Randomized 4-week exercise program in patients with impaired left ventricular function

Exercise, Physical Activity, and Cardiometabolic Health: Insights into the Prevention and Treatment of Cardiometabolic Diseases

Physical activity (PA) and exercise are widely recognized as essential components of primary and secondary cardiovascular disease (CVD) prevention efforts and are emphasized in the health promotion guidelines of numerous professional societies and committees. The protean benefits of PA and exercise extend across the spectrum of CVD, and include the improvement and reduction of risk factors and events for atherosclerotic CVD (ASCVD), cardiometabolic disease, heart failure, and atrial fibrillation (AF), respectively. Here, we highlight recent insights into the salutary effects of PA and exercise on the primary and secondary prevention of ASCVD, including their beneficial effects on both traditional and nontraditional risk mediators; exercise "prescriptions" for ASCVD; the role of PA regular exercise in the prevention and treatment of heart failure; and the relationships between, PA, exercise, and AF. While our understanding of the relationship between exercise and CVD has evolved considerably, several key questions remain including the association between extreme volumes of exercise and subclinical ASCVD and its risk; high-intensity exercise and resistance (strength) training as complementary modalities to continuous aerobic exercise; and dose- and intensity-dependent associations between exercise and AF. Recent advances in molecular profiling technologies (ie, genomics, transcriptomics, proteomics, and metabolomics) have begun to shed light on interindividual variation in cardiometabolic responses to PA and exercise and may provide new opportunities for clinical prediction in addition to mechanistic insights.

Cardiac physiology in post myocardial infarction patients: the effect of cardiac rehabilitation programs-a systematic review and update meta-analysis

Cardiac rehabilitation program (CRP) is a recognized non-pharmacological modality to decrease mortality after acute myocardial infarction (AMI) events. We aimed to evaluate the effect of CRP on the cardiac physiology in patients post myocardial infarction (MI). Online database search of PubMed, MEDLINE, EMBASE, SCOPUS, COCHRANE, and GOOGLE SCHOLAR were performed (1988-Mar 2016); key bibliographies were reviewed. Studies comparing post MI patients who were enrolled in a CRP to those who were not, were included. Standardized mean difference (SMD) with the corresponding 95% confidence intervals (CI) by random and fixed effects models of pooled data were calculated. Study quality was assessed using CONSORT criteria. Outcomes of interest measured included resting and maximum heart rate (HR), peak VO₂, ejection fraction (EF%), wall motion score index (WMSI), left ventricular end diastolic volume (LVEDV) in cardiac rehabilitation patients versus control. Search strategy yielded 147 studies, 23 studies fulfilled the selection criteria, 19 of which were RCTs. These included a total of 1,683 patients; 827 were enrolled in a CRP while 855 did not receive the intervention. Median age was 58 years. There was no significant difference between the two groups in terms of age, comorbidities, severity of CAD, baseline EF or HR. Meta-analysis of data included demonstrated that CRP patients had lower post-intervention resting HR than non-CRP patients (SMD: -0.59; 95% CI: -0.73 to -0.46, fixed effect model P<0.05). EF% was significantly improved after CRP compared to control (SMD: 0.21; 95% CI: 0.02 to 0.40, P=0.03). Peak VO₂ was significantly improved by CRP (SMD: 1.00; 95% CI: 0.56 to 1.45; P<0.0001). LVEDV was significantly less in CRP patients (SMD: -0.31; 95% CI: -0.59 to -0.02, fixed effect model P<0.05). WMSI was significantly less in CRP patients (SMD: -0.41; 95% CI: -0.78 to -0.05, P=0.024). CRP improves cardiac function in post MI patients. This may explain the reported improvement of functionality and mortality among those patients. Further randomized trials may help evaluate the long-term benefits of CRP.

Interventions to support return to work for people with coronary heart disease

BACKGROUND

People with coronary heart disease (CHD) often require prolonged absences from work to convalesce after acute disease events like myocardial infarctions (MI) or revascularisation procedures such as coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). Reduced functional capacity and anxiety due to CHD may further delay or prevent return to work.

OBJECTIVES

To assess the effects of person- and work-directed interventions aimed at enhancing return to work in patients with coronary heart disease compared to usual care or no intervention.

SEARCH METHODS

We searched the databases CENTRAL, MEDLINE, Embase, PsycINFO, NIOSHTIC, NIOSHTIC-2, HSELINE, CISDOC, and LILACS through 11 October 2018. We also searched the US National Library of Medicine registry, clinicaltrials.gov, to identify ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) examining return to work among people with CHD who were provided either an intervention or usual care. Selected studies included only people treated for MI or who had undergone either a CABG or PCI. At least 80% of the study population should have been working prior to the CHD and not at the time of the trial, or study authors had to have considered a return-to-work subgroup. We included studies in all languages. Two review authors independently selected the studies and consulted a third review author to resolve disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and independently assessed the risk of bias. We conducted meta-analyses of rates of return to work and time until return to work. We considered the secondary outcomes, health-related quality of life and adverse events among studies where at least 80% of study participants were eligible to return to work.

