Randomized, controlled trial of long-term moderate exercise training in chronic heart failure: effects on functional capacity, quality of life, and clinical outcome

BACKGROUND: It is still a matter of debate whether exercise training (ET) is a beneficial treatment in chronic heart failure (CHF). METHODS AND RESULTS: To determine whether long-term moderate ET improves functional capacity and quality of life in patients with CHF and whether these effects translate into a favorable outcome, 110 patients with stable CHF were initially recruited, and 99 (59+/-14 years of age; 88 men and 11 women) were randomized into 2 groups. One group (group T, n=50) underwent ET at 60% of peak &f1;O2, initially 3 times a week for 8 weeks, then twice a week for 1 year. Another group (group NT, n=49) did not exercise. At baseline and at months 2 and 14, all patients underwent a cardiopulmonary exercise test, while 74 patients (37 in group T and 37 in group NT) with ischemic heart disease underwent myocardial scintigraphy. Quality of life was assessed by questionnaire. Ninety-four patients completed the protocol (48 in group T and 46 in group NT). Changes were observed only in patients in group T. Both peak &f1;O2 and thallium activity score improved at 2 months (18% and 24%, respectively; P<0. 001 for both) and did not change further after 1 year. Quality of life also improved and paralleled peak VO2. Exercise training was associated both with lower mortality (n=9 versus n=20 for those with training versus those without; relative risk (RR)=0.37; 95% CI, 0.17 to 0.84; P=0.01) and hospital readmission for heart failure (5 versus 14; RR=0.29; 95% CI, 0.11 to 0.88; P=0.02). Independent predictors of events were ventilatory threshold at baseline (beta-coefficient=0.378) and posttraining thallium activity score (beta-coefficient -0.165). CONCLUSIONS: Long-term moderate ET determines a sustained improvement in functional capacity and quality of life in patients with CHF. This benefit seems to translate into a favorable outcome.     

Beneficial effects of exercise training in heart failure patients with low cardiac output response to exercise – a comparison of two training models

BACKGROUND: Exercise capacity of patients with chronic heart failure (CHF) correlates poorly with estimates of cardiac function. Yet, it has been suggested that only patients without severely impaired cardiac output (CO) benefit from exercise training. Comparisons of different training models have not been made in the same study. AIMS: To evaluate whether the response to different training models diverges according to the cardiac output response to exercise in patients with chronic heart failure. METHODS: Sixteen CHF patients (63 +/- 11 years) with an ejection fraction of 30 +/- 11% underwent a baseline cardiopulmonary exercise test, right heart catheterization and leg muscle biopsy. Cardiac output (CO) response to exercise was defined as the ratio between CO increase and the increase in oxygen uptake (CO response index) during exercise. Patients were randomized into two training regimens, differing with regard to active muscle mass, i.e. whole body and one-legged exercise. RESULTS: Baseline exercise capacity expressed as W kg-1 correlated with the CO response index (r = 0.51, P < 0.05). Exercise capacity on the cycle ergometer increased in both groups but more in the one-legged than in the two-legged training group (P < 0.05). The improvement in exercise capacity did not correlate with base-line exercise capacity. It correlated with CO response index in the one-legged (r = 0.75, P < 0.01) but not in the two-legged training group. CO response index correlated negatively with the pulmonary capillary wedge pressure at peak exercise (r = - 0.60, P < 0.05). The increase in leg muscle citrate synthase activity after training correlated negatively with the baseline CO response index (r = - 0. 50, P < 0.05). CONCLUSIONS: The improvement of exercise capacity after one-legged training correlates with the CO increase in relation to the O2 uptake before training. In patients with low CO response, individualization of the exercise regimen is needed and the benefits of training a limited muscle mass at a time deserve further study.     

