Abstract
BACKGROUND: The impact of recent consensus definitions of cancer therapy-related cardiac dysfunction (CTRCD) from the European Society of Cardiology cardio-oncology guidelines on the reported incidence of CTRCD has not yet been assessed. OBJECTIVES: The aim of this study was to assess the: 1) cumulative incidence; 2) point prevalence during and after adjuvant therapy; and 3) prognostic value of CTRCD as defined by different asymptomatic CTRCD guideline criteria. METHODS: The cumulative incidence and point prevalence of CTRCD were retrospectively assessed in 118 patients participating in the PRADA (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy) trial. Asymptomatic CTRCD was assessed using alternative cardiac troponin (cTn) 99th percentile upper reference limits (URLs) to define cTnT and cTnI elevation. RESULTS: The cumulative incidence of moderate or severe CTRCD was low (1.7%), whereas the cumulative incidence of mild asymptomatic CTRCD was higher and differed markedly according to the biomarker criteria applied, ranging from 49.2% of patients when cTnT greater than the sex-specific 99th percentile URL was used to define cTn elevation to 9.3% when sex-neutral cTnI was used. The point prevalence of CTRCD was highest at the end of anthracycline therapy (47.8%) and was driven primarily by asymptomatic cTn elevation. CTRCD during adjuvant therapy was not prognostic for CTRCD at extended follow-up of 24 months (Q1-Q3: 21-29 months) after randomization. CONCLUSIONS: Mild asymptomatic CTRCD during adjuvant breast cancer therapy was frequent and driven mainly by cTn elevation and was not prognostic of subsequent CTRCD. The incidence of mild, asymptomatic CTRCD differed markedly depending on the cTn assay and whether sex-neutral or sex-dependent URLs were applied. (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy [PRADA]; NCT01434134).