Don't Go Changing? Or Please Do! Variability of Troponin as a Good Omen

Background: Patients on chronic haemodialysis (HD) have higher risk for major adverse cardiovascular events. Haemodynamic and volume changes in between dialysis sessions lead to cardiac burden which could increase cardiac troponin. The aim of this study was to analyze cardiac troponin I (cTnI) in asymptomatic patients on chronic HD as a potential predictor for all-cause mortality (primary outcome). Methods: Troponin levels were measured 4 times during the period of one year, using Beckman Coulter High-Sensitivity Troponin I (hs-cTnI) assay - before the first weekly session. Mean cTnI values (cTnI_mean), standard deviation (cTnI_SD) and coefficient of variability (cTnI-variability) of these four values were calculated. Patients with a minimum of 24 months on chronic HD were included and were followed up retrospectively from the start of chronic HD till the primary outcome or till end of April 2025. Survival was computed by the Kaplan-Meier method. Cox proportional hazards method was used to determine the predictive value of cTnI variables for primary outcome. Results: A total of 55 patients undergoing chronic HD were included (67.3% men) with median age at cTnI evaluation of 70 years (interquartile range, IQR = 61-79). Median follow-up time was 113 months (Standard error, SE = 17.3). 15 patients (27.3%) reached the primary outcome. Median for cTnI_mean was 18.15 ng/l (IQR = 12.28-33.30), for cTnI_SD 4.77 (IQR = 2.15-12.23) and for cTnI_variability 0.27 (IQR = 0.14-0.40). In univariate Cox proportional hazards regression analysis cTnI variability (Hazard ratio, HR = 0.034; 95% confidence interval CI = 0.001-0.830) and vascular access (venous catheter vs. AV-fistula; HR = 7.223, 95%CI = 2.014-25.900) were significantly associated with primary outcome. In a multivariate model with age, gender, cTnI variability and vascular access, gender (men vs. women, HR = 9.941, 95%CI = 1.961-50.385), vascular access (venous catheter vs. AV-fistula; HR = 25.545, 95%CI = 4.407-148.065) and cTnI variability (HR = 0.006, 95%CI = 0.000-0.560) were independent predictors of primary outcome. Cardiac troponin_mean and cTnI_SD were not significant predictors in univariate analysis. Conclusion: Higher cTnI variability, as well as female gender and AV-fistula as vascular access were associated with lower risk of all-cause mortality in asymptomatic chronic HD patients. Funding: Government Support – Non-U.S.