Time to adopt a new standard method for assessing cardiac function in chemotherapy-induced cardiotoxicity in breast cancer? A systematic review and meta-analysis.

[BACKGROUND] Anthracycline-induced cardiotoxicity is a major cause of morbidity in breast cancer survivors. Although left ventricular ejection fraction (LVEF) is the gold standard for monitoring cardiac function, it is often considered a late and insensitive marker of myocardial damage. New methods have emerged: global longitudinal strain (GLS) and cardiac magnetic resonance (CMR) derived parameters as potentially superior tools for detecting subclinical dysfunction. This study aimed to systematically compare the diagnostic accuracy and temporal sensitivity of GLS, LVEF, and CMR índices in the early detection of chemotherapy-induced cardiotoxicity.

[METHODS] A systematic review and meta-analysis of clinical studies was conducted to evaluate the outcomes and technical accuracy of the main methods for assessing cardiac function in breast cancer patients undergoing chemotherapy, using the PubMed, Web of Science, and Scopus databases. Twenty-nine studies were included in the systematic review and meta-analysis.

[RESULTS] The meta-analysis revealed a distinct temporal dissociation between methods. GLS detected a significant absolute reduction of 1.81% (95% CI: 1.14 - 2.49; z = 5.25, p < .001) as early as 1-3 months after treatment initiation. In contrast, LVEF showed a significant reduction of 3.59% only at mid-term follow-up (4-6 months), typically remaining within the range of clinical normality (>50%). The HSROC analysis for GLS (10 studies) demonstrated robust diagnostic performance, with an Area Under the Curve (AUC) of 0.818, a pooled sensitivity of 74.6% (95% CI: 64.8%-82.4%), and a specificity of 76.3% (95% CI: 68.2%-82.9%).

[CONCLUSION] Comparative analysis of data from our meta-analyses supports the recommendation of Global Longitudinal Strain (GLS) as the preferred method for screening for cardiotoxicity, over isolated assessment by Left Ventricular Ejection Fraction (LVEF).