Exercise training in heart failure with reduced ejection fraction and permanent atrial fibrillation: A randomized clinical trial.

BACKGROUND: Heart failure (HF) associated with atrial fibrillation increases patients' physical inactivity, worsening their clinical condition and mortality. Exercise training is safe and has clear benefits in HF. However, little is known about the effects of exercise training on patients with HF with reduced ejection fraction and permanent atrial fibrillation (HFAF). OBJECTIVE: The purpose of this study was to test the hypothesis that exercise training improves functional capacity, cardiac function, and quality of life in patients with HFAF. METHODS: This randomized clinical trial was conducted at the Heart Institute. Patients with HFAF, left ventricular ejection fraction ≤40%, and resting heart rate (HR) ≤80 beats/min were included in the study. Cardiopulmonary testing, echocardiography, nervous system, and quality of life assessment were performed before and after the 12-week protocol period. RESULTS: Twenty-six patients (mean age 58 ± 1 years) were randomized to exercise training (HFAF-trained group; n = 13) or no training (HFAF-untrained group; n = 13). At baseline, no differences between the groups were found. Exercise improved peak oxygen consumption, slope of ventilation per minute/carbon dioxide production, and quality of life. The HFAF-trained group had significantly decreased resting HR (from 73 ± 2 to 69 ± 2 beats/min; P = .02) and recovery HR (from 148 ± 11 to 128 ± 9 beats/min; P = .001). Concomitantly, left ventricular ejection fraction increased (from 31% ± 1% to 36% ± 0.9%; P = .01), left atrial dimension decreased (from 52 ± 1.2 to 47 ± 1 mm; P = .03), and left ventricular end-systolic volume and left ventricular end-diastolic volume deceased (from 69 ± 2 to 64 ± 1.8 mL/m2 and from 99 ± 2.1 to 91 ± 2 mL/m2, respectively; P < .05). No changes were observed in the HFAF-untrained group. CONCLUSION: Exercise training can improve exercise capacity, quality of life, and cardiac function in patients with HF with reduced ejection fraction and permanent atrial fibrillation.

Contemporary review of exercise in heart transplant recipients.

Heart transplantation (HTx) is a therapeutic option for a selected group of patients with end-stage heart failure. Although secondary prevention including exercise therapy is recommended in the management of patients following HTx, little information is available on their metabolic and physiological consequences in HTx. Therefore, we aimed to conduct a contemporary review the effectiveness of exercise therapy on functional capacity, cardiovascular health and health-related quality of life for adult HTx patients. We searched the database MEDLINE for articles published between January 2015 and October 2020 and were able to include 6 studies involving 202 patients. Larger improvements in exercise capacity were seen after high-intensity interval training and in patients with evidence of cardiac reinnervation. Clinically relevant reductions were observed for daytime and 24 h ambulatory blood pressure after exercise training and following a single bout of aerobic exercise. Finally, limited data suggest that quality of life is higher in HTx patients following high-intensity training. In summary, the available evidence shows the potential for exercise as a vital treatment in patients following HTx. Yet, the scant data calls for more well-designed and adequately powered studies to support its effectiveness and to unravel optimal exercise characteristics, which would allow for more effective and person-tailored exercise prescription.

Effects of the exercise training on skeletal muscle oxygen consumption in heart failure patients with reduced ejection fraction.

AIMS: Skeletal muscle dysfunction is a systemic consequence of heart failure (HF) that correlates with functional capacity. However, the impairment within the skeletal muscle is not well established. We investigated the effect of exercise training on peripheral muscular performance and oxygenation in HF patients. METHODS AND RESULTS: HF patients with ejection fraction ≤40% were randomized 2:1 to exercise training or control for 12 weeks. Muscle tissue oxygen was measured noninvasively by near-infrared spectroscopy (NIRS) during rest and a symptom-limited cardiopulmonary exercise test (CPET) before and after intervention. Measurements included skeletal muscle oxygenated hemoglobin concentration, deoxygenated hemoglobin concentration, total hemoglobin concentration, VO2 peak, VE/VCO2 slope, and heart rate. Muscle sympathetic nerve activity by microneurography, and muscle blood flow by plethysmography were also assessed at rest pre and post 12 weeks. Twenty-four participants (47.5 ± 7.4 years, 58% men, 75% no ischemic) were allocated to exercise training (ET, n = 16) or control (CG, n = 8). At baseline, no differences between groups were found. Exercise improved VO2 peak, slope VE/VCO2, and heart rate. After the intervention, significant improvements at rest were seen in the ET group in muscle sympathetic nerve activity and muscle blood flow. Concomitantly, a significant decreased in Oxy-Hb (from 29.4 ± 20.4 to 15.7 ± 9.0 µmol, p = 0.01), Deoxi-Hb (from 16.3 ± 8.2 to 12.2 ± 6.0 µmol, p = 0.003) and HbT (from 45.7 ± 27.6 to 27.7 ± 13.4 µmol, p = 0.008) was detected at peak exercise after training. No changes were observed in the control group. CONCLUSION: Exercise training improves skeletal muscle function and functional capacity in HF patients with reduced ejection fraction. This improvement was associated with increased oxygenation of the peripheral muscles, increased muscle blood flow, and decreased sympathetic nerve activity.

Hypotensive Effect of Heated Water-Based Exercise Persists After 12-Week Cessation of Training in Patients With Resistant Hypertension.

