Increased Platelet FcɣRIIa Identifies Patients at Greater Risk of Multiple Cardiovascular Events After Myocardial Infarction.

BACKGROUND

After myocardial infarction (MI), quantifying platelet FcɣRIIa (pFCG) stratifies ischemic risk.

OBJECTIVES

This study aimed to assess a prognostic biomarker, pFCG, in patients with and without subsequent ischemic and bleeding events.

METHODS

Patients (n = 765) with type 1 MI were enrolled in a prospective noninterventional trial. Inclusion criteria included at least 2 of the following: age ≥65 years, multivessel coronary artery disease, prior MI, chronic kidney disease, and diabetes. Flow cytometry quantified pFCG at a core laboratory. Ischemic endpoints (n = 158) were MI, stroke, and death. Bleeding endpoints (n = 74) were Bleeding Academic Research Consortium 2, 3, and 5.

RESULTS

Patients were categorized as no events (n = 562), bleeding events alone (n = 45), single ischemic event (n = 101), bleeding + ischemic events (n = 29), multiple ischemic events (n = 23), and fatal MI (defined as MI combined with death within 2 days, n = 5). Average pFCG (molecules/platelet) in patient groups was 1,491 ± 655 (no events), 1700 ± 740 (single ischemic), 1850 ± 625 (multiple ischemic), and 1880 ± 440 (fatal MI, P < 0.001 for trend). Early ischemic events associated with high pFCG were driven by first ischemic endpoints and were accentuated between 6 months and 1 year by additional ischemic endpoints (HR: 2.7; 95% CI: 1.82-4.02; P < 0.0001). The average expression (molecules/platelet) in patients with bleeding (without ischemia) 1,491 ± 517 was similar to that in patients without ischemia or bleeding.

CONCLUSIONS

High pFCG is associated with a greater risk of both first and additional ischemic endpoints. The strong association of pFCG with a greater risk of recurrent ischemic events may be useful to inform clinical decision-making.

CLINICAL TRIAL REGISTRATION INFORMATION: NCT05175261.