Prognostic comparison between creatinine-based glomerular filtration rate formulas for the prediction of 10-year outcome in patients with non-ST elevation acute coronary syndrome treated by percutaneous coronary intervention

Abstract

Background: Estimated glomerular filtration rate (eGFR) is a predictor of outcome among patients with non-ST-elevation acute coronary syndrome (NSTE-ACS), but which estimation formula provides the best long-term risk stratification in this setting is still unclear. We compared the prognostic performance of four creatinine-based formulas for the prediction of 10-year outcome in a NSTE-ACS population treated by percutaneous coronary intervention. Methods: In 222 NSTE-ACS patients submitted to percutaneous coronary intervention, eGFR was calculated using four formulas: Cockcroft–Gault, re-expressed modification of diet in renal disease (MDRD), chronic kidney disease epidemiology collaboration (CKD-Epi), and Mayo-quadratic. Predefined endpoints were all-cause death and a composite of cardiovascular death, non-fatal reinfarction, clinically driven repeat revascularisation, and heart failure hospitalisation. Results: The different eGFR values showed poor agreement, with prevalences of renal dysfunction ranging from 14% to 35%. Over a median follow-up of 10.2 years, eGFR calculated by the CKD-Epi and Mayo-quadratic formulas independently predicted outcome, with an increase in the risk of death and events by up to 17% and 11%, respectively, for each decrement of 10 ml/min/1.73 m2. The Cockcroft–Gault and MDRD equations showed a borderline association with mortality and did not predict events. When compared in terms of goodness of fit, discrimination and calibration, the Mayo-quadratic outperformed the other formulas for the prediction of death and the CKD-Epi showed the best performance for the prediction of events (net reclassification improvement values 0.33–0.35). Conclusions: eGFR is an independent predictor of long-term outcome in patients with NSTE-ACS treated by percutaneous coronary intervention. The Mayo-quadratic and CKD-Epi equations might be superior to classic eGFR formulas for risk stratification in these patients.