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

BACKGROUND

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.

OBJECTIVE

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

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Economic evaluation of restrictive vs. liberal transfusion strategy following acute myocardial infarction (REALITY): trial-based cost-effectiveness and cost-utility analyses

AIMS

To estimate the cost-effectiveness and cost-utility ratios of a restrictive vs. liberal transfusion strategy in acute myocardial infarction (AMI) patients with anaemia.

METHODS AND RESULTS

Patients (n = 666) with AMI and haemoglobin between 7-8 and 10 g/dL recruited in 35 hospitals in France and Spain were randomly assigned to a restrictive (n = 342) or a liberal (n = 324) transfusion strategy with 1-year prospective collection of resource utilization and quality of life using the EQ5D3L questionnaire. The economic evaluation was based on 648 patients from the per-protocol population. The outcomes were 30-day and 1-year cost-effectiveness, with major adverse cardiovascular events (MACEs) averted as the effectiveness outcome. and a 1-year cost-utility ratio.The 30-day incremental cost-effectiveness ratio was €33 065 saved per additional MACE averted with the restrictive vs. liberal strategy, with an 84% probability for the restrictive strategy to be cost-saving and MACE-reducing (i.e. dominant). At 1 year, the point estimate of the cost-utility ratio was €191 500 saved per quality-adjusted life year gained; however, the cumulated MACE was outside the pre-specified non-inferiority margin, resulting in a decremental cost-effectiveness ratio with a point estimate of €72 000 saved per additional MACE with the restrictive strategy.

CONCLUSION

In patients with AMI and anaemia, the restrictive transfusion strategy was dominant (cost-saving and outcome-improving) at 30 days. At 1 year, the restrictive strategy remained cost-saving, but clinical non-inferiority on MACE was no longer maintained.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02648113.

ONE SENTENCE SUMMARY

The use of a restrictive transfusion strategy in patients with acute myocardial infarction is associated with lower healthcare costs, but more evidence is needed to ascertain its long-term clinical impact.