Association Between Prior Antiplatelet Therapy and Prognosis in Patients With Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis.

Purpose: Approximately 20% to 30% of intracerebral hemorrhage (ICH) patients were reported to be on antiplatelet therapy (APT), and association between prior APT and prognosis was unclear. We aimed to clarify the impact of APT on the prognosis of ICH through an updated systematic review and meta-analysis, and to further compare the risk of single APT (SAPT) or dual APT (DAPT) prior to ICH as well as the risk associated with various antiplatelet drugs.

Methods: EMBASE, MEDLINE via Ovid SP and Web of Science were searched from inception of each database to November 4, 2023. Included studies reported prognosis in both patients with prior APT and those without.

Findings: A total of 433,103 patients from 43 studies were included in the meta-analysis. Both univariate and multivariate analyses demonstrated a significant association between prior-APT and an increased mortality risk (odd ratio [OR] 1.43, 95% confidence interval [CI] 1.28-1.59; OR 1.20, 95%CI 1.10-1.30, respectively). The risk was higher in short term follow-up (Univariate OR 1.73, 95%CI 1.22-2.46; Multivariate OR 1.94, 95%CI 1.48-2.55). A notably increased risk of hematoma expansion was also observed in patients previously treated with APT (Univariate OR 1.47, 95%CI 1.12-1.94; Multivariate OR 1.88, 95%CI 1.30-2.71), which were mainly attributed to events within 24 hours. The impact of prior-APT on poor functional outcome was inconsistent between univariate and multivariate analyses. Both direct and indirect comparisons showed that SAPT significantly reduced the risk of mortality (OR 0.67, 95%CI 0.64-0.70; OR 0.84, 95%CI 0.71-0.99) and poor functional outcome (OR 0.84, 95%CI 0.72-0.98; OR 0.81, 95%CI 0.72-0.91) compared to DAPT.

Implications: Prior-APT increased the risk of mortality and hematoma expansion in patients with ICH. The increased risk of mortality and hematoma expansion was more obvious in the short term follow-up and within 24 hours, respectively. The effect of APT on poor functional outcome exhibited inconsistency between univariate and multivariate analyses, suggesting that further investigation is warranted to clarify this relationship. In comparison with DAPT, SAPT could decrease the risk of mortality and poor functional outcome. Further studies focusing on antiplatelet drug response, racial differences, and specific APT regimens may help verify the influence.