MAIN RESULTS

We found 39 RCTs (including one cluster- and four three-armed RCTs). We included the return-to-work results of 34 studies in the meta-analyses.Person-directed, psychological counselling versus usual careWe included 11 studies considering return to work following psychological interventions among a subgroup of 615 participants in the meta-analysis. Most interventions used some form of counselling to address participants' disease-related anxieties and provided information on the causes and course of CHD to dispel misconceptions. We do not know if these interventions increase return to work up to six months (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.84 to 1.40; six studies; very low-certainty evidence) or at six to 12 months (RR 1.24, 95% CI 0.95 to 1.63; seven studies; very low-certainty evidence). We also do not know if psychological interventions shorten the time until return to work. Psychological interventions may have little or no effect on the proportion of participants working between one and five years (RR 1.09, 95% CI 0.88 to 1.34; three studies; low-certainty evidence).Person-directed, work-directed counselling versus usual careFour studies examined work-directed counselling. These counselling interventions included advising patients when to return to work based on treadmill testing or extended counselling to include co-workers' fears and misconceptions regarding CHD. Work-directed counselling may result in little to no difference in the mean difference (MD) in days until return to work (MD -7.52 days, 95% CI -20.07 to 5.03 days; four studies; low-certainty evidence). Work-directed counselling probably results in little to no difference in cardiac deaths (RR 1.00, 95% CI 0.19 to 5.39; two studies; moderate-certainty evidence).Person-directed, physical conditioning interventions versus usual careNine studies examined the impact of exercise programmes. Compared to usual care, we do not know if physical interventions increase return to work up to six months (RR 1.17, 95% CI 0.97 to 1.41; four studies; very low-certainty evidence). Physical conditioning interventions may result in little to no difference in return-to-work rates at six to 12 months (RR 1.09, 95% CI 0.99 to 1.20; five studies; low-certainty evidence), and may also result in little to no difference on the rates of patients working after one year (RR 1.04, 95% CI 0.82 to 1.30; two studies; low-certainty evidence). Physical conditioning interventions may result in little to no difference in the time needed to return to work (MD -7.86 days, 95% CI -29.46 to 13.74 days; four studies; low-certainty evidence). Physical conditioning interventions probably do not increase cardiac death rates (RR 1.00, 95% CI 0.35 to 2.80; two studies; moderate-certainty evidence).Person-directed, combined interventions versus usual careWe included 13 studies considering return to work following combined interventions in the meta-analysis. Combined cardiac rehabilitation programmes may have increased return to work up to six months (RR 1.56, 95% CI 1.23 to 1.98; number needed to treat for an additional beneficial outcome (NNTB) 5; four studies; low-certainty evidence), and may have little to no difference on return-to-work rates at six to 12 months' follow-up (RR 1.06, 95% CI 1.00 to 1.13; 10 studies; low-certainty evidence). We do not know if combined interventions increased the proportions of participants working between one and five years (RR 1.14, 95% CI 0.96 to 1.37; six studies; very low-certainty evidence) or at five years (RR 1.09, 95% CI 0.86 to 1.38; four studies; very low-certainty evidence). Combined interventions probably shortened the time needed until return to work (MD -40.77, 95% CI -67.19 to -14.35; two studies; moderate-certainty evidence). Combining interventions probably results in little to no difference in reinfarctions (RR 0.56, 95% CI 0.23 to 1.40; three studies; moderate-certainty evidence).Work-directed, interventionsWe found no studies exclusively examining strictly work-directed interventions at the workplace.

AUTHORS' CONCLUSIONS

Combined interventions may increase return to work up to six months and probably reduce the time away from work. Otherwise, we found no evidence of either a beneficial or harmful effect of person-directed interventions. The certainty of the evidence for the various interventions and outcomes ranged from very low to moderate. Return to work was typically a secondary outcome of the studies, and as such, the results pertaining to return to work were often poorly reported. Adhering to RCT reporting guidelines could greatly improve the evidence of future research. A research gap exists regarding controlled trials of work-directed interventions, health-related quality of life within the return-to-work process, and adverse effects.

Exercise and heart failure: an update

The present update is dedicated to the evolution of the interaction between heart failure (HF) and exercise and how the scientific community has handled it. Indeed, on the one hand, HF is a leading cause of morbidity and mortality with a stable prevalence from 1998 onward varying between 6.3% and 13.3%. On the other hand, exercise is seen as a diagnostic and prognostic tool as well as a therapeutic intervention in chronic HF. More precisely, the knowledge, the clinical application, and the research interest on the mutual interactions between exercise and HF have different phases in disease progression: Before HF onset (past): exercise provides protective benefit in preventing HF (primary prevention). With HF present: exercise improvement with training provides benefits in HF (secondary prevention). The prediction of future in HF patients: exercise impairment, as a leading characteristic of HF, is used as a prognostic factor.

Effect of cardiac rehabilitation on cardiovascular risk factors in chronic heart failure patients

Introduction

Cardiac rehabilitation improves disease-related symptoms, quality of life, and clinical outcomes. This study was done to evaluate the effect of cardiac rehabilitation program on cardiovascular risk factors in chronic heart failure patients as well as functional capacity and health related quality of life.

Methods

The study was conducted on 80 Patients with chronic stable heart failure. All patients had full history and thorough physical examination. Body mass index (BMI), waist circumference, glycated hemoglobin (HbA1c), lipid profile, and echocardiography, all of which were done before and after recruitment in a 2 months cardiac rehabilitation program (through prescribed exercise training, 2 sessions/week for 2 months). The changes in functional capacity were evaluated by 6-min walk test (6MWT) and the changes in the health related quality of life were measured by Minnesota living with heart failure questionnaire (MLHFQ), both were done before and after the rehabilitation program.

Results

There was a highly significant reduction in the blood pressure, heart rate, BMI, waist circumference, the smokers' number and the glycated hemoglobin (HbA1c) (P < 0.01). However, there was no statistically significant reductions in low density lipoproteins (LDL), Triglycerides (P > 0.05). Highly significant improvements were noted in the functional capacity and the health related quality of life as evidenced by improvement in the 6MWT and the MLHFQ scores (total score, physical and psychological domains, P < 0.01).

Conclusion

Cardiac rehabilitation had a significant improvement of cardiovascular risk factors, functional capacity and Health related quality of life in patients with chronic heart failure.

The Effect of Cardiac Rehabilitation Exercise Training on Cardiopulmonary Function in Ischemic Cardiomyopathy With Reduced Left Ventricular Ejection Fraction

OBJECTIVE

To observe the effect and safety of cardiac rehabilitation (CR) exercise in ischemic cardiomyopathy and to compare the results between patients with preserved left ventricular ejection fraction (LVEF) and reduced LVEF.

METHODS

Patients with ischemic cardiomyopathy with LVEF <50% were included as subjects. The patients were classified into the preserved LVEF (pLVEF; LVEF 41%-49%) group and the reduced LVEF (rLVEF; LVEF ≤40%) group. Patients underwent hourly aerobic exercise training sessions with an intensity of 60%-85% of heart rate reserve, three times a week for 6 weeks. Graded exercise test and transthoracic echocardiogram were performed in all study patients before and after completion of the CR exercise program.

RESULTS

After completion of the CR exercise program, both groups (pLVEF, n=30; rLVEF, n=18) showed significant increases in LVEF and VO2max. In the pLVEF group, LVEF and VO2max increased from 45.1%±4.8% to 52.5%±9.6% (p<0.001) and from 24.1±6.3 to 28.1±8.8 mL/kg/min (p=0.002), respectively. In the rLVEF group, LVEF and VO2max increased from 29.7%±7.7% to 37.6%±10.3% (p<0.001) and from 17.6±4.7 to 21.2±5.1 mL/kg/min (p<0.001), respectively. Both groups completed their exercise program safely.

CONCLUSION

In both groups, patients with ischemic cardiomyopathy who completed a 6-week supervised CR exercise program demonstrated remarkable improvements in cardiopulmonary function. This result implies that neither of the two groups showed higher efficacy in comparison to each other, but we can conclude that CR exercise in the rLVEF group was as effective and safe as that in the pLVEF group.

Aerobic Training after Myocardial Infarction: Remodeling Evaluated by Cardiac Magnetic Resonance

Background

Numerous studies show the benefits of exercise training after myocardial infarction (MI). Nevertheless, the effects on function and remodeling are still controversial.

