Risk factors associated with cardiac events among breast cancer survivors at a Saudi tertiary cancer center: a retrospective cohort study.

Background: Cardiac disease and cancer are leading global causes of death. The prevalence of breast cancer (BC) is rising, and although advances in therapy have significantly improved BC survival, some treatments increase the risk of long-term cardiac events. In this retrospective study, we assessed the prevalence of cardiac events and risk factors in patients with BC. Methods: The study included all adult women diagnosed with BC from 2008 to 2020 at King Abdulaziz University Hospital. Patient data were collected in an Excel worksheet and analyzed with SPSS 25.0. Results: Our study included 676 patients with BC, with 57.34% were aged 41-60 years, and 38.1% were obese. Mastectomy was performed in 58.28% of cases. Cardiac events occurred in 6.07% of patients, with a higher incidence in those aged >80 years (P=0.04). Significant associations were found between cardiac events and diabetes, ischemic heart disease (IHD), heart failure, peripheral vascular disease, and dyslipidemia (P<0.001). Furthermore, a significant association was found between cardiac events and the mortality of patients with BC (P<0.001). Although no significant association was found between radiotherapy and cardiac events (P=0.64), they were significantly associated with adjuvant chemotherapy (P=0.01) and the anti-human epidermal growth factor receptor 2 (HER2) drug trastuzumab (P=0.03). Conclusions: Cardiac events in BC patient are associated with higher mortality and found more prevalent in patient receiving anti-HER2 treatments and chemotherapy. Larger randomized controlled trials are needed to further identify patients at high risk and guide prevention strategies.