Evaluating the Utility of Baseline Cardiac Function Screening in Early-Stage Breast Cancer Treatment

Background: Cardiotoxicity can be a complication of anthracycline- or trastuzumab-based therapy for breast cancer patients. Screening echocardiograms (ECHOs) and radionuclide ventriculograms (RVGs) are often performed before administration of these agents to evaluate cardiac function. Limited evidence for the clinical utility of these screening tests is available.

Methods: Early-stage breast cancer patients diagnosed from 2006 to 2011 (n = 1,067) with baseline ECHOs/RVGs were identified in a single institution prospective registry. Medical record review was performed to obtain pre- and post-ECHO/RVG treatment plans, baseline ECHO/RVG results, cardiac risk factors, and cardiac events. Patients with cardiac history were excluded. ECHO/RVG abnormalities were defined as ejection fraction (EF) <55%, valvular disease, left ventricular hypertrophy, and diastolic dysfunction. Cardiac events were defined as heart failure, myocardial infarction, arrhythmia, valvular disease, or angina during or after chemotherapy.

Results: Among 600 eligible patients, abnormal ECHO/RVG results were observed in 13 (2.2%, 1.2%-3.7%), including 9 with baseline EF <55%. There were no detected changes in treatment plans, although more frequent cardiac monitoring was recommended for 2 patients. There were no significant differences in age, race, menopausal status, smoking history, alcohol use, body mass index, or medical comorbidities between patients with abnormal and normal results. In follow-up (mean, 4.0 years; range, 0-8.3), 15 patients developed cardiac events (none of whom had had abnormal baseline ECHOs/RVGs).

Conclusion: Baseline ECHO/RVG in patients without prior cardiac history rarely yields an abnormality that prompts change in planned anthracycline- and/or trastuzumab-based treatment. Moreover, few cardiac events developed in this screened population in follow-up.

Implications for practice: Baseline cardiac function screening with echocardiograms or radionuclide ventriculograms is frequently performed before administration of anthracycline- or trastuzumab-based chemotherapy in breast cancer patients due to the relatively low cost and risk to patients and the concern for potential cardiotoxicity. However, at a population level, these tests can take up time and can add up to significant costs for both patients and the health care system. This study finds that in patients with no history of cardiac disease, baseline cardiac function screening rarely identifies abnormalities that change treatment plans. Moreover, few cardiac events develop in an average of 4 years of follow-up, including none in patients with abnormal baseline cardiac function screening results. This suggests that baseline cardiac function screening may have limited utility in chemotherapy planning in young breast cancer patients with no history of cardiac disease.