Objectives

To evaluate, in patients after (MI), the effects of aerobic exercise of moderate intensity on ventricular remodeling by cardiac magnetic resonance imaging (CMR).

Methods

26 male patients, 52.9 ± 7.9 years, after a first MI, were assigned to groups: trained group (TG), 18; and control group (CG), 8. The TG performed supervised aerobic exercise on treadmill twice a week, and unsupervised sessions on 2 additional days per week, for at least 3 months. Laboratory tests, anthropometric measurements, resting heart rate (HR), exercise test, and CMR were conducted at baseline and follow-up.

Results

The TG showed a 10.8% reduction in fasting blood glucose (p = 0.01), and a 7.3-bpm reduction in resting HR in both sitting and supine positions (p < 0.0001). There was an increase in oxygen uptake only in the TG (35.4 ± 8.1 to 49.1 ± 9.6 mL/kg/min, p < 0.0001). There was a statistically significant decrease in the TG left ventricular mass (LVmass) (128.7 ± 38.9 to 117.2 ± 27.2 g, p = 0.0032). There were no statistically significant changes in the values of left ventricular end-diastolic volume (LVEDV) and ejection fraction in the groups. The LVmass/EDV ratio demonstrated a statistically significant positive remodeling in the TG (p = 0.015).

Conclusions

Aerobic exercise of moderate intensity improved physical capacity and other cardiovascular variables. A positive remodeling was identified in the TG, where a left ventricular diastolic dimension increase was associated with LVmass reduction.

Possible neurocognitive benefits of exercise in persons with heart failure

More than 6 million Americans have heart failure (HF) and more than 500,000 are diagnosed each year. In addition to its many adverse medical consequences, HF is also a significant risk factor for neurological disorders like Alzheimer's disease and associated with cognitive impairment long prior to the onset of these conditions. Converging bodies of literature suggest cognitive dysfunction in HF may be at least partially modifiable. One key mechanism for cognitive improvement is improved cerebral blood flow, which may be possible with exercise in patients with HF. This brief review provides a model for the likely neurocognitive benefits of exercise in HF and encourages further work in this area.

The effects of different initiation time of exercise training on left ventricular remodeling and cardiopulmonary rehabilitation in patients with left ventricular dysfunction after myocardial infarction

PURPOSE

The purpose of this study was to determine whether different initiation of exercise training (ET) produces different effect sizes for left ventricular (LV) remodeling and cardiopulmonary rehabilitation in patients with LV dysfunction after myocardial infarction (MI).

METHOD

Trials evaluating ET outcomes identified by searches in OVID MEDLINE, EMBASE, PubMed and WEB OF SCIENCE were used. Meta-analysis was conducted with the use of the software STATA 11.0. The results were expressed as the standardized mean difference (SMD), with corresponding 95% CI and p value.

RESULTS

The largest changes in LV remodeling and cardiopulmonary capacity rehabilitation were obtained when programs began the acute phase after MI. With the healing of MI, the beneficial effects of ET on LV ejection fraction (LVEF), LV end-systolic diameter (LVDs) and peak VO2 were gradually weakened even worse. The incidence of major adverse cardiac events was not significantly increased in acute phase post-MI. Sensitivity analyses show that ET still had significant effect in reducing LVDs and increasing peak VO2, while ET no longer had statistical effect in increasing LVEF but showed favorable trends when the same research institution's works were excluded.

CONCLUSIONS

ET has favorable effects on LV remodeling and cardiopulmonary rehabilitation in LV dysfunction post-MI patients. The greatest benefits are obtained when ET starts at the acute phase following MI.

IMPLICATIONS FOR REHABILITATION

Early exercise training is safe and feasible in acute and healing phase after myocardial infarction. Early exercise training could attenuate LV remodeling and improve cardiopulmonary capacity in patients with myocardial infarction after hospital discharge (around one week post-MI). Exercise training has favorable effects on LV remodeling and cardiopulmonary capacity rehabilitation. Exercise training should be treated to have the same roles with drugs in secondary prevention of myocardial infarction.

Exercise training in patients with heart failure and preserved ejection fraction: meta-analysis of randomized control trials

BACKGROUND

Heart failure with preserved ejection fraction (HFPEF) is common and characterized by exercise intolerance and lack of proven effective therapies. Exercise training has been shown to be effective in improving cardiorespiratory fitness (CRF) in patients with systolic heart failure. In this meta-analysis, we aim to evaluate the effects of exercise training on CRF, quality of life, and diastolic function in patients with HFPEF.

METHODS AND RESULTS

Randomized controlled clinical trials that evaluated the efficacy of exercise training in patients with HFPEF were included in this meta-analysis. Primary outcome of the study was change in CRF (measured as change in peak oxygen uptake). Effect of exercise training on quality of life (estimated using Minnesota living with heart failure score), and left ventricular systolic and diastolic function was also assessed. The study included 276 patients who were enrolled in 6 randomized controlled trials. In the pooled data analysis, patients with HFPEF undergoing exercise training had significantly improved CRF (mL/kg per min; weighted mean difference, 2.72; 95% confidence interval, 1.79-3.65) and quality of life (weighted mean difference, -3.97; 95% confidence interval, -7.21 to -0.72) when compared with the control group. However, no significant change was observed in the systolic function (EF-weighted mean difference, 1.26; 95% confidence interval, -0.13% to 2.66%) or diastolic function (E/A-weighted mean difference, 0.08; 95% confidence interval, -0.01 to 0.16) with exercise training in patients with HFPEF.

CONCLUSIONS

Exercise training in patients with HFPEF is associated with an improvement in CRF and quality of life without significant changes in left ventricular systolic or diastolic function.

Effects of exercise on cardiovascular performance in the elderly

Progressive aging induces several structural and functional alterations in the cardiovascular system, among whom particularly important are a reduced number of myocardial cells and increased interstitial collagen fibers, which result in impaired left ventricular diastolic function. Even in the absence of cardiovascular disease, aging is strongly associated to a age-related reduced maximal aerobic capacity. This is due to a variety of physiological changes both at central and at peripheral level. Physical activity (PA) appears in general to have a positive effect on several health outcomes in the elderly. This review aims to illustrate the beneficial effects of exercise on the physiologic decline of cardiovascular performance occurring with age. Furthermore, it will be stressed also the positive effect of physical activity in elderly patients affected by cardiovascular diseases, such as heart failure and hypertension, and multiple comorbidities which may significantly worse prognosis in this high risk population.

