Troponin T for the detection of dialysis-induced myocardial stunning in hemodialysis patients.
BACKGROUND AND OBJECTIVES: Circulating troponin T levels are frequently elevated in patients undergoing long-term dialysis. The pathophysiology underlying these elevations is controversial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In 70 prevalent hemodialysis (HD) patients, HD-induced myocardial stunning was assessed echocardiographically at baseline and after 12 months. Nineteen patients were not available for the follow-up analysis. The extent to which predialysis troponin T was associated with the occurrence of HD-induced myocardial stunning was assessed as the primary endpoint. RESULTS: The median troponin T level in this hemodialysis cohort was 0.06 ng/ml (interquartile range, 0.02-0.10). At baseline, 64% of patients experienced myocardial stunning. These patients showed significantly higher troponin T levels than patients without stunning (0.08 ng/ml [0.05-0.12] versus 0.02 ng/ml [0.01-0.05]). Troponin T levels were significantly correlated to measures of myocardial stunning severity (number of affected segments: r=0.42; change in ejection fraction from beginning of dialysis to end of dialysis: r=-0.45). In receiver-operating characteristic analyses, predialytic troponin T achieved an area under the curve of 0.82 for the detection of myocardial stunning. In multivariable analysis, only ultrafiltration volume (odds ratio, 4.38 for every additional liter) and troponin T (odds ratio, 9.33 for every additional 0.1 ng/ml) were independently associated with myocardial stunning. After 12 months, nine patients had newly developed myocardial stunning and showed a significant increase in troponin T over baseline (0.03 ng/ml at baseline versus 0.05 ng/ml at year 1). CONCLUSIONS: Troponin T levels in HD patients are associated with the presence and severity of HD-induced myocardial stunning.