Safety of Platelet Transfusion in Patients on Antiplatelet Therapy With Traumatic Head Injury

Overview

The objective of this study is to determine if the administration of platelets will improve outcome in patients with ICH who are being treated with either aspirin, a thienopyridine (ticlodipine, clopidogrel, prasugrel) or a combination of both. The study has four specific aims: 1. To determine what affect platelet administration will have on bleeding in the brain. 2. To determine what affect platelet administration will have on brain function. Several assessments to test the functioning of the brain will be performed at enrollment and throughout the study. Comparing the results of these assessments between the experimental and control groups should allow us to determine if platelet administration improves outcomes in patients with bleeding in the brain exposed to antiplatelet therapy. 3. An important risk of reversing antiplatelet therapy is exposing the patient to the very complications this therapy was designed to prevent. Therefore, tracking complications will be a very important part of this study. The investigators will compare the rates of death, heart attack, stroke and clots in the veins between groups. 4. Some patients (10-40%) have limited responsiveness to antiplatelet therapy. While platelet responsiveness, as measured by a special platelet blood test, will not affect enrollment, the investigators feel it will be important to measure.

Intracranial hemorrhage (ICH), or bleeding in the brain, is the major cause of death in trauma patients. The initial volume and early growth of the hematoma are critical determinants of mortality and functional outcome. As our population ages, a significant and growing number of patients present with ICH while on antiplatelet therapy. Bleeding is a well known complication of this therapy. It is likely that patients with ICH who are exposed to antiplatelet therapy would have an increased risk of hemorrhage growth and poor outcome compared to patients that are not using antiplatelet therapy. There are no pharmacologic agents that can reverse the antithrombotic effect of aspirin or the thienopyridines. There is a paucity of published data, one small phase one trial and two retrospective studies that address the use of platelets as a means to reverse the effects of antiplatelet therapy in patients suffering ICH. In addition, transfusion of platelets may be associated with transfusion reactions, such as infection and fluid overload. Furthermore, these patients are then exposed to the very thromboembolic complications the antiplatelet therapy was designed to prevent. Given the lack of data, which is primarily retrospective and likely underpowered, The investigators feel it's important to conduct a trial to more definitively study the efficacy of antiplatelet reversal in patients with life threatening ICH. Furthermore, it would be important to understand that, if there is a benefit to antiplatelet reversal in patients with ICH, that this benefit will outweigh the risks of antiplatelet reversal.