Effect of exercise training on myocardial remodeling in patients with reduced left ventricular function after myocardial infarction: application of magnetic resonance imaging

Mechanisms of myocardial reverse remodelling and its clinical significance: A scientific statement of the ESC Working Group on Myocardial Function

Cardiovascular disease (CVD) is the leading cause of morbimortality in Europe and worldwide. CVD imposes a heterogeneous spectrum of cardiac remodelling, depending on the insult nature, that is, pressure or volume overload, ischaemia, arrhythmias, infection, pathogenic gene variant, or cardiotoxicity. Moreover, the progression of CVD-induced remodelling is influenced by sex, age, genetic background and comorbidities, impacting patients' outcomes and prognosis. Cardiac reverse remodelling (RR) is defined as any normative improvement in cardiac geometry and function, driven by therapeutic interventions and rarely occurring spontaneously. While RR is the outcome desired for most CVD treatments, they often only slow/halt its progression or modify risk factors, calling for novel and more timely RR approaches. Interventions triggering RR depend on the myocardial insult and include drugs (renin-angiotensin-aldosterone system inhibitors, beta-blockers, diuretics and sodium-glucose cotransporter 2 inhibitors), devices (cardiac resynchronization therapy, ventricular assist devices), surgeries (valve replacement, coronary artery bypass graft), or physiological responses (deconditioning, postpartum). Subsequently, cardiac RR is inferred from the degree of normalization of left ventricular mass, ejection fraction and end-diastolic/end-systolic volumes, whose extent often correlates with patients' prognosis. However, strategies aimed at achieving sustained cardiac improvement, predictive models assessing the extent of RR, or even clinical endpoints that allow for distinguishing complete from incomplete RR or adverse remodelling objectively, remain limited and controversial. This scientific statement aims to define RR, clarify its underlying (patho)physiologic mechanisms and address (non)pharmacological options and promising strategies to promote RR, focusing on the left heart. We highlight the predictors of the extent of RR and review the prognostic significance/impact of incomplete RR/adverse remodelling. Lastly, we present an overview of RR animal models and potential future strategies under pre-clinical evaluation.

Impact of exercise training on myocardial contractile functions assessed by cardiac magnetic resonance in post-myocardial infarction patients

Background

Improvement of functional capacity and mortality reduction in post-MI patients were found to be associated with regular exercise training. The cardiac magnetic resonance (CMR) is considered the most accurate non-invasive modality in quantitative assessment of left ventricular (LV) volumes and systolic functions. Our main objective was to investigate the impact of exercise training on LV systolic functions in patients post anterior MI using CMR. 32 patients on recommended medical treatment 4 week after having a successful primary PCI for an anterior MI were recruited, between May 2018 and May 2019. They were divided into two groups, training group (TG): 16 assigned to a 12 week exercise training program and control group (CG): 16 who received medical treatment without participating in the exercise training program. Treadmill exercise using modified Bruce protocol was done to TG before and after the training program in order to record the resting and maximum HR, metabolic equivalent (MET), and calculate HR reserve. CMR was performed for all patients 4 weeks after PCI and was repeated after completion of the study period to calculate ejection fraction (EF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and wall motion score index (WMSI).

Results

100% were males. 6 patients from CG dropped during follow-up, no statistically significant difference between the two groups regarding age, BMI, smoking status, hypertension, diabetes mellitus and dyslipidemia. Using the CMR, the TG showed significant improvement in EF (36.6 ± 14.2% to 43.1 ± 12.4%; P < 0.001) and WMSI (2.03 ± 0.57 to 1.7 ± 0.49; P < 0.001), without statistically significant change in LV volumes. Regarding CG no significant changes in EF, WMSI, LV volumes were found. There was significant improvement in EF and WMSI change before and after study in TG vs. CG [6.5 (2.3–9.0) vs. − 2.0 (− 6.8 to 1.3), P value < 0.001] and [− 0.3 (− 0.5 to 0.1) vs. 0.1 (− 0.1 to − 0.5), P value 0.001] respectively.

Conclusions

12 weeks of exercise training program in post-MI patients have a favorable impact on LV global and regional systolic functions without adversely affecting LV remodeling (as assessed by CMR).

Conditioning Program Prescribed from the External Training Load Corresponding to the Lactate Threshold Improved Cardiac Function in Healthy Dogs

This research focuses on the adjustments in systolic and diastolic functions that are not fully understood in dogs submitted to athletic training. Beagle dogs carried out an endurance training program (ETP) prescribed from the external training load, corresponding to 70-80% of the lactate threshold (VLT) velocity. Eighteen dogs were randomly assigned to two groups: control (C, n = 8), active dogs that did not perform any forced exercise, and trained (T, n = 10), submitted to the ETP during eight weeks. All dogs were evaluated before and after the ETP period using two-dimensional echocardiography, M-mode, Doppler, and two-dimensional speckle tracking. A principal component analysis (PCA) of the echocardiographic variables was performed. The ETP improved the left ventricular internal dimension at the end of diastole (LVDd), the left ventricular internal dimension at the end of diastole to aorta ratio (LVDd: Ao), and the strain rate indices. PCA was able to capture the dimensionality and qualitative echocardiography changes produced by the ETP. These findings indicated that the training prescribed based on the lactate threshold improved the diastolic and systolic functions. This response may be applied to improve myocardial function, promote health, and mitigate any injuries produced during heart failure.

Beneficial Effects of Baduanjin Exercise on Left Ventricular Remodelling in Patients after Acute Myocardial Infarction: an Exploratory Clinical Trial and Proteomic Analysis

BACKGROUND

The beneficial effects of physical exercise on cardiac remodelling improvement after myocardial infarction have already been suggested. However, the results of previous clinical trials have not been consistent. Moreover, the putative molecular mechanisms leading to the clinically observed effects of physical exercise still remain elusive.

AIM

We aimed to evaluate whether the well-defined and strictly controlled traditional Chinese Qigong Baduanjin exercise (BE) would attenuate the adverse left ventricular (LV) remodelling in patients with ST-elevation myocardial infarction (STEMI).

METHODS

A total of 110 clinically stable STEMI patients, following successful revascularization of their infarcted coronary arteries, were randomized and enrolled in two groups: 56 were subjected to a 12-week BE-based cardiac rehabilitation programme (BE group), and the remaining 54 were exposed to the usual physical exercise (control group) for the same time period. The primary outcome was the change from baseline to 6 months in the echocardiographic LV end-diastolic volume index (ΔLVEDVi). Proteomic analysis was also performed to uncover associated mechanisms.

