Improved predictive value of GRACE risk score combined with platelet reactivity for 1-year cardiovascular risk in patients with acute coronary syndrome who underwent coronary stent implantation.

Both high platelet reactivity (HPR) and Global Registry of Acute Coronary Events (GRACE) risk score have moderate predictive value for major adverse cardiovascular disease (CVD) events in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI), whereas the prognostic significance of GRACE risk score combined with platelet function testing remains unclear. A total of 596 patients with non-ST elevation ACS who underwent PCI were enrolled. The P2Y12 reaction unit (PRU) value was measured by VerifyNow P2Y12 assay and GRACE score was calculated by GRACE risk 2.0 calculator. Patients were stratified by a pre-specified cutoff value of PRU 230 and GRACE score 140 to assess 1-year risk of cardiovascular death, non-fatal myocardial infarction (MI), and stent thrombosis. Seventy-two (12.1%) patients developed CVD events during 1-year follow-up. Patients with CVD events had a higher PRU value (244.6 ± 50.9 vs. 203.7 ± 52.0, p < 0.001) and GRACE score (185.2 ± 45.6 vs. 149.7 ± 40.1, p < 0.001) than those without events. Multivariate logistic analysis showed that both platelet reactivity and GRACE score were associated with 1-year CVD risk independently. Compared to patients with normal platelet reactivity (NPR) and GRACE score < 140, those with HPR and GRACE score ≥ 140 were exposed to significantly elevated CVD risk (HR: 5.048; 95% CI: 2.268-11.237; p < 0.001). Adding platelet reactivity on the top of GRACE risk score yielded superior risk predictive capacity beyond GRACE score alone, which is shown by improved c-statistic value (0.871, p = 0.002) as well as net reclassification improvement (NRI 0.263, p < 0.001) and integrated discrimination improvement (IDI 0.018, p = 0.002). In patients with NSTE-ACS who underwent PCI, high on-treatment platelet reactivity and high GRACE score led to greater risk of adverse CVD events. The combination of platelet function testing and GRACE score predicted 1-year CVD risk better.