Improvement in heart rate variability, cardiorespiratory fitness and quality of life in breast cancer survivors across the covid-19 pandemic: insight from the "movement and health beyond care" (MOVIS) clinical trial

Aims: breast cancer (BC) is the most common invasive cancer in women and evidence has shown that exercise can significantly improve the outcomes of BC survivors. MoviS: 'Movement and health beyond care' is an ongoing randomized controlled trial comparing the benefits of exercise and proper nutritional plan vs. usual care on quality of life (QoL) in BC survivors within the 12 month post‐surgery period. Methods and results: The study included the first group of the MOVIS trial with patients enrolled up to January the 30th 2020. Thirty women (17.4% of the total planned cohort of 172 women) with stage I‐III non‐metastatic BC recruited (age: 53.5±7.6; BMI: 25.3±4.9) were randomized in two groups: intervention arm (IA) underwent 3‐month aerobic training (3‐day/week) with increasing exercise intensity (40 to 70% heart rate reserve) and duration (20 to 60 min); control arm (CA) received usual care recommendations. As the planned protocol was changed due to the unexpected COVID‐19 pandemic, both groups were recommended to train at home, with a more frequent and strict follow‐up for the IA group. Cardiorespiratory fitness (by estimated maximal oxygen uptake (VO2max)), QoL (by EORTC QLQ‐C30 questionnaire), fatigue, cardiac function indexes (by echocardiography with speckle tracking imaging), and heart rate variability (HRV; by 24‐Holter monitoring) were evaluated at baseline and after 3 months. There were no adverse events during training. Baseline evaluation revealed no systolic disfunction (mean LVEF 60.4±4.5) and a mild reduction (values > ‐18%) in global longitudinal strain (GLS) in 26% of patients. Statistical analysis revealed a significant improvement in cardiorespiratory fitness level (VO2max from 30.7±5.7 to 33.9±6.6 mL/kg/min, coefficient of variation (CV) 10.3%; p=0.000). HRV improved in both time and frequency domains: average SDNN/5 min and VLF increased from 50.6±14.4 to 55.2±16.7 msec (p=0.033) and form 1597±967 to 1881±963 msec (p=0.04), respectively. Mean and resting heart rate decreased from 76.6±7.8 to 73.768.3 b.p.m. (p=0.009) and from 68±7.5 to 63.2±8 b.p.m. (p=0.001), respectively. QLQ scale score FOR QoL assessment increased even during the pandemic: in global health status (from 64.7±17 to 15.9±13 var 15.9; p=0.0015); physical functioning (from 54.4±12.3 to 62±6.6 CV 13.9%; p=0.0005); fatigue (from 26.3±23.4 to 11.9±14.3 CV ‐54.9%; p=0.0008), and showed a general improvement over time even on the social functioning (from 47.2±22.8 to 66.7±00 CV 41.2%; p=0.0001). There was no difference between the two groups probably due to small sample size (17.4% of the total planned cohort of 172 women). Conclusion: In BC survivors, short‐term remotely‐supervised exercise training and recommendations of a healthy life‐style lead to a significant improvement in HRV parameters, cardiorespiratory fitness, and QoL.