Pressure response to dynamic exercise and antihypertensive therapy

OBJECTIVES: To study the exercise systolic pressure (SP) in hypertensive patients, its relation with left ventricular (LV) mass and the efficacy of its control by some antihypertensive drugs. DESIGN: To study the echocardiogram (ECHO) and exercise test (ET) in hypertensives (HT), before and after rest blood pressure (BP) control. SETTING: Out-patient cardiology clinic in a military hospital. METHODS: 53 male moderate HT, 30 to 60 years old, without other pathology, were studied with ECHO and ET. 28 HT repeated ET after rest BP control: Group A--Diuretic (Hchlt/Triam), n: 7; Group B--Atenolol, n: 10; Group C--Nifedipine, n: 11. RESULTS: 1. There was a positive correlation between LV mass index and exercise SP (r: 0.37; p less than 0.01), but not rest blood pressure. 2. Exercise test duration was increased only in group C. 3. Hypertensives with rest BP control had also normal exercise SP in group B, but not in groups A or C (Qui2: 11 735; p less than 0.001). CONCLUSIONS: 1. Exercise systolic blood pressure seems to be more important than rest blood pressure to the development of LVH in hypertensive patients. 2. The observed increase of exercise capacity in Nifedipine group must be considered in the treatment of physically active hypertensives. 3. Hypertensives with rest BP controlled by Atenolol have also, very probably, a normal exercise systolic pressure. 4. In physically active HT with rest BP controlled by Diuretic or Nifedipine may be useful an exercise test to evaluate exercise systolic pressure.     

Response of the oxygen uptake efficiency slope to exercise training in patients with chronic heart failure

BACKGROUND: The oxygen uptake efficiency slope (OUES) is a new exercise parameter that provides prognostic power in patients with CHF. Little is known about the effects of exercise training (ET) on OUES. AIM: To describe the response of OUES to 6 months of ET in CHF patients and compare its evolution to that of other exercise variables. METHODS: 35 patients with CHF (NYHA II-III, age 54+/-9y, LVEF 31+/-10%) performed 3 maximal exercise tests, i.e. at the start, middle and end of a 6 month ET program. OUES, PeakVO(2), ventilatory anaerobic threshold (VAT) and slope VE/VCO(2) were determined. RESULTS: OUES, peakVO(2), VAT, slope VE/VCO(2), peak Watt, 6MWT and NYHA-class improved during the first part of the ET period (p<0.05). Only VAT, peak Watt and 6MWT continued to improve during the second part of the ET period (p<0.05) Improvements in OUES correlated better with improvements in peakVO(2) (r=0.77, p<0.001), than changes in other prognostic variables. DISCUSSION: OUES improves significantly after 6 months of ET. Changes in peakVO(2) correlate best with changes in OUES. OUES is sensitive to ET and can be used to evaluate the progression of exercise capacity in CHF patients.     

运动对心脏的保护作用及其机制的研究进展

运动训练有益心脏健康,可以改善心血管疾病患者的运动能力和生活质量,降低其致死率和致残率。尽管运动的益处显而易见,但是运动训练对于心脏疾病的保护机制尚不明确。本文重点综述了运动保护心脏的主要机制,以及运动对于心肌梗死、缺血再灌注损伤、病理性心肌肥厚、心脏衰老等心脏疾病的保护作用及最新研究进展,以期从"运动"这一独特视角,为心脏疾病的防治提供新思路和新策略。     

Long-term effects of physical training on coronary patients with impaired ventricular function.

Eighteen patients with coronary heart disease and an ejection fraction of 0.40 or less were entered into an individualized exercise training program. Maximal symptom-limited exercise stress test and cardiac catheterization studies were performed initially and 12--42 months (average 18.5 months) after exercise training. At the time of the follow-up study, the mean functional aerobic impairment (FAI) improved from 32.1 to 23.4% (p less than or equal to 0.01); resting and submaximal heart rates were significantly lower (p less than 0.01 and 0.05, respectively). There was no significant change in the pulmonary artery or left ventricular end-diastolic pressure, cardiac index, stroke index, left ventricular end-diastolic volume or ejection fraction. Exercise training, therefore, can be beneficial even for patients with impaired ventricular function. Increase in physical work capacity was not correlated with improvement of ventricular function; on the other hand, exercise training did not cause deterioration of ventricular function.     

