Is Electrocardiogram Helpful in Predicting a Rise in Troponin I as a Marker of Anthracycline Cardiotoxicity?

Objective: Screening patients on anthracycline-based chemotherapy regimens for the development of cardiotoxicity can be resource intensive. We therefore studied various traditional electrocardiogram (ECG) parameters to correlate and possibly predict the development of elevated Troponin I as a surrogate marker of anthracycline-induced cardiotoxicity.

Materials and methods: This was a single-centre prospective cohort study done between January 2014 to January 2016. Baseline ECG was compared with ECG performed after chemotherapy and different parameters were compared. Patients were divided into Troponin I positive and negative groups based on the test performed at the end of chemotherapy, using a cut-off of 0.06 ng/dL.

Results: Of the 160 patients studied, 131 (81.9%) were Troponin I negative (TnI-) and 29 (18.1%) were positive (TnI+). Breast cancer accounted for 79% of all cancers in this study. Many ECG parameters were compared between the TnI- and TnI+ groups. Of them, TP segment and TP/QT showed a significant decrease in the TnI+ group. The mean (95% confidence interval) TP in the TnI- group was 162.9 ms (145.4, 180.4) and in TnI+ groups was 117.9 ms (89, 146.8) (p = 0.03). Corresponding values for TP/QT were 0.47 (0.42, 0.51) and 0.35 (0.27, 0.42) (p = 0.02). These changes were not significant in multivariate analysis and likely reflected the different mean heart rates (HR) in both the groups, as suggested by partial correlation which was run with HR as a confounder.

Conclusion: ECG parameters, such as QTcH, TP and TP/QT do not helpful predicting Troponin I elevations in patients on anthracycline-based chemotherapy. Further studies based on hard endpoints, for example, clinical systolic dysfunction occurring at one year, would give better information on their utility.