Biomarkers enhance the long-term predictive ability of the KAMIR risk score in Chinese patients with ST-elevation myocardial infarction

Abstract

Background: The Global Registry of Acute Coronary Events (GRACE) score is recommended by current ST-elevation myocardial infarction (STEMI) guidelines. But it has inherent defects. The present study aimed to investigate the more compatible risk stratification for Chinese patients with STEMI and to determine whether the addition of biomarkers to the Korea Acute Myocardial Infarction Registry (KAMIR) score could enhance its predictive value for long-term outcomes.

Methods: A total of 1093 consecutive STEMI patients were included and followed up 48.2 months. Homocysteine, hypersensitive C-reactive protein (hs-CRP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were detected. The KAMIR score and the GRACE score were calculated. The performance between the KAMIR and the GRACE was compared. The predictive power of the KAMIR alone and combined with biomarkers were assessed by the receiver-operating characteristic (ROC) curve.

Results: The KAMIR demonstrated a better risk stratification and predictive ability than the GRACE (death: AUC = 0.802 vs. 0.721, P < 0.001; major adverse cardiovascular events (MACE): AUC = 0.683 vs. 0.656, P < 0.001). It showed that the biomarkers could independently predict death [homocysteine: HR = 1.019 (1.015-1.024), P < 0.001; hs-CRP: HR = 1.052 (1.000-1.104), P = 0.018; NT-pro BNP: HR = 1.142 (1.004-1.280), P = 0.021] and MACE [homocysteine: HR = 1.019 (1.015-1.024), P < 0.001; hs-CRP: HR = 1.012 (1.003-1.021), P = 0.020; NT-pro BNP: HR = 1.136 (1.104-1.168), P = 0.006]. When they were used in combination with the KAMIR, the area under the ROC curve (AUC) significantly increased for death [homocysteine: AUC = 0.802 vs. 0.890, Z = 5.982, P < 0.001; hs-CRP: AUC = 0.802 vs. 0.873, Z = 3.721, P < 0.001; NT-pro BNP: AUC = 0.802 vs. 0.871, Z = 2.187, P = 0.047; homocysteine, hs-CRP and NT-pro BNP: AUC = 0.802 vs. 0.940, Z = 6.177, P < 0.001] and MACE [homocysteine: AUC = 0.683 vs. 0.771, Z = 6.818, P < 0.001; hs-CRP: AUC = 0.683 vs. 0.712, Z = 2.022, P = 0.031; NT-pro BNP: AUC = 0.683 vs. 0.720, Z = 2.974, P = 0.003; homocysteine, hs-CRP and NT-pro BNP: AUC = 0.683 vs. 0.789, Z = 6.900, P < 0.001].

Conclusion: The KAMIR is better than the GRACE in risk stratification and prognosis prediction in Chinese STEMI patients. A combination of above-mentioned biomarkers can develop a more predominant prediction for long-term outcomes.

Figure 1

Receiver-operating characteristic curve analysis. The accuracy for all-cause death (A) and MACE (B) between the KAMIR risk score and the GRACE risk score. GRACE: the Global Registry of Acute Coronary Events risk score; KAMIR: the Korea Acute Myocardial Infarction Registry risk score; MACE: major adverse cardiovascular events.

Figure 2

Kaplan-Meier survival curve analysis. The probability of all-cause death (A) and MACE (B) among groups divided in terms of the KAMIR risk score. KAMIR: the Korea Acute Myocardial Infarction Registry risk score.

Figure 3

Kaplan-Meier survival curve analysis. The probability of all-cause death (A) and MACE (B) increased with the increase of homocysteine (1), hs-CRP (2), and NT-pro BNP (3). MACE: major adverse cardiovascular events.

Figure 4

ROC curve analysis. The addition into the KAMIR score with homocysteine (1), hs-CRP (2), and NT-pro BNP (3) and a combination of the three (4). The addition of homocysteine, hs-CRP, and NT-pro BNP improved the predictive power of the KAMIR risk scoring system for all-cause death (A) and MACE (B). KAMIR: the Korea Acute Myocardial Infarction Registry risk score; ROC: receiver-operating characteristic.