Cardiovascular exercise and wellness. Exercise training for cardiac rehabilitation patients: meeting the challenges of the millennium

Exercise training for cardiac rehabilitation has evolved over the past decades in response to a growing knowledge base in exercise physiology, an expanding understanding to the knowledge base of coronary disease, and a change in the patients presenting for cardiac rehabilitation. The patient population has changed from a post myocardial infarction patient group, to patients who have had coronary artery revascularization (coronary artery bypass surgery or percutaneous transluminal coronary angioplasty) with the implantation of intraarterial stents. Program goals have evolved from enhancing endurance fitness in deconditioned patients to initiating the long-term adoption of an active exercising lifestyle with the use of strength training to complement endurance training. An increased understanding of behavioral issues in the adoption of an active lifestyle will influence the evolution of cardiac rehabilitation exercise training. During the next several years, it is anticipated that the patient population will change to include patients with significant left ventricular systolic dysfunction and congestive heart failure. The exercise training programs will then further evolve to reflect the successful exercise training formats utilized in the multicenter trials of exercise training for patients with congestive heart failure. (c) 2000 by CHF, Inc.     

Exercise performance and training in cardiac patients with atrial fibrillation

PURPOSE: Exercise training in cardiac patients with chronic atrial fibrillation (AF) has received little attention in the literature. Therefore, this study compared exercise performance and the effect of an exercise training program over a period of 3 months in patients with and without AF. METHODS: Data in patients with AF (n = 19) were compared with a control group of patients in sinus rhythm (n = 44), drawn from a database of 2,116 patients. Patients performed a maximal exercise test on the bicycle until exhaustion before and after an ambulatory exercise training program where exercise training was offered 3 times a week for 3 months. RESULTS: Before training, peak oxygen uptake (VO2) was significantly lower in patients with AF compared with the control group (1271 +/- 368 versus 1496 +/- 414 mL/min, P < 0.05). Exercise training significantly increased peak VO2 in both groups (+31%, P < 0.001 in AF and +25%, P < 0.001 in the control group). The gain in peak VO2 did not significantly differ between both groups. A significant decrease in resting heart rate was achieved in both groups after exercise training. AF was also a significant and independent determinant of peak VO2 in the total database, but not of the change in peak VO2. CONCLUSIONS: Exercise training significantly improves exercise performance in cardiac patients with AF. AF affects exercise performance but does not impair the beneficial effects of training. Patients with chronic AF should therefore not be dissuaded from participating in exercise training after a cardiac event.     

O2 extraction during exercise determines training effect after cardiac rehabilitation in myocardial infarction.

Correlations between baseline hemodynamic and oximetric variables during an invasive exercise test and an improvement in peak oxygen uptake (peak VO2) after exercise training (ET) were examined in 20 patients who participated in a cardiac rehabilitation program after acute myocardial infarction (AMI). Peak VO2 significantly increased by 23 +/- 21% (p < 0.01) after ET and the improvement best correlated with the change in O2 extraction fraction ([arterial O2 content-venous O2 content]/arterial O2 content) during an exercise testbefore ET (r = -0.61, p<0.01). Exercise capacity was improved to a greater extent by ET in patients with a smaller increase in O2 extraction fraction during an exercise test before ET. Thus, O2 extraction fraction during an exercise test before ET may be a useful predictor of the improvement in exercise capacity after ET in post-AMI patients.     

The effects of captopril on training in patients with ischemic heart disease.

We studied a group of 30 patients to determine the effect of captopril on the exercise training response after a period of training in patients with ischemic heart disease but without cardiac failure. The study was a double-blind placebo-controlled comparison of captopril and placebo. The patients studied were 28 men and 2 women, mean age 53.6 +/- 6.9 years. All were 8 to 12 weeks postmyocardial infarction or coronary artery bypass surgery. These patients underwent an organized exercise training program consisting of exercise training sessions 3 times weekly for a period of 8 weeks. On commencement and completion of the program patients were assessed for exercise tolerance using submaximal exercise stress testing. Patients were assessed in the untreated state. Both groups showed a statistically significant training effect with increased exercise duration, decreased heart rate for equal workload, increased energy expenditure, and reduced functional aerobic impairment. There was no statistically significant change in systolic blood pressure, but the captopril group alone showed a significant reduction in diastolic blood pressure (p less than 0.001). The change in heart rate at rest over the 8-week period was not significant in both groups. In summary, this study shows that treatment with captopril does not affect the exercise training response in patients with ischemic heart disease undergoing an organized exercise training program.     

