Exercise training enhances autonomic function after acute myocardial infarction: a randomized controlled study

Physical activity lowers all-cause and cardio-cerebrovascular mortality in adults with coronary heart disease

BACKGROUND

The health outcomes and their adherence to guideline-based secondary prevention physical activity in US patients with coronary heart disease (CHD), together with the association between physical activity (PA) and mortality risk, were investigated.

METHODS

Data on CHD patients (aged 18 to 85 years) was acquired from the US National Health and Nutrition Examination Survey (NHANES) 1999-2018. The patients were divided into four groups according to the level and frequency of PA, namely, a) sedentary (n = 1178), b) moderate PA (moderate, n = 270), c) vigorous PA once or twice per week (vigorous ≤2×, n = 206), and d) vigorous PA three or more times per week (vigorous >2×, n = 598). Logistic analysis was used to determine the relationship between PA and all-cause or cardio-cerebrovascular mortality in CHD patients.

RESULTS

A total of 2252 patients with CHD were enrolled, of whom 47.69% reported adequate PA. During the investigation, there were 296 (13.14%) cardio-cerebrovascular and 724 (32.15%) all-cause deaths. The incidence of all-cause or cardio-cerebrovascular death was lowest in the vigorous ≤2× group. Patients who undertook vigorous PA ≤ 2× showed the lowest risk of all-cause (odds ratio 0.32; 95% confidence interval 0.22-0.47; P < 0.01) or cardio-cerebrovascular death (odds ratio 0.43; 95% confidence interval 0.25-0.73; P < 0.01) relative to those in the sedentary group. More frequent vigorous PA did not lead to improved benefits.

CONCLUSIONS

Vigorous PA once or twice per week was more effective for reducing all-cause and cardio-cerebrovascular mortality compared with patients performing no or a moderate level of PA in US adults with CHD.

Exercise-based cardiac rehabilitation for coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is the most common cause of death globally. However, with falling CHD mortality rates, an increasing number of people living with CHD may need support to manage their symptoms and prognosis. Exercise-based cardiac rehabilitation (CR) aims to improve the health and outcomes of people with CHD. This is an update of a Cochrane Review previously published in 2016.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of exercise-based CR (exercise training alone or in combination with psychosocial or educational interventions) compared with 'no exercise' control, on mortality, morbidity and health-related quality of life (HRQoL) in people with CHD.

SEARCH METHODS

We updated searches from the previous Cochrane Review, by searching CENTRAL, MEDLINE, Embase, and two other databases in September 2020. We also searched two clinical trials registers in June 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of exercise-based interventions with at least six months' follow-up, compared with 'no exercise' control. The study population comprised adult men and women who have had a myocardial infarction (MI), coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI), or have angina pectoris, or coronary artery disease.

DATA COLLECTION AND ANALYSIS

We screened all identified references, extracted data and assessed risk of bias according to Cochrane methods. We stratified meta-analysis by duration of follow-up: short-term (6 to 12 months); medium-term (> 12 to 36 months); and long-term ( > 3 years), and used meta-regression to explore potential treatment effect modifiers. We used GRADE for primary outcomes at 6 to 12 months (the most common follow-up time point).  MAIN RESULTS: This review included 85 trials which randomised 23,430 people with CHD. This latest update identified 22 new trials (7795 participants). The population included predominantly post-MI and post-revascularisation patients, with a mean age ranging from 47 to 77 years. In the last decade, the median percentage of women with CHD has increased from 11% to 17%, but females still account for a similarly small percentage of participants recruited overall ( < 15%). Twenty-one of the included trials were performed in low- and middle-income countries (LMICs). Overall trial reporting was poor, although there was evidence of an improvement in quality over the last decade. The median longest follow-up time was 12 months (range 6 months to 19 years). At short-term follow-up (6 to 12 months), exercise-based CR likely results in a slight reduction in all-cause mortality (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.73 to 1.04; 25 trials; moderate certainty evidence), a large reduction in MI (RR 0.72, 95% CI 0.55 to 0.93; 22 trials; number needed to treat for an additional beneficial outcome (NNTB) 75, 95% CI 47 to 298; high certainty evidence), and a large reduction in all-cause hospitalisation (RR 0.58, 95% CI 0.43 to 0.77; 14 trials;  NNTB 12, 95% CI 9 to 21; moderate certainty evidence). Exercise-based CR likely results in little to no difference in risk of cardiovascular mortality (RR 0.88, 95% CI 0.68 to 1.14; 15 trials; moderate certainty evidence), CABG (RR 0.99, 95% CI 0.78 to 1.27; 20 trials; high certainty evidence), and PCI (RR 0.86, 95% CI 0.63 to 1.19; 13 trials; moderate certainty evidence) up to 12 months' follow-up. We are uncertain about the effects of exercise-based CR on cardiovascular hospitalisation, with a wide confidence interval including considerable benefit as well as harm (RR 0.80, 95% CI 0.41 to 1.59; low certainty evidence). There was evidence of substantial heterogeneity across trials for cardiovascular hospitalisations (I2 = 53%), and of small study bias for all-cause hospitalisation, but not for all other outcomes. At medium-term follow-up, although there may be little to no difference in all-cause mortality (RR 0.90, 95% CI 0.80 to 1.02; 15 trials), MI (RR 1.07, 95% CI 0.91 to 1.27; 12 trials), PCI (RR 0.96, 95% CI 0.69 to 1.35; 6 trials), CABG (RR 0.97, 95% CI 0.77 to 1.23; 9 trials), and all-cause hospitalisation (RR 0.92, 95% CI 0.82 to 1.03; 9 trials), a large reduction in cardiovascular mortality was found (RR 0.77, 95% CI 0.63 to 0.93; 5 trials). Evidence is uncertain for difference in risk of cardiovascular hospitalisation (RR 0.92, 95% CI 0.76 to 1.12; 3 trials). At long-term follow-up, although there may be little to no difference in all-cause mortality (RR 0.91, 95% CI 0.75 to 1.10), exercise-based CR may result in a large reduction in cardiovascular mortality (RR 0.58, 95% CI 0.43 to 0.78; 8 trials) and MI (RR 0.67, 95% CI 0.50 to 0.90; 10 trials). Evidence is uncertain for CABG (RR 0.66, 95% CI 0.34 to 1.27; 4 trials), and PCI (RR 0.76, 95% CI 0.48 to 1.20; 3 trials). Meta-regression showed benefits in outcomes were independent of CHD case mix, type of CR, exercise dose, follow-up length, publication year, CR setting, study location, sample size or risk of bias. There was evidence that exercise-based CR may slightly increase HRQoL across several subscales (SF-36 mental component, physical functioning, physical performance, general health, vitality, social functioning and mental health scores) up to 12 months' follow-up; however, these may not be clinically important differences. The eight trial-based economic evaluation studies showed exercise-based CR to be a potentially cost-effective use of resources in terms of gain in quality-adjusted life years (QALYs).