Rescue of heart lipoprotein lipase-knockout mice confirms a role for triglyceride in optimal heart metabolism and function

Hearts utilize fatty acids as a primary source of energy. The sources of those lipids include free fatty acids and lipoprotein triglycerides. Deletion of the primary triglyceride-hydrolyzing enzyme lipoprotein lipase (LPL) leads to cardiac dysfunction. Whether heart LPL-knockout (hLPL0) mice are compromised due a deficiency in energetic substrates is unknown. To test whether alternative sources of energy will prevent cardiac dysfunction in hLPL0 mice, two different models were used to supply nonlipid energy. 1) hLPL0 mice were crossed with mice transgenically expressing GLUT1 in cardiomyocytes to increase glucose uptake into the heart; this cross-corrected cardiac dysfunction, reduced cardiac hypertrophy, and increased myocardial ATP. 2) Mice were randomly assigned to a sedentary or training group (swimming) at 3 mo of age, which leads to increased skeletal muscle production of lactate. hLPL0 mice had greater expression of the lactate transporter monocarboxylate transporter-1 (MCT-1) and increased cardiac lactate uptake. Compared with hearts from sedentary hLPL0 mice, hearts from trained hLPL0 mice had adaptive hypertrophy and improved cardiac function. We conclude that defective energy intake and not the reduced uptake of fat-soluble vitamins or cholesterol is responsible for cardiac dysfunction in hLPL0 mice. In addition, our studies suggest that adaptations in cardiac metabolism contribute to the beneficial effects of exercise on the myocardium of patients with heart failure.

Testosterone therapy during exercise rehabilitation in male patients with chronic heart failure who have low testosterone status: a double-blind randomized controlled feasibility study

BACKGROUND

This study assessed the feasibility of a 12-week program of exercise, with and without intramuscular testosterone supplementation, in male patients with chronic heart failure (CHF) and low testosterone status and collected preliminary data for key health outcomes.

METHODS

Male patients with CHF (n = 41, age 67.2 years, range 51-84 years) with mean ± SD testosterone levels of 10.7 ± 2.6 nmol/L (309 ± 76 ng/dL) were randomly allocated to exercise with testosterone or placebo groups. Feasibility was assessed in terms of recruitment, intervention compliance, and attrition. Outcomes included an incremental shuttle walk test, peak oxygen uptake, muscular strength, echocardiographic measures, N-terminal pro-brain natriuretic peptide, inflammatory markers, depression (Beck Depression Inventory), and health-related quality of life (Minnesota Living with Heart Failure Questionnaire and Medical Outcomes Study Short-Form).

RESULTS

Attrition was 30% but with 100% compliance to exercise and injections in patients who completed the study. Similar improvements in shuttle walk test (18% vs 19%), body mass (-1.3 kg vs -1.0 kg), and hand grip strength (2.1 kg vs 2.5 kg) from baseline were observed in both groups. The exercise with testosterone group showed improvements from baseline in peak oxygen uptake (P < .01), Beck Depression Inventory (P < .05), leg strength (P < .05), and several Medical Outcomes Study Short-Form quality of life domains (P < .05), which were generally not apparent in the exercise with placebo group. Echocardiographic measures, N-terminal pro-brain natriuretic peptide, and inflammatory markers were mostly unchanged.

CONCLUSIONS

This study shows for the first time that testosterone supplementation during a program of exercise rehabilitation is feasible and can positively impact on a range of key health outcomes in elderly male patients with CHF who have a low testosterone status.

Effect of endurance training on the determinants of peak exercise oxygen consumption in elderly patients with stable compensated heart failure and preserved ejection fraction

OBJECTIVES

The purpose of this study was to evaluate the mechanisms for improved exercise capacity after endurance exercise training (ET) in elderly patients with heart failure and preserved ejection fraction (HFPEF).

BACKGROUND

Exercise intolerance, measured objectively by reduced peak oxygen consumption (VO(2)), is the primary chronic symptom in HFPEF and is improved by ET. However, the mechanisms are unknown.

METHODS

Forty stable, compensated HFPEF outpatients (mean age 69 ± 6 years) were examined at baseline and after 4 months of ET (n = 22) or attention control (n = 18). The VO(2) and its determinants were assessed during rest and peak upright cycle exercise.

RESULTS

After ET, peak VO(2) in those patients was higher than in control patients (16.3 ± 2.6 ml/kg/min vs. 13.1 ± 3.4 ml/kg/min; p = 0.002). That was associated with higher peak heart rate (139 ± 16 beats/min vs. 131 ± 20 beats/min; p = 0.03), but no difference in peak end-diastolic volume (77 ± 18 ml vs. 77 ± 17 ml; p = 0.51), stroke volume (48 ± 9 ml vs. 46 ± 9 ml; p = 0.83), or cardiac output (6.6 ± 1.3 l/min vs. 5.9 ± 1.5 l/min; p = 0.32). However, estimated peak arterial-venous oxygen difference was significantly higher in ET patients (19.8 ± 4.0 ml/dl vs. 17.3 ± 3.7 ml/dl; p = 0.03). The effect of ET on cardiac output was responsible for only 16% of the improvement in peak VO(2).

CONCLUSIONS

In elderly stable compensated HFPEF patients, peak arterial-venous oxygen difference was higher after ET and was the primary contributor to improved peak VO(2). This finding suggests that peripheral mechanisms (improved microvascular and/or skeletal muscle function) contribute to the improved exercise capacity after ET in HFPEF. (Prospective Aerobic Reconditioning Intervention Study [PARIS]; NCT01113840).

Modest increase in peak VO2 is related to better clinical outcomes in chronic heart failure patients: results from heart failure and a controlled trial to investigate outcomes of exercise training

BACKGROUND

The prognostic ability of a single measurement of peak oxygen uptake (VO(2)) is well established in patients with chronic heart failure. The relation between a change in peak VO(2) and clinical outcomes is not well defined.

METHODS AND RESULTS

This investigation determined whether an increase in peak VO(2) was associated with a lower risk of the primary end point of time to all-cause mortality or all-cause hospitalization and 3 secondary end points. In Heart Failure and a Controlled Trial to Investigate Outcomes of Exercise Training, an exercise training trial for patients with systolic heart failure, cardiopulmonary exercise tests were performed at baseline and ≈3 months later in 1620 participants. Median peak VO(2) in the combined sample increased from 15.0 (11.9-18.0 Q1-Q3) to 15.4 (12.3-18.7 Q1-Q3) mL·kg(-1)·min(-1). Every 6% increase in peak VO(2,) adjusted for other significant predictors, was associated with a 5% lower risk of the primary end point (hazard ratio=0.95; CI=0.93-0.98; P<0.001); a 4% lower risk of the secondary end point of time to cardiovascular mortality or cardiovascular hospitalization (hazard ratio=0.96; CI=0.94-0.99; P<0.001); an 8% lower risk of cardiovascular mortality or heart failure hospitalization (hazard ratio=0.92; CI=0.88-0.96; P<0.001); and a 7% lower all-cause mortality (hazard ratio=0.93; CI=0.90-0.97; P<0.001).

