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.