RESULTS

Compared with the control group, the BE group showed significantly lower ΔLVEDVi (-5.1 ± 1.1 vs. 0.3 ± 1.2 mL/m², P < 0.01). Proteomic analysis revealed BE-induced variations in the expression of 80 proteins linked to regulation the of metabolic process, immune process, and extracellular matrix reorganization. Furthermore, correlation analyses between the validated serum proteomes and primary endpoint demonstrated a positive association between ΔLVEDVi and MMP-9 expression, but a negative correlation between ΔLVEDVi and CXCL1 expression.

CONCLUSION

This is the first study indicating that BE in STEMI patients can alleviate adverse LV remodelling associated with beneficial energy metabolism adaptation, inflammation curbing, and extracellular matrix organization adjustment.

Irisin vs. Treadmill Exercise in Post Myocardial Infarction Cardiac Rehabilitation in Rats

BACKGROUND

Irisin is an exercise-induced myokine that could play a role in post-myocardial infarction (MI) cardiac rehabilitation.

AIM OF THE STUDY

We investigated the ability of dihydromyricetin to mimic the effects of exercise on raising serum irisin and on enhancing cardiac function and remodeling following MI in rats.

METHODS

MI was induced in albino rats by subcutaneous injection of isoproterenol (85 mg/kg) for 2 consecutive days at an interval of 24 h. One week post-MI, rats either underwent physical exercise by running on a motor-driven treadmill at 25 m/min, 30 min/d, 5 d/week or received orally dihydromyricetin 100 mg/kg/d, for 8 weeks.

RESULTS

Exercise and dihydromyricetin raised serum irisin 1.8 and 1.9 folds as compared to sedentary rats (p <0.001) with no difference between both regimens (p = 0.992). There was an improvement of cardiac remodeling where β-myosin heavy chain level was not different in exercise and dihydromyricetin groups from normal group (p = 0.695, p = 0.470). The heart rate variability domains increased back to normal. However, exercise was superior to dihydromyricetin in improving cardiac contractility by increasing carotid blood flow, stroke volume and cardiac output to be insignificant from normal rats (p = 0.899, p = 0.850, p = 0.912). Meanwhile, treatment with dihydromyricetin showed reduction by 29% of carotid blood flow, 24% of stroke volume and 25% of cardiac output compared to normal rats (p <0.001).

CONCLUSIONS

DHM could mimic the effect of exercise in stimulating irisin secretion but it is not as effective as exercise in improving myocardial contractility.

Validity of the Low-Impact Dance for exercise-based cardiac rehabilitation program

PURPOSE

The aim of this study was to evaluate the oxygen uptake in patients with cardiovascular disease during the low-impact dance program and to compare the findings with the values at peak oxygen uptake (VO2) and aerobic threshold (AT).

METHODS

The study included 19 patients with cardiovascular disease [age, 68.3±8.7 years; left-ventricular ejection fraction, 60.3%±8.7%; peak VO2, 6.6±1.1 metabolic equivalents (METs)] who were receiving optimal medical treatment. Their heart rate and VO2 were monitored during cardiopulmonary exercise testing (CPET) and during the low impact dance. The dance involved low-impact dynamic sequences. The patients completed two patterns of low-impact dance, and metabolic gas exchange measurements were obtained using a portable ergospirometry carried in a backpack during the dance sessions.

RESULTS

The mean values of VO2 (4.0±0.2 METs and 3.9±0.3 METs) and those of heart rate (105.2±2.9 bpm and 96.8±2.6 bpm) during the dance program were not significantly differ from the AT value (4.5±0.2 METs) obtained in CPET. The median (and interquartile range) RPE reported after the dance exercise trials was 11 (9-13). No signs of overexertion were observed in any of the patients during either dance exercise trial.

CONCLUSIONS

The results suggest that it is reasonable to consider the low-impact dance program as an aerobic exercise program in cardiac rehabilitation. Our findings have important implications for exercise training programs in the cardiac rehabilitation setting and for future studies.

Improvement in cardiac dysfunction with a novel circuit training method combining simultaneous aerobic-resistance exercises. A randomized trial

Introduction

Exercise is considered a valuable nonpharmacological intervention modality in cardiac rehabilitation (CR) programs in patients with ischemic heart disease. The effect of aerobic interval exercise combined with alternating sets of resistance training (super-circuit training, SCT) on cardiac patients' with reduced left ventricular function, post-myocardial infarction (MI) has not been thoroughly investigated.

Aim of study

to improve cardiac function with a novel method of combined aerobic-resistance circuit training in a randomized control trial by way of comparing the effectiveness of continuous aerobic training (CAT) to SCT on mechanical cardiac function. Secondary to compare their effect on aerobic fitness, manual strength, and quality of life in men post MI. Finally, to evaluate the safety and feasibility of SCT.

Methods

29 men post-MI participants were randomly assigned to either 12-weeks of CAT (n = 15) or SCT (n = 14). Both groups, CAT and SCT exercised at 60%-70% and 75–85% of their heart rate reserve, respectively. The SCT group also engaged in intermittently combined resistance training. Primary outcome measure was echocardiography. Secondary outcome measures were aerobic fitness, strength, and quality of life (QoL). The effectiveness of the two training programs was examined via paired t-tests and Cohen's d effect size (ES).

Results

Post-training, only the SCT group presented significant changes in echocardiography (a reduction in E/e' and an increase in ejection fraction, P<0.05). Similarly, only the SCT group presented significant changes in aerobic fitness (an increase in maximal metabolic equivalent, P<0.05). In addition, SCT improvement in the physical component of QoL was greater than this observed in the CAT group. In both training programs, no adverse events were observed.

Conclusion

Men post-MI stand to benefit from both CAT and SCT. However, in comparison to CAT, as assessed by echocardiography, SCT may yield greater benefits to the left ventricle mechanical function as well as to the patient's aerobic fitness and physical QoL. Moreover, the SCT program was found to be feasible as well as safe.

