Characteristics of intracerebral hemorrhage associated with dual antiplatelet treatment

Background: Antiplatelet treatment is associated with hematoma expansion (HE) and poor outcome in intracerebral hemorrhage (ICH). We aimed to describe the characteristics of ICH associated with dual antiplatelet treatment (DAPT), compared with single (SAPT) and no antiplatelet treatment (NAPT). Methods: A retrospective analysis of ICH patients admitted at nine academic stroke centers in Italy, Germany, and China was conducted. The main outcomes of the analysis were HE (hemorrhage growth > 33% and/or > 6 mL) and poor prognosis at 3 months (modified Rankin Scale 4–6). To account for potential confounders we calculated every patients’ predicted probability of the outcome of interest, using logistic regression estimates and summarizing the predicted probability as a continuous variable ranging from 0 to 1. Results: A total of 1644 patients were included, of whom 463 (28.2%) were on SAPT and 25 (1.5%) on DAPT (aspirin plus clopidogrel). DAPT-associated ICH had the highest risk of HE (expressed as mean predicted probability (95% confidence interval, CI): NAPT 0.23 (95% CI 0.23–0.24), SAPT 0.31 (95% CI 0.30–0.32), DAPT 0.42 (95% CI 0.35–0.49), p < 0.001. DAPT patients had also the highest risk of poor outcome: NAPT 0.48 (95% CI 0.47–0.50), SAPT 0.55 (95% CI 0.52.0.57), DAPT 0.70 (95% CI 0.60–0.79), p < 0.001. Among patients on SAPT, the comparison between ICH associated with aspirin (n = 420) and clopidogrel (n = 43) showed similar rates of HE, and poor outcome (all p > 0.1). Conclusion: DAPT is associated with higher risk of HE and poor outcome in acute ICH. These findings might inform clinical practice and future trials.