Abstract 18830: Increase in Platelet Reactivity After Red Blood Cell Transfusion in Coronary and Non-coronary Patients: Results from the Transfusion-2 Study
BACKGROUND: Red blood cell (RBC) transfusion increases platelet activation and aggregation in vitro in healthy volunteers. This provides a possible mechanism for the increase in recurrent ischemic events and mortality reported after RBC transfusion in acute coronary syndrome (ACS) patients. The aim of the study was to replicate these findings in coronary and non-coronary patients exposed to RBC transfusion.
METHODS: Platelet reactivity was measured before and 12 hours after RBC transfusion using light transmission aggregometry with four different agonists and Vasodilatator-Stimulated Phosphoprotein Platelet Reactivity Index (VASP-PRI) by flow cytometry. Consecutive and unselected patients were considered. Relative changes in maximum platelet aggregation (MPA) and in residual platelet aggregation assessed 6 minutes after initiation were considered as well as VASP-PRI.
RESULTS: Our study population consisted of 53 patients (45% of coronary patients) of whom 25 were on dual antiplatelet therapy (DAPT) (20 with clopidogrel and 5 with prasugrel) and 11 on aspirin alone. Transfusion led to a significant increase in MPA irrespective of the agonists used: 8.8% with ADP (52.1 ± 3.1 vs. 56.7 ± 2.8 p=0.03) and 12.5% with TRAP (46.8 ± 22 vs. 53.7 ± 24, p=0.02). A similar trend was observed with arachidonic acid and with the VASP PRI index (13.0 ± 23 vs. 16.5 ± 25, p = 0.2 and 46.3 ± 31 vs. 50.2 ± 27, p=0.3 respectively), although the difference was not significant. The impact of transfusion was more pronounced in patients exposed to DAPT (coronary patients) although P2Y12 Inhibitors provided lower levels of baseline platelet aggregation (Relative changes of +13.8%, p=0.02 with ADP, +24.5%, p=0.01 with TRAP, and +10%, p = 0.6 for the VASP-PRI).
CONCLUSION: Red blood cell transfusion increase platelet reactivity in patients. This effect is more pronounced among patients treated with P2Y12 inhibitors and may account for the detrimental effect of RBC in the context of ACS.
- © 2012 by American Heart Association, Inc.