Cystatin C-based estimated glomerular filtration rate after percutaneous coronary intervention in the prediction of inhospital mortality in acute myocardial infarction

Aim . To assess the significance of changes cystatin C-based estimated glomerular filtration rate (eGFR cys ) in predicting inhospital mortality in patients with acute ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI). Material and methods . In 133 patients with STEMI, serum creatinine and cystatin C were determined. Creatinine clearance (CrCl) was estimated according to Cockcroft-Gault equation. Creatinine-based estimated glomerular filtration rate (eGFR cr ) was assessed using the MDRD (eGFR cr _MDRD) and CKD-EPI 2009 (eGFR cr _CKD-EPI). In addition, eGFR cys and a combination of serum creatinine and cystatin C (eGFR cr-cys ) was assessed using the CKD-EPI 2012 equation at admission and 24-48 hours after PCI. In the groups of deceased patients and survivors, the studied parameters were compared. Their relationship with imhospital mortality was assessed by logistic regression adjusted for acute kidney injury (AKI) and GRACE risk. To assess the informativeness of identified independent predictors, an ROC analysis was performed. Results . After PCI, serum creatinine level increased by 9,8%, cystatin C — by 38,2%. CrCl decreased by 9,0%, eGFR cr _MDRD — by 10,2%, eGFR cr _CKD-EPI — by 5,2%, eGFR cys — by 29,5%, eGFR cr-cys — by 19,3%. AKI was diagnosed in 21 people (15,8%). Among the deceased patients (n=12), compared with the survivors, serum creatinine level was higher at baseline and after PCI, cystatin C — after PCI, eGFR of any calculation method was lower, while AKI developed more often. According to multivariate regression analysis, the eGFRcr-cys after PCI and the GRACE risk score were independent predictors of the endpoint. The area under the ROC curve for eGFR cr-cys after PCI was 0,835 [0,712-0,958], while the cut-off point was 38 ml/min/1,73 m 2 , below which the odds ratio of developing a fatal outcome was 22,2 with a 95% confidence interval of 5,7- 86,8. Conclusion . Estimated GFR determined 24-48 h after PCI based on the combination of serum creatinine and cystatin C using the CKD-EPI 2012 equation was an independent predictor of inhospital mortality in STEMI. The cut-off point of this parameter was 38 ml/min/1,73 m 2 , below which the death risk increases significantly. The results indicate the viability of introducing novel methods for assessing renal function based on cystatin C to improve the quality of prediction in STEMI.