The prevalence of cardiac dysfunction among breast cancer survivors: a systematic review and meta-analysis

PURPOSE: Breast cancer treatment, commonly involving chemo- and/or radiotherapy, is associated with adverse cardiac effects, including cardiac dysfunction. While most research focuses on adverse effects during treatment, breast cancer survivors may also be at risk of developing cardiac dysfunction ≥ 5 years post-treatment. This study aimed to assess the prevalence of cardiac dysfunction in long-term female breast cancer survivors. METHODS: CINAHL, Embase, and MEDLINE were systematically searched for articles that included breast cancer survivors treated with chemo- and/or radiotherapy and measured left ventricular ejection fraction (LVEF) ≥ 5 years post-diagnosis. The pooled prevalence of cardiac dysfunction, defined as LVEF ≤ 54% or a decline in LVEF of > 10% compared to baseline, was calculated and presented in a forest plot. Subgroup analyses based on treatment modality were performed, along with additional explorative forest plots to explore heterogeneity. RESULTS: Twenty-three studies encompassing 7309 patients were included with a median follow-up time since diagnosis of 5-30 years; Four studies included patients all treated with radiotherapy, of which two studies with radiotherapy as monotherapy and twenty studies included patients all treated with chemotherapy in combination with other therapies. Prevalence of cardiac dysfunction varied from 0% to 30%,. The pooled prevalence was estimated to be 10.8%, with significant heterogeneity (I² = 92.4%). Visual exploration of stratified analysis did not indicate explanations for this heterogeneity. CONCLUSIONS: Prevalence of cardiac dysfunction appears to be higher among long-term breast cancer survivors compared to the general population. IMPLICATIONS FOR CANCER SURVIVORS: Long-term breast cancer survivors remain at risk of cardiac dysfunction years after treatment, supporting the integration of cardiovascular risk assessment into survivorship care.