Association of Elevated Blood Pressure Levels with Outcomes in Acute Ischemic Stroke Patients Treated with Intravenous Thrombolysis: A Systematic Review and Meta-Analysis

Background and Purpose Although arbitrary blood pressure (BP) thresholds exist for acute ischemic stroke (AIS) patients eligible for intravenous thrombolysis (IVT), current international recommendations lack clarity on the impact of mean pre- and post-IVT BP levels on clinical outcomes. Methods Eligible studies involving IVT-treated AIS patients were identified that reported the association of mean systolic BP (SBP) or diastolic BP levels before and after IVT with the following outcomes: 3-month favorable functional outcome (modified Rankin Scale [mRS] scores of 0-1) and 3-month functional independence (mRS scores of 0-2), 3-month mortality and symptomatic intracranial hemorrhage (sICH). Unadjusted analyses of standardized mean differences and adjusted analyses of studies reporting odds ratios (ORadj) per 10 mm Hg BP increment were performed using random-effects models. Results We identified 26 studies comprising 56,513 patients. Higher pre- (P=0.02) and post-treatment (P=0.006) SBP levels were observed in patients with sICH. Patients with 3-month functional independence had lower post-treatment (P<0.001) SBP whereas trended towards lower pre- treatment (P=0.06) SBP. In adjusted analyses, elevated pre- (ORadj, 1.08; 95% confidence interval [CI], 1.01 to 1.16) and post-treatment (ORadj, 1.13; 95% CI, 1.01 to 1.25) SBP levels were associated with increased likelihood of sICH. Increasing pre- (ORadj, 0.91; 95% CI, 0.84 to 0.98) and post-treatment (ORadj, 0.70; 95% CI, 0.57 to 0.87) SBP values were also related to lower odds of 3-month functional independence. Conclusions We found that elevated BP levels adversely impact AIS outcomes in patients receiving IVT. Future randomized-controlled clinical trials will provide definitive data on the aforementioned association.