A prospective cohort study was conducted at the Cardiovascular Rehabilitation Center of the Cardiology Department of the North Lisbon University Hospital Center (CHULN), Faculty of Medicine of the University of Lisbon (FMUL) and Cardiovascular Rehabilitation Center of the University of Lisbon (CRECUL) a European Association of Preventive Cardiology-accredited Preventive Cardiology Center, in April 2020.

The primary aim was to assess the amount of physical activity after a three-month home-based multidisciplinary digital CR program. The secondary aim was the assessment of adherence to the program determined by the number of exercise training and educational sessions attended, dietary habits, subjective psychological impact, risk factor control, and occurrence of minor and major adverse events in general and during the exercise sessions.

The primary and secondary aims were assessed via an online questionnaire at baseline and at three months after starting the home-based CR program. The core components of the program are presented in Table 1. The study was carried out in accordance with the recommendations of the Declaration of Helsinki for human research.

Patients (men and women), independently of age, who had been participating at the CR center of the CHULN/FMUL/CRECUL were invited to participate in this study after the center-based CR program was forced to close due to COVID-19. Informed consent was obtained from all participants included in the study. Inclusion criteria were age over 18 years, with diagnosed CVD, clinically stable, and participation at the center-based CR program before COVID-19. Exclusion criteria were unstable cardiovascular or non-cardiovascular status, a medical condition that contraindicated exercise, or lack of access to the technology required to complete the online questionnaires.

At baseline (three weeks after suspension of the center-based CR program due to pandemic lockdown in April 2020) and at three months after starting the home-based CR program, patients completed an online questionnaire regarding cardiovascular and non-cardiovascular symptoms and signs, feelings towards the pandemic, pharmacological therapy, resting heart rate and blood pressure, blood glucose (if diabetic), body weight, height, physical activity, and diet.

The International Physical Activity Questionnaire-Short Form (IPAQ-SF), validated for the Portuguese language, was used to assess physical activity.8 The IPAQ-SF records the last seven-day recall for four intensity levels of physical activity: vigorous-intensity activity, moderate-intensity activity, walking and sitting.

Diet was assessed by asking about changes in eating patterns (including vegetables, meat, fish, fruit, beverages, water, etc.) before COVID-19 and at three-month follow-up, based on questions from a national study on eating habits and physical activity during the pandemic (REACT-COVID).9

The online exercise training sessions included in the home-based CR program consisted of recorded videos and real-time online exercise training sessions.

A recorded video of an exercise session was provided weekly on an online platform. Six exercise training sessions were recorded by exercise physiologists and physiotherapists. Participants were recommended to do each session three times a week, for 60 min (10 min warm-up, 40 min circuit training and 10 min cool-down), performing eight different exercises (two upper limbs, two lower limbs, two core stability, two balance). Each exercise had three levels of progression (easy, moderate, difficult) with two or three sets of 10-15 repetitions, and all exercises were done with body weight and/or household objects (e.g. books, bottles of water, packs of rice, etc.). The aim, using the Borg Rating of Perceived Exertion scale (6-20), was to reach moderate intensity, i.e. a score of 11-14.

The participants performed the exercise program in their own home, without simultaneous professional supervision. However, a pictorial exercise training guidebook was available to all participants, including instructions regarding safety, clothing and warm-up, and a detailed illustrated description of each home-based exercise session. Also, for questions or difficulties regarding the exercises, an e-mail address and telephone number were provided.

Once a month, real-time CR exercise sessions lasting 60 min were provided via computer, tablet or smartphone with internet access, at a specific time slot that allowed healthcare professionals to follow 6-8 patients per class at home, ensuring adherence and supporting them throughout the session.

A personal health diary was provided for documenting vital signs, adherence to the exercise training program (including online sessions, walking, cycling or other forms of physical activity), and adverse events. Serious adverse events were defined as symptoms that posed a threat to the participant's health and that led to study suspension for immediate medical treatment or consultation with a physician. Minor adverse events were categorized as meaningful events of moderate or minor clinical severity.

A structured online educational program was provided for patients and family members/caregivers including educational videos and webinars.

One recorded video of an educational session per week was uploaded to the platform, followed by a healthy cooking recipe and nutritional tips aimed at improving cardiovascular health. The educational sessions, lasting 10-15 min, were delivered by the corresponding health professional from the CR team. These sessions aimed to educate and inform patients and their family members or caregivers on behavioral and lifestyle changes. The educational sessions covered the following topics: COVID-19 and CVD; coronary artery disease and cardiovascular risk factors; heart failure; hypertension; dyslipidemia; smoking cessation; diabetes; medical therapy and adherence; healthy food and the Mediterranean diet; exercise and physical activity; sedentary behavior; and sexual dysfunction and CVD.

One real-time webinar on nutritional myths lasting 90 min was developed as a replacement for the regular face-to-face workshop provided at the center-based CR program that took place every three months.

Self-monitoring of blood pressure, heart rate and blood glucose (if diabetic) was promoted, as was smoking cessation.

The psychological group sessions included online support group sessions and relaxation sessions.

Monthly 60-min online face-to-face group support sessions, called ‘heart talks’, were provided, moderated by a psychiatrist, a cardiologist, and other members of the CR team.

The online relaxation sessions, lasting 45 min, were run by the psychologist of the CR team. These sessions were recorded and placed on the online platform to allow participants to re-watch and repeat them.

An online short-form follow-up questionnaire was completed in every two weeks. Patients who did not respond received a telephone call from the CR nurses emphasizing the need to complete it.

Physician appointments (teleconsultations) were scheduled according to the signs and symptoms presented in the follow-up questionnaire or if patients requested one (by e-mail or telephone) to avoid non-urgent hospital visits and hence unnecessary exposure to COVID-19.