AUTHORS' CONCLUSIONS

This updated Cochrane Review supports the conclusions of the previous version, that exercise-based CR provides important benefits to people with CHD, including reduced risk of MI, a likely small reduction in all-cause mortality, and a large reduction in all-cause hospitalisation, along with associated healthcare costs, and improved HRQoL up to 12 months' follow-up. Over longer-term follow-up, benefits may include reductions in cardiovascular mortality and MI. In the last decade, trials were more likely to include females, and be undertaken in LMICs, increasing the generalisability of findings. Well-designed, adequately-reported RCTs of CR in people with CHD more representative of usual clinical practice are still needed. Trials should explicitly report clinical outcomes, including mortality and hospital admissions, and include validated HRQoL outcome measures, especially over longer-term follow-up, and assess costs and cost-effectiveness.

Long Non-Coding RNAs in Cardiovascular Diseases: Potential Function as Biomarkers and Therapeutic Targets of Exercise Training

Despite advances in treatments and therapies, cardiovascular diseases (CVDs) remain one of the leading causes of death worldwide. The discovery that most of the human genome, although transcribed, does not encode proteins was crucial for focusing on the potential of long non-coding RNAs (lncRNAs) as essential regulators of cell function at the epigenetic, transcriptional, and post-transcriptional levels. This class of non-coding RNAs is related to the pathophysiology of the cardiovascular system. The different expression profiles of lncRNAs, in different contexts of CVDs, change a great potential in their use as a biomarker and targets of therapeutic intervention. Furthermore, regular physical exercise plays a protective role against CVDs; on the other hand, little is known about its underlying molecular mechanisms. In this review, we look at the accumulated knowledge on lncRNAs and their functions in the cardiovascular system, focusing on the cardiovascular pathology of arterial hypertension, coronary heart disease, acute myocardial infarction, and heart failure. We discuss the potential of these molecules as biomarkers for clinical use, their limitations, and how the manipulation of the expression profile of these transcripts through physical exercise can begin to be suggested as a strategy for the treatment of CVDs.

Exercise-Based Interventions in Middle-Aged and Older Adults after Myocardial Infarction: A Systematic Review

This study summarized the relevant literature and aimed to determine the effect of exercise-based interventions after myocardial infarction in middle-aged and older adults. Studies were identified and analyzed according to the PRISMA guidelines. The following electronic databases were used: Google Scholar, PubMed, Mendeley, Science Direct, and Scopus. The identified studies had to be longitudinal, be published in English, have taken place between 2010 and 2020, involve participants who had suffered myocardial infarction, and address different types of exercise-based interventions to be included. Of the 592 relevant studies identified, 20 were included in the qualitative analysis. After analyzing the results obtained, it could be concluded that different types of exercise-based interventions or their combination have a positive effect after myocardial infarction in middle-aged and elderly adults. It can also be suggested that the combination of a cycle ergometer and a treadmill may be the most effective exercise-based intervention. An adequate choice of intensity and volume is crucial, with the optimal duration of the experimental program and the type(s) of exercises adapted to participants after myocardial infarction.

