Meta-Analysis Comparing Usefulness of Beta Blockers to Preserve Left Ventricular Function During Anthracycline Therapy
The purpose of this analysis was to evaluate the cardioprotective benefit of beta blockers in preventing anthracycline-induced cardiotoxicity (AIC) in breast cancer patients. Anthracyclines are the cornerstone treatment for breast cancer. Yet, their use has declined in the last decade due to associated AIC. Although beta blockers may protect left ventricular (LV) function, previous trials were underpowered with equivocal results. The authors systematically searched online databases through August 2018 for studies evaluating effectiveness of beta blockers in preventing AIC in breast cancer patients. We analyzed 9 studies including 771 patients. Data on converting-enzyme inhibitors, trastuzumab, or other malignancies were excluded. The primary outcome was comparison of postchemotherapy LV ejection fraction (LVEF) between beta blocker and placebo. Secondary outcomes were changes in global longitudinal strain, LV end-diastolic diameter (LVEDD), and diastolic function parameters, as assessed by 2D echocardiogram and MRI. The mean pre-chemotherapy LVEF was >60% in all studies. Our pooled analysis demonstrated significantly higher LVEF postchemotherapy in the beta blocker group in comparison to placebo: mean difference -3.84 with 95% confidence interval [-(6.19 to 1.48) p=0.001]. The absolute change in EF also favored beta blockers: mean difference -3.66 with 95% confidence interval [-(6.20 to 1.12) p=0.005]. Diastolic function, global longitudinal strain, and LVEDD were also preserved by beta blockers, but only LVEDD reached statistical significance. In conclusion, this study suggests that beta blockers during anthracycline chemotherapy may prevent cardiotoxicity by preserving LV function.
Shah, P., Garris, R., Abboud, R., Vasudev, R., Patel, H., Doshi, R., Shamoon, F., & Bikkina, M. (2019). Meta-Analysis Comparing Usefulness of Beta Blockers to Preserve Left Ventricular Function During Anthracycline Therapy. The American Journal of Cardiology, 124 (5), 789-794. https://doi.org/10.1016/j.amjcard.2019.05.046