ABC | Volume 114, Nº5, May 2020

Arq Bras Cardiol. 2020; 114(5):943-987 Guidelines Brazilian Cardiovascular Rehabilitation Guideline – 2020 Resistance training also appears to have a major therapeutic effect on bone metabolism. After HTx, patients commonly experience significant bone loss at femur head andmineral total bone loss. In one study, patients were enrolled for resistance training 2 months after HTx, and training was shown to be able to restore bone mineral density to pre-transplant levels. 236 6.5.2. Pre-Exercise Evaluation and Unique Features HTx recipients must undergo a thorough history, physical examination, 12-lead resting ECG, color Doppler echocardiogram, and other tests at the discretion of the CVR team. Ideally, a functional stress test should be performed, preferably CPET, which is the gold-standard method for assessing functional capacity in this patient population. The stress test must be performed by a trained physician; it evaluate the cardiopulmonary and metabolic responses to increasing exercise and yields several variables that have an impact on the clinical examination and the exercise prescription. 246 The physical therapist and/or physical educator will prescribe, administer, supervise, and guide exercise, following the safety limits recommended by the physician on the basis of the pre-exercise evaluation. 6,247 The impossibility of performing CPET should not be considered an impediment to exercises; if CPET is not available, a TMET is suggested. 170 When even this is unavailable or otherwise impossible, the 6-minute walk test can assist in clinical assessment, in addition to providing a parameter for comparing functional capacity during training. 248,249 6.5.3. Exercise Prescription Aerobic exercise is most recommended, with supplemental resistance training, starting on the 6th week after HTx. Different training methodologies have been studied in isolation and have proven effective in promoting cardiovascular health in individuals undergoing CVR. 6,170 In patients who have undergone HTx, most studies evaluated the effect of MICT. Depending on the patient’s clinical condition, the intensity of aerobic exercise may be gradually increased from moderate to high over the course of training, in order to optimize adaptation and obtain greater benefit, as exercise intensity is directly associated with the magnitude of cardiovascular adaptations. 250 In this sense, programs that include interval training (even HIIT) have demonstrated good outcomes. 233 However, an optimized and safe exercise prescription requires proper individualization of each component of the training session. 170 The determination of target training zones is advised as a means of optimizing the exercise prescription. 170 However, as recent HTx recipients will exhibit a compromised chronotropic response, 251 prescriptions based on percent of peak HR or threshold HR will not be useful during the first training sessions, although they may be used once there has been improvement in autonomic response. 224 Continuous assessment of the HR response to exercise and during recovery is thus extremely important. When CPET is available, the prescription of aerobic exercise can be based on the ventilatory thresholds or on established percentages of VO 2 peak. Another simple and feasible strategy is assessment of subjective perceived exertion using the Borg scale. 4,170,252 The multidisciplinary team must be firmly committed to educating the patient regarding the various levels of perceived exertion and the symptoms of which they should be aware. 4,6 In addition to the evaluation and prescription of aerobic exercises, resistance exercises are essential. The methods traditionally used for pre-exercise assessment and exercise prescription are 1RM load tests. However, the use of these protocols after HTx – especially after a recent procedure – may be inappropriate, and clinical investigations on the safety of these tests in this specific patient population are still lacking. An alternative evaluation method is the 30-second sit-to-stand test. 253 This test has been validated in active older adults and proved to be reasonably reliable in providing information about lower limb strength, and is now widely used in rehabilitation centers and scientific research on a wide range of clinical conditions. 254-256 Resistance exercises may also be prescribed subjectively, on the basis of perceived exertion alone. The variable repetition method may be used, whereby the aim of the user is not a set number but a range of repetitions (e.g., 10 to 15 repetitions). If the patient is unable to perform at the lower end of the range, the applied load is too high; if the patient can execute the maximum number of repetitions with ease, the load is too light. Thus, the load can be adjusted so that training takes place within the proposed range of repetitions. During training, particular attention should be paid to any complications or intercurrent events, such as infections related to the transplant procedure. A. survey found that 36% of HTx recipients are hospitalized within the first year after transplantation, and 61% at 4 years. 257,258 This clearly demonstrates the importance of patient supervision throughout training, should any intercurrent event arise that warrants discontinuation of the exercise session. In view of the foregoing, some authors suggest that patients should not perform physical exercise when receiving pulse steroid therapy and on the days of myocardial biopsies. 170 6.5.4. Home-Based Cardiovascular Rehabilitation Previous studies have shown that HBCR programs are safe and effective, 1 and are recommended as an alternative to traditional CVR in low-risk patients. 71 Wu et al. 259 conducted a prospective, randomized study to evaluate the effect of a home exercise program for 2 months in 37 patients after HTx. The control group maintained their usual lifestyle throughout the study period. Individuals in the intervention group performed an exercise program at least three times a week which included a 5-min warm-up, upper limb and lower limb strength training, 15 to 20 min of aerobic exercise at an intensity of 60 to 70% of VO 2 peak, and a 5-min cooldown period. To ensure proper exercise performance at home, an initial period of direct supervision was enforced. At the end of the 2-month period, patients had improved muscle strength and endurance, fatigue index, and quality of life (physical domain). CPET revealed an increase in workload, but with no change in VO 2 peak, probably due to the short follow-up period or the less-intense methodology used to guide the training prescription. 963