Antihypertensive Interventions in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis Evaluating Clinical Outcomes Through an Emergency Medicine Paradigm

High blood pressure (HBP) is usually prominent after the onset of acute ischemic stroke (AIS). Although previous studies have found that about half of patients with AIS have a background of hypertension, there is no clear etiology for HBP in AIS. The literature reveals discrepancies in the relationship between HBP and clinical outcomes of AIS, pointing toward the contested effect of blood pressure (BP) reduction clinical outcomes. Thus, the potential benefits and hazards of HBP treatment were explored in the context of clinical outcomes after AIS. An electronic database and a manual search were carried out to identify all the articles related to this topic and published between 2000 and January 2023. The Review Manager software was also used to perform the meta-analysis and quality appraisal. In analyses related to patients not treated with reperfusion therapies, mortality, and dependency outcomes were categorized as short-term (<3 months) or long-term (≥3 months). Our search strategy yielded 2459 articles, of which only 15 met the inclusion criteria. The results of our meta-analysis demonstrate that in patients not treated with reperfusion therapies, BP lowering had no significant impact on either short-term or long-term mortality (risk ratio (RR): 1.18; 95% confidence interval (CI): 0.81-1.73; p = 0.39, and RR: 1.04; 95% CI: 0.77-1.40; p = 0.81, respectively) and dependency (RR: 1.12; 95% CI: 0.97-1.30; p = 0.11, and RR: 0.98; 95% CI: 0.90-1.07; p = 0.61, respectively). Furthermore, BP lowering prior to reperfusion showed no significant effect on mortality (RR: 0.7; 95% CI: 0.23-2.26; p = 0.58), but it did significantly reduce the risk of dependency (RR: 0.89; 95% CI: 0.85-0.94; p < 0.00001). When the dataset was restricted to patients who had successful reperfusion, intensive BP lowering (target systolic BP <120 mmHg) was found to increase the risk of dependency (RR: 1.23; 95% CI: 1.09-1.39; p = 0.0009). In addition, BP reduction had an insignificant effect on the risk of recurrent strokes and combined vascular events (RR: 1.00; 95% CI: 0.54-1.84; p = 1.00, and RR: 0.99; 95% CI: 0.70-1.41; p = 0.95, respectively). Lowering BP in patients not treated with reperfusion therapies is not beneficial in reducing the risk of either short or long-term mortality and dependency. However, BPR before reperfusion reduces the risk of dependency, while aggressive BPR (target systolic blood pressure (SBP) <120 mmHg) after successful reperfusion increases the risk of dependency. Therefore, we recommend BPR as early as possible for patients undergoing reperfusion therapies but suggest against aggressive BPR in patients who have undergone successful reperfusion.