Prevalence of cardiac dysfunction and longitudinal changes in cardiac function after breast cancer treatment with chemotherapy with/without radiation therapy compared with controls.

[INTRODUCTION] Breast cancer survivors are known to have a higher prevalence of mild systolic cardiac dysfunction compared to the general population, due to the effects of chemotherapy with/without radiation therapy. However, the long-term prevalence of cardiac dysfunction and changes in (dys)function over time, remain unclear.

[MATERIALS AND METHODS] We added a follow-up measurement to a matched-cohort study. Women were recruited from general practices, and echocardiographic data and medical records from general practices were collected for analysis. The primary outcome was the prevalence of mild left ventricular systolic dysfunction, defined as a left ventricular ejection fraction (LVEF) <54%. Secondary outcomes were diastolic dysfunction, right ventricular dysfunction and longitudinal changes of LVEF over time.

[RESULTS] Of the 700 women enrolled in the initial study (T1), 336 (48%) were included in the follow-up (T2). At T2, the median age was 70 years (IQR 65-75) for breast cancer survivors, with a median follow-up time of 19 years (IQR 17-22) after diagnosis. The prevalence of mild left ventricular systolic dysfunction was 10.4% among breast cancer survivors, versus 3.5% of controls (OR 3.1, 95% CI 1.2-8.1). Mixed-effects modeling showed that LVEF slightly improved over time across groups, without interactions between timepoint and group.

[CONCLUSION AND DISCUSSION] Long-term breast cancer survivors who received chemotherapy with/without radiation therapy are at increased risk of mild left ventricular systolic dysfunction compared to controls. Despite this elevated risk, left ventricular function slightly improved for all women over time and remained clinically irrelevant.