Risk stratification for cardiac events based on high sensitive cardiac troponin T (hs-cTnT) for cardio-oncologic patients

Background: The 2022 Cardio-Oncology Guideline of the European Society of Cardiology (ESC) divides cancer patients in four different risk categories (low, medium, high and very high) to develop cardiovascular toxicity. The stratification depends on therapy-related risk (anthracyclines, HER2-targeted therapies, VEGF inhibitors, BCR-ABL inhibitors, therapies for multiple myeloma and RAF and MEK inhibitors) and patient-related risk (cardiovascular risk factors, cardiac biomarkers (hs-cTnT and NT-proBNP), history of cardiovascular disease and cancer history). In our previous work, a cutoff of hs-cTnT of <7ng/l was identified to be sufficient to identify a low-risk cohort for mortality.

Aims: To investigate whether measuring hs-cTnT alone is sufficient for predicting the outcome regarding cardiac events compared to the more extensive surveillance protocols described in the ESC Guideline.

Methods: In a post-hoc analysis of patient data from the cardio-oncology registry in Heidelberg, 1385/4164 (33.2%) cancer patients were identified with a hs-cTnT <7 ng/l (January 1st 2016 until August 1st 2024). Troponin T levels were assessed at the respective initial presentation in the outpatient clinic. All data for ESC risk stratification were collected from the patients’ electronic files. The primary outcomes were defined as drop in left ventricular ejection fraction (LVEF) of >10% or below 55%, coronary artery disease with relevant stenosis, myocardial infarction, cardiomyopathy and hs-cTnT elevation compared to initial presentation.

Results: 521/1385 (37.6%) patients with hs-cTnT below 7ng/l were in the low ESC risk group, 667/1385 (48.2%) in the medium, 175/1385 (12.6%) in the high and 22/1385 (1.6%) in the very high ESC risk group. 51 of 1385 patients developed a relevant cardiac event (3.6%, median follow-up 73.5 days). 9/51 (17.6%) were classified as low ESC risk, 26/51 (51.0%) as medium, 16/51 (31.4%) as high and none were classified as very high. ROC curve analysis for the prediction of cardiotoxicity showed that the AUC for hs-cTnT alone was 0.53 (95% CI: 0.44 – 0.61) while it was 0.66 (95% CI: 0.59 – 0.73) for the ESC risk groups alone. AUC comparison showed no statistical difference (p=0.45). For a combined model, the AUC was 0.66 (95% CI: 0.58 – 0.73).

Conclusions: In cancer patients with very low hs-cTnT levels (below 7 ng/l), development of cardiac events is rare. In this low-risk cohort, the ESC-score overestimates risk for cardiac toxicity and hs-cTnT alone is non-inferior in the prediction of cardiovascular side effects.