Thavendiranathan P, et al. - Prechemotherapy cardiac imaging practices were assessed relative to patients’ heart failure (HF) risk. Findings suggested that chemotherapy regimen, rather than HF risk, drive baseline cardiac imaging. Among patients receiving chemotherapy for breast cancer, this risk-imaging mismatch is an impetus to reconsider current cardiac imaging practices.

Methods

• A population-based retrospective cohort study of women receiving chemotherapy for early-stage breast cancer in Ontario was performed between 2007 and 2012.
• Baseline cardiac imaging was surveyed 6 months before chemotherapy or within 30 days thereafter.
• Researchers assessed the proportion of patients who underwent imaging and cumulative incidence of major adverse cardiac event (MACE) rates based on chemotherapy regimen and HF risk factors.
• Predictors of pretreatment cardiac imaging were assessed using logistic regression.

Results

• This cohort study included 18,444 women receiving chemotherapy (median age, 55 years).
• Nearly all women treated with trastuzumab-containing regimens underwent imaging, including those with no additional HF risk factors.
• Imaging was performed more frequently among women who received anthracyclines without trastuzumab if they had additional HF risk factors (73.3% vs 62.6%; P < .001).
• Patients with HF risk factors demonstrated two to six times higher 5-year incidence of MACE across all treatment regimens.
• A higher 5-year incidence of MACE (4.5%) was noted among patients with HF risk factors who received anthracyclines without trastuzumab than among patients without HF risk factors who received trastuzumab without anthracyclines (2.6%); the former group, however, underwent cardiac imaging less frequently (73.3% vs 93.6%; P < .001).
• As per logistic regression, most variation in baseline imaging was noted to be associated with chemotherapy, followed by physician-level factors.
• With female physicians, the odds of imaging were doubled.
• Variation in imaging was minimally driven by patient-specific factors, including HF risk factors.