Association between Magnitude of Differential Blood Pressure Reduction and Secondary Stroke Prevention: A Meta-analysis and Meta-Regression

Importance: The degree to which more intensive blood pressure reduction is better than less intensive for secondary stroke prevention has not been delineated. Objective: To perform a standard meta-analysis and a meta-regression of randomized clinical trials to evaluate the association of magnitude of differential blood pressure reduction and recurrent stroke in patients with stroke or transient ischemic attack (TIA). Data Sources: PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched from January 1, 1980, to June 30, 2022. Study Selection: Randomized clinical trials that compared more intensive vs less intensive blood pressure lowering and recorded the outcome of recurrent stroke in patients with stroke or TIA. Data Extraction and Synthesis: The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was used for abstracting data and assessing data quality and validity. Risk ratio (RR) with 95% CI was used as a measure of the association of more intensive vs less intensive blood pressure lowering with primary and secondary outcomes. The univariate meta-regression analyses were conducted to evaluate a possible moderating effect of magnitude of differential systolic blood pressure (SBP) and diastolic blood pressure (DBP) reduction on the recurrent stroke and major cardiovascular events. Main Outcomes and Measures: The primary outcome was recurrent stroke and the lead secondary outcome was major cardiovascular events. Results: Ten randomized clinical trials comprising 40710 patients (13752 women [34%]; mean age, 65 years) with stroke or TIA were included for analysis. The mean duration of follow-up was 2.8 years (range, 1-4 years). Pooled results showed that more intensive treatment compared with less intensive was associated with a reduced risk of recurrent stroke in patients with stroke or TIA (absolute risk, 8.4% vs 10.1%; RR, 0.83; 95% CI, 0.78-0.88). Meta-regression showed that the magnitude of differential SBP and DBP reduction was associated with a lower risk of recurrent stroke in patients with stroke or TIA in a log-linear fashion (SBP: regression slope, -0.06; 95% CI, -0.08 to -0.03; DBP: regression slope, -0.17; 95% CI, -0.26 to -0.08). Similar results were found in the association between differential blood pressure lowering and major cardiovascular events. Conclusions and Relevance: More intensive blood pressure-lowering therapy might be associated with a reduced risk of recurrent stroke and major cardiovascular events. These results might support the use of more intensive blood pressure reduction for secondary prevention in patients with stroke or TIA..