BACKGROUND: Heated water-based exercise (HEx) promotes a marked reduction of blood pressure (BP), but it is not entirely clear whether its effects on BP persist after cessation of HEx. METHODS: We analyzed the effects of cessation of HEx on 24-hour ambulatory BP monitoring (ABPM) in patients with resistant hypertension (RH). Thirty-two patients (aged 53 ± 6 years) with RH (4 to 6 antihypertensive drugs) were randomly assigned to HEx (n = 16) or control (n = 16) groups. Antihypertensive therapy remained unchanged during the protocol. The HEx group participated in 36 sessions (60 minutes) in a heated pool (32oC [89.6°F]) for 12 weeks (training), followed by 12 weeks of cessation of training. The control group was evaluated during the same period and instructed to maintain their habitual activities. RESULTS: HEx and control groups had similar BP levels at baseline. HEx training reduced the 24-hour systolic (-19.5 ± 4.6 vs 3.0 ± 0.7 mm Hg, P = 0.001) and diastolic BP (-11.1 ± 2.4 vs 2.06 ± 0.9 mm Hg, P = 0.001) at week 12, compared with the control group. After 12 weeks of training cessation (week 24), 24-hour BP remained significantly lower in the HEx group than in the control group (-9.6 ± 3.8 vs 6.3 ± 3.5 mm Hg, P = 0.01 and -7.5±2.2 vs 2.2 ± 1.0 mm Hg, P = 0.009, for systolic and diastolic BP, respectively), although these differences were attenuated. CONCLUSIONS: BP remained lower after cessation of 12-week training among patients with RH who underwent HEx compared with the controls. The carryover effects of HEx on BP may help to overcome the challenging problem of exercise compliance in long-term follow-up.

Postexercise Hypotension after Heart Transplant: Water- versus Land-Based Exercise.

PURPOSE: Heart transplant recipients (HTx) have a high prevalence of hypertension. Although exercise training promotes blood pressure (BP) reduction in HTx, the effects of a single exercise bout are unknown. Thus, we analyzed the acute effects of heated water-based exercise (HEx) versus land-based exercise (LEx) on ambulatory BP (ABP) in HTx. METHODS: Eighteen (six females) clinically stable HTx (time since surgery = 5.0 ± 0.7 yr) age 45.7 ± 2.7 yr underwent 30 min of HEx (walking inside the pool), LEx (walking on a treadmill), and nonexercise control (CON) intervention in random order (2-5 d between interventions). HEx and LEx intensity was set at 11-13 in the 6-20 RPE scale. Twenty-four-hour (24-h) ABP monitoring was performed after each intervention. RESULTS: No significant differences between interventions were found in 24-h and nighttime BP. However, daytime diastolic BP was significantly lower after HEx than CON (-4 ± 1.6 mm Hg, P = 0.03), and daytime diastolic BP tended to be lower after LEx than CON (-2.3 ± 1.1 mm Hg, P = 0.052). Hourly analysis showed that systolic and diastolic BP values were lower after HEx (average reductions of 6.6 to 12.3 mm Hg, P < 0.01) and LEx (average reductions of 5 to 8.3 mm Hg, P < 0.05) than after CON in several hours. No significant differences between HEx and LEx were found in any ABP data. CONCLUSION: HEx and LEx promoted similar reductions in ABP of heart transplant recipients, which suggests that they may be a tool to counteract hypertension in this high-risk population.

Prescribing and Regulating Exercise with RPE after Heart Transplant: A Pilot Study.

PURPOSE: The objective of this study is to analyze the use of the 6-20 RPE scale for prescribing and self-regulating heated water-based exercise (HEx) and land-based exercise (LEx) in heart transplant recipients. METHODS: Fifteen (five females) clinically stable heart transplant recipients (time since surgery = 4.0 ± 2.5 yr) age 46.7 ± 11.8 yr underwent a symptom-limited maximal graded exercise test on a treadmill to determine their HR at anaerobic threshold (HRAT), respiratory compensation point (HRRCP), and maximal effort (HRmax). After a week, patients were randomized to perform 30 min of both HEx (walking inside the pool) and LEx (treadmill walking) sessions at a pace between 11 and 13 on the 6-20 RPE scale and had their HR measured every 4 min. The interval between sessions was 48-72 h. RESULTS: No significant differences between sessions were found in the average HR during HEx and LEx. Patients showed a delay in HR increase during both interventions, with the stabilization beginning after 8 min of exercise. Exercise HR was maintained between the HRAT and HRRCP (in the aerobic exercise training zone) for the most part of both HEx (72% of HR measurements) and LEx (66% of HR measurements). Only a few HR measurements stayed below HRAT (HEx = 9%, LEx = 13%) or above HRRCP (HEx = 19%, LEx = 21%) during both exercise sessions. CONCLUSION: Exercise HR was maintained in the aerobic exercise training zone (between HRAT and HRRCP) for the most part of both sessions, suggesting that the 6-20 RPE scale may be an efficient tool for prescribing and self-regulating HEx and LEx in heart transplant recipients.

Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients.

BACKGROUND: Hypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients. METHODS: 40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX). RESULTS: The ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p < 0.01) and daytime (4.8 ± 1.6 mm Hg, p < 0.01) systolic ABP, and 24-hour (7.0 ± 1.4 mm Hg, p < 0.001) daytime (7.5 ± 1.6 mm Hg, p < 0.001) and nighttime (5.9 ± 1.5 mm Hg, p < 0.001) diastolic ABP after the intervention. The ET group also had improved Vo2MAX (9.7% ± 2.6%, p < 0.001) after the intervention. However, PWV did not change after ET. No variable was changed in the control group after the intervention. CONCLUSIONS: The 12-week ET program was effective for reducing ABP but not PWV in heart transplant recipients. This result suggests that endurance ET may be a tool to counteract hypertension in this high-risk population.