心脏术后恢复期患者的运动处方及实施方案

目的:探讨心脏术后恢复期患者安全有效而又实用的运动处方及实施方案。方法:21例心脏术后患者均接受医疗体操、缓慢步行、功率自行车、跑台等运动训练,从低运动强度开始,逐渐增加运动量,运动强度为最大心率的70%-85%.或RPE12-14级,并采用症状限制性心电图运动试验对训练前、后的各项指标进行比较。结果:心脏术后恢复期患者均能顺利完成本处方所规定的运动量,且无1例发生异常情况。康复运动训练后,患者运动时间延长、最大运动负荷增加、安静及同等负荷运动时心率减慢、血压及二项乘积(间接心肌耗氧量)下降(P<0.05-<0.01),安静及运动诱发的最大ST段下移改善(P<0.01)。结论:此运动处方对于心脏术后恢复期患者是安全、有效的。     

运动康复训练对老年慢性心力衰竭患者预后的影响

目的探讨运动康复训练对老年慢性心力衰竭患者预后的影响。方法65例老年慢性心衰患者随机分为干预组33例和对照组32例。对照组给予常规治疗,干预组在常规治疗基础上采用运动康复训练,疗程均为8周。结果治疗8周后,干预组较对照组左室射血分数增加、NYHA心功能改善、6 min步行距离延长（P均〈0.05）;随访12个月后干预组较对照组生活质量明显提高（P〈0.05）,因心衰再入院率降低（P〈0.05）;干预组患者康复训练中未发生心衰加重、恶性心律失常等不良事件。结论对老年慢性心力衰竭患者实施运动康复训练安全有效。     

Exercise training reduces sympathetic nerve activity in heart failure patients treated with carvedilol

BACKGROUND: Evidence suggests that carvedilol decreases muscle sympathetic nerve activity (MSNA) in patients with heart failure (HF) but carvedilol fails to improve forearm vascular resistance and overall functional capacity. Exercise training in HF reduces MSNA and improves forearm vascular resistance and functional capacity. AIMS: To investigate whether the beneficial effects exercise training on MSNA are maintained in the presence of carvedilol. METHODS AND RESULTS: Twenty seven HF patients, NYHA Class II-III, EF <35%, peak VO(2) <20 ml/kg/min, treated with carvedilol were randomly divided into two groups: exercise training (n=15) and untrained (n=12). MSNA was recorded by microneurography. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. The four-month training program consisted of three 60-min exercise/week on a cycloergometer. Baseline parameters were similar between groups. Exercise training reduced MSNA (-14+/-3.3 bursts/100 HB, p=0.001) and increased forearm blood flow (0.6+/-0.1 mL/min/100 g, p<0.001) in HF patients on carvedilol. In addition, exercise training improved peak VO(2) in HF patients (20+/-6%, p=0.002). MSNA, FBF and peak VO(2) were unchanged in untrained HF patients on carvedilol. CONCLUSION: Exercise training reduces MSNA in heart failure patients treated with carvedilol. In addition, the beneficial effects of exercise training on muscle blood flow and functional capacity are still realized in patients on carvedilol.     