Baduanjin Exercise Prevents post-Myocardial Infarction Left Ventricular Remodeling (BE-PREMIER trial): Design and Rationale of a Pragmatic Randomized Controlled Trial

BACKGROUND

Left ventricular (LV) remodeling following myocardial infarction (MI) is an established prognostic factor for adverse cardiovascular events and the leading cause of heart failure. Empirical observations have suggested that Baduanjin exercise, an important component of traditional Chinese Qigong, may exert potential benefits on cardiopulmonary function. However, the impact of a Baduanjin exercise-based cardiac rehabilitation program for patients recovering from a recent MI has yet to be assessed. The aim of this trial is to evaluate the potential role of Baduanjin exercise in preventing the maladaptive progression to adverse LV remodeling in patients post-MI.

METHODS

A total of 110 clinically stable patients following an MI after undergoing successful infarct-related artery reperfusion will be randomly assigned to the Baduanjin exercise group or usual exercise control group. In addition to usual physical activity, participants in the Baduanjin exercise group will participate in a 45 min Baduanjin exercise training session twice a week, for a total of 12 weeks. The primary endpoint will be the percentage change in LV end-diastolic volume index (LVEDVi) assessed using echocardiography from baseline to 6 months.

CONCLUSION

The results of this study may provide novel evidence on the efficacy of Baduanjin exercise therapy in post-MI patients in reversing adverse LV remodeling and improving clinical outcome.

TRIAL REGISTRATION

Clinical Trials.gov: NCT02693795.

High-intensity interval training, but not continuous training, reverses right ventricular hypertrophy and dysfunction in a rat model of pulmonary hypertension

Exercise is beneficial in pulmonary arterial hypertension (PAH), although studies to date indicate little effect on the elevated pulmonary pressures or maladaptive right ventricle (RV) hypertrophy associated with the disease. For chronic left ventricle failure, high-intensity interval training (HIIT) promotes greater endothelial stimulation and superior benefit than customary continuous exercise training (CExT); however, HIIT has not been tested for PAH. Therefore, here we investigated acute and chronic responses to HIIT vs. CExT in a rat model of monocrotaline (MCT)-induced mild PAH. Six weeks of treadmill training (5 times/wk) were performed, as either 30 min HIIT or 60 min low-intensity CExT. To characterize acute hemodynamic responses to the two approaches, novel recordings of simultaneous pulmonary and systemic pressures during running were obtained at pre- and 2, 4, 6, and 8 wk post-MCT using long-term implantable telemetry. MCT-induced decrement in maximal aerobic capacity was ameliorated by both HIIT and CExT, with less pronounced pulmonary vascular remodeling and no increase in RV inflammation or apoptosis observed. Most importantly, only HIIT lowered RV systolic pressure, RV hypertrophy, and total pulmonary resistance, and prompted higher cardiac index that was complemented by a RV increase in the positive inotrope apelin and reduced fibrosis. HIIT prompted a markedly pulsatile pulmonary pressure during running and was associated with greater lung endothelial nitric oxide synthase after 6 wk. We conclude that HIIT may be superior to CExT for improving hemodynamics and maladaptive RV hypertrophy in PAH. HIIT's superior outcomes may be explained by more favorable pulmonary vascular endothelial adaptation to the pulsatile HIIT stimulus.

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.

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.

Cardiac remodeling and physical training post myocardial infarction

After myocardial infarction (MI), the heart undergoes extensive myocardial remodeling through the accumulation of fibrous tissue in both the infarcted and noninfarcted myocardium, which distorts tissue structure, increases tissue stiffness, and accounts for ventricular dysfunction. There is growing clinical consensus that exercise training may beneficially alter the course of post-MI myocardial remodeling and improve cardiac function. This review summarizes the present state of knowledge regarding the effect of post-MI exercise training on infarcted hearts. Due to the degree of difficulty to study a viable human heart at both protein and molecular levels, most of the detailed studies have been performed by using animal models. Although there are some negative reports indicating that post-MI exercise may further cause deterioration of the wounded hearts, a growing body of research from both human and animal experiments demonstrates that post-MI exercise may beneficially alter the course of wound healing and improve cardiac function. Furthermore, the improved function is likely due to exercise training-induced mitigation of renin-angiotensin-aldosterone system, improved balance between matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1, favorable myosin heavy chain isoform switch, diminished oxidative stress, enhanced antioxidant capacity, improved mitochondrial calcium handling, and boosted myocardial angiogenesis. Additionally, meta-analyses revealed that exercise-based cardiac rehabilitation has proven to be effective, and remains one of the least expensive therapies for both the prevention and treatment of cardiovascular disease, and prevents re-infarction.

[Effects of long-term exercise training on left ventricular function and remodeling in patients with anterior wall myocardial infarction]

OBJECTIVE

To assess the effects of long-term exercise training on the function and remodeling of the left ventricle after myocardial infarction.

METHODS

We studied 90 patients with a first acute anterior-wall myocardial infarction, all received conventional medical treatment. Symptom-limited maximal exercise stress tests, echocardiograms and effort-rest isotopic ventriculographies at 2, 6 and 12 months after myocardial infarction were performed; the follow-up time averaged 36.3±17 months. All patients joined a cardiac rehabilitation program with moderate or intense exercise training lasting at least a year. Of all patients, 41.1% suffered severe left ventricle dysfunction.

RESULTS

Ergometric parameters that expressed functional capacity increased significantly (P<.0005) at the sixth month evaluation and remained unchanged after a year. There was significant decrease (P<.01) of exercise myocardial ischemia at 6 months. The variables that measured size and function of left ventricle did not change during evolution. Morbidity amounted to 16.7% and total mortality of the series was 13.3%, with 8.9% of cardiovascular cause.

CONCLUSIONS

Long-term exercise training showed no deleterious effects on left ventricle function or remodeling and beneficial functional and clinical effects were obtained in these rehabilitated postinfarction patients.