CONCLUSIONS

Among patients with chronic systolic heart failure, a modest increase in peak VO(2) over 3 months was associated with a more favorable outcome. Monitoring the change in peak VO(2) for such patients may have benefit in assessing prognosis.

A meta-analysis of the effects of exercise training on left ventricular remodeling following myocardial infarction: start early and go longer for greatest exercise benefits on remodeling

Background

The effects of variations in exercise training on Left ventricular (LV) remodeling in patients shortly after Myocardial Infarction (MI) are important but poorly understood.

Methods

Systematic review incorporating meta-analysis using meta-regression. Studies were identified via systematic searches of: OVID MEDLINE (1950 to 2009), Cochrane Central Register of Controlled Trials (1991 to 2009), AMED (1985 to 2009), EMBASE (1988 to 2009), PUBMED (1966 to 2009), SPORT DISCUS (1975 to 2009), SCOPUS (1950 to 2009) and WEB OF SCIENCE (1950 to 2009) using the medical subject headings: myocardial infarction, post myocardial infarction, post infarction, heart attack, ventricular remodeling, ventricular volumes, ejection fraction, left ventricular function, exercise, exercise therapy, kinesiotherapy, exercise training. Reference lists of all identified studies were also manually searched for further relevant studies. Studies selected were randomized controlled trials of exercise training interventions reporting ejection fraction (EF) and/or ventricular volumes in patients following recent MI (≤ 3 months) post-MI patients involving control groups. Studies were excluded if they were not randomized, did not have a 'usual-care' control (involving no exercise), evaluated a non-exercise intervention, or did not involve human subjects. Non-English studies were also excluded.

Results

After screening of 1029 trials, trials were identified that reported EF (12 trials, n = 647), End Systolic Volumes (ESV) (9 trials, n = 475) and End Diastolic Volumes (EDV) (10 trials, n = 512). Meta-regression identified that changes in EF effect size difference decreased as the time between MI and initiation of the exercise program lengthened, and increased as the duration of the program increased (Q = 25.48, df = 2, p < 0.01, R² = 0.76). Greater reductions in ESV and EDV (as indicated by effect size decreases) occurred with earlier initiation of exercise training and with longer training durations (ESV: Q = 23.89, df = 2, p < 0.05, R² = 0.79; EDV: Q = 27.42, df = 2, p < 0.01, R² = 0.83). Differences remained following sensitivity analysis. Each week that exercise was delayed required an additional month of training to achieve the same level of benefit on LV remodeling.

Conclusions

Exercise training has beneficial effects on LV remodeling in clinically stable post-MI patients with greatest benefits occurring when training starts earlier following MI (from one week) and lasts longer than 3 months.

Role and benefits of exercise in the management of patients with heart failure

Initial research established the feasibility of exercise training in patients with heart failure, as well as associated physiological benefits. This review summarizes the findings from over two dozen single-site studies that address the effect of exercise training on exercise capacity and cardiovascular and peripheral function. In addition, it incorporates the results from two meta-analyses and a recently completed multi-center trial, all of which studied the effects of exercise training on clinical outcomes. The major conclusions from these studies are that exercise training is safe; improves health status and exercise capacity; helps attenuate much of the abnormal pathophysiology that develops with heart failure; and yields a modest reduction in clinical events. The magnitude of the clinical benefits appears related to the volume of exercise completed. Future research is needed to identify which patient subgroups might benefit the most from exercise training, the optimal exercise dose or load needed to lessen disease-related symptoms and maximize clinical benefit, and the effects of exercise training in patients with heart failure and preserved left ventricular systolic function.

Mechanisms by which exercise training benefits patients with heart failure

Clinical consequences of heart failure are fatigue, dyspnea, and progressive impairment of exercise tolerance. Regular exercise training is associated with health-improving effects. In patients with stable heart failure, exercise training can relieve symptoms, improve exercise capacity and quality of life, as well as reduce hospitalization and, to some extent, risk of mortality. Progressive exercise training is associated with pulmonary, cardiovascular, and skeletal muscle metabolic adaptations that increase oxygen delivery and energy production. This Review focuses on current knowledge of mechanisms by which progressive and moderate exercise training can have sustained beneficial effects on patients with heart failure.

Physical exercise improves the functional capacity and quality of life in patients with heart failure

OBJECTIVE

The purpose of this study was to investigate the effects of physical exercise on the functional capacity and quality of life in heart failure patients.

METHODS

Forty-two patients of both sexes with heart failure of NYHA class II and III with different etiologies were randomly divided into untrained or trained groups. The six-month exercise program consisted of aerobic training, muscle strength training, agility and joint flexibility activities. Physical fitness was evaluated by testing the performance on these trained components. Quality of life was evaluated by scored answers to a standardized questionnaire involving multiple domains.

RESULTS

Baseline values did not differ between groups. Improvement in the trained group was identified in all components of functional capacity when compared to the untrained group (p<0.001). Quality of life improved in the trained patients concerning physical, psychological, social and environmental domains (p<0.001), whereas no significant change was found in the untrained patients.

CONCLUSIONS

Guided and monitored physical exercise is safe and has the potential to improve functional capacity and quality of life in heart failure patients with multiple etiologies.

Enhancement of isokinetic muscle strength with a combined training programme in chronic heart failure

BACKGROUND

Patients with congestive heart failure (CHF) exhibit an impaired exercised tolerance that dramatically limits their functional capacity and alters their quality of life.

DESIGN

The aim of this study was to compare the effects of two types of training programmes on isokinetic muscle strength and aerobic capacities in patients with CHF.

METHODS

A group of 23 stable CHF patients included consecutively followed an exercise training programme, 3 days a week for 8 weeks. The first group (P1, n=11) exercised on a cycloergometer for 45 min at 65% of peak VO2. The second group (P2, n=12) followed a 45-min combined bicycle and quadricipital strength training. Strength training consisted of 10 series of 10 repetitions at 70% of maximal voluntary force. Incremental maximal cardiopulmonary exercise tests as well as an isokinetic quadricipital dynamometry evaluation were performed before and after training.

RESULTS AND CONCLUSIONS

In P1, peak VO2 increased by 20% (22.3+/-4.9 versus 17.8+/-4.5 ml min(-1) kg(-1); P<0.05) without any significant change in isokinetic muscle strength. In P2, peak VO2 improved within the same range (20.5+/-2.8 versus 18.6+/-3.7 ml min(-1) kg(-1); P<0.01). This last rehabilitation programme significantly increased isokinetic muscle strength at each angular velocities (+10.5+/-13.5%, P<0.04; +5.6+/-7.0%, P<0.03; for 180 degrees s(-1) and 60 degrees s(-1) respectively). Only the combined endurance/strength training programme was associated with an improvement in both peak VO2 and peripheral muscle strength, two significant parameters of outcome and quality of life in CHF.

