Serial versus single troponin measurements for the prediction of cardiovascular events and mortality in stable chronic haemodialysis patients

AIM: This study aims to describe the variability of pre-dialysis troponin values in stable haemodialysis patients and compare the performance of single versus fluctuating or persistently elevated troponins in predicting a composite of mortality and cardiac arrest, myocardial infarction or stroke. METHODS: A total of 128 stable ambulatory chronic haemodialysis patients were enrolled. Pre-dialysis troponin I was measured for three consecutive months. The patients were followed for 1 year. A troponin elevation (>0.06 μg/L) was considered high risk, and patients were classified into three risk groups: (i) patients who had normal troponin levels on all three measurements; (ii) patients with at least one elevated and one normal troponin value; and (iii) patients with elevated troponin values on all measurements. RESULTS: A total of 81 patients had all three troponin values in the normal range; 29 had fluctuating values; 18 had all three values elevated. Twenty-seven deaths or composite events were observed: eight in the first risk group, 10 in the second and nine in the third. Persistently elevated and fluctuating troponin values were associated with higher mortality and cardiovascular event rate. Serial troponin measurement had a higher sensitivity for the composite outcome than single troponin measurement when either fluctuating or persistently elevated values were considered to confer high risk. CONCLUSION: Most haemodialysis patients do not have elevated troponin levels at baseline. Troponin levels that remain elevated or fluctuate are associated with worse outcomes. A serial troponin measurement strategy is associated with better sensitivity and higher negative predictive value compared with single troponin measurement.