Exercise: a “new drug” for elderly patients with chronic heart failure

Patients with chronic heart failure (CHF) experience progressive deterioration of functional capacity and quality of life (QoL). This prospective, randomized, controlled trial assesses the effect of exercise training (ET) protocol on functional capacity, rehospitalization, and QoL in CHF patients older than 70 years compared with a control group. A total of 343 elderly patients with stable CHF (age, 76.90±5.67, men, 195, 56.9%) were randomized to ET (TCG, n=170) or usual care (UCG, n=173). The ET protocol involved supervised training sessions for 3 months in the hospital followed by home-telemonitored sessions for 3 months. Assessments, performed at baseline and at 3 and 6 months, included: ECG, resting echocardiography, NT-proBNP, 6-minute walk test (6MWT), Minnesota Living with Heart Failure Questionnaire, and comprehensive geriatric assessment with the InterRAI-HC instrument. As compared to UCG, ET patients at 6 months showed: i) significantly increased 6MWT distance (450±83 vs. 290±97 m, p<0.001); ii) increased ADL scores (5.00±2.49 vs. 6.94±5.66, p=0.037); iii) 40% reduced risk of rehospitalisation (hazard ratio=0.558, 95%CI, 0.326-0.954, p=0.033); and iv) significantly improved perceived QoL (28.6±12.3 vs. 44.5±12.3, p<0.001). In hospital and home-based telemonitored exercise confer significant benefits on the oldest CHF patients, improving functional capacity and subjective QoL and reducing risk of rehospitalisation.     

Exercise training in Diastolic Heart Failure (Ex‐DHF): rationale and design of a multicentre,prospective, randomized,controlled, parallel group trial

Heart failure with preserved ejection fraction (HFpEF) is a common disease with high incidence and increasing prevalence. Patients suffer from functional limitation, poor health‐related quality of life, and reduced prognosis. A pilot study in a smaller group of HFpEF patients showed that structured, supervised exercise training (ET) improves maximal exercise capacity, diastolic function, and physical quality of life. However, the long‐term effects of ET on patient‐related outcomes remain unclear in HFpEF. The primary objective of the Exercise training in Diastolic Heart Failure (Ex‐DHF) trial is to investigate whether a 12 month supervised ET can improve a clinically meaningful composite outcome score in HFpEF patients. Components of the outcome score are all‐cause mortality, hospitalizations, NYHA functional class, global self‐rated health, maximal exercise capacity, and diastolic function. After undergoing baseline assessments to determine whether ET can be performed safely, 320 patients at 11 trial sites with stable HFpEF are randomized 1:1 to supervised ET in addition to usual care or to usual care alone. Patients randomized to ET perform supervised endurance/resistance ET (3 times/week at a certified training centre) for 12 months. At baseline and during follow‐up, anthropometry, echocardiography, cardiopulmonary exercise testing, and health‐related quality of life evaluation are performed. Blood samples are collected to examine various biomarkers. Overall physical activity, training sessions, and adherence are monitored and documented throughout the study using patient diaries, heart rate monitors, and accelerometers. The Ex‐DHF trial is the first multicentre trial to assess the long‐term effects of a supervised ET programme on different outcome measures in patients with HFpEF.     

Intensive home-based exercise training in cardiac rehabilitation increases exercise capacity and heart rate variability.

BACKGROUND: Reduced heart rate variability (HRV) is a risk factor for cardiac death. Animal studies have shown increased HRV and reduced mortality after physical training. We evaluated the change in exercise capacity and HRV in cardiac rehabilitation patients, randomised to routine or home-based intensive training. The design was prospective, stratified randomisation with pre-specified subgroup analysis. METHODS: Maximal bicycle exercise test and 24-h Holter were performed 1 (baseline), 4 and 12 months after myocardial infarction (MI) or coronary artery by-pass surgery (CABG). Patients were randomised to physical training either two (N) or six (I) times per week for 3 months Sixty-two patients (43 MI and 19 CABG patients) were evaluated. RESULTS: Exercise capacity increased significantly more after 3 months of training in group I (mean (S.E.)); 29.0 (3.4) vs. 7.2 (2.6) watts, P<0.001). One year later the difference in exercise capacity remained (26.5 (3.3) vs. 11.8 (3.8) watts, P<0.001). Global HRV measurements SDNN and SDANN increased significantly more in group I after training (17.1 (5.6) vs. 1.7 (3.7) and 16.2 (4.9) vs. 2.8 (3.1) ms, P<0.05) and 1 year later the differences were still significant. Subgroup analysis showed more pronounced HRV response in CABG than MI patients. CONCLUSION: Intensive exercise training in cardiac rehabilitation increases exercise capacity and global HRV, which could be of prognostic significance.     

