Submaximal fitness and mortality risk reduction in coronary heart disease: a retrospective cohort study of community-based exercise rehabilitation

Efficacy and safety of Qixue Tongzhi Granule in improving the exercise capacity of stable coronary artery disease: study protocol for a multicenter, randomized, double-blind, placebo-controlled trial

Background

Despite optimal medical therapy, patients with stable coronary artery disease (SCAD) still have a high risk of recurrent cardiovascular events. Exercise capacity measured by cardiopulmonary exercise testing (CPET) is a good surrogate marker for the long-term prognosis of SCAD. Qixue Tongzhi Granule (QTG) is created by academician Chen Keji and has the function of tonifying qi, promoting blood circulation, and regulating qi-flowing. This trial aims to investigate the efficacy and safety of QTG in improving exercise tolerance, alleviating angina pectoris and anxiety/depression symptoms, promoting health-related quality of life, and reducing the risk of adverse cardiovascular events in subjects with SCAD.

Methods

This is a randomized, double-blind, placebo-controlled trial. 150 SCAD patients with qi deficiency, blood stasis, and liver qi stagnation syndrome are enrolled. Patients will be randomly allocated to the QTG or placebo groups at a 1:1 ratio. QTG and placebo will be added to the modern guideline-directed medical therapy for 12 weeks and patients will be followed up for another 24 weeks. The primary outcome is the improvement of metabolic equivalents measured by CPET. The secondary outcomes are cumulative incidence of composite endpoint events, other indicators in CPET, changes in the Seattle Angina Questionnaire, traditional Chinese medicine syndrome scale, 12 items of Short Form Health Survey Questionnaire, Patient Health Questionnaire-9, and Generalized Anxiety Disorder-7, changes of ST-T segment in the electrocardiogram, improvement of left ventricular ejection fraction and left ventricular end-diastolic diameter in echocardiography. In addition, metabolomics analysis will be performed based on blood samples. Adverse events and safety evaluations will also be documented. A full analysis set, per protocol set, and safety analysis set will be conducted.

Discussion

This clinical trial can enrich treatment options for CHD patients with low cardiorespiratory fitness and psychological imbalance, and it may also create a new situation for promoting the application of traditional Chinese medicine in cardiac rehabilitation.Clinical Trial Registration: [http://www.chictr.org.cn], identifier: [ChiCTR2200058988].

Cardiorespiratory fitness measured with cardiopulmonary exercise testing and mortality in patients with cardiovascular disease: A systematic review and meta-analysis

BACKGROUND

Cardiorespiratory fitness (CRF) is inversely associated with mortality in apparently healthy subjects and in some clinical populations, but evidence for the association between CRF and all-cause and/or cardiovascular disease (CVD) mortality in patients with established CVD is lacking. This study aimed to quantify this association.

METHODS

We searched for prospective cohort studies that measured CRF with cardiopulmonary exercise testing in patients with CVD and that examined all-cause and CVD mortality with at least 6 months of follow-up. Pooled hazard ratios (HRs) were calculated using random-effect inverse-variance analyses.

RESULTS

Data were obtained from 21 studies and included 159,352 patients diagnosed with CVD (38.1% female). Pooled HRs for all-cause and CVD mortality comparing the highest vs. lowest category of CRF were 0.42 (95% confidence interval (95%CI): 0.28-0.61) and 0.27 (95%CI: 0.16-0.48), respectively. Pooled HRs per 1 metabolic equivalent (1-MET) increment were significant for all-cause mortality (HR = 0.81; 95%CI: 0.74-0.88) but not for CVD mortality (HR = 0.75; 95%CI: 0.48-1.18). Coronary artery disease patients with high CRF had a lower risk of all-cause mortality (HR = 0.32; 95%CI: 0.26-0.41) than did their unfit counterparts. Each 1-MET increase was associated with lower all-cause mortality risk among coronary artery disease patients (HR = 0.83; 95%CI: 0.76-0.91) but not lower among those with heart failure (HR = 0.69; 95%CI: 0.36-1.32).

CONCLUSION

A better CRF was associated with lower risk of all-cause mortality and CVD. This study supports the use of CRF as a powerful predictor of mortality in this population.

Association of Physical Activity With Maximal and Submaximal Tests of Exercise Capacity in Middle- and Older-Aged Adults

Although physical activity (PA) is an important determinant of exercise capacity, the association between these constructs is modest. The authors investigated the associations of self-reported and objectively measured PA with maximal and submaximal tests of exercise capacity. Participants aged ≥40 years (N = 413; 49.6% female) completed a PA questionnaire, wore a uniaxial accelerometer (5.2 ± 1.1 days), and performed maximal (cardiopulmonary exercise test [CPET]) and submaximal (long-distance corridor walk) tests with indirect calorimetry (oxygen consumption, V˙O2). Linear regression models were fitted to assess the variation in exercise capacity explained (partial eta squared, η2) by PA variables. Accelerometer-measured vigorous (η2 = 22% female; η2 = 16% male) and total PA (η2 = 17% female; η2 = 13% male) explained the most variance in CPET V˙O2 (p < .001). All η2 values were lower for long-distance corridor walk V˙O2 (η2 ≤ 11%). Age contributed more to CPET V˙O2 than any PA variable in males (η2 = 32%), but not in females (η2 = 19%). Vigorous and total PA play important roles in CPET V˙O2 in mid to late life.

