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

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: 53.567.6 yrs; BMI: 25.364.9 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 60 min, respectively. Both arms received nutritional and lifestyle counsel- ling based on WCRF 2018 guidelines through the DIANA–Web platform and motiva- tional interviewing. As the planned protocol was changed due to nationwide lock- down to contain the spread of COVID–19, IA performed home–based exercise sessions, which were remotely supervised using heart rate monitors. Heart rate vari- ability (HRV; by 24–Holter monitoring), cardiac function indexes (by echocardiogra- phy with speckle tracking imaging), and cardiorespiratory fitness (by estimated maxi- mal 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 60.464.5%) and a mild reduction (values 3 –18%) in global longitudinal strain in 26% of patients. HRV improved in both time and fre- quency domains: ASDNN/5min (50.6614.4 to 55.2616.7 msec, p¼ 0.033); very low frequency (VLF) (15976967 to 18816963 msec, p¼ 0.04); low frequency (LF) (6136404 to 7316542 msec, p¼ 0.004); total power (262761393 to 303461669 msec, p¼ 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 30.765.7 to 33.966.6 mL/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 improve- ment in HRV parameters and cardiorespiratory fitness in BC survivors.