Safety and improvement in exercise tolerance with interval training vs moderate-intensity continuous training in heart disease patient of very high cardiovascular risk

Objetivo:

Evaluar la seguridad y el efecto del entrenamiento por intervalos de moderada y alta intensidad (EIMI, EIAI) y compararlo con el entrenamiento de intensidad moderada continua (EIMC) en pacientes de riesgo cardiovascular (RCV) muy alto.

Método:

Estudio cuasi experimental de 81 pacientes que ingresaron al programas de rehabilitación cardíaca y prevención secundaria (PRHCPS); en la estratificación de riesgo, todos los pacientes presentaron ≥ 2 factores de RCV alto. Entrenamiento concurrente: aeróbico supervisado: 2 semanas de entrenamiento de base de EIMC; luego el grupo EIMC con la misma prescripción, EIMI a 3 intervalos de 3’ al 70 a 80% de FCR con pausas activas de 3’ al 60 a 70% de FCR; EIAI, 3 intervalos de 3’ a 80 a 90% de FCR con pausas activas de 3’ al 70 a 80% de FCR, entrenamiento de fuerza con tres sesiones semanales de ejercicios isotónicos y una de calistenia e intervención multidisciplinaria.

Resultados:

81 pacientes asignados en tres grupos: 61 a EIMC, 13 a EIMI y 7 a EIAI, sin diferencias significativas en las variables epidemiológicas. Hubo ganancias porcentuales en MET-carga de 45%, 60% y 86% (p = 0.17) y carga-vatios de 51, 44 y 48 en EIMC, EIMI, EIAI, respectivamente (p = 0.54). A pesar de no existir diferencias estocásticamente significativas intergrupales, sí se registró una ganancia mayor en MET-carga en el grupo de EIAI. No se observó desenlace adverso en ningún tipo de entrenamiento.

Conclusiones:

En cardiópatas de riesgo cardiovascular muy alto, el entrenamiento interválico EIMI/EIAI supervisado es seguro, con tendencia a mayor ganancia en tolerancia al esfuerzo (MET-carga) con el EIAI en comparación con el EIMC.

Wearable Devices for Physical Activity and Healthcare Monitoring in Elderly People: A Critical Review

The availability of wearable devices (WDs) to collect biometric information and their use during activities of daily living is significantly increasing in the general population. These small electronic devices, which record fitness and health-related outcomes, have been broadly utilized in industries such as medicine, healthcare, and fitness. Since they are simple to use and progressively cheaper, they have also been used for numerous research purposes. However, despite their increasing popularity, most of these WDs do not accurately measure the proclaimed outcomes. In fact, research is equivocal about whether they are valid and reliable methods to specifically evaluate physical activity and health-related outcomes in older adults, since they are mostly designed and produced considering younger subjects' physical and mental characteristics. Additionally, their constant evolution through continuous upgrades and redesigned versions, suggests the need for constant up-to-date reviews and research. Accordingly, this article aims to scrutinize the state-of-the-art scientific evidence about the usefulness of WDs, specifically on older adults, to monitor physical activity and health-related outcomes. This critical review not only aims to inform older consumers but also aid researchers in study design when selecting physical activity and healthcare monitoring devices for elderly people.

Exercise-based cardiac rehabilitation and parasympathetic function in patients with coronary artery disease: a systematic review and meta-analysis

PURPOSE

The effects of exercise-based cardiac rehabilitation (CR) on parasympathetic modulation are controversial. This systematic review and meta-analysis aims to (a) determine the effect of exercise-based CR on heart-rate-derived indices associated with cardiac parasympathetic modulation in resting and post-exercise conditions in coronary artery disease (CAD) patients and (b) identify the possible moderator variables of the effect of exercise-based CR on parasympathetic modulation.

METHODS

We searched CENTRAL and Web of Science up to November 2018 for the following terms: adult CAD patients, controlled exercise-based CR interventions and parasympathetic modulation measured in resting (vagal-related heart rate variability [HRV] indices of the root mean square of the differences in successive in RR interval [RMSSD] and high frequency [HF]) and post-exercise (heart rate recovery [HRR]) pre- and post-intervention. We estimated a random-effects model of standardised mean difference (SMD) and mean difference (MD) for vagal-related HRV indices and HRR, respectively. We assessed the influence of categorical and continuous variables.

RESULTS

The overall effect size showed significant differences in RMSSD (SMD₊ = 0.30; 95% confidence interval [CI] = 0.12-0.49) and HRR (MD₊ = 5.35; 95% CI = 4.08-6.61 bpm) in favour of the exercise-based CR group. The overall effect size showed no differences in HF between groups (SMD₊ = 0.14; 95% CI,  -0.12-0.40). Heterogeneity analyses reached statistical significance, with high heterogeneity for HF (p < 0.001; I² = 70%) and HRR (p < 0.001; I² = 85%). Analysis of the moderator variables showed that the effect on HRR is greater in young patients (p = 0.008) and patients treated with percutaneous intervention (p = 0.020).

