Predictors of Chemotherapy-Induced Cardiotoxicity in Breast Cancer: A Real-World Cohort Study

Abstract

Chemotherapy-induced cardiotoxicity is a major complication in breast cancer patients treated with anthracycline- and trastuzumab-based regimens. Most prediction models come from North American or Western European cohorts. We aimed to develop and internally validate a 12-month cardiotoxicity model in Albanian breast cancer patients and to assess the added value of global longitudinal strain (GLS). It has been performed a retrospective cohort study of 314 consecutive female breast cancer patients treated with anthracycline- and/or trastuzumab-based regimens at the University Hospital Center “Mother Teresa” in Tirana between 2015 and 2022. All underwent baseline and follow-up echocardiography with left ventricular ejection fraction (LVEF) and GLS. Cardiotoxicity at 12 months, defined by contemporary cardio-oncology criteria, was the primary outcome. Multivariable logistic and Cox models were built and internally validated with 1,000-sample bootstrapping. Cardiotoxicity occurred in 63 of 314 patients (20.1%). Age and BMI were similar between groups, whereas patients with cardiotoxicity more often received combined anthracycline–trastuzumab therapy and had worse baseline GLS. A clinical model including age, BMI, hypertension, diabetes, dyslipidemia, previous cardiovascular disease, anthracycline and trastuzumab exposure, and left-sided radiotherapy achieved an AUC of about 0.72. Adding GLS increased the AUC to about 0.79 and improved overall performance. In Cox models, combined anthracycline–trastuzumab therapy and baseline GLS remained independently associated with time-to-cardiotoxicity. In this Albanian cohort, one in five breast cancer patients developed cardiotoxicity within 12 months. A GLS-augmented clinical model showed good performance and may support individualized risk stratification and surveillance in South-Eastern European cardio-oncology practice.