Keeping breast cancer survivors exercising with the “movement and health beyond care” (MOVIS) clinical trial in the age of COVID-19: Amelioration of heart rate variability and cardiorespiratory fitness

ABSTRACT

Background: MoviS 'Movement and health beyond care' is an ongoing randomized controlled trial aiming to educate breast cancer (BC) survivors on the benefits of exercise and proper nutrition habits. Methods: The study included thirty women (17.4% of the total planned cohort of 172 patients) with stage 0-III non-metastatic BC (age 53.5±7.6 yrs;BMI 25.3±4.9 kg/ m2) randomly allocated to the Intervention Arm (IA;supervised exercise training “MoviS Training”) or control arm. The MoviS Training consists of 12 weeks of aerobic exercise (2 d/week of supervised and 1 d/week of unsupervised exercise) which intensity and duration gradually increased from 40 to 70% of heart rate reserve and from 20 to 60min, respectively. Both arms received nutritional and lifestyle counselling based on WCRF 2018 guidelines through the DIANA-Web platform and motivational interviewing. As the planned protocol was changed due to nationwide lockdown to contain the spread of COVID-19, IA performed home-based exercise sessions, which were remotely supervised using heart rate monitors. Heart rate variability (HRV;by 24-Holter monitoring), cardiac function indexes (by echocardiography with speckle tracking imaging), and cardiorespiratory fitness (by estimated maximal oxygen uptake [VO2max]) were evaluated at baseline and after the intervention period. Results: There were no adverse events during training. Baseline evaluation revealed no systolic disfunction (mean LVEF 60.4±4.5%) and a mild reduction (values 3 -18%) in global longitudinal strain in 26% of patients. HRV improved in both time and frequency domains ASDNN/5min (50.6±14.4 to 55.2±16.7 msec, p=0.033);very low frequency (VLF) (1597±967 to 1881±963 msec, p=0.04);low frequency (LF) (613±404 to 731±542 msec, p=0.004);total power (2627±1393 to 3034±1669 msec, p=0.034). HRV parameters tended to improve to a greater extent in IA group (Coefficient of Variation ASDNN/5min 13.7% vs 4.6%, LF 27% vs 10%, total power 26.5% vs 5.1%). Cardiorespiratory fitness level increased significantly in both groups (VO2max from 30.7±5.7 to 33.9±6.6mL/kg/min, p<0.001). Conclusion: During COVID-19 lockdown, short-term remotely supervised exercise training and recommendations on a healthy lifestyle lead to a significant improvement in HRV parameters and cardiorespiratory fitness in BC survivors.