CONCLUSIONS

Exercise-based CR improves the post-exercise parasympathetic function, with greater effects in younger CAD patients and in those who were revascularised with percutaneous intervention. The effects on resting parasympathetic function are more controversial due to methodological inconsistencies in measuring HRV, with the use of RMSSD recommended instead of HF because its results show higher consistency. Future studies involving women, focusing on methodological issues, and performing other training methods are needed to increase our knowledge about this topic.

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.

Need for Systematic Efforts to Modify Health-Related Behaviors After Acute Myocardial Infarction in Korea

BACKGROUND

Modification of health-related behaviors may improve clinical outcomes after acute myocardial infarction (AMI), but the need for systematic efforts to modify such behaviors and the estimated effect have not been investigated, especially in Asian populations. The aim of the study was to investigate changes in smoking and physical activity after AMI and their associations with death and recurrent revascularization. Methods and Results: Using the Korean National Insurance Health Service database, we included 13,452 patients with AMI in 2011, who were stable until 1.5 years on average after onset. Patients were grouped according to their smoking status and physical activity before and after AMI. After AMI, 44.6% of smokers continued smoking and only 11.0% of inactive patients increased their physical activity to a sufficient level. The 'smoker/smoker' group and 'non-smoker/smoker' group showed higher mortality (hazard ratio (HR): 1.566, 95% confidence interval (CI): 1.192-2.035; HR: 1.785, 95% CI: 1.061-2.815, respectively). On the other hand, the 'active/active' group and 'inactive/active' group showed less mortality (HR: 0.625, 95% CI: 0.460-0.832; HR: 0.681, 95% CI: 0.438-1.009, respectively) and the 'inactive/active' group showed less recurrent revascularization (HR: 0.761, 95% CI: 0.599-0.952).

CONCLUSIONS

Smoking cessation and maintaining sufficient physical activity after AMI remain challenging for many Korean patients, and are associated with higher rates of mortality and recurrent revascularization. Systematic nationwide efforts such as cardiac rehabilitation (CR) to change health-related behaviors after AMI are required in Korea.

Effect of exercise training on heart rate recovery in patients post anterior myocardial infarction

Background

Regular exercise training has been shown to reduce mortality, improve functional capacity; and control the risk factors in myocardial infarction (MI) patients. Heart rate recovery (HRR) is a strong independent mortality predictor in patients with previous MI.

Aim

The main objective of this study was to investigate the impact of exercise training on heart rate recovery in patients post anterior myocardial infarction.

Methods

We recruited patients one month after having anterior MI who were referred to cardiac rehabilitation (CR) clinic in Ain Shams University hospital between October 2016 and July 2017. All the patients participated in exercise training sessions 3 times a week for 12 weeks. Symptom limited treadmill exercise test was done before and after exercise training program to calculate heart rate recovery in 1st minute (HRR1) and 2nd minute (HRR2).

Results

A total of 50 patients, including 44 (88%) males, completed the exercise training program. The mean age was 51 years. Statistically significant improvement in HRR1 and HRR2 was observed (p value <0.001) after completion of exercise based cardiac rehabilitation program. Significant improvement in resting heart rate was also observed (p value <0.001). Moreover, metabolic equivalent (METs) and HR reserve were improved significantly (p value <0.001). No statistically significant changes were observed in resting systolic and diastolic blood pressures and maximum HR (p value = 0.95, 0.76 and 0.31 respectively).

Conclusion

Exercise training improves HRR, resting HR, METs and HR reserve in post anterior MI patients.

Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients

BACKGROUND

Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO₂peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continuous training (MCT) versus a high intensity interval training (HIIT) programme on VO₂peak and HRR.

METHODS

Seventy three coronary patients were assigned to either HIIT or MCT groups for 8weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO₂peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data.

RESULTS

Both exercise programmes significantly increase VO₂peak with a higher increase in the HIIT group (HIIT: 4.5±4.46ml/kg/min vs MCT: 2.46±3.57ml/kg/min; p=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22±6,62, p<0,0001 and 23,73±9,64 vs 31,52±8,02, p<0,0001, respectively).

CONCLUSIONS

The results of our research show that the application of HIIT to patients with chronic ischemic heart disease of low risk resulted in an improvement in VO₂peak, and also improvements in post-exercise heart-rate recovery, compared with continuous training.

Effectiveness of endurance exercise training in patients with coronary artery disease: A meta-analysis of randomised controlled trials

BACKGROUND

Exercise interventions apparently reduce the risks of and prevent coronary artery disease (CAD). Developing an exercise intervention for patients with CAD is a rapidly expanding focus worldwide. The results of previous studies are inconsistent and difficult to interpret across various types of exercise programme.

AIM

This study aimed to update prior systemic reviews and meta-analyses in order to determine the overall effects of endurance exercise training on patients with CAD.