The impacts of cardiac rehabilitation program on echocardiographic parameters in coronary artery disease patients with left ventricular dysfunction

Introduction. The accurate impact of exercise on coronary artery disease (CAD) patients with left ventricular dysfunction is still debatable. We studied the effects of cardiac rehabilitation (CR) on echocardiography parameters in CAD patients with ventricular dysfunction. Methods. Patients with CAD who had ventricular dysfunction were included into an exercise-based rehabilitation program and received rehabilitation for eight weeks. All subjects underwent echocardiography before and at the end of the rehabilitation program. The echocardiography parameters, including left ventricular ejection fraction (LVEF), LV end-diastolic (LVEDD) and end-systolic diameters (LVESD), and peak exercise capacity measured in metabolic equivalents (METs), were assessed. Results. Seventy patients (mean age = 57.5 ± 10.2 years, 77.1% males) were included into the study. At the end of rehabilitation period, the LVEF increased from 45.14 ± 5.77% to 50.44 ± 8.70% (P < 0.001), and the peak exercise capacity increased from 8.00 ± 2.56 to 10.08 ± 3.00 METs (P < 0.001). There was no significant change in LVEDD (54.63 ± 12.96 to 53.86 ± 8.95 mm, P = 0.529) or in LVESD (38.91 ± 10.83 to 38.09 ± 9.04 mm, P = 0.378) after rehabilitation. Conclusion. Exercise training in postmyocardial infarction patients with ventricular dysfunction could have beneficial effects on cardiac function without adversely affecting LV remodeling or causing serious cardiac complications.

Functional and psychosocial effects of either a traditional dancing or a formal exercising training program in patients with chronic heart failure: a comparative randomized controlled study

OBJECTIVE

To compare the effects of traditional dancing with formal exercise training in terms of functional and cardiovascular benefits and motivation in patients with chronic heart failure.

DESIGN

Randomized controlled trial.

SETTING

Sports Medicine Laboratory.

SUBJECTS

Fifty-one Greek male patients aged 67.1±5.5 years with chronic heart failure of New York Heart Association (NYHA) class II-III, participated in an eight-month study.

INTERVENTIONS

They were randomly assigned to either training with Greek traditional dances (group A, n=18), formal exercise training (group B, n=16) or a sedentary control group (group C, n=17).

MAIN MEASURES

At entry and the end of the study all patients underwent cardiopulmonary exercise testing, functional ability assessment and quality of life evaluations. The Intrinsic Motivation Inventory was also used to assess participants' subjective experience.

RESULTS

After training group A showed increased peak oxygen consumption by 33.8% (19.5 vs. 26.1 ml/kg/min, p<0.05) and B by 32.3% (19.5 vs. 25.8 ml/kg/min, p<0.05), maximal treadmill tolerance by 48.5% (p<0.05) and by 46.4% (p<0.05), and a decreased Slope of expired minute ventilation for carbon dioxide output (VE/VCO2) slope by 18% (p<0.05) and 19.5% (p<0.05), respectively. Trained patients revealed significant improvement in the quality of life indices. Intrinsic Motivation Inventory was increased only in group A by 26.2% (3.08 vs. 3.87, p<0.05).

CONCLUSIONS

Exercise training in chronic heart failure patients with Greek traditional dances led to functional and cardiovascular benefits similar to formal exercise training and to a higher level of motivation.

Exercise training post-MI favorably modifies heart extracellular matrix in the rat

PURPOSE

In order to assess the effect of daily exercise on extracellular matrix remodeling in the heart after myocardial infarction (MI), we measured collagen concentration (%COL) and nonreducible collagen cross-linking (hydroxylysylpyridinoline, HP) in the right ventricle (RV), and regionally within the infarcted (INF) and viable left ventricular free wall (LVF) and septum (LVS), using a rodent MI training model.

METHODS

Infarcts (19%-24% of LV) were surgically induced in adult rats that were assigned to either trained (MI-TR) or sedentary (MI-SED) groups and compared to sham-surgery sedentary controls (SHAM).

RESULTS

In LVF, 10 wk of treadmill running had no effect on the increase (P < 0.001) in %COL seen with MI (MI-SED = 7.14% ± 0.15%, MI-TR = 7.61% ± 0.19%, SHAM = 3.55% ± 0.19%). However, it normalized the increase (P < 0.05) in HP cross-linking (MI-SED = 0.43 ± 0.02, MI-TR = 0.27 ± 0.03, SHAM = 0.30 ± 0.04 mol HP·mol(-1) collagen). The INF scar in MI-SED rats showed a sevenfold increase in %COL (P < 0.001) compared to SHAM LVF myocardium, an increase that was attenuated by training (MI-SED = 26% ± 1% vs MI-TR = 21% ± 2%; P < 0.05). However, training had no effect on MI-induced increases in cross-linking in the INF scar (1.01 ± 0.22 vs 0.84 ± 0.14 mol HP·mol(-1) collagen). In LVS, although a small but significant increase in %COL was seen in both MI groups, HP cross-linking was unaltered compared to SHAM rats. Training also normalized the increase observed in cross-linking in RV after MI.

CONCLUSIONS

Because increased HP cross-linking in the heart is associated with decreased chamber compliance, these findings may help to explain the improved heart function seen after daily exercise in cardiac rehabilitation patients.

Association between heart rate at rest and myocardial perfusion in patients with acute myocardial infarction undergoing cardiac rehabilitation - a pilot study

INTRODUCTION

This study was conducted to determine if there was a link among heart rate at rest (rHR), muscle volume changes, and single photon emission computed tomography (SPECT) parameters after 6-month cardiac rehabilitation in patients with acute myocardial infarction (AMI).

MATERIAL AND METHODS

Twenty-nine consecutive AMI patients (mean age: 63.0 ±9.1 years) who received appropriate percutaneous coronary intervention on admission were enrolled. (99m)Tc-Sestamibi myocardial SPECT images were obtained at the early (30 min) and delayed (4 h) phases after tracer injection at 2 weeks (0M) and 6 months (6M) after the onset of AMI. Within a few days of SPECT, all patients underwent cardiopulmonary exercise test for evaluation of cardiac rehabilitation effects. Before the initiation of exercise test, leg muscle volume was measured. All patients were stratified into the ≥ 70 beats per minute (bpm) (n = 15) or < 70 bpm (n = 14) group based on rHR at 6M.

RESULTS

There were no significant differences in the recanalization time, peak cardiac enzyme, or initial left ventricular ejection fraction between the two groups. After the 6-month training, the muscle volume changes in the lower limbs (< 70 bpm, 0.23 ±0.22; ≥ 70 bpm, -0.07 ±0.26, p < 0.05) were significantly greater in the < 70 bpm group than the ≥ 70 bpm group. The decreased rate of rHR had a significant correlation with the improved global severity (r = 0.62, p = 0.001) and extent (r = 0.48, p = 0.017) of left ventricle evaluated by (99m)Tc-Sestamibi myocardial SPECT delayed phase.

CONCLUSIONS

The result of this preliminary study demonstrated that improved myocardial perfusion was closely related to decreased rHR after cardiac rehabilitation.

