Impact of transfusion strategy on platelet aggregation and biomarkers in myocardial infarction patients with anemia

Higher rates of thrombotic events have been reported in myocardial infarction (MI) patients requiring blood transfusion. The impact of blood transfusion strategy on thrombosis and inflammation is still unknown.

To compare the impact of a liberal vs. a restrictive transfusion strategy on P2Y12 platelet reactivity and biomarkers in the multicentric randomized REALITY trial.

Patients randomized to a liberal (hemoglobin ≤10 g/dL) or a restrictive (hemoglobin ≤8 g/dL) transfusion strategy had VASP-PRI platelet reactivity measured centrally in a blinded fashion and platelet reactivity unit (PRU) measured locally using encrypted VerifyNow; at baseline and after randomization. Biomarkers of thrombosis (P-selectin, PAI-1, vWF) and inflammation (TNF-α) were also measured. The primary endpoint was the change in the VASP-PRI (difference from baseline and post randomization) between the randomized groups.

A total of 100 patients randomized were included in this study (n = 50 in each group). Transfused patients received on average 2.4 ± 1.6 units of blood. We found no differences in change of the VASP PRI (difference 1.2% 95% CI (−10.3–12.7%)) or by the PRU (difference 13.0 95% CI (−21.8–47.8)) before and after randomization in both randomized groups. Similar results were found in transfused patients (n = 71) regardless of the randomized group, VASP PRI (difference 1.7%; 95% CI (−9.5–1.7%)) or PRU (difference 27.0; 95% CI (−45.0–0.0)). We did not find an impact of transfusion strategy or transfusion itself in the levels of P-selectin, PAI-1, vWF, and TNF-α.

In this study, we found no impact of a liberal vs. a restrictive transfusion strategy on platelet reactivity and biomarkers in MI patients with anemia. A conclusion that should be tempered due to missing patients with exploitable biological data that has affected our power to show a difference.