Minor and major adverse events such as hospitalizations for cardiac or other reasons, cardiac death, or death from non-cardiac causes were collected.

Descriptive statistics including means, standard deviation and percentages were calculated for all main and secondary outcome variables. Chi-square tests were performed to assess differences in categorical variables between the different time points. Normality was tested using Q-Q plots.

A paired Student's t test was performed to compare changes in BMI and parameters of physical activity and sedentary behavior from baseline to three-month follow-up. The Wilcoxon signed-rank test was used if a normal distribution could not be assumed.

A subanalysis was performed of differences in age, gender and adherence between groups. Changes over time within each group and any interactions were assessed by two-way repeated measures analysis of variance.

Statistical significance was set at an alpha level of 0.05. Data analysis was performed using IBM SPSS Statistics version 25.0 (IBM SPSS Inc., Chicago, IL).

A favorable main effect of time was evident after three months for moderate to vigorous physical activity (p<0.001) (Table 3). At three-month follow-up, almost 70% of the patients met the WHO recommendations for physical activity and 41% of the sample population attained more than 300 min per week of moderate to vigorous physical activity.

When fulfilling the questionnaire, participants were asked to choose which type of physical activity they did most (they could choose more than one). Walking was the most frequent type of exercise at baseline (56.1%) and at three months (72.4%), followed by cycling at baseline (13.3%) and at three months (16.3%), jogging at baseline (8.2%) and at three months (10.2%), and other physical activities at baseline (21.4%) and at three months (22.4%).

A main effect of time was observed in sedentary time on weekdays and weekends after three months (p<0.001 on both weekdays and weekends). Eighty percent of the participants spent their sedentary time watching TV (80.4% at baseline and 71.3% at three months); the second most frequent sedentary activity was using computers, tablets or mobile phones (68% at baseline and 63.2% at three months), followed by teleworking (35.7% at baseline and 31.6% at three-month follow-up).

Similar results were seen for gender (female vs. male), age (<60 years vs. >60 years) and attendance of the online sessions (attended vs. did not attend).

Nearly half (46.9%) of the participants did at least one online exercise training session per week. Among those who did training sessions, 58% did two or three times per week, 27% once per week and 15% more than four times per week. The main reasons for participants doing less than one session per week were as follows: lack of motivation to train alone (37.8%); preference for a different mode of exercise training such as walking or jogging (26.2%); other reasons (19%); unable to open or follow the online videos (11%); reluctance to perform the online exercise training sessions without supervision (4.1%); and limited space at home to perform the exercise training session (4%).

Regarding the educational sessions, 49% of the participants attended at least one of the 13 online educational sessions, and the most attended webinar was on nutrition (22.4%). Only 6.1% of the participants made one of the healthy cooking recipes.

More than half of the participants (58.2%) stated that the CR home-based program helped them to keep a healthier lifestyle throughout the quarantine.

At baseline, 18.4% of the participants reported cardiovascular symptoms such as tiredness (6.2%), chest pain (6.1%), aching legs (3.1%) and/or dizziness (3.1%), and cardiovascular signs such as low blood pressure (2.1%). Regarding non-cardiovascular symptoms, 20.4% of the patients reported weight gain (6.1%), cough (3.1%), diarrhea (3.1%), weakness (3.1%), stomach pain (2%), unintentional weight loss (2%), fever (1%) and/or depression (1%).

At three months, 19.4% of the participants reported cardiovascular symptoms including tiredness (12.2%), chest pain (8.2%), shortness of breath (8.2%), aching legs (6.1%) and/or dizziness (5.1%). The only cardiovascular sign reported was low blood pressure (5.1%). Regarding non-cardiovascular symptoms, 21.4% reported weight gain (6.1%), weakness (3.1%), diarrhea (2.0%) and/or headache (2.0%).

All patients (n=28) with cardiovascular or non-cardiovascular symptoms were assessed by a physician in teleconsultations. Twenty-one patients had a consultation with the CR cardiologist, five with the CR psychologist and two with the CR nutritionist.

Regarding feelings toward the pandemic, at baseline 46.9% did not feel any mood changes, 19.4% felt anxious, 12.2% felt sad, 11.2% felt stressed and 10.2% had other feelings. The main reasons that more than half of the participants had these feelings were directly related to COVID-19 and the need to adapt to lockdown and/or teleworking. After three months, fewer patients felt sad (8.2%, p=0.007), and maintained anxiety (16.3%, p=0.077) and stress levels (5.1%, p=0.456).

Eighty-one patients (82.7%) had a blood pressure monitor at home to measure and record blood pressure and heart rate. When asked if they monitored their blood pressure and heart rate at least once per week, the answer was in the affirmative in 71 patients at baseline and in 83 patients after three months. After three months, systolic blood pressure decreased (117±14 vs. 114±12 mmHg, p=0.007) and diastolic blood pressure did not change significantly (71±9 vs. 70±9 mmHg, p=0.096). In our sample, 21 patients had type 2 diabetes and 16 (76%) measured their blood glucose at least once per day at baseline and 19 after three months.

There were no changes in BMI from baseline to three months (Table 3).

After subanalysis of differences between gender (female vs. male), age (<60 years vs. >60 years) and attendance of the online sessions (attended vs. did not attend), the results were similar.

After the three-month follow-up, some improvements were found. Patients increased their consumption of fish (14.0% vs. 23.3%, p=0.005) and water (20.9% vs. 47.7%, p=0.004) and decreased alcohol consumption (23.3% vs. 12.8%, p=0.003). Regarding salty snacks, a slight, but significant, increase was observed from 7% to 8% (p=0.006). No changes were found in the consumption of red meat, fruit, vegetables, sweets, fast foods, takeaways or beverages. More than half of the participants (54.1%) reported eating an average of three or four meals per day.