Abstract 16737: Cardiopulmonary Fitness and Cardiac Reserve 12-Months Following the Completion of Anthracycline-Based Chemotherapy With or Without Concurrent Exercise Training

Abstract

Introduction: Anthracycline chemotherapy (AC) has been associated with reductions in cardiac function that increases long-term risk of heart failure. We have previously shown that AC is associated with a reduction in cardiopulmonary fitness (VO 2 peak) that occurs alongside a subtle reduction in the heart’s contractile response to exercise. However the degree to which these changes recover following the completion of AC is unknown. Hypothesis. We sought to determine whether change in cardiopulmonary fitness (VO 2 peak) and cardiac function persisted at 12-months post-AC completion. Methods: 28 women with breast cancer who had self-selected to undergo 12-weeks of aerobic and resistance training twice per week during AC (ET; n=14) or usual care during AC (UC; n=14) were followed up at 12-months from AC completion. Prior to AC and at 12-months, participants completed a cardiopulmonary exercise test (VO 2 peak) and cardiac MRI with exercise to assess the stroke volume (SV), heart rate (HR) and cardiac output (CO) response to exercise (measured at rest, and during high-intensity supine cycling). Results: Seventeen women (UC: n=8; ET: n=9) have completed follow-up evaluation. AC was associated with reductions in fitness at 12-months in both the UC (22.4±6.8 to 19.1±6.9 ml/kg/min; 15%) and ET (28.5±6.0 to 26.5±5.4 ml/kg/min; 6%, P<0.01), and these declines were not attenuated by ET (interaction, P=0.42). Peak CO was reduce by 13% as compared with pre-AC values (14.0 ± 2.5L/min vs 12.2 ± 2.6 L/min, P<0.01). The reduction in CO was due to a 14% reduction in the SV response to exercise (98.3 ± 12.1 ml vs 84.6 ± 14.5 ml, P<0.01), whereas the HR response was similar (146 ± 16 bpm vs 151 ± 17bpm, P=0.70). No differences were found between resting CO and SV from pre-AC to 12-months (P=0.25 and P=0.27 respectively). Conclusion: Cardiopulmonary fitness reductions persisted 12-months following AC-based chemotherapy, which was not attenuated by exercise during AC. Reductions in fitness coincided with reductions in peak cardiac output during exercise.