Search

Background Low-range troponin elevations without clear coronary manifestations remain a major diagnostic challenge. We sought to determine if troponin velocity could allow for early identification of patients without an obvious cardiac diagnosis and who are at increased risk for cardiac-specific events. Methods & results All patients presenting to South Australian public hospitals between 1 September 2011 and 30 September 2012, with at least two troponin measurements during the first 6 h after ED presentation were included. Diagnoses were classified as ‘coronary’, ‘non-coronary cardiac’, and ‘non-cardiac’ using the International Classification of Diseases 10 codes. The relationship between troponin velocity and cardiac-specific mortality and combined cardiac outcome (death and myocardial infarction) was assessed using Fine and Gray competing risk models in patients with an initial troponin < 52 ng/L. Sensitivity analyses were performed using different initial and maximum troponin cut-off values. In total, 7300 patients were identified. A troponin velocity of 2.5 ng/L/h or greater in the non-cardiac (n = 2793) patient group was significantly associated with an increased risk for 12-month cardiac mortality (sub-hazard ratio [SHR] 2.90, 95% CI 1.33–6.34) and combined cardiac outcome (SHR 2.08, 95% CI 1.01–4.27). This association was consistent for coronary (n = 3835) and non-coronary cardiac (n = 672) patient groups, and remained after sensitivity analyses. Conclusions The significant association observed across all patient groups suggests that troponin velocity could be used for early risk stratification of patients with low-range troponin elevations without clear cardiac symptoms. These results may help guide future clinical trials aimed at assessing the utility of cardiac-targeted interventions in this challenging patient population. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]