Exercise capacity improvement after cardiac rehabilitation following myocardial infarction and its association with long-term cardiovascular events

AIMS 

Cardiovascular rehabilitation (CR) improves aerobic capacity and quality of life in patients after myocardial infarction (MI). The aim was to examine the associations between exercise capacity improvement and different clinically relevant cardiovascular events.

METHODS AND RESULTS 

This was a registry-based study of post-MI patients, referred to CR. All patients were submitted to exercise testing before and after CR (36 sessions, 2-3 times/week, and combined exercise). Patients were divided into two groups, based on the difference in exercise capacity before and after the CR programme with the cut-off of two metabolic equivalents (METs) improvement. We assessed the correlation between the extent of exercise capacity improvement and the following cardiovascular events: major adverse cardiac events (MACE), cardiovascular-related hospitalizations, and unplanned coronary angiography. A total of 499 patients were included (mean age 56 ± 10 years, 20% women). Both groups significantly improved in terms of exercise capacity, natriuretic peptide levels, resting heart rate, and resting diastolic pressure; however, lipid status significantly improved only in patients with ≥2 METs difference in exercise capacity. A total of 13.4% patients suffered MACE (median follow-up 858 days); 21.8% were hospitalized for cardiovascular reasons (median follow-up 791 days); and 19.8% had at least one unplanned coronary angiography (median follow-up 791 days). Exercise capacity improvement of ≥2 METs was associated with lower rates of MACE, cardiovascular hospitalizations, and unplanned coronary angiography in all examined univariate and multivariate models.

CONCLUSION 

This study has shown that exercise improvement of ≥2 METs is associated with a significant decrease in MACE, cardiac hospitalizations, and unplanned coronary angiography.

A comparison of high versus low dose of exercise training in exercise-based cardiac rehabilitation: a randomized controlled trial with 12-months follow-up

OBJECTIVE

To assess if a higher dose of exercise training in exercise-based cardiac rehabilitation could affect improvements in aerobic capacity and muscle strength.

DESIGN

Assessor-blinded randomized controlled trial with 12-months follow-up.

SETTING

Aarhus University Hospital, Aarhus, Denmark.

SUBJECTS

A total of 164 cardiac patients referred to exercise-based cardiac rehabilitation were recruited.

INTERVENTIONS

Patients were randomized to 1-hour exercise sessions either three times weekly for 12 weeks (36 sessions, high-dose group) or twice weekly for 8 weeks (16 sessions, low-dose group). The same standardized exercise and intensity protocol including aerobic and muscle strength training was used in all participants.

MAIN MEASURES

Primary outcome was changes in VO_2peak. Secondary outcomes were changes in maximal workload, muscle strength and power. Measures were obtained at baseline, after termination of the rehabilitation programme and at follow-up after 6 and 12 months.

RESULTS

After the end of intervention, statistically significant between-group differences were seen in favour of the high-dose group in all outcomes: VO_2peak 2.6 (mL kg^-1 min^-1) (95% confidence interval (CI): 0.4-4.8), maximal workload 0.3 W kg^-1 (95%CI: 0.02-0.5), isometric muscle strength 0.7 N m kg^-1 (95%CI: 0.1-1.2) and muscle power 0.3 W kg^-1 (95%CI: 0.04-0.6). After 12 months, a significant between-group difference only persisted in VO_2peak and maximal workload.

CONCLUSION

A higher dose of exercise training had a small effect on all outcomes at termination of intervention. A long-term effect persisted in VO_2peak and maximal workload. Although the effect was small, it is an important finding because VO_2peak is the most important predictor of all-cause mortality in cardiac patients.

Does exercise prescription based on estimated heart rate training zones exceed the ventilatory anaerobic threshold in patients with coronary heart disease undergoing usual-care cardiovascular rehabilitation? A United Kingdom perspective

Background

In the United Kingdom (UK), exercise intensity is prescribed from a fixed percentage range (% heart rate reserve (%HRR)) in cardiac rehabilitation programmes. We aimed to determine the accuracy of this approach by comparing it with an objective, threshold-based approach incorporating the accurate determination of ventilatory anaerobic threshold (VAT). We also aimed to investigate the role of baseline cardiorespiratory fitness status and exercise testing mode dependency (cycle vs. treadmill ergometer) on these relationships.

Design and methods

A maximal cardiopulmonary exercise test was conducted on a cycle ergometer or a treadmill before and following usual-care circuit training from two separate cardiac rehabilitation programmes from a single region in the UK. The heart rate corresponding to VAT was compared with current heart rate-based exercise prescription guidelines.

