Objective: The purpose of this study was to compare the impact of achieving tight versus usual systolic blood pressure (SBP) control on stroke prevention through meta-analysis of randomized controlled trials.
Methods: We searched PubMed and bibliographies of recent review articles. Relative risk with 95% confidence interval was used as a measure of the association between an active treatment group with achieved SBP <130 mmHg versus a comparator group with achieved SBP 130 to 139 mmHg, and risk of stroke after pooling data across trials.
Results: The search identified 11 studies with 42,572 participants and 794 stroke events. The final SBPs, weighted for trial size, were a mean of 126.5 mmHg in the intensive treatment arms and 132.6 mmHg in the conventional arms (mean SBP reduction, 6.1 mmHg). Achieving a tight SBP level was associated with a lower stroke risk (relative risk, 0.80; 95% confidence interval, 0.70-0.92; p < 0.01) and a lower risk of major vascular events (0.91; 0.86-0.96; p < 0.001). In subgroup analyses, subjects with risk factors but no established cardiovascular disease showed substantial reduction of future stroke risk with tight control (0.49; 0.34-0.69), but those with established cardiovascular disease at entry did not experience stroke risk reduction with tight control (0.92; 0.83-1.03).
Interpretation: Achieving an SBP <130 mmHg compared to 130 to 139 mmHg appears to provide additional stroke protection only among people with risk factors but no established cardiovascular disease.
Copyright © 2011 American Neurological Association.