Akt1-mediated skeletal muscle growth attenuates cardiac dysfunction and remodeling after experimental myocardial infarction

BACKGROUND

It is appreciated that aerobic endurance exercise can attenuate unfavorable myocardial remodeling following myocardial infarction. In contrast, little is known about the effects of increasing skeletal muscle mass, typically achieved through resistance training, on this process. Here, we utilized transgenic (TG) mice that can induce the growth of functional skeletal muscle by switching Akt1 signaling in muscle fibers to assess the impact of glycolytic muscle growth on post-myocardial infarction cardiac remodeling.

METHODS AND RESULTS

Male-noninduced TG mice and their nontransgenic littermates (control) were subjected to left anterior coronary artery ligation. Two days after surgery, mice were provided doxycycline in their drinking water to activate Akt1 transgene expression in a skeletal muscle-specific manner. Myogenic Akt1 activation led to diminished left ventricular dilation and reduced contractile dysfunction compared with control mice. Improved cardiac function in Akt1 TG mice was coupled to diminished myocyte hypertrophy, decreased interstitial fibrosis, and increased capillary density. ELISA and protein array analyses demonstrated that serum levels of proangiogenic growth factors were upregulated in Akt1 TG mice compared with control mice. Cardiac eNOS was activated in Akt1 TG mice after myocardial infarction. The protective effect of skeletal muscle Akt activation on cardiac remodeling and systolic function was abolished by treatment with the eNOS inhibitor l-NAME.

CONCLUSIONS

Akt1-mediated skeletal muscle growth attenuates cardiac remodeling after myocardial infarction and is associated with an increased capillary density in the heart. This improvement appears to be mediated by skeletal muscle to cardiac communication, leading to activation of eNOS-signaling in the heart.

The effect of regular physical activity on the left ventricle systolic function in patients with chronic coronary artery disease

The purpose of this study was to assess the influence of aerobic training on the left ventricular (LV) systolic function. Thirty patients with stable coronary artery disease, who had participated in the conducted 3-month physical training, were retrospectively divided into 2 cohorts. While patients in the cohort I (n=14) had continued training individually for 12 months, patients in the cohort II (n=16) had stopped training after finishing the conducted program. Rest and stress dobutamine/atropine echocardiography was performed in all patients before the training program and 1 year later. The peak systolic velocities of mitral annulus (Sa) were assessed by tissue Doppler imaging for individual LV walls. In addition, to determine global LV systolic longitudinal function, the four-site mean systolic velocity was calculated (Sa glob). According to the blood supply, left ventricular walls were divided into 5 groups: A- walls supplied by nonstenotic artery; B- walls supplied by coronary artery with stenosis ≤50 %; C- walls supplied by coronary artery with stenosis 51-70 %; D- walls with stenosis of supplying artery 71-99 %; and E- walls with totally occluded supplying artery. In global systolic function, the follow-up values of Sa glob in cohort I were improved by 0.23±0.36 as compared with baseline values at rest, and by 1.26±0.65 cm/s at the maximal load, while the values of Sa glob in cohort II were diminished by 0.53±0.22 (p=NS), and by 1.25±0.45 cm/s (p<0.05), respectively. Concerning the resting regional function, the only significant difference between cohorts in follow-up changes was found in walls E: 0.37±0.60 versus -1.76±0.40 cm/s (p<0.05). At the maximal load, the significant difference was found only in walls A (0.16±0.84 versus -2.67±0.87 cm/s; p<0.05). Patients with regular 12-month physical activity improved their global left ventricle systolic function mainly due to improvement of contractility in walls supplied by a totally occluded coronary artery.

The impact of early regular cardiac rehabilitation program on myocardial function after acute myocardial infarction

Objective

To determine if an early regular cardiac rehabilitation program would have an adverse effect on myocardial function after acute myocardial infarction (AMI).

Method

Patients who received percutaneous coronary intervention (PCI) after AMI were divided into the exercise group and control group in accordance with their willingness to participate. Patients in the exercise group (n=18) received ECG monitored exercise for six weeks and were instructed to maintain self exercise in their communities for four months. The control group (n=16) patients were just instructed of risk factor control. All the subjects underwent echocardiography at the time of the AMI as well as six months later. The echocardiography parameters, including the left ventricular ejection fraction (LVEF), stroke volume (SV), left ventricular end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD), were measured.

Results

In the exercise group, the LVEF increased to 59.58±9.24% and 61.58±9.63% after six weeks and six months, respectively (p<0.05), but SV, LVEDD and LVESD did not change (p>0.05).

Conclusion

Active participation in the cardiac rehabilitation program approximately two weeks after AMI did not have an adverse effect on the size of the left ventricle and myocardial function.

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.

Long-term myocardial adaptations after cardiac rehabilitation in heart failure: a randomized six-year evaluation using magnetic resonance imaging

OBJECTIVE

To assess exercise capacity and left ventricular function using magnetic resonance imaging (MRI) among patients with chronic heart failure randomized to a residential rehabilitation programme at baseline and six years after participation.

DESIGN

Randomized controlled study.

SETTING

Residential cardiac rehabilitation centre and community hospital.

INTERVENTION

One month of intensive exercise and risk reduction therapy including educational sessions, a low-fat diet, and 2 hours of individually prescribed exercise daily. Control subjects received usual care. Subjects were evaluated at baseline, after completing the one-month residential programme and six years later.

SUBJECTS

From an original study group of 50, 16 patients (8 exercise, 8 controls) with chronic heart failure were alive and available for evaluation after six years.

MAIN MEASURES

Cardiopulmonary exercise test responses and ventricular size and function using MRI.

RESULTS

Peak Vo(2) was 20.0 and 12.4% higher after the rehabilitation programme and six years later, respectively, whereas minimal changes were observed among controls. Left ventricular mass and volumes tended to decrease among subjects in the exercise group, whereas left ventricular mass and volumes tended to increase among control subjects after six years. Ejection fraction increased approximately 20% in both groups.

CONCLUSION

Six years after participation in a concentrated residential rehabilitation programme, exercise capacity was preserved and no significant changes were observed in ventricular size or function. These findings provide further support for exercise rehabilitation in chronic heart failure.

