Physical Activity During Breast Cancer Therapy Associates With Preserved Exercise Capacity and Cardiac Function (WF97415)

BACKGROUND Cancer treatment increases cardiovascular disease risk, but physical activity (PA) may prevent cardiovascular disease.OBJECTIVES This study examined whether greater PA was associated with better submaximal exercise capacity and cardiac function during cancer therapy.METHODS Participants included 223 women with stage I to III breast cancer (BC) before and 3 months after undergoing treatment and 126 control participants. Leisure-time PA (LTPA) was reported using the Godin-Shephard LTPA questionnaire. Cardiac function was assessed by cardiac magnetic resonance. Submaximal exercise capacity was determined by 6-minute walk distance.RESULTS BC participants reported similar baseline LTPA scores (24.7; 95% CI: 21.7-28.0) as control participants (29.4; 95% CI: 25.0-34.2). The BC group declined to 16.9 (95% CI: 14.4-19.6) at 3 months relative to 30.8 (95% CI: 26.2-35.8) in control participants. Among BC participants, more LTPA was related to better exercise capacity (b +/- SE: 7.1 +/- 1.6; 95% CI: 4.0-10.1) and left ventricular (LV) circumferential strain (-0.16 +/- 0.07; 95% CI:-0.29 to-0.02). Increased LTPA over the 3 months was associated with decreased likelihood of treatment-induced cardiac dysfunction according to LV circumferential strain classifications (OR: 0.98; 95% CI: 0.97-0.998). BC participants reporting insufficient LTPA according to PA guidelines exhibited deteriorations in exercise capacity (adjusted mean difference +/- SE:-29 +/- 10 m; P = 0.029), LV end-systolic volume (5.8 +/- 1.3 mL; P < 0.001), LV ejection fraction (-3.2% +/- 0.8%; P = 0.002), and LV circumferential strain (2.5% +/- 0.5%; P < 0.001), but BC participants meeting LTPA guidelines did not exhibit these adverse changes.CONCLUSIONS PA declined during BC therapy; however, PA participation was associated with attenuated declines in exercise capacity and cardiac function that are often observed in this population. (Understanding and Predicting Breast Cancer Events After Treatment [WF97415 UPBEAT]; NCT02791581) (J Am Coll Cardiol CardioOnc 2023;5:641-652) (c) 2023 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.