Prognostic impact of established and novel renal function biomarkers in myocardial infarction with cardiogenic shock: A biomarker substudy of the IABP-SHOCK II-trial

Background In cardiogenic shock (CS) renal dysfunction is an important parameter of inadequate end-organ perfusion and an independent predictor of adverse outcome. Early detection of renal dysfunction is therefore important, and novel biomarkers such as Neutrophil Gelatinase-Associated Lipocalin (NGAL), Kidney Injury Molecule 1 (KIM1) and Cystatin C (CysC) have been suggested. However, in high-risk CS patients their role for assessing renal injury has not yet been investigated in comparison to the most widely used serum creatinine. Methods This predefined substudy included 190 patients of the randomized Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II)-trial. Blood samples were collected directly during primary percutaneous coronary intervention, one day and two days after randomization. The primary endpoint for outcome assessment was 1 year mortality. Results Creatinine, NGAL and KIM-1 were significantly higher in non-survivors in comparison to survivors over time in ANOVA (p < 0.001; p = 0.002 and p = 0.04, respectively). In contrast, CysC levels were not associated with the primary endpoint (p = 0.15). Receiver operator characteristics revealed that creatinine at any time point had the best predictive value for 1 year mortality. This was also true when comparing creatinine to different equations for glomerular filtration rate. In multivariable Cox-regression analysis creatinine remained the only significant independent predictor of kidney biomarkers of time to death during the first year. Conclusions Assessment of novel biomarkers such as CysC, NGAL and KIM-1 or calculation of glomerular filtration rate provide no additional prognostic information in patients with CS complicating acute myocardial infarction in comparison to creatinine.