Beneficial effects of exercise training after myocardial infarction require full eNOS expression

Exercise training attenuates left ventricular (LV) dysfunction after myocardial infarction (MI). It could be speculated that these effects of exercise are mediated by increased endothelial NO synthase (eNOS) activity. In the present study we tested the hypothesis that eNOS plays a critical role in the exercise-induced amelioration of LV dysfunction after MI. MI or sham was induced in eNOS(-/-), eNOS(+/-) and eNOS(+/+) mice. After 8 weeks of voluntary wheel running (approximately 7 km/day in all groups) or sedentary housing, global cardiac function was determined in vivo and (immuno)histochemistry was performed to assess cardiomyocyte size, fibrosis, capillary density and apoptosis in remote myocardium. At baseline eNOS(-/-) mice had higher mean aortic pressure compared to eNOS(+/-) and eNOS(+/+) mice, but had normal global cardiac function. MI resulted in marked LV remodeling, including cardiomyocyte hypertrophy and a reduction in capillary density, increased fibrosis and apoptosis, as well as LV systolic and diastolic dysfunction to the same extent in all genotypes. In eNOS(+/+) MI mice exercise abolished fibrosis and apoptosis in the remote myocardium, attenuated LV systolic dysfunction and ameliorated pulmonary congestion. These beneficial effects were lost in eNOS(+/-) and eNOS(-/-) mice, while LV systolic dysfunction and pulmonary congestion in eNOS(+/-) mice were exacerbated by exercise. In conclusion, the beneficial effects of exercise after MI on LV remodeling and dysfunction depend critically on endogenous eNOS. The observation that the lack of one eNOS allele is sufficient to negate all beneficial effects of exercise, strongly suggests that exercise depends on full eNOS expression.

Prior exercise improves survival, infarct healing, and left ventricular function after myocardial infarction

We investigated the effects of voluntary wheel running before an acute myocardial infarction (MI) on survival, left ventricular (LV) remodeling and dysfunction and whether exercise before and after MI provides superior protection compared with either exercise intervention alone. After 2 wk of voluntary wheel running or sedentary housing, MI was induced in C57Bl/6 mice, after which exercise was stopped (EX-MI-SED and SED-MI-SED groups, where EX is exercise and SED is sedentary) or continued (EX-MI-EX and SED-MI-EX groups) for a period of 8 wk. Exercise after MI in SED-MI-EX mice had no effect on survival, the area of infarction, and global LV remodeling, but attenuated fibrosis and apoptosis in the remote myocardium and blunted LV dysfunction and pulmonary congestion compared with SED-MI-SED mice. Exercise before MI in both EX-MI-SED and EX-MI-EX mice decreased post-MI mortality compared with both SED-MI-SED and SED-MI-EX mice. Furthermore, in both pre-MI exercise groups, the infarct area was thicker, whereas interstitial fibrosis and apoptosis in the remote LV myocardium were blunted. In contrast, the ameliorating effects of either pre-MI or post-MI exercise alone on LV dysfunction were lost in EX-MI-EX mice, which may in part be related to the increased daily exercise distance in the first week post-MI in EX-MI-EX versus SED-MI-EX mice. In conclusion, exercise before or after MI blunted LV dysfunction, whereas only exercise before MI improved survival. These findings suggest that even when regular physical activity fails to prevent an acute MI, it can still act to improve cardiac function and survival after MI.

Effects of aerobic or aerobic and resistance training on cardiorespiratory and skeletal muscle function in heart failure: a randomized controlled pilot trial

OBJECTIVE

To examined the effects of different training modalities on exercise capacity (Vo( 2peak)), systolic function, muscular strength and endurance and quality of life in heart failure patients.

DESIGN

Randomized controlled trial.

SETTING

Cardiac rehabilitation centre in Canada.

SUBJECTS

Forty-two individuals with heart failure (62 +/- 12 years; New York Heart Association (NYHA) classes I-III).

INTERVENTIONS

Aerobic training (n = 14), combined aerobic and resistance training (n = 15) or usual care (n = 13) three times per week for 12 weeks.

MAIN MEASURES

(1) Vo( 2peak) measured by symptom-limited graded exercise test on cycle ergometer; (2) systolic function assessed by two-dimensional echocardiography; (3) muscular strength and muscular endurance measured by one-repetition maximum procedure; and (4) quality of life assessed by questionnaires.

RESULTS

In the intention-to-treat analysis, neither aerobic nor combined aerobic and resistance training significantly improved Vo(2peak), systolic function or quality of life compared with usual care. However, combined aerobic and resistance training significantly improved upper extremity strength (40.7 (14.0)-48.5 (16.0) kg, P<0.05) and muscular endurance (5.7 (2.7)-11.6 (7.6) reps, P<0.05) compared with aerobic training or usual care. In compliant participants (exercise adherence 80%), Vo(2peak) increased in the aerobic group (16.9 (6.0)-19.0 (6.8), P= 0.026) and tended to increase in the combined training group (15.9 (5.0)-17.6 (5.6), P= 0.058) compared with usual care. Quality of life was improved in the aerobic group only.

CONCLUSIONS

Both aerobic and combined aerobic and resistance training are effective interventions to improve Vo(2peak) in compliant heart failure patients. Combined training may be more effective in improving muscle strength and endurance.

Both aerobic endurance and strength training programmes improve cardiovascular health in obese adults

Regular exercise training is recognized as a powerful tool to improve work capacity, endothelial function and the cardiovascular risk profile in obesity, but it is unknown which of high-intensity aerobic exercise, moderate-intensity aerobic exercise or strength training is the optimal mode of exercise. In the present study, a total of 40 subjects were randomized to high-intensity interval aerobic training, continuous moderate-intensity aerobic training or maximal strength training programmes for 12 weeks, three times/week. The high-intensity group performed aerobic interval walking/running at 85-95% of maximal heart rate, whereas the moderate-intensity group exercised continuously at 60-70% of maximal heart rate; protocols were isocaloric. The strength training group performed 'high-intensity' leg press, abdominal and back strength training. Maximal oxygen uptake and endothelial function improved in all groups; the greatest improvement was observed after high-intensity training, and an equal improvement was observed after moderate-intensity aerobic training and strength training. High-intensity aerobic training and strength training were associated with increased PGC-1alpha (peroxisome-proliferator-activated receptor gamma co-activator 1alpha) levels and improved Ca(2+) transport in the skeletal muscle, whereas only strength training improved antioxidant status. Both strength training and moderate-intensity aerobic training decreased oxidized LDL (low-density lipoprotein) levels. Only aerobic training decreased body weight and diastolic blood pressure. In conclusion, high-intensity aerobic interval training was better than moderate-intensity aerobic training in improving aerobic work capacity and endothelial function. An important contribution towards improved aerobic work capacity, endothelial function and cardiovascular health originates from strength training, which may serve as a substitute when whole-body aerobic exercise is contra-indicated or difficult to perform.

