Preserved hemodynamics in breast cancer survivors not a function of cancer, but fitness
Authors: Sherman Sara , Grigoriadis Georgios , Lima Natalia , Hibner Brooks , Dubose Noah , Fernhall Bo , Baynard Tracy 
Published: May 2023

Introduction: One in eight U.S. women will develop breast cancer (BC), and cardiovascular disease is the second leading cause of death among survivors. Improving cardiorespiratory fitness (CRF) and increasing physical activity (PA) reduces risk of adverse cardiovascular events among the general population without BC. Specifically, improved heart rate recovery (HRR) and hemodynamic modulation established through greater PA are traditional methods of risk assessment for cardiovascular disease that may be beneficial for BC survivors. Purpose: The purpose of this study was to examine HRR and hemodynamic adjustments following a maximal test of CRF among active and inactive BC survivors compared to women without a BC diagnosis. Methods: Twenty-two BC survivors were separated into active (n=11, 48±9 yrs, 24.8±3 kg/m2, 373±172 min/wk) and inactive (n=11, 51±9 yrs, 26.1±3 kg/m2, 52±68 min/wk) groups and compared to 18 active women without BC (48±9 yrs, 25.3±5 kg/m2, 327±178 min/wk) based on the Paffenberger PA Questionnaire. Mean arterial pressure (MAP), cardiac output (CO), total peripheral resistance (TPR), and stroke volume (SV) were measured before and 5 minutes after after a cycle ergometry test of CRF (expressed as VO2peak) using an oscillometric device. Continuous heart rate was assessed using a three-lead ECG throughout and following the test to calculate the slow phase (Peak exercise [VO2peak] to 2-min post) of HRR. Results: Active BC survivors demonstrated similar HRR from peak exercise (-52±15 bpm) compared to active individuals without BC (-46±12 bpm), both of which were greater than the HRR observed in non-active BC survivors (-38±12 bpm; p for interaction=0.05). We found a significant relationship between CRF and HRR for the three groups (VO2peak, active BC survivors: 32.6±4 mL/kg·min-1; inactive BC survivors: 20.9±3 mL/kg·min-1; active controls: 29.5±6 mL/kg·min-1; r=0.38, p=0.01). Likewise, inactive BC survivors experienced a blunted change in SV following a maximal CRF test, compared to active BC survivors and control counterparts (%ΔSV [mL/min], active BC survivors: 32.7%; inactive BC survivors: 23.5%; active controls: 39.3%; p for interaction≤0.001). Active BC survivors (before: 1.32±0.1 mmHg/L·min-1, after: 1.13±0.2 mmHg/L·min-1) experienced a greater reduction in TPR following the maximal CRF test compared to their inactive BC survivors (before: 1.23±0.2 mmHg/L·min-1, after: 1.18±0.14 mmHg/L·min-1) and active individuals without BC (before: 1.20±0.2 mmHg/L·min-1, after: 1.16±0.12 mmHg/L·min-1; p for interaction=0.03). MAP was not different between the 3 groups ( p for interaction≥0.05). Conclusion: Physically active BC survivors exhibit preserved cardiac autonomic and hemodynamic control following maximal exercise, similar to active individuals without BC. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.