Improved exercise tolerance and cardiac function in severe chronic heart failure patients undergoing a supervised exercise program

BACKGROUND

Exercise intolerance is a widespread and serious problem in chronic heart failure (CHF) patients. However, the impact of a supervised exercise and rehabilitation program on exercise tolerance and cardiac performance in severe CHF patients has not yet been fully investigated.

METHODS

Of 56 consecutive patients with severe CHF (New York Heart Association functional class III, Stage D) 44 underwent a hospital-based supervised 18-week, cardiac exercise and rehabilitation program (exercise group), and 12 did not (control group). Cardiac performance was assessed by a 6-minute walk test, peak exercise VO(2), exercise duration time, resting and immediate post peak exercise stroke index (SI), cardiac index (CI) and systemic vascular resistance (SVR), before and after exercise.

RESULTS

Both groups were comparable regarding baseline clinical characteristics. Post exercise training, functional and hemodynamic parameters improved significantly in the exercise group compared to controls. A highly significant interaction between the groups and change was found in the 6-minute walk test (p<0.001), exercise test duration (p<0.001), METs during exercise (p<0.001), immediate post peak exercise CI (0.016), delta peak VO(2) (p=0.028), and immediate post peak exercise SVR (p=0.045).

CONCLUSIONS

A hospital-based supervised exercise and rehabilitation program significantly improves functional and hemodynamic parameters in severe CHF patients, and may partially contribute to better physical conditioning detected in these patients after exercise training.

Patients with large myocardial infarction gain a greater improvement in exercise capacity after exercise training than those with small to medium infarction

BACKGROUND

It remains unclear whether patients with large-size myocardial infarction (MI) achieve the same benefit from exercise training as do those with small- to medium-size MI.

HYPOTHESIS

This study was designed to determine the magnitude and mechanisms underlying improvement in exercise capacity in patients with large-size MI after cardiac rehabilitation.

METHODS

In all, 296 patients who participated in a cardiac rehabilitation program after acute MI were divided into two groups according to the peak serum creatine phosphokinase (CPK) level: the group with large infarction (Group 1) (> or = 5000 U/l peak CPK, 64 patients) and the group with less extensive infarction (Group 2) (< 5000 U/I, 232 patients). Exercise capacity was assessed before and after a 3-month cardiac rehabilitation program that included exercise training.

RESULTS

Before exercise training, both the peak work rate (p < 0.05) and peak oxygen uptake (VO2) (p < 0.01) were significantly lower in Group 1 than in Group 2. After exercise training, the changes in peak work rate and peak VO2 were significantly greater in Group 1 than in Group 2 (both p < 0.01). The infarction size measured by the peak CPK level correlated significantly with both the baseline exercise capacity and its improvement after exercise training, although these correlations were insignificant in a multivariate analysis. In the multivariate analysis, the improvement in exercise capacity is determined by age and baseline exercise capacity, which is determined by the duration of inactivity, minute ventilation (VE)/VCO2 slope and left ventricular end-diastolic pressure.

CONCLUSIONS

Compared with patients with small- to medium-size myocardial infarction, patients with large infarction gain a greater improvement in exercise capacity after exercise training due to reversal of physical deconditioning and improvement in congestive heart failure.

Long-term versus intermediate-term supervised exercise training in advanced heart failure: Effects on exercise tolerance and mortality

AIM

To date there have been no studies exploring the effects of long-term versus intermediate-term and short-term supervised exercise training program in patients with severe chronic heart failure (CHF) on optimal medical therapy. We assessed exercise tolerance and mortality in CHF patients undergoing long- versus intermediate-term exercise training (ET).

METHODS

Forty-two consecutive severe CHF patients (New York Heart Association functional class III) were referred for a supervised exercise and cardiac rehabilitation program and were followed-up for 3 years: 20/42 (48%) patients discontinued ET after intermediate-term period of 1.6+/-0.8 years (Group A, intermediate-term ET), and 22/42 (52%) remained on the ET program for 3.0+/-0.3 years (Group B, long-term ET). Exercise duration, 6-min walked distance and metabolic equivalents (METs) assessed by modified Bruce protocol were recorded before, 4.5 months after, and 3 years after initiation of ET.

RESULTS

Both groups were comparable regarding age, gender, prevalence of ischemic etiology, mean ejection fraction and medications. Risk factors for ischemic heart disease were similar, except for the prevalence of diabetes, which was higher in Group A compared to Group B (11/20 versus 5/22, p=0.03). Significantly more Group A patients died after ET discontinuation (4/20 versus 0/22, p=0.01). At the end of follow-up a significant improvement could be seen in Group B patients compared to A in exercise duration, 6-min walked distance and metabolic equivalents (p<0.01 for all).

CONCLUSIONS

Higher survival rate was observed in severe CHF patients undergoing long-term versus intermediate-term exercise training. Long-term supervised exercise training is safe and improves exercise tolerance in these patients.

Exercise and the heart failure patient: aerobic vs strength training--is there a need for both?

Heart failure (HF) is characterized by general muscular weakness, muscle atrophy, and exercise intolerance that lead to reductions in functional capacity, ability to perform activities of daily living, and health-related quality of life. Until recently, exercise programs for patients with HF were centered on aerobic exercise training alone. Although many activities of daily living require significant muscle strength, the role of strength training for HF patients, either alone or in combination with aerobic exercise, has not been well studied. There is suggestive evidence that combined strength-aerobic exercise training may offer additional benefits in terms of health-related quality of life and functional capacity. Strength training can be targeted to reduce muscle atrophy to a greater extent than aerobic training. Further research is required to isolate the specific role of strength training regarding improvements in prognosis, HF-related morbidity and hospitalization, and health-related quality of life for patients with HF.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

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.

Exercise rehabilitation in chronic heart failure

The past 15 years of research involving patients with heart failure have provided a lot of new information regarding how exercise training lessens the exercise intolerance that is characteristic of these patients. Despite these new understandings, the prescription of regular exercise and rehabilitation in eligible patients is not embraced by all practitioners. Such reluctance may be due, in part, to concerns about either the safety of the treatment or the absence of multisite, randomized, controlled trial data that evaluates clinical end-points. This paper focuses on how exercise capacity is improved through training in patients with heart failure and suggests future considerations with respect to the study and application of this novel therapy.

Cardiovascular Adaptations to Exercise Training After Uncomplicated Acute Myocardial Infarction

OBJECTIVE

This study examined the cardiovascular adaptations of an exercise training program and evaluated the role of peripheral vasodilator capacity in contributing to these adaptations after myocardial infarction.