Favourable effects of exercise-based Cardiac Rehabilitation after acute myocardial infarction on left atrial remodeling

BACKGROUND

Left atrial enlargement is an important predictor of cardiovascular outcomes in patients after acute myocardial infarction. While the favourable effect of exercise exercise-based Cardiac Rehabilitation (CR) on postinfarction LV remodeling has been well documented, those on LA remodeling have yet to be defined. This study investigated the effects of CR on LA remodeling in postinfarction patients with moderate left ventricular (LV) dysfunction.

METHODS

Sixty postinfarction patients were randomised randomized into two groups, each composed of 30 patients: group T (LV ejection fraction (EF) 43.7+/-4.2%, mean+/-SD) entered a 6-month CR program, whereas group C (EF 44.7+/-4.4%, P=ns) did not. Doppler echocardiography and cardiopulmonary exercise test were performed upon enrolment and at 6-month.

RESULTS

At 6-month, trained patients showed a significant (P<0.001) improvement in peak oxygen consumption (DeltaVO(2peak)=+5.2+/-2.1 ml/kg/min) and a reduction in LA (DeltaLAV(MAX)=-1.9+/-3.7 ml/m(2)) and in LV volumes (DeltaLVEDV=-3.6+/-4.4 ml/m(2)). At 6-month, untrained patients showed LAV(MAX) (+3.6+/-4.4 ml/m(2), P<0.001) and LV dilation (+4.2+/-5.1 ml/m(2), P<0.001; group T vs. C, P<0.001); whereas no significant changes in VO(2peak) were observed. Multiple linear regression analysis showed that age (beta=0.442, P<0.001), inclusion in the training group (beta=-0.599, P<0.001), E/A ratio (beta=-0.210, P=0.038), LVEDV (beta=0.376, P<0.001), and LVEF (beta=-0.279, P=0.007) are significant predictors of LA remodeling.

CONCLUSIONS

Six-month exercise-based CR in postinfarction patients with mild to moderate LV dysfunction induced a favourable LA remodeling.

Left ventricular remodelling in patients with moderate systolic dysfunction after myocardial infarction: favourable effects of exercise training and predictive role of N-terminal pro-brain natriuretic peptide

AIMS

To investigate the effects of exercise training (ET) on left ventricular (LV) volumes, cardiopulmonary functional capacity and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in postinfarction patients with moderate LV dysfunction.

METHODS

Sixty-one postinfarction patients were randomized into two groups: group T [n=30, LV ejection fraction (EF) 41.6+/-11.3%, mean+/-SD] entered a 6-month ET programme, whereas group C (n=31, EF 42.0+/-7.6%, P=NS) did not. NT-proBNP assay, Doppler-echocardiography and cardiopulmonary exercise test were performed upon enrolment and at sixth months.

RESULTS

At sixth months, trained patients showed an improvement in workload (+26%, P<0.001), Vo2peak (+31%, P<0.001), LV end-diastolic volume index (LVEDVI; -9%, P<0.001), a reduction in NT-proBNP (-71%, P<0.001) and a significant correlation between changes in NT-proBNP and in LVEDVI (r=0.858, P<0.001). Baseline NT-proBNP correlated with changes in LVEDVI in both trained (r=0.673, P<0.001) and untrained (r=0.623, P<0.001) patients. Group C showed unfavourable LVEDVI dilation (+8%, P<0.001; T vs. C group, P<0.001) and a smaller reduction in NT-proBNP (-40%, P<0.001; T vs. C group, P<0.001).

CONCLUSIONS

Six month ET induced a favourable LV remodelling and a marked fall in NT-proBNP that could predict LV remodelling in postinfarction patients with moderate LV dysfunction.

Exercise capacity, physical activity patterns and outcomes six years after cardiac rehabilitation in patients with heart failure

OBJECTIVE

To determine the short- and long-term effects of an intensive, concentrated rehabilitation programme in patients with chronic heart failure.

DESIGN

Randomized controlled trial, with one-month and six-year evaluations.

SETTING

Residential rehabilitation centre in Switzerland.

SUBJECTS

Fifty patients with chronic heart failure, randomized to exercise or control groups.

INTERVENTIONS

A rehabilitation programme lasting one month, including educational sessions, a low-fat diet, and 2 hours of individually prescribed exercise daily.

MAIN MEASURES

Exercise test responses, health outcomes and physical activity patterns.

RESULTS

Peak Vo(2) increased 21.4% in the exercise group during the rehabilitation programme (P<0.05), whereas peak Vo(2) did not change among controls. After the six-year follow-up period, peak Vo(2) was only slightly higher than that at baseline in the trained group (7%, NS), while peak Vo(2) among controls was unchanged. During long-term follow-up, 9 and 12 patients died in the exercise and control groups, respectively (P = 0.63). At six years, physical activity patterns tended to be higher in the exercise group; the mean energy expenditure values over the last year were 2,704 +/- 1,970 and 2,085 +/- 1,522 kcal/week during recreational activities for the exercise and control groups, respectively. However, both groups were more active compared to energy expenditure prior to their cardiac event (P<0.001).

CONCLUSIONS

Six years after participation in a residential rehabilitation programme, patients with chronic heart failure had slightly better outcomes than control subjects, maintained exercise capacity and engaged in activities that exceed the minimal amount recommended by guidelines for cardiovascular health.

Exercise training after coronary angioplasty improves cardiorespiratory function

AIM

The aim of this prospective randomized study was to evaluate the impact of long-term aerobic exercise training on respiratory function, left ventricular systolic function and remodeling in patients with coronary heart disease and ischemic heart failure after successful angioplasty.

DESIGN

Patients (n=185) have undergone Doppler echocardiography and ergospirometry. Ninety-five patients practiced 6 month-term aerobic exercise training, less by 10% to their anaerobic threshold. Ninety patients were studied as controls. They were given only drug treatment without training. Measurements were repeated after 6 and 12 months.

