Cardiovascular Disease in Patients With Breast Cancer Treated in the Modern Era

Abstract

With improving cancer survivorship, cardiovascular disease (CVD) has become a leading cause of death in breast cancer (BC) survivors. At present, there is no prospectively validated, contemporary risk assessment tool specific to this patient cohort. Accordingly, we sought to investigate long-term cardiovascular outcomes in early-stage BC patients utilising a well characterised database at a quaternary referral centre. With the assembly of this cohort, we have derived a BC cardiovascular risk index titled the 'CRIB (Cardiovascular Risk Index in Breast Cancer)' to estimate the risk of a major adverse cardiovascular event (MACE) in women undergoing treatment for BC. A retrospective cohort study was conducted examining all female patients aged ≥18 years of age who underwent treatment for early-stage BC at a cancer centre in Melbourne, Australia, between 2009 and 2019. The primary aim of this study was to assess causes and predictors of MACE. A total of 1,173 women with early-stage BC were included. During a median follow-up of 4.4 (1.8-6.7) years, 80 (6.8%) women experienced a MACE. These women were more likely to be older, with a high burden of cardiovascular risk factors and were more likely to have a history of established coronary artery disease (CAD) (p≤0.001 for all). A CRIB ≥3 (2 points: renal impairment, 1 point: age ≥65 years, body mass index [BMI]>27, diabetes, hypertension, history of smoking) demonstrated moderate discrimination (c-statistic 0.75) with appropriate calibration. A CRIB ≥3, which represented 23.9% of our cohort, was associated with a high risk of MACE (odds ratio [OR] 17.85, 95% confidence interval [CI] 6.36-50.05; p<0.001). A total of 138 (11.8%) women died during the study period. Mortality was significantly higher in patients who experienced a MACE (HR 2.72, 95%CI 1.75-4.23; p<0.001). Cardiovascular risk stratification at the time of BC diagnosis using the novel CRIB may help guide surveillance and the use of cardioprotective therapies as well as identify those who require long-term cardiac follow-up.