How Often Do Patients on Haemodialysis Have a Change of Heart? Variability of Troponin I Levels in Patients on Haemodialysis over 1 Year

Background: Patients on chronic haemodialysis (HD) have remarkably higher risk for major adverse cardiovascular events. Haemodynamic and volume changes inbetween dialysis sessions lead to constant cardiac burdain and strain which could increase cardiac troponin levels without signs and symptoms of an acute coronary syndrome (ACS). This makes it more difficult to diagnose acute disorders. Primary goal was to evaluate the basal troponin values of HD patients on their first weekly treatment (the highest volume overload) and observe its oscillations over one year. Our previous trial showed the weekly coefficient of variability (CV) of 20% for troponin in HD patients. Methods: Data of 55 patients (18 female, 37 male) undergoing chronic HD programme at Dubrava University Hospital were collected after aquiring informed consent. Troponin levels were measured 4 times during the period of one year (every 3 months) while collecting regular monthly tests, using Beckman Coulter High-Sensitivity Troponin I (hs-cTnI) assay - before the first session that week. The upper reference limit (URI) for hs-cTnI is <14.9 ng/L for female patients and <19.8 ng/L for male patients. Results: The mean hs-cTnI were 30,1 ng/L, 28,0 ng/L, 29,1 ng/L and 33,3 ng/L with mean value of every measurement 29,9 ng/L. The mean values were higher in male patients (33,4 ng/L) than in female patients (22,7 ng/L), but twice more male patients had troponin values in the refference interval, 57% opposed to just 28% in female patients. However, more male patients had troponin values higher than 50 ng/L (6 males, 1 female). Comparing patients on HD and haemodiafiltration (HDF) the average troponine value was two times lower in HD patients (21,9 ng/L) than in HDF patients (43,2 ng/L). The coefficient of variation was measured for each patient and the mean CV for hs-cTnI values was 31% (3% - 91%) with significant difference between female (26%) and male (34%) patients, and between HD (29%) and HDF (34%) patients. Conclusion: Our results show that hs-cTnI values were elevated in 53% of patients on chronic HD without signs of ACS. During one year hs-cTnI values had variability of 31%. The variability was lower in female patients (26%) and in patients on HD (29%). Patient's hs-cTnI mean value could be taken as a personal basal value for comparison when diagnosing ACS. Funding: Government Support – Non-U.S.