The proxy of renal function that most accurately predicts short- and long-term outcome after acute coronary syndrome

Abstract

The aim of this study is to determine the most accurate renal function formula that predicts short- and long-term mortality in a wide spectrum of acute coronary syndrome (ACS) patients. We analyzed 8,726 consecutive patients (46.3% ST-elevation myocardial infarction [STEMI] and 53.7% non-ST-elevation ACS [NSTE-ACS]) enrolled in the ACS survey in Israel. Renal function, assessed using 5 formulas as proxies of creatinine clearance or estimated glomerular filtration rate (Cockcroft-Gault, modification of diet in renal disease [MDRD], Chronic Kidney Disease Epidemiology Collaboration, Mayo quadratic, and inulin clearance based), varied in applying the different formulas. For both STEMI and NSTE-ACS patients, the Mayo formula yielded the highest mean value (88.9 ± 27.7 and 81.4 ± 29.2 mL/min per 1.73 m(2), respectively) and Chronic Kidney Disease Epidemiology Collaboration the lowest (73.0 ± 23.1 and 67.0 ± 24.1 mL/min per 1.73 m(2), respectively). Using multivariate analysis, worse renal function was independently associated with increased mortality risk by 30% to 40% for each decrement of 10 U of creatinine clearance or estimated glomerular filtration rate in STEMI patients and by 25% to 30% for NSTE-ACS patients, using all 5 formulas. The only formula that more accurately predicted 1-year mortality than the MDRD formula was the Mayo quadratic formula with a 1-year net reclassification index of 0.26 and 0.14 for STEMI and NSTE-ACS patients, respectively, after multivariable adjustment. Worse renal function was an independent predictor for short- and long-term mortality using all 5 formulas in a broad spectrum of ACS patients, but only the Mayo quadratic formula had better accuracy in predicting mortality relative to the MDRD, suggesting that it may be the preferred prognosticator among ACS patients.