Does achieving an intensive versus usual blood pressure level prevent stroke?

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.

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.

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).

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.