Left Ventricular Global Longitudinal Strain for Early Detection of Anthracycline-Induced Cardiotoxicity in Adult Breast Cancer Patients: A Systematic Review

Introduction: Anthracycline-based chemotherapy remains an important component of breast cancer treatment, but its use is limited by the risk of cardiotoxicity, including subclinical left ventricular dysfunction and cancer therapy-related cardiac dysfunction. Conventional monitoring based on left ventricular ejection fraction may detect myocardial injury relatively late. Left ventricular global longitudinal strain (LV GLS), assessed by speckle-tracking echocardiography, has emerged as a more sensitive parameter for identifying early myocardial impairment. This systematic review summarizes current evidence on the role of LV GLS in the early detection of anthracycline-induced cardiotoxicity in adult breast cancer patients. Methods: A systematic literature review was performed using PubMed/MEDLINE. The search strategy combined terms related to breast cancer, anthracyclines, global longitudinal strain, speckle-tracking echocardiography, and cardiotoxicity. Original English-language studies focused on adult breast cancer patients receiving anthracycline-based chemotherapy and undergoing strain echocardiographic assessment were considered eligible. After title, abstract, and full-text screening, seven studies were included in the qualitative synthesis. Results: The included studies consistently suggested that LV GLS detects subclinical myocardial dysfunction earlier than conventional left ventricular ejection fraction assessment in breast cancer patients treated with anthracyclines. Several studies reported early impairment in myocardial deformation parameters during or shortly after chemotherapy, even in the presence of preserved ejection fraction. The reviewed evidence also indicated that changes in GLS may have diagnostic and prognostic relevance for subsequent cardiotoxicity and later decline in cardiac function. More recent studies additionally supported the value of integrating GLS with other echocardiographic parameters in the assessment of cancer therapy-related cardiac dysfunction. Conclusions: LV GLS appears to be a sensitive and clinically useful echocardiographic marker for the early detection of anthracycline-induced cardiotoxicity in adult breast cancer patients. Its use may improve identification of subclinical cardiac dysfunction before a measurable decline in left ventricular ejection fraction occurs. Further studies are needed to clarify optimal cutoff values, monitoring intervals, and the role of GLS within standardized cardio-oncology surveillance protocols.