Prognostic value of troponin I in cardiac risk stratification of cancer patients undergoing high-dose chemotherapy

Background - In patients with aggressive malignancies who are undergoing high-dose chemotherapy, even minimal elevation of troponin I (TnI) is associated with late left ventricular dysfunction. The time course of the subclinical myocardial damage and its impact on the clinical outcome have never been investigated previously. Methods and Results - In 703 cancer patients, we measured TnI soon after chemotherapy ( early TnI) and 1 month later ( late TnI). Troponin was considered positive for values greater than or equal to 0.08 ng/mL. Clinical and left ventricular ejection fraction evaluation (echocardiography) were performed before chemotherapy, 1, 3, 6, and 12 months after the end of the treatment, and again every 6 months afterward. Three different TnI patterns were identified, and patients were grouped accordingly. In 495 patients, both early and late TnI values were <0.08 ng/mL (TnI(-/-) group); in 145, there was only an early increase (TnI(+/-) group); and in 63 patients, both values increased ( TnI(+/+) group). In the TnI(-/-) group, no significant reduction in ejection fraction was observed during the follow-up, and there was a very low incidence of cardiac events (1%). In contrast, a greater incidence of cardiac events occurred in TnI-positive patients, particularly in the TnI(+/+) group (84% versus 37% in the TnI(+/-) group; P < 0.001). Conclusions - TnI release pattern after high-dose chemotherapy identifies patients at different risks of cardiac events in the 3 years thereafter. This stratification allows us to differentiate the monitoring program and to plan, in selected patients, preventive strategies aimed at improving clinical outcome.