Prognostic value of home versus ambulatory blood pressure monitoring: a systematic review and meta-analysis of outcome studies

Objectives: Ambulatory (ABP) and self-home blood pressure (HBP) measurements are known to be superior to office blood pressure (OBP) measurements in predicting cardiovascular events. Whether ABP has superior prognostic ability than HBP, or the reverse, has not been adequately investigated. Methods: A systematic literature search was conducted to identify outcome studies investigating HBP and ABP in the same population. A meta-analysis was conducted to calculate the pooled measure of risk regarding the primary endpoint of each study for each method. Primary analysis included the comparison of pooled estimates of HBP versus 24h ABP. Results: Among 2587 articles retrieved, 6 fulfilled the inclusion criteria. Meta-analysis of five studies (n = 4439, weighted age 57 years, men 52%, hypertension 68%, diabetes 15%, cardiovascular disease 11%) indicated pooled hazard ratio per 10mmHg increase in systolic HBP 1.36 (95% CI 1.23- 1.50) and in 24 h ABP 1.38 (1.22-1.57) for the primary endpoint of each study (z-test P = NS). Metaanalysis of five studies (n = 4497, weighted age 58 years, men 51%, hypertension 65%, diabetes 15%, cardiovascular disease 9%) indicated pooled hazard ratio per 10mmHg increase in systolic HBP 1.29 (1.14-1.47), daytime ABP 1.30 (1.15- 1.46) and nighttime ABP 1.31 (1.14- 1.50) (z-test, P = NS). Data for DBP were similar. All studies were deemed to have low risk of bias. In studies comparing all the three methods, OBP provided the lowest hazard ratio. Conclusion: This meta-analysis of the available prospective outcome studies suggested that HBP and ABP have similar ability in predicting outcome and superior to OBP.