Carvedilol for prevention of cardiotoxicity in patients receiving anthracycline-based chemotherapy: a systematic review and meta-analysis

Chemotherapy-induced cardiotoxicity, particularly from anthracyclines, limits treatment in oncology patients. Carvedilol, a third-generation β-blocker with antioxidant properties, may offer cardio protection. However, comparative evidence for carvedilol and its metabolites remains inconclusive. This systematic review and meta-analysis adhered to PRISMA-NMA guidelines and was registered in PROSPERO. A comprehensive search of PubMed, Cochrane, and Scopus (inception–May 2025) identified randomized controlled trials (RCTs) evaluating carvedilol or its metabolites in adult cardio-oncology patients. The primary outcome was preservation of left ventricular ejection fraction (LVEF) at 4 and 6 months. Secondary outcomes included LV end-systolic diameter (LVESD), LV end-diastolic diameter (LVEDD), E/A ratio, and E wave velocity. Data were synthesized using a random-effects model; subgroup and meta-regression analyses explored dose–response relationships and heterogeneity. Nine RCTs ( n = 902 participants) were included. Carvedilol did not significantly preserve LVEF at 4 months (MD: -0.60; 95% CI: -1.71 to 0.52) or 6 months (MD: 3.49; 95% CI: -0.80 to 7.77), with substantial heterogeneity at 6 months (I² = 91%), largely driven by a single outlier study. LVEDD was modestly reduced at 4 months (MD: -2.35 mm; 95% CI: -4.02 to -0.69), but this effect was not sustained at 6 months. E wave velocity at 4 months demonstrated an increase (MD: 4.99 cm/s; 95% CI: 2.14–7.83), with baseline E wave velocities across studies ranging approximately 6.5–6.9 cm/s in both groups. However, interpretation of isolated E wave changes is limited. Carvedilol did not show statistically significant maintenance of LVEF in adult patients undergoing anthracycline-based chemotherapy. A slight decrease in LVEDD was seen after 4 months, but the structural and functional benefits were inconsistent and did not last. To clarify its role, larger, well-designed randomized trials that use modern cardio-oncology endpoints are needed.