Cardiology Involvement in Patients With Breast Cancer Treated With Trastuzumab

Abstract Background There is limited evidence regarding the impact of cardiology involvement in the care of cancer patients. Objectives This study evaluated the impact of cardiology involvement on guideline-adherent cardiovascular monitoring and risk factor management in patients with breast cancer treated with trastuzumab. Methods In a single-center retrospective cohort study, electronic health records from 1,047 patients with breast cancer receiving trastuzumab between January 2009 and July 2018 were evaluated. A visit to a cardiology provider beginning from the 3 months before cancer therapy initiation until the last contact date defined cardiology involvement. Guideline-adherent monitoring, defined by echocardiography assessment within the 4 months before trastuzumab initiation and follow-up echocardiography at least every 4 months during therapy, was compared in patients with and without cardiology involvement before treatment initiation. Multivariable associations between cardiology involvement and the time-varying risk factors blood pressure and body mass index (BMI) were assessed by using generalized estimating equations. Results Cardiology involvement occurred in 293 (28%) patients. A higher proportion of patients with cardiology involvement before trastuzumab initiation had guideline-adherent monitoring (76.4% vs. 60.1%; p = 0.007). Cardiology involvement was associated with an average 1.5 mm Hg (95% CI: –2.9 to –0.1; p = 0.035) lower systolic blood pressure, which was more pronounced in those with hypertension (–2.7 mm Hg; 95% CI: –4.6 to –0.7; p = 0.007). Cardiology involvement was associated with a lower BMI in patients with baseline BMI ≥25 kg/m2 (mean difference: –0.5 kg/m2; 95% CI: –1.0 to –0.1; p = 0.027). Conclusions Cardiology involvement in patients with breast cancer treated with trastuzumab is associated with greater adherence to cardiovascular monitoring and modest improvements in risk factor control.