DESIGN

A total of 44 consecutive patients with uncomplicated myocardial infarction underwent 3 wks of exercise training. Controls (n = 12) with comparable myocardial infarction were selected from our database and were restricted to a program with minimal activity. All patients performed cardiopulmonary exercise testing with hemodynamic measurements. Forearm and calf reactive hyperemic flow were measured by venous occlusive plethysmography as indices of peripheral vasodilator capacity.

RESULTS

Despite no change in arteriovenous oxygen difference at peak exercise after training, training resulted in significant increases in oxygen consumption, cardiac output, and stroke volume and a significant decrease in systemic vascular resistance at peak exercise (overall, P < 0.05). Calf reactive hyperemic flow increased significantly after training (P < 0.001), but forearm reactive hyperemic flow did not. Furthermore, increase in calf reactive hyperemic flow after training had a positive correlation with increases in peak cardiac output, stroke volume, and oxygen consumption after training and an inverse correlation with peak systemic vascular resistance.

CONCLUSIONS

Exercise training improved exercise tolerance by improving hemodynamic responses to exercise after myocardial infarction. This improved exercise performance was linked to a training-induced increase in calf vasodilator capacity.

Peak oxygen uptake. Myth and truth about an internationally accepted reference value

This article critically examines the execution of VO(2)-peak testing in cardiac patients and questions their appropriate interpretation. In the first part, the most common clinical implications of VO(2)peak measurements are discussed: assessment of (changes in) functional capacity, evaluation of the necessity of invasive diagnostic/therapeutic measures, reference for exercise prescriptions, determination of prognosis. In the second part, important methodological problems and constraints are addressed and illustrated by references to scientific studies. Finally, recommendations are given for meaningful VO(2)peak testing. It is evident that failure to strictly follow such recommendations might result in misleading ergometric findings and, thus, in over- or underestimation of endurance capacity and/ or training effects.

Motivational interviewing to promote physical activity for people with chronic heart failure

AIM

This paper reports a study comparing, over a 5-month period, two different methods of increasing physical activity: a traditional exercise programme and one based on motivational interviewing.

BACKGROUND

Chronic heart failure is associated with poor quality of life that can be improved by increased physical activity. Patients who are directed to engage in physical activity have a record of low compliance.

METHOD

Sixty older aged heart failure patients were randomly assigned to standard care, motivational interviewing or both treatments. The primary outcome was physical activity (kcal/kg/day), with the 6-minute walk test as a secondary outcome.

FINDINGS

At entry, no significant differences were observed between the three groups. Following treatment, the 'motivational interviewing' and 'both treatments' groups reported an increase in their level and type of activities, whereas the 'standard care' group did not. All groups significantly increased their 6-minute walk distance.

CONCLUSIONS

Motivational interviewing, which incorporates established behaviour change principles and a flexible approach to promotion of activity, increases reported physical activity in older patients with heart failure over a short period. In terms of level and type of activity, this approach gives a better outcome than standard care, and nurses should explore alternative strategies to promote health in this population.

Exercise programmes for patients with chronic heart failure

The safety and efficacy of exercise training in patients with chronic heart failure (CHF) have been reported in a large number of scientific studies, with endurance training representing the most frequently applied training stimulus. Beneath the common continuous method of endurance training, the interval method (short bouts of intense exercise interspersed with pre-scheduled rest intervals), was also applied in some studies. Ergometric testing is a prerequisite for all individualised training prescription and is an appropriate method of efficacy documentation. However, there is a surprisingly large range of exercise intensities being prescribed to patients with CHF. Most of the prescription models refer to maximal ergometric measurements. Submaximal references from lactate and ventilatory curves represent an alternative method in measuring accuracy and efficacy of training. The course of heart rate during submaximal incremental exercise can be reliably used to indicate endurance gains in CHF. Some positive reports exist for carefully executed strength endurance training for patients with CHF and there are convincing arguments for the use of coordination and flexibility exercises; however, substantial scientific evidence is lacking.

Effects of exercise training on aerobic capacity and quality of life in individuals with heart failure

PURPOSE

The purpose of this study was to determine whether subjects with chronic heart failure, who completed a 12-week rehabilitation program, would have significantly greater quality of life, better aerobic fitness, less difficulty with symptoms of heart failure, greater self-efficacy for exercise, and higher daily activity levels when compared with subjects in a control group.

METHODS

Thirty-one males, aged 64 +/- 10 years with left ventricular ejection fraction of 29 +/- 7%, were randomized to a moderate intensity supervised aerobic exercise program (n = 15) or a control group (n = 16). Twenty-seven subjects completed at least 1 follow-up assessment.

RESULTS

After 12 weeks there were significant differences in the change scores for perceived physical function (using RAND Corporation's 36-item short form) (P =.025) and peak oxygen uptake (P =.019) between the exercise and control groups with the exercise group experiencing improved physical function and fitness.

CONCLUSIONS

Exercise training in adults with heart failure increases exercise tolerance and perceived physical function. Improved heart failure symptoms, self-efficacy for exercise, or increased physical activity may not be associated with enhancement of exercise tolerance.

Exercise training for patients with heart failure: a systematic review of factors that improve mortality and morbidity

PURPOSE

To determine the efficacy of exercise training and its effects on outcomes in patients with heart failure.

METHODS

MEDLINE, Medscape, and the Cochrane Controlled Trials Registry were searched for trials of exercise training in heart failure patients. Data relating to training protocol, exercise capacity, and outcome measures were extracted and reviewed.

RESULTS

A total of 81 studies were identified: 30 randomized controlled trials, five nonrandomized controlled trials, nine randomized crossover trials, and 37 longitudinal cohort studies. Exercise training was performed in 2387 patients. The average increment in peak oxygen consumption was 17% in 57 studies that measured oxygen consumption directly, 17% in 40 studies of aerobic training, 9% in three studies that only used strength training, 15% in 13 studies of combined aerobic and strength training, and 16% in the one study on inspiratory training. There were no reports of deaths that were directly related to exercise during more than 60,000 patient-hours of exercise training. During the training and follow-up periods of the randomized controlled trials, there were 56 combined (deaths or adverse events) events in the exercise groups and 75 combined events in the control groups (odds ratio [OR] = 0.98; 95% confidence interval [CI]: 0.61 to 1.32; P = 0.60). During this same period, 26 exercising and 41 nonexercising subjects died (OR = 0.71; 95% CI: 0.37 to 1.02; P = 0.06).

CONCLUSION

Exercise training is safe and effective in patients with heart failure. The risk of adverse events may be reduced, but further studies are required to determine whether there is any mortality benefit.

