Associations of age at diagnosis of breast cancer with incident myocardial infarction and heart failure: a prospective cohort study

Background The associations of age at diagnosis of breast cancer with incident myocardial infarction (MI) and heart failure (HF) remain unexamined. Addressing this problem could promote understanding of the cardiovascular impact of breast cancer. Methods Data were from the UK Biobank. Information on the diagnosis of breast cancer, MI, and HF were collected at baseline and follow-ups (median=12.8 years). The propensity score matching method and Cox proportional hazards models were employed. Results A total of 251 277 female participants (mean age: 56.8±8.0 years), of whom 16 241 had breast cancer, were included. Among participants with breast cancer, younger age at diagnosis (per 10-year decrease) was significantly associated with elevated risks of MI (HR=1.36, 95%CI: 1.19 to 1.56, P <0.001) and HF (HR=1.31, 95% CI: 1.18 to 1.46, P <0.001). After propensity score matching, breast cancer patients with younger diagnosis ages had significantly higher risks of MI and HF than healthy controls. Conclusion Younger age at diagnosis of breast cancer was associated with higher risks of incident MI and HF, underscoring the necessity to pay additional attention to the cardiovascular health of breast cancer patients diagnosed at younger ages to conduct timely interventions to attenuate the subsequent risks of incident cardiovascular diseases.