Minor Increases in Plasma Troponin I Predict Decreased Left Ventricular Ejection Fraction after High-Dose Chemotherapy

Increased cardiac troponin I (cTnI) in patients treated with high-dose chemotherapy (HDCT) for aggressive malignancy has been proposed as an early marker of late HDCT-induced cardiac dysfunction. We investigated whether cTnI measured by the Stratus CS (Dade Behring) would allow detection of minimal cTnI increases in patients treated with HDCT. Plasma cTnI concentrations were determined in 179 consecutive patients before HDCT, at the end of the treatment, and after 12, 24, 36, and 72 h. Cardiac function was explored by echocardiography, and left ventricular ejection fraction (LVEF) was recorded during follow-up. The greatest variation in LVEF from the baseline value was used as a measure of cardiac damage. In 99 healthy volunteers, the 99th percentile was at 0.07 microg/L. On the basis of ROC curve analysis (area under the curve, 0.89), a cutoff of 0.08 microg/L was chosen (sensitivity, 82%; specificity, 77%). cTnI > or =0.08 microg/L occurred in 57 patients (32%) with echocardiographic monitoring revealing a mean decrease in LVEF of 18%. In comparison, the group of cTnI-negative patients had a mean decrease in LVEF of 2.5% (P