Exercise at ventilatory threshold aggravates left ventricular remodeling in patients with extensive anterior acute myocardial infarction

BACKGROUND

The effects of physical training on ventricular remodeling after extensive anterior acute myocardial infarction (AMI) have not yet been defined. This randomized controlled study examines whether exercise aggravates left ventricular (LV) remodeling in patients with extensive anterior AMI.

METHODS

Forty-eight consecutive patients with a first extensive anterior AMI and an LV ejection fraction (EF) of <45% assessed with left ventriculography (LVG) within 3 days of onset were randomly allocated to a training group (n = 24) or a control group (n = 24). Exercise intensity was determined by the heart rate of each patient at ventilatory threshold (VT). Three weeks after onset, a second LVG was performed, followed by a supervised exercise program at VT for 12 weeks. The LVG was reassessed after the exercise program. We then calculated the global LV volume (end-diastolic volume index [EDVI], end-systolic volume index [ESVI]) and systolic expansion volume index (SEVI), a new parameter for measuring the infarction site expansion at the end-systolic phase.

RESULTS

Both EDVI and ESVI significantly decreased in the control group from 1 to 4 months after onset (91.2 +/- 26.1 to 83.3 +/- 24.0 mL/m2, P <.05; 52.4 +/- 22.5 to 45.7 +/- 18.8 mL/m2, P <.01, respectively), but not in the exercise group. The SEVI also significantly decreased in the control group from 1 to 4 months (33.1 +/- 16.9 to 25.7 +/- 13.9 mL/m2, P <.05), but not in the training group (34.2 +/- 12.9 to 36.5 +/- 15.5 mL/m2, P = not significant).

CONCLUSION

Exercise while healing in patients with extensive anterior AMI, even at the VT level, induces LV enlargement and thus might aggravate LV remodeling. Therefore, in these patients, clinicians should consider withholding exercise training for at least 8 weeks, versus the 3-week period used in this trial.

Exercise based rehabilitation for heart failure

BACKGROUND

The prevalence of chronic heart failure is increasing, and increases with increasing age. Major symptoms include breathlessness and restricted activities of daily living due to reduced functional capacity, which in turn affects quality of life. Exercise training has been shown to be effective in patients with coronary heart disease and has been proposed as an intervention to improve exercise tolerance in patients with heart failure.

OBJECTIVES

To determine the effectiveness of exercise based interventions compared with usual medical care on the mortality, morbidity, exercise capacity and health related quality of life, of patients with heart failure.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (The Cochrane Library Issue 2, 2001), MEDLINE (2000 to March 2001), EMBASE (1998 to March 2001), CINAHL (1984 to March 2001) and reference lists of articles. We also sought advice from experts.

SELECTION CRITERIA

RCTs of exercise based interventions. The comparison group was usual medical care as defined by the study, or placebo. Adults of all ages with chronic heart failure. Only those studies with criteria for diagnosis of heart failure (based on clinical findings or objective indices) have been included.

DATA COLLECTION AND ANALYSIS

Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information.

MAIN RESULTS

Twenty-nine studies met the inclusion criteria, with 1126 patients randomised. The majority of studies included both patients with primary and secondary heart failure, NYHA class II or III. None of the studies specifically examined the effect of exercise training on mortality and morbidity as most were of short duration. Exercise training significantly increased VO(2) max by (WMD random effects model) 2.16 ml/kg/min (95% CI 2.82 to 1.49), exercise duration increased by 2.38 minutes (95% CI 2.85 to 1.9), work capacity by 15.1 Watts (95% CI 17.7 to 12.6) and distance on the six minute walk by 40.9 metres (95% CI 64.7 to 17.1). Improvements in VO(2) max were greater for training programmes of greater intensity and duration. HRQoL improved in the seven of nine trials that measured this outcome.

REVIEWERS' CONCLUSIONS

Exercise training improves exercise capacity and quality of life in patients mild to moderate heart failure in the short term. There is currently no information regarding the effect of exercise training on clinical outcomes. The findings are based on small-scale trials in patients who are unrepresentative of the total population of patients with heart failure. Other groups (more severe patients, the elderly, women) may also benefit. Large-scale pragmatic trials of exercise training of longer duration, recruiting a wider spectrum of patients are needed to address these issues.

Cardiac rehabilitation following percutaneous revascularization, heart transplant, heart valve surgery, and for chronic heart failure

This review discusses the scientific and clinical evidence for cardiac rehabilitation in patients who have undergone percutaneous revascularization, heart transplant, and heart valve surgery, and in patients with chronic heart failure. Across these diagnoses, regardless of age, there is considerable benefit of cardiac rehabilitation and supervised exercise training for increasing functional capacity, favorably modifying disease-related risk factors, decreasing symptoms, detecting signs and symptoms of disease before they become serious complications, and improving quality of life. The available evidence for this component of cardiovascular disease management, albeit not perfect, still warrants its more widespread application.

Mechanisms of exercise training in patients with heart failure

BACKGROUND

The reduction of exercise capacity because of fatigue and dyspnea in patients with heart failure can be improved with exercise training. We sought to examine the mechanisms of exercise training as an adjunctive treatment strategy for patients with heart failure.

METHODS

We reviewed the published data on the possible mechanisms of effect of exercise training in heart failure.

RESULTS

Symptoms of heart failure may be explained on the basis of abnormal skeletal muscle perfusion and structure and endothelial function. Exercise training has been shown to engender changes in muscle structure and biochemistry and vascular function, although effects on cardiac function have not been detected uniformly and may require longer training periods.

CONCLUSIONS

A suitable, long-term program of exercise training may reverse unfavorable interactions among the heart, vessels, and skeletal muscles. These improvements may be preserved with an ongoing maintenance program.

Effect of aerobic and resistance exercise on central hemodynamic responses in severe chronic heart failure

Exercise is now considered an important component of management in chronic heart failure (CHF), but little is known about central hemodynamic changes that occur during different exercise modalities in these patients. Seventeen patients (ejection fraction 25 +/- 2%) undertook brachial artery and right heart catheterization and oxygen consumption assessment at rest, during submaximal and peak cycling (Cyc), and during submaximal upper and lower limb resistance exercise. Cardiac output (CO) increased relative to baseline during peak Cyc (P < 0.05) but did not change during submaximal Cyc or upper or lower limb exercise. Heart rate (HR) was lowest during upper limb exercise and progressively increased during lower limb exercise, submaximal Cyc, and peak Cyc, with significant differences between each of these (P < 0.01). Conversely, stroke volume (SV) decreased during submaximal Cyc and lower limb exercise and was lower during peak and submaximal Cyc and lower limb exercise than during upper limb exercise (P < 0.05). CHF patients are dependent on increases in HR to increase CO during exercise when SV may decline. Resistance exercise, performed at appropriate intensity, induces a similar hemodynamic burden to aerobic exercise in patients with CHF.