METHODS

The databases (PubMed, Medline, CINAHL, EMBASE and Cochrane Library) were searched for the interventions published between January 1, 2000, and May 31, 2015. Comprehensive meta-analysis software was used to evaluate the heterogeneity of the selected studies and to calculate mean differences (MDs) while considering effect size.

RESULTS

A total of 18 studies with 1286 participants were included. Endurance exercise interventions at a moderate to high training intensity significantly reduced resting systolic blood pressure (MD: -3.8 mmHg, p = 0.01) and low-density lipoprotein cholesterol (MD: -5.5 mg/dL, p = 0.02), and increased high-density lipoprotein cholesterol (MD: 3.8 mg/dL, p < 0.001). There were also significant positive changes in peak oxygen consumption (MD: 3.47 mL/kg/min, p < 0.001) and left ventricular ejection fraction (MD: 2.6%, p = 0.03) after the interventions. Subgroup analysis results revealed that exercise interventions of 60-90 minutes per week with a programme duration of >12 weeks had beneficial effects on functional capacity, cardiac function and a number of cardiovascular risk factors.

CONCLUSIONS

Endurance exercise training has a positive effect on major modifiable cardiovascular risk factors and functional capacity. Nurses can develop endurance exercise recommendations for incorporation into care plans of clinically stable CAD patients following an acute cardiac event or revascularisation procedure.

Physical activity in primary and secondary prevention of cardiovascular disease: Overview updated

Although the observed progress in the cardiovascular disease treatment, the incidence of new and recurrent coronary artery disease remains elevated and constitutes the leading cause of death in the developed countries. Three-quarters of deaths due to cardiovascular diseases could be prevented with adequate changes in lifestyle, including increased daily physical activity. New evidence confirms that there is an inverse dose-response relationship between physical activity and cardiovascular disease and mortality risk. However, participation in moderate to vigorous physical activity may not fully attenuate the independent effect of sedentary activities on increased risk for cardiovascular diseases. Physical activity also plays an important role in secondary prevention of cardiovascular diseases by reducing the impact of the disease, slowing its progress and preventing recurrence. Nonetheless, most of eligible cardiovascular patients still do not benefit from secondary prevention/cardiac rehabilitation programs. The present review draws attention to the importance of physical activity in the primary and secondary prevention of cardiovascular diseases. It also addresses the mechanisms by which physical activity and regular exercise can improve cardiovascular health and reduce the burden of the disease.

Effects of a Phase IV Home-Based Cardiac Rehabilitation Program on Cardiorespiratory Fitness and Physical Activity

BACKGROUND

Cardiovascular diseases are the leading cause of death globally and sedentary lifestyle is one of the main risk factors. Home-based cardiac rehabilitation (CR) programs appear to be effective to improve exercise tolerance. The aim of the study, therefore, was to evaluate the effects of a phase IV (maintenance) home-based CR program on cardiorespiratory fitness and daily physical activity of patients recovering from an acute myocardial infarction.

METHODS

This pilot study, with a sub-group randomised controlled trial, included 32 individuals recovering from a myocardial infarction, randomly divided into the experimental group (EG, n=16) and the control group (CG, n=16). The EG performed an exercise program, three times per week, at home during eight weeks. The two groups received health education sessions. Baseline and final assessments included cardiorespiratory fitness, resting and peak heart rate, blood pressure and rate pressure, heart rate recovery and daily physical activity. (ClinicalTrials.gov: NCT01887080).

RESULTS

At baseline no significant differences were observed between groups. After eight weeks of exercise, the EG significantly increased peak oxygen uptake (p=0.02), test duration (p=0.019), peak rate pressure (p=0.003), peak heart rate (p=0.003) and heart rate recovery (0.025) when compared to the CG. No changes were observed on daily physical activity in both groups.

CONCLUSION

This specific phase IV home-based exercise program seems to improve cardiorespiratory fitness, haemodynamics at peak exercise and heart rate recovery, an indicator of cardiac autonomic function.

Exercise-based cardiac rehabilitation for coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is the single most common cause of death globally. However, with falling CHD mortality rates, an increasing number of people live with CHD and may need support to manage their symptoms and prognosis. Exercise-based cardiac rehabilitation (CR) aims to improve the health and outcomes of people with CHD. This is an update of a Cochrane systematic review previously published in 2011.

OBJECTIVES

To assess the effectiveness and cost-effectiveness of exercise-based CR (exercise training alone or in combination with psychosocial or educational interventions) compared with usual care on mortality, morbidity and HRQL in patients with CHD.To explore the potential study level predictors of the effectiveness of exercise-based CR in patients with CHD.

