6.10.3. Impact of the COVID-19 on Cardiac Rehabilitation Services

The recent COVID-19 pandemic created many barriers to the implementation of center-based cardiac rehabilitation programs. Consequently, cardiac rehabilitation programs have been affected for extended periods, leading to poor patient outcomes [94].

Some cardiac rehabilitation centers remained partially operational, whereas, in other centers, staff developed remote exercise training. Over half of centers were forced to halt operations completely, with staff being redeployed. A study by Pires objectively compared physical activity and sedentary time during the COVID-19 pandemic with those in the previous two years in cardiac patients attending center-based cardiac rehabilitation and after the suspension of programs due to COVID-19, with patients continuing onto a home-based digital program. The conclusions drawn were that most patients showed significant decreases in their average daily time of moderate to vigorous training when compared with the period before COVID-19. Nevertheless, after training resumption, these patients regained cardiovascular fitness and were able to meet the recommendations for moderate to vigorous training [95]. On the other hand, COVID-19 emphasized the importance of home-based and remotely controlled cardiac rehabilitation programs. Cardiac telerehabilitation utilizing advanced technology for both monitoring and communicating with the cardiac population became an innovative alternative, helping to overcome some of the barriers preventing participation in programs, considering that remote technology delivers sufficient training information—i.e., in terms of intensity; time; distance—and allows patients' heart rate, blood pressure, and electrocardiograms to be recorded, enabling an optimal, individualized, and safe exercise prescription [96].

## 6.10.4. Exercise following the COVID-19

Due to the short time since the outbreak of COVID-19, there is still a lack of evidence about the effect of rehabilitation based on exercise training in COVID-19 survivors. It has been documented that appropriately prescribed physical exercise reduces inflammatory status; thus, in-hospital physiotherapy interventions should modulate the inflammatory status initiated by the virus and intervene in endothelial dysfunction [97,98]. The following conclusions can be drawn from the accumulation of clinical experience of COVID-19 in Chinese studies [99]:

### Acute phase

Physiotherapy interventions should be based on the patient's condition. Early respiratory rehabilitation in severely and critically ill patients should be postponed if the patient's condition remains unstable or progressively deteriorates. Bed and bedside activities for severely and critically ill patients include positioning, early mobilization, and respiratory physiotherapy (airway clearance techniques). Exercise regimens for mildly and moderately ill patients include light exercises <3.0 METs, performed twice a day, with duration based on the patient's physical status and lasting between 15 and 45 min. The oxygen saturation, heart rate, blood pressure, and rating of perceived exertion should be constantly monitored during physiotherapy interventions. Oxygen saturation should remain above 92–93%; heart rate should not increase above more than 20 beats per minute from the baseline; systolic blood pressure should be between ≥90 mmHg and ≤180 mmHg, and the rating of perceived exertion should not exceed a score of 11–12 during exercise.

Contraindications for physiotherapy entail [100]:


### Post-acute phase:

A statement by Davies et al. delivers valuable recommendations for rehabilitation after the acute phase of COVID-19. A period of rest is recommended post infection, depending on the severity of disease and the left ventricular function, in order to minimize the risk of post infection cardiac failure. Patients with symptoms such as severe sore throat, muscle pain, shortness of breath, general fatigue, chest pain, cough, and fever should avoid exercises > 3 METs for 2–3 weeks after the cessation of these symptoms [101]. Post-discharge hospital-based cardiac rehabilitation consists of progressive aerobic exercises so that patients can gradually recover their level of activity before the onset of disease. Prior to exercise training, an initial assessment should be performed, including the six-minute walking test, strength assessment, and the identification of existing deficits in the basic activities of daily living. Interval training with an initial intensity of 2–3 MET, 3 to 5 times a week, is recommended. In addition, resistance training at moderate intensity should be implemented. Generally accepted exercise training exclusion criteria are a heart rate of >100 beats/min, blood pressure of <90/60 or >140/90 mmHg, and oxygen saturation of < 95% [102]. An influential account of the beneficial effects of exercise training for COVID-19 patients comes from Hermann et al. In

their study, patients (mean age 66 years, average duration of stay 19.3 days before referral) participated in a 2–4-week inpatient cardiac rehabilitation program, with protocols adapted to the severity of the disease. The program typically included 25–30 therapy sessions, performed 5–6 days per week. It entailed individualized aerobic and strength training, with intensity derived from an initial six-minute walk test [103]. The aerobic program consisted of supervised walking or stationary cycling, with a pulse oximeter used for monitoring during the exercise. In addition, strength training and respiratory physiotherapy were performed. After completing exercise sessions, significant improvements in the six-minute walk test of 130 m were observed. Further studies are required to optimize exercise parameters and establish a consensus regarding the use of cardiopulmonary programs for this emerging group of patients.
