Optimization of GRACE Risk Stratification by N-Terminal Pro-B-type Natriuretic Peptide Combined With D-Dimer in Patients With Non-ST-Elevation Myocardial Infarction

We aimed to explore the utility of multiple biomarkers with GRACE risk stratification for non-ST-elevation myocardial infarction (NSTEMI). A total of 1,357 patients diagnosed with NSTEMI were enrolled in this study at multiple medical centers in Tianjin, China. The outcomes were 1-year all-cause death and major adverse cardiac events (MACE: all-cause death, hospital admission for unstable angina, hospital admission for heart failure, nonfatal recurrent myocardial infarction, and stroke). C-index, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to verify that the biomarkers improve the predictive accuracy of the GRACE score. A total of 57 participants died, while 211 participants experienced 231 MACEs during follow-up (mean: 339 days). For all-cause death, the combination of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and D-dimer improved the predictive accuracy of GRACE the most, with C-index, IDI, and NRI values of 0.88, 0.085, and 1.223, respectively. For MACE, trigeminal combination of NT-proBNP, fibrinogen, and D-dimer resulted in C-index, IDI, and NRI values of 0.80, 0.079, and 0.647, respectively. As a result, NT-proBNP, D-dimer, fibrinogen, and GRACE comprise a new scoring system for assessing 1-year clinical events. Kaplan-Meier analysis revealed a significant increase in 1-year mortality (score ≥3.85 vs <3.85, p < 0.0001) and 1-year MACE (score ≥1.72 vs <1.72, p < 0.0001) between different score groups. In conclusion, the combination of NT-proBNP and D-dimer added prognostic value to GRACE for all-cause death. Combining NT-proBNP, fibrinogen, and D-dimer increased the prognostic value of GRACE for MACE. This newly developed scoring system is strongly correlated with all-cause mortality and MACE, and can be easily utilized in clinical practice.