SEARCH METHODS

We updated searches from the previous Cochrane review, by searching Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 6, 2014) from December 2009 to July 2014. We also searched MEDLINE (Ovid), EMBASE (Ovid), CINAHL (EBSCO) and Science Citation Index Expanded (December 2009 to July 2014).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of exercise-based interventions with at least six months' follow-up, compared with a no exercise control. The study population comprised men and women of all ages who have had a myocardial infarction (MI), coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI), or who have angina pectoris, or coronary artery disease. We included RCTs that reported at least one of the following outcomes: mortality, MI, revascularisations, hospitalisations, health-related quality of life (HRQL), or costs.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references for inclusion based on the above inclusion and exclusion criteria. One author extracted data from the included trials and assessed their risk of bias; a second review author checked data. We stratified meta-analysis by the duration of follow up of trials, i.e. short-term: 6 to 12 months, medium-term: 13 to 36 months, and long-term: > 3 years.

MAIN RESULTS

This review included 63 trials which randomised 14,486 people with CHD. This latest update identified 16 new trials (3872 participants). The population included predominantly post-MI and post-revascularisation patients and the mean age of patients within the trials ranged from 47.5 to 71.0 years. Women accounted for fewer than 15% of the patients recruited. Overall trial reporting was poor, although there was evidence of an improvement in quality of reporting in more recent trials.As we found no significant difference in the impact of exercise-based CR on clinical outcomes across follow-up, we focused on reporting findings pooled across all trials at their longest follow-up (median 12 months). Exercise-based CR reduced cardiovascular mortality compared with no exercise control (27 trials; risk ratio (RR) 0.74, 95% CI 0.64 to 0.86). There was no reduction in total mortality with CR (47 trials, RR 0.96, 95% CI 0.88 to 1.04). The overall risk of hospital admissions was reduced with CR (15 trials; RR 0.82, 95% CI 0.70 to 0.96) but there was no significant impact on the risk of MI (36 trials; RR 0.90, 95% CI 0.79 to 1.04), CABG (29 trials; RR 0.96, 95% CI 0.80 to 1.16) or PCI (18 trials; RR 0.85, 95% CI 0.70 to 1.04).There was little evidence of statistical heterogeneity across trials for all event outcomes, and there was evidence of small study bias for MI and hospitalisation, but no other outcome. Predictors of clinical outcomes were examined across the longest follow-up of studies using univariate meta-regression. Results show that benefits in outcomes were independent of participants' CHD case mix (proportion of patients with MI), type of CR (exercise only vs comprehensive rehabilitation) dose of exercise, length of follow-up, trial publication date, setting (centre vs home-based), study location (continent), sample size or risk of bias.Given the heterogeneity in outcome measures and reporting methods, meta-analysis was not undertaken for HRQL. In five out of 20 trials reporting HRQL using validated measures, there was evidence of significant improvement in most or all of the sub-scales with exercise-based CR compared to control at follow-up. Four trial-based economic evaluation studies indicated exercise-based CR to be a potentially cost-effective use of resources in terms of gain in quality-adjusted life years.The quality of the evidence for outcomes reported in the review was rated using the GRADE method. The quality of the evidence varied widely by outcome and ranged from low to moderate.

AUTHORS' CONCLUSIONS

This updated Cochrane review supports the conclusions of the previous version of this review that, compared with no exercise control, exercise-based CR reduces the risk of cardiovascular mortality but not total mortality. We saw a significant reduction in the risk of hospitalisation with CR but not in the risk of MI or revascularisation. We identified further evidence supporting improved HRQL with exercise-based CR. More recent trials were more likely to be well reported and include older and female patients. However, the population studied in this review still consists predominantly of lower risk individuals following MI or revascularisation. Further well conducted RCTs are needed to assess the impact of exercise-based CR in higher risk CHD groups and also those presenting with stable angina. These trials should include validated HRQL outcome measures, explicitly report clinical event outcomes including mortality and hospital admissions, and assess costs and cost-effectiveness.

Supervised exercise improves autonomic modulation in participants in cardiac rehabilitation programs

BACKGROUND AND OBJECTIVES

An attenuated heart rate recovery (HRR) response after exercise testing is a robust predictor of mortality. Regular exercise can enhance various physiological parameters. Studies indicate that participation in a cardiac rehabilitation program can improve heart rate recovery. The aim of this study was to analyze changes in functional capacity and autonomic modulation in patients following a cardiac rehabilitation program.

METHODS

Between 2009 and 2014, 248 individuals were assessed through exercise testing, at baseline and after six months of participation in a cardiac rehabilitation program. The exercise test was performed on a treadmill using a ramp protocol. The first minute of active recovery was standardized at a speed of 1.5 mph and slope of 2.5%. The degree of parasympathetic modulation was assessed by the difference between peak exercise heart rate and heart rate at one minute of recovery. The subjects were divided into two groups according to pre-training HRR (≤ 12 bpm and >12 bpm).

RESULTS

Exercise training resulted in a similar increase in metabolic equivalent values in both groups, but only the HRR ≤ 12 bpm group showed improvement after training (F=16.13; p<0.001), with a mean increase from 7.4 ± 3.69 bpm to 13.0 ± 9.74 bpm.

