Library through March 2007. In addition, reference lists of retrieved articles and review articles were examined for further publications. Only studies that prospectively followed ≥100 individuals for ≥1 year, and that reported at least one effect estimate of interest were included.
Data extraction Two independent investigators extracted information regarding study design, subject characteristics, BP measurements, outcome assessment, effect estimates and adjustment for potential confounders.
Data synthesis We identified 20 eligible articles based on 15 independent cohort studies. The primary outcome, the association between 24-hour systolic BP and a combined cardiovascular endpoint, was assessed in 9 cohort studies including 9299 participants who were followed between 1.9 and 11.1 years, and had 881 outcome events. Using a random effect model, the summary hazard ratio (HR) (95% confidence interval (CI)) per 10-mmHg increase of 24-hour systolic BP was 1.27 (1.18 –1.38) (p<0.001). Further adjustment for office BP did not substantially alter the summary estimate (HR (95% CI) per 10-mmHg increase of 24-systolic BP 1.21 (1.10 –1.33) (p<0.001)). We found no significant variability according to age, gender, population origin, baseline office BP, follow-up time, diabetes or study quality. There was a consistent association between 24-hour systolic BP and stroke, cardiovascular mortality, total mortality and cardiac events, each independent of office BP. The corresponding HRs (95% CI) per 10-mmHg increase of 24-hour systolic BP were 1.33 (1.22–1.44)), 1.19 (1.13–1.26), 1.12 (1.07–1.17), and 1.17 (1.09 –1.25), respectively (all p<0.001).
Conclusion This meta-analysis demonstrates that 24-hour systolic BP is a strong predictor of cardiovascular events, providing prognostic information independent of conventional office BP.