Classification, prevalence, and outcomes of anticancer therapy-induced cardiotoxicity: The CARDIOTOX registry

Aim: Cardiotoxicity (CTox) is a major side effect of cancer therapies, but uniform diagnostic criteria to guide clinical and research practices are lacking. Methods and results: We prospectively studied 865 patients, aged 54.7 ± 13.9; 16.3% men, scheduled for anticancer therapy related with moderate/high CTox risk. Four groups of progressive myocardial damage/dysfunction were considered according to current guidelines: normal, normal biomarkers (high-sensitivity troponin T and N-Terminal natriuretic pro-peptide), and left ventricular (LV) function; mild, abnormal biomarkers, and/or LV dysfunction (LVD) maintaining an LV ejection fraction (LVEF) ≥50%; moderate, LVD with LVEF 40-49%; and severe, LVD with LVEF ≤40% or symptomatic heart failure. Cardiotoxicity was defined as new or worsening of myocardial damage/ventricular function from baseline during follow-up. Patients were followed for a median of 24 months. Cardiotoxicity was identified in 37.5% patients during follow-up [95% confidence interval (CI) 34.22-40.8%], 31.6% with mild, 2.8% moderate, and 3.1% with severe myocardial damage/dysfunction. The mortality rate in the severe CTox group was 22.9 deaths per 100 patients-year vs. 2.3 deaths per 100 patients-year in the rest of groups, hazard ratio of 10.2 (95% CI 5.5-19.2) (P < 0.001). Conclusions: The majority of patients present objective data of myocardial injury/dysfunction during or after cancer therapy. Nevertheless, severe CTox, with a strong prognostic relationship, was comparatively rare. This should be reflected in protocols for clinical and research practices.