CONCLUSIONS

The cardiac rehabilitation program had a positive impact in a group that had both low functional capacity and reduced parasympathetic activity, producing a favorable effect on these recognized prognostic markers.

Cardiovascular autonomic neuropathy in patients with type 2 diabetes

AIMS/INTRODUCTION

Heart rate recovery (HRR) after exercise is considered to be a new index of autonomic dysfunction associated with cardiovascular disease and mortality. The present study aimed to investigate the risk factors of HRR and the effects of exercise on the abnormal HRR in type 2 diabetes.

MATERIALS AND METHODS

A total of 123 type 2 diabetes patients were recruited, and the oral glucose tolerance test and exercise test were carried out to analyze the risk factors associated with abnormal HRR. Among these patients, 42 patients with abnormal HRR were further randomized to either the conventional therapy group (CT group; n = 20) or the intensive therapy group (IT group; n = 22). The CT group patients underwent metformin and diet control, whereas the IT group additionally underwent a combined moderate intensity aerobic and resistance training three times per week for 12 weeks. The results of blood sample analysis and HRR were recorded before and after the training.

RESULTS

Abnormal HRR was related to fasting blood glucose, glycosylated hemoglobin, low-density lipoprotein cholesterol, and resting and maximum heart rates (P < 0.05 for both). After training, the IT group had significantly lower levels of fasting blood glucose, glycosylated hemoglobin and resting heart rate than the CT group (all P < 0.01 or P < 0.005). Significant improvement in HRR and metabolic equivalents was observed in the IT group compared with the CT group (P < 0.05).

CONCLUSIONS

These data suggested that combined aerobic and resistance training improved cardiac autonomic dysfunction as measured by HRR in type 2 diabetes patients. This might be due to better improvement of glycemic control, resting heart rate and physical fitness.

The Effect of Park and Urban Environments on Coronary Artery Disease Patients: A Randomized Trial

Aim. To test the hypothesis that walking in a park has a greater positive effect on coronary artery disease (CAD) patients' hemodynamic parameters than walking in an urban environment. Methods. Twenty stable CAD patients were randomized into two groups: 30-minute walk on 7 consecutive days in either a city park or busy urban street. Wilcoxon signed-rank test was employed to study short-term (30 min) and cumulative changes (following 7 consecutive days of exposure) in resting hemodynamic parameters in different environments. Results. There were no statistically significant differences in the baseline and peak exercise systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), exercise duration, or HR recovery in urban versus park exposure groups. Seven days of walking slightly improved all hemodynamic parameters in both groups. Compared to baseline, the city park group exhibited statistically significantly greater reductions in HR and DBP and increases in exercise duration and HR recovery. The SBP and DBP changes in the urban exposed group were lower than in the park exposed group. Conclusions. Walking in a park had a greater positive effect on CAD patients' cardiac function than walking in an urban environment, suggesting that rehabilitation through walking in green environments after coronary events should be encouraged.

Heart rate recovery and aerobic endurance capacity in cancer survivors: interdependence and exercise-induced improvements

PURPOSE

Whilst evidence supports beneficial effects of exercise on heart rate variability in cancer patients, its impact on heart rate recovery (HRR) and possible associations of exercise capacity and HRR have not yet been investigated. We aimed to evaluate the effects of an exercise intervention on HRR in relation to the baseline aerobic capacity.

METHODS

Cancer patients (n = 309, 178 females) performed a cardiopulmonary exercise test at baseline and at a 4-month interval follow-up with home-based and supervised exercise programs in-between. VO2 and heart rate were assessed during and HRR at 60 and 120 s after test termination. Based on a median split of the VO2 peak baseline values, participants were dichotomized into two groups: below median (47 female; 57.5 ± 10 years) and above median (48 female; 54.3 ± 12 years).

RESULTS

In the baseline sample (n = 309), VO2 peak correlated significantly with HRR60 (r = .327, p < .01) and HRR120 (r = .524, p < .01). For the compliers who completed intervention and assessments (n = 158), group comparisons demonstrated differences between below median versus above median group in absolute changes of HRR60 (3.1 ± 10.5 bpm (95% CI +0.6; +5.4) vs -1.8 ± 8.7 bpm (95% CI -3.7; +0.5)) and VO2 peak (2.9 ± 3.5 ml/kg/min (95% CI +2.1; +3.7) vs 0.66 ± 4 ml/kg/min (95% CI -0.6; +1.5)) (p < .01), but not in HRR120 (3.9 ± 11.8 bpm (95% CI +1.2; +6.6) vs 0.8 ± 10.8 bpm (95% CI -1.7; +3.5); p > .05).

CONCLUSIONS

These findings point toward a positive linear relationship between aerobic capacity and vagal reactivation in cancer patients. Patients with initial VO2 peak values below median showed improved VO2 peak, HRR60 and HRR120 following the moderate aerobic exercise intervention and differences to patients above median in all outcomes compared.

