Thrombocyte transfusion and rebleeding rate in patients using antiplatelet agents before aneurysmal subarachnoid hemorrhage

OBJECTIVE The reason for a rebleed after an initial hemorrhage in patients with aneurysmal subarachnoid hemorrhage (aSAH) is considered multifactorial. Antiplatelet use is one of the factors that has been related to early rebleed and worse outcome after aSAH. Thrombocyte transfusion overcomes the inhibitory effects of antiplatelet agents by increasing the number of functional thrombocytes, but its impact on the rebleed rate and clinical outcome remains unknown. The aim of this study was to assess the effect of thrombocyte transfusion on rebleeding and clinical outcome in patients with aSAH and prehemorrhage antiplatelet use, considering confounding factors. METHODS Data were prospectively collected at a single tertiary reference center for aSAH in Zurich, Switzerland. Patients with aSAH and prehemorrhage antiplatelet use were divided into "thrombocyte transfusion" and "nontransfusion" groups based on whether they did or did not receive any thrombocyte transfusion in the acute stage of aSAH after hospital admission and before the exclusion of the bleeding source. Using multivariate logistic regression analysis, the impact of thrombocyte transfusion on the rebleed rate and on clinical outcome (defined as Glasgow Outcome Scale score 1-3) was calculated. RESULTS One hundred fifty-seven patients were included, 87 (55.4%) of whom received thrombocyte transfusion. Eighteen (11.5%) of 157 patients had a rebleed during the hospital stay. The rebleed risk was 6.9% in the thrombocyte transfusion group and 17.1% in the nontransfusion group. After adjusting for confounders, thrombocyte transfusion showed evidence for a reduction in the rebleed rate (adjusted OR [aOR] 0.29, 95% CI 0.10-0.87). Fifty-seven patients (36.3%) achieved a poor outcome at 6 months' follow-up. Among those 57 patients, 31 (54.4%) underwent at least one thrombocyte transfusion. Thrombocyte transfusion was not associated with poor clinical outcome at 6 months' follow-up (aOR 0.91, 95% CI 0.39-2.15). CONCLUSIONS Thrombocyte transfusion in patients with aSAH and prehemorrhage antiplatelet use is independently associated with a reduction in rebleeds but shows no impact on clinical outcome at 6 months' follow-up. Larger and randomized studies are needed to investigate the impact of thrombocyte transfusion on rebleed and outcome.