Does The Aspirin Response Test Help Determine Whether Patients Should Receive Platelet Transfusion After Intracerebral Hemorrhage?

. Background: Platelet transfusion for the reversal of aspirin therapy is often used in an effort to minimize hematoma expansion following intracerebral hemorrhage (ICH). We investigated whether, in patients taking Aspirin, the Aspirin Response Test (ART) is a useful predictor of hematoma expansion, in order to identify a subset of patients who would benefit from platelet transfusion. We hypothesized that patients with platelet dysfunction (ART <550) will have an ICH expansion without the transfusion, and those with normal platelet function (ART >550) will not. Methods: In this IRB approved, retrospective cohort analysis, we reviewed patients presenting to our institution between May 2009 and June 2012 with acute ICH. We only include cases where only aspirin and no other antithrombotic was used prior to the ICH. ICH was measured with the ABC/2 formula, on head CT in the Emergency Department and again within the first 24 hours. Results: We analyzed 45 patients, 30 (66.67%) of whom had documented aspirin use, and 15 (33.33%) had suspected aspirin use with ART indicative of platelet dysfunction. There were 19 patients who did not receive a platelet transfusion: of these, 18 had platelet dysfunction by ART, and 4 (22%) had hemorrhage expansion; 1 had no platelet dysfunction by ART but had hematoma expansion. The small size of the latter group prevented useful statistical analysis. In total, there were 42 patients with platelet dysfunction: of these, 18 did not get a platelet transfusion and 4 of the 18 (22%) had hemorrhage expansion. 24 did get a platelet transfusion, and 11/24 (45.8%) had hemorrhage expansion. The difference in expansion rates was not statistically significant (p=0.19). Conclusions: In this group, having an abnormal ART did not seem to predict hemorrhage expansion, and did not predict response to platelet transfusion. A larger, prospective study would better characterize the clinical utility of ART in patients with ICH.