Aerobic exercise inhibits sympathetic nerve sprouting and restores β-adrenergic receptor balance in rats with myocardial infarction

Background

Cardiac sympathetic nerve sprouting and the dysregulation of β-adrenergic receptor (β-AR) play a critical role in the deterioration of cardiac function after myocardial infarction (MI). Growing evidence indicates that exercise provides protection against MI. The aims of this study were to investigate whether aerobic exercise following MI could inhibit sympathetic nerve sprouting and restore the balance of β3-AR/β1-AR.

Methods

Male Sprague-Dawley rats were divided into three groups: sham-operated control group (SC), MI group (MI), and MI with aerobic exercise group (ME). The rats in ME group were assigned to 8 weeks of exercise protocol (16 m/min, 50 min/d, 5 d/wk). The expression of nerve growth factor (NGF), the sympathetic nerve marker-tyrosine hydroxylase (TH), the nerve sprouting marker-growth associated protein 43 (GAP43), and β1- and β2-AR expression in the peri-infarct area of the left ventricle (LV) were measured by Western blot and immunohistochemistry, while β3-AR expression was determined by Western blot and immunofluorescence. Endothelial nitric oxide synthase (NOS2), phospho-NOS2 (p-NOS2), and neuronal nitric oxide synthase (NOS1) were measured by Western blot.

Results

MI increased LV end-diastolic pressure (LVEDP), and decreased LV systolic pressure (LVSP). Compared with the MI group, aerobic exercise significantly decreased LVEDP and increased LVSP. The protein expression of TH, GAP43 and NGF was significantly increased after MI, which was normalized by exercise. Compared with the SC group, the ratios of β2-AR/β1-AR and β3-AR/β1-AR were elevated in the MI group, and the protein expression of β3-AR and NOS1 increased after MI. Compared with the MI group, the ratios of β2-AR/β1-AR and β3-AR/β1-AR were normalized in the ME group, while the protein expression of β3-AR and NOS1 significantly increased, and NOS2 was activated by exercise.

Conclusions

Aerobic exercise inhibits cardiac sympathetic nerve sprouting, restores β3-AR/β1-AR balance and increases β3-AR expression through the activation of NOS2 and NOS1 after myocardial infarction.

Peripheral vascular insufficiency impairs functional capacity in patients with heart failure

INTRODUCTION: Heart failure (HF) is a complex syndrome in which effort limitation is associated with deterioration of peripheral musculature. Improving survival rates among these patients have led to the appearance of cases in which other pathologies are associated with HF, such as peripheral vascular insufficiency (PVI). The combination of these two pathologies is common, with significant repercussions for affected patients. OBJECTIVE: To compare functional limitations and quality of life between patients with HF in isolation or HF + PVI. METHOD: Twelve patients with HF+PVI were paired to 12 patients with HF in isolation. All had ejection fraction <40%. The following were conducted: 6 minute walk test (6MWT), chair test (CT), step test (ST), one repetition maximum test (1RM) and quality of life questionnaire. RESULTS: The results for the 6MWT (311±27 vs. 447±29), ST (49±3 vs. 81±10) and CT (17±1 vs. 21±1) were lower in the HF+PVI group than in the HF group (p<0.05). The HF+PVI group exhibited a reduction in the number of steps taken from the first to the second minute of the ST, in relation to the HF group. The HF group exhibited better HR recovery than the HF+PVI group (50±4 vs. 26±3; p<0.05). No differences were found in results for the Borg scale, the peripheral muscle strength test (1RM) or the questionnaires (p>0.05). CONCLUSIONS: The study participants who had mixed disease exhibited a greater degree of functional impairment than the group with HF, without reporting worsened quality of life.

Effect of aerobic training on heart rate recovery in patients with established heart disease; a systematic review

Background

Although a delayed decrease in heart rate during the first minute after graded exercise has been identified as a powerful predictor of overall mortality in cardiac patients, the potential to influence this risk factor by aerobic training remains to be proven.

Objective

The aim was to study the relationship between aerobic training and Heart Rate Recovery (HRR) in patients with established heart disease.

Methods

(Quasi) randomized clinical trials on aerobic exercise training in adults with established heart disease were identified through electronic database and reference screening. Two reviewers extracted data and assessed the risk of bias and therapeutic validity. Methodological validity was evaluated using an adapted version of the Cochrane Collaboration’s tool for assessing risk of bias and the therapeutic validity of the interventions was assessed with a nine-itemed, expert-based rating scale (CONTENT). Scores range from 0 to 9 (score ≥ 6 reflecting therapeutic validity).

Results

Of the 384 articles retrieved, 8 studies (449 patients) were included. Three of the included studies demonstrated adequate therapeutic validity and five demonstrated low risk of bias. Two studies showed both adequate therapeutic validity and a low risk of bias. For cardiac patients aerobic exercise training was associated with more improvement in HRR compared to usual care.

Conclusion

The present systematic review shows a level 1A evidence that aerobic training increases HRR in patients with established heart disease.