Chronic kidney disease epidemiology collaboration equations and global registry for acute coronary events risk score for the prediction of mortality in non-ST elevation acute coronary syndromes

Aims: The CKD-EPI equations are newly developed formulas for estimate glomerular filtration rate (GFR) that are more accurate than MDRD equation. The aim of this study is to evaluate whether these new CKD-EPI equations improve the risk stratification of patients with non-ST elevation acute coronary syndromes (ACS), and to asses whether they add complementary information to GRACE risk score. Methods and results: 314 subjects (age 66±12y, male 70%) with non-ST elevation ACS were studied. Non-ST elevation ACS was defined as ischemic symptoms lasting 10 minutes or more and occurring within 72 hours before randomization and either ST-segment deviation of 1 mm or more or elevated levels of a cardiac biomarker of necrosis. All blood samples were obtained before coronary angiography within 24 hours of hospital admission. Estimated GFR was calculated using CKD-EPI equations based on serum creatinine and/or cystatin C concentrations. Patients were clinically followed and the occurrence of death was recorded in all. Over the study period (median 648 days [IQR 236 to 1042], 29 patients (9.2%) died. Decedents had poorer renal function parameters (p<0.001). After multivariate adjustment, all CKD-EPI equations were independent predictors of mortality (CKD-EPI creatinine, per ml/min/1.73m2: HR 0.97 [95% CI 0.95-0.99], p=0.024; CKD-EPI cystatin C, per ml/min/1.73m2: HR 0.95 [95% CI 0.95-0.99], p=0.004; CKD-EPI creatinine-cystatin C, per ml/min/1.73m2: HR 0.97 [95% CI 0.95-0.99], p=0.005). Reclassification analyses showed that all CKD-EPI equations added complementary prognostic information to the GRACE risk score (Table 1). Furthermore, the lowest mortality rates were observed for patients with eGFR >60ml/min/1.73m2 and GRACE risk score below the 140 points, whereas the mortality rate observed among patients with with eGFR <60ml/min/1.73m2 and GRACE risk score above 140 points was the highest (all log rank test p<0.001). Table 1. Added predictive ability of adding CKD-EPI equations to GRACE risk score Conclusion: In patients with non-ST elevation ACS, CKD-EPI equations improved clinical risk stratification for mortality and added complementary prognostic information to GRACE risk score.