Effects of exercise training on cardiac performance, exercise capacity and quality of life in patients with heart failure: a meta-analysis

BACKGROUND: Despite major advances in pharmacological treatment of chronic heart failure (CHF), a number of patients still suffer from dyspnoea, fatigue, diminished exercise capacity and poor quality of life. It is in this context that exercise training is being intensively evaluated for any additional benefit in the treatment of CHF. AIMS: To determine the effect of exercise training in patients with CHF on cardiac performance, exercise capacity and health-related quality of life. A meta-analysis was performed to obtain this goal. METHODS AND RESULTS: After including 35 randomised controlled trials, the methodological quality of each study was assessed, summary effect sizes (SESs) and the concomitant 95% confidence intervals (95% CI) were calculated for each outcome. Quantitative analysis showed statistically significant SESs, at rest, for diastolic blood pressure and end-diastolic volume. During maximal exercise, significant SESs were found for systolic blood pressure, heart rate, cardiac output, peak oxygen uptake, anaerobic threshold and 6-min walking test. The Minnesota Living with Heart Failure Questionnaire improved by an average of 9.7 points. CONCLUSIONS: Exercise training has clinically important effects on exercise capacity and HRQL, and may have small positive effects on cardiac performance during exercise.     

Endurance Exercise Training in Older Patients with Heart Failure: Results from a Randomized, Controlled, Single-Blind Trial

OBJECTIVES: To test the hypothesis that exercise training (ET) improves exercise capacity and other clinical outcomes in older persons with heart failure with reduced ejection fraction (HfrEF). DESIGN: Randomized, controlled, single‐blind trial. SETTING: Outpatient cardiac rehabilitation program. PARTICIPANTS: Fifty‐nine patients aged 60 and older with HFrEF recruited from hospital records and referring physicians were randomly assigned to a 16‐week supervised ET program (n=30) or an attention‐control, nonexercise, usual care control group (n=29). INTERVENTION: Sixteen‐week supervised ET program of endurance exercise (walking and stationary cycling) three times per week for 30 to 40 minutes at moderate intensity regulated according to heart rate and perceived exertion. MEASUREMENTS: Individuals blinded to group assignment assessed four domains pivotal to HFrEF pathophysiology: exercise performance, left ventricular (LV) function, neuroendocrine activation, and health‐related quality of life (QOL). RESULTS: At follow‐up, the ET group had significantly greater exercise time and workload than the control group, but there were no significant differences between the groups for the primary outcomes: peak exercise oxygen consumption (VO₂ peak), ventilatory anaerobic threshold (VAT), 6‐minute walk distance, QOL, LV volumes, EF, or diastolic filling. Other than serum aldosterone, there were no significant differences after ET in other neuroendocrine measurements. Despite a lack of a group “training” effect, a subset (26%) of individuals increased VO₂ peak by 10% or more and improved other clinical variables as well. CONCLUSION: In older patients with HFrEF, ET failed to produce consistent benefits in any of the four pivotal domains of HF that were examined, although the heterogeneous response of older patients with HFrEF to ET requires further investigation to better determine which patients with HFrEF will respond favorably to ET.     

Exercise in children before and after coarctectomy: hemodynamic, echocardiographic, and biochemical assessment

After repair of coarctation of the aorta, some patients with normal blood pressure at rest have an exaggerated hypertensive response to activity. Blood pressure response to exercise was studied in 15 children, aged 5 to 15 years, prior to and at periods up to 6 months following coarctectomy. Preoperatively, 11 of 15 children had systolic hypertension at rest and 12 of 15 after exercise. After surgery, only one child had mild systolic hypertension at rest, whereas exercise-induced hypertension persisted in 33% of patients (all older than 10 years). Exercise plasma renin activity was elevated preoperatively but normalized following surgery. No significant difference was seen in resting and exercise plasma catecholamine levels measured before and after surgery. Over the follow-up period of 6 months, echocardiographic evidence of left ventricular hypertrophy regressed in the younger patients but not in the older patients with exercise-induced hypertension. Exercise testing defines a subgroup of patients with exercise-induced hypertension evident soon after surgery. Structural upper segment arterial vessel wall changes in the older patient may explain these observations.