Abstract Body (Do not enter title and authors here): Introduction:
Anti-neoplastic agents, including anthracyclines and trastuzumab, frequently employed in breast cancer treatment carry on considerable cardiotoxic effects impairing both cardiac chamber and cardiac fiber parameters leading to incident heart failure. In response to this challenging side effect, numerous randomized controlled trials (RCTs) have investigated the cardioprotective efficacy of RAASi and beta-blockers (BBs) in patients undergoing anthracycline and trastuzumab chemotherapy. We aim to perform an updated meta-analysis to elucidate the potential cardioprotective properties of these medications in patients undergoing chemotherapy for breast cancer.

Methods:
A comprehensive search of the literature was performed through April 2024 on PubMed, EMBASE and Clinicaltrials.gov. In total, data from 4 randomized studies were extracted and analyzed. The primary analysis was the effect of RAASi and BBs on LVEF as well as global longitudinal strain (GLS). Data were analyzed using a random-effects model to derive weighted mean differences (WMDs) and 95% confidence intervals for both LVEF and GLS. Data was analyzed using Review Manager 5.3 (RevMan 5.3) software.

Results:
In total, data from 248 patients (N = 124 on cardioprotection; N = 124 without cardioprotection) undergoing treatment with anti-neoplastic agents for breast cancer were included. At the end of treatment, patients undergoing cardioprotective therapy demonstrated improved LVEF preservation compared to the control group, (mean difference 2.14 [0.03, 4.25]; P=0.05; I2 = 79%). In addition, patients undergoing dual RAASi + BB therapy showed better GLS preservation compared to control group (mean difference –1.37 [-2.01, -0.72]; P < 0.0001; I2 = 0%).

Conclusion:
In breast cancer patients undergoing anti-neoplastic regimens comprising anthracycline and trastuzumab, the concomitant administration of RAASi and BBs demonstrated better LVEF as well as GLS preservation upon completion of treatment over those without cardioprotective therapy. These findings shed light on the potential benefit derived from the synergistic effects of RAASi and BBs therapy in safeguarding both cardiac chamber and fiber functions amidst aggressive anti-cancer regimens, although further investigations still need to be conducted.