RESULTS

Training group patients after 6 months showed significant (p<0.05) improvement in exercise capacity, oxygen consumption and ventilating equivalents. The Doppler echocardiographic findings revealed significant (p<0.05) improvement in ejection fraction, left ventricular and atria morphometric data. Improved ergospirometric and echocardiographic data were established after 12 months, too.

CONCLUSIONS

Long-term aerobic exercise training is an effective and workable measure improving respiratory efficiency, left ventricular systolic function, attenuating negative remodeling and stopping further progression in patients with coronary heart disease and chronic heart failure after successful angioplasty.

Lifestyle changes and clinical profile in coronary heart disease patients with an ejection fraction of <or=40% or >40% in the Multicenter Lifestyle Demonstration Project

BACKGROUND

Lifestyle changes are recommended for coronary heart disease (CHD) patients at risk for heart failure (HF) [ACC/AHA stage B; left ventricular ejection fraction (LVEF)<or=40%]. However, it is not clear whether changes in lifestyle are feasible and beneficial in these patients.

AIM

To investigate the feasibility of intensive lifestyle changes for CHD patients at risk for HF.

METHODS

We compared 50 patients (18% female) with angiographically documented LVEF<or=40% (mean=33.4+/-7.3; range: 15-40%) to 186 patients (18% female) with LVEF>40% (mean=58.2+/-9.6; range: 42-87%), who were participants in the Multicenter Lifestyle Demonstration Project (MLDP). All were non-smoking CHD patients. The MLDP was a community-based, insurance-sponsored intervention (low-fat, plant-based diet; exercise; stress management) implemented at 8 sites in the US. Coronary risk factors, lifestyle and quality of life (SF-36) were assessed at baseline, 3 and 12 months.

RESULTS

Regardless of LVEF, patients showed significant improvements (all p<.05) in lifestyle behaviours, body weight, body fat, blood pressure, resting heart rate, total and LDL-cholesterol, exercise capacity, and quality of life by 3 months; most improvements were maintained over 12 months.

CONCLUSION

CHD patients at risk for heart failure with an LVEF<or=40%, can make changes in lifestyle to achieve similar medical and psychosocial benefit to patients with an LVEF>40%.

Physical training in patients with chronic heart failure of ischemic origin: effect on exercise capacity and left ventricular remodeling

BACKGROUND

Physical training is a well-known complementary treatment for chronic heart failure (CHF); however, many aspects require further studies. One of them is the impact on remodeling of the left ventricle (LV). The purpose of this study was to evaluate the effect of 6 months of training on LV, exercise capacity and safety issues in patients with ischemic CHF.

METHODS

Fifty patients (mean age 60.1+/-9.2 years) with ischemic CHF, New York Heart Association (NYHA) classification class II and III and left ventricular ejection fraction (LVEF) <or=35% were randomized into groups: undergoing 6-month training (25 patients) and not trained (25 patients). In both groups at baseline and at 6 months a cardiopulmonary exercise test and magnetic resonance imaging (MRI) with evaluation of LV were performed. Training was limited by the achievement of 80% of the predicted heart rate at VO2peak achieved at the baseline cardiopulmonary exercise test.

RESULTS

All patients completed the 6-month observation. No serious adverse events were found in either group. Exercise capacity improved only in the trained group (VO2peak increased by 31%). At 6 months in the trained group there was a tendency towards an improvement in some LV parameters: ejection fraction, end-diastolic volume and wall motion score index (WMSI), whereas an opposite trend was seen in the controls (P<0.05, P<0.05 and P<0.01 for comparison of LVEFs, end-diastolic volumes and WMSIs, respectively).

CONCLUSIONS

Six-month training in ischemic CHF patients is a safe modality. Training improves exercise capacity. There was no negative impact on LV morphology, and a trend towards improvement of functional parameters on MRI may suggest an anti-remodeling effect of training in patients with ischemic 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.

Reduction of N terminal-pro-brain (B-type) natriuretic peptide levels with exercise-based cardiac rehabilitation in patients with left ventricular dysfunction after myocardial infarction

INTRODUCTION

N-terminal-pro-brain (B-type) natriuretic peptide (NT-pro-BNP) is a peptide hormone released from ventricles in response to myocyte stretch. The aim of the study was to investigate the influence of exercise training on plasma NT-pro-BNP to verify if this parameter could be used as a biological marker of left ventricular remodelling in myocardial infarction patients undergoing an exercise training programme.

METHODS

Forty-four patients after myocardial infarction were enrolled into a cardiac rehabilitation programme, and were randomized in two groups of 22 patients each. Group A patients followed a 3-month exercise training programme, while group B patients received only routine recommendations. All patients underwent NT-pro-BNP assay, and cardiopulmonary exercise test before hospital discharge and after 3 months.

RESULTS

In Group A, exercise training reduced NT-pro-BNP levels (from 1498+/-438 to 470+/-375 pg/ml, P=0.0026), increased maximal (VO2peak+4.3+/-2.9 ml/kg per min, P<0.001; Powermax+38+/-7, P<0.001) exercise parameters and work efficiency (Powermax/VO2peak+1.3+/-0.4 Power/ml per kg per min, P<0.001); there was also an inverse correlation between changes in NT-pro-BNP levels and in VO2peak (r=-0.72, P<0.001), E-wave (r=-0.51, P<0.001) and E/A ratio (r=0.59, P<0.001). In group B, at 3 months, no changes were observed in NT-pro-BNP levels, exercise and echocardiographic parameters.

CONCLUSION

Three months exercise training in patients with moderate left ventricular systolic dysfunction after myocardial infarction induced a reduction in NT-pro-BNP levels, an improvement of exercise capacity and early left ventricular diastolic filling, without negative left ventricular remodelling. Whether the reduction of NT-pro-BNP levels could be useful as a surrogate marker of favourable left ventricular remodelling at a later follow-up remains to be further explored.

Exercise training in heart failure

The reduction of exercise capacity with early occurrences of fatigue and dyspnea is a hallmark of heart failure syndrome. There are objective similarities between heart failure and muscular deconditioning. Deficiencies in peripheral blood flow and skeletal muscle function, morphology, metabolism, and function are present. The protective effects of physical activity have been elucidated in many recent studies: training improves ventilatory control, skeletal muscle metabolism, autonomic nervous system, central and peripheral circulation, and heart function. These provide the physiologic basis to explain the benefits in terms of survival and freedom from hospitalization demonstrated by physical training in heart failure.