Results

We included 112 referred patients (61 years (59–63); body mass index 29 kg·m–2 (29–30); 88% male). There was a significant but relatively weak correlation ( r = 0.32; p = 0.001) between measured and predicted %HRR, and values were significantly different from each other ( p = 0.005). Within this cohort, we found that 55% of patients had their VAT identified outside of the 40–70% predicted HRR exercise training zone. In the majority of participants (45%), the VAT occurred at an exercise intensity <40% HRR. Moreover, 57% of patients with low levels of cardiorespiratory fitness achieved VAT at <40% HRR, whereas 30% of patients with higher fitness achieved their VAT at >70% HRR. VAT was significantly higher on the treadmill than the cycle ergometer ( p < 0.001).

Conclusion

In the UK, current guidelines for prescribing exercise intensity are based on a fixed percentage range. Our findings indicate that this approach may be inaccurate in a large proportion of patients undertaking cardiac rehabilitation.

A secondary analysis of data from the OPTICARE randomized controlled trial investigating the effects of extended cardiac rehabilitation on functional capacity, fatigue, and participation in society

OBJECTIVE

In this secondary analysis of data from the OPTICARE trial, we compared the effects of two behavioral interventions integrated into cardiac rehabilitation to standard rehabilitation with regard to functional capacity, fatigue, and participation in society.

DESIGN

This is a randomized controlled trial.

SETTING

This study was conducted in a cardiac rehabilitation setting.

SUBJECTS

A total of 740 patients with acute coronary syndrome were recruited for this study.

INTERVENTIONS

Patients were randomized to (1) three months of standard rehabilitation; (2) cardiac rehabilitation plus nine months after-care with face-to-face group lifestyle counseling; or (3) cardiac rehabilitation plus nine months after-care with individual lifestyle telephone counseling.

MAIN MEASURES

Functional capacity (6-minute walk test), fatigue (Fatigue Severity Scale), and participation in society (Utrecht Scale for Evaluation of Rehabilitation-Participation) were measured at randomization, 3, 12, and 18 months.

RESULTS

Additional face-to-face sessions resulted at 12 months in 12.49 m more on the 6-minute walk test compared to standard rehabilitation (P = .041). This difference was no longer present at 18 months. Prevalence of fatigue decreased from 30.2% at baseline to 11.9% at 18 months compared to an improvement from 37.3% to 24.9% after standard rehabilitation (between-group difference: odds ratio = 0.47; P = .010). The additional improvements in functional capacity seemed to be mediated by increases in daily physical activity. No mediating effects were found for fatigue. No additional improvements were seen for participation in society. Additional telephonic sessions did not result in additional intervention effects.

CONCLUSION

Extending cardiac rehabilitation with a face-to-face behavioral intervention resulted in additional long-term improvements in fatigue and small improvements in functional capacity up to 12 months. A telephonic behavioral intervention provided no additional benefits.

Effects of traditional Chinese exercise on cardiac rehabilitation after percutaneous coronary intervention: study protocol for network meta-analysis of randomised controlled trials

INTRODUCTION

Coronary heart disease (CHD) is the most common cause of death worldwide. Percutaneous coronary intervention (PCI) has been shown to reduce mortality in patients with CHD. However, there are still recurrences of cardiovascular events after PCI. Cardiac rehabilitation (CR) in patients with established CHD is associated with reductions in cardiovascular mortality and hospital admissions, as well as improved quality of life. More and more clinical trials suggest that traditional Chinese exercise (TCE) plays a positive role in patients post-PCI. The primary purposes of the current study are to conduct a network meta-analysis of randomised trials to determine the effects of TCE in patients after PCI, and to separately compare the effects of tai chi, baduanjin and yijinjing on CR after PCI.

METHODS AND ANALYSIS

Studies will be retrieved from the following databases: PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang Data, Chinese BioMedical Database and Chinese Science and Technology Periodicals Database, from inception to December 2018. We will include randomised controlled trials that are related to the effects of TCE therapies in patients after PCI. The primary outcomes will be all-cause mortality, revascularisations, health-related quality of life and hospitalisations. Two reviewers will independently select eligible articles. For each included article, two reviewers will independently extract the data and assess the risk of bias by using the Cochrane risk of bias tool. Bayesian network meta-analyses will be conducted to pool all treatment effects. The ranking probabilities for the optimal intervention of various treatments (tai chi, baduanjin or yijinjing) will be estimated by the mean ranks and surface under the cumulative ranking curve. The Grading of Recommendations Assessment, Development and Evaluation System will be used to assess the quality of evidence.

ETHICS AND DISSEMINATION

The results will be disseminated through peer-reviewed publications. They will provide consolidated evidence to inform clinicians on the potential functions of TCE in CR, and to provide reliable evidence for the application of TCE.

TRIAL REGISTRATION NUMBER

CRD42018088415.

The role and outcome of cardiac rehabilitation program in patients with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is associated with diminished cardiac function, and exercise tolerance.

HYPOTHESIS

We sought to investigate the role of cardiac rehabilitation program (CR) in patients with AF.

METHODS

The study included 2165 consecutive patients that participated in our CR program between the years 2009 to 2015. All were evaluated by a standard exercise stress test (EST) at baseline, and upon completion of at least 3 months of training. Participants were dichotomized according to baseline fitness and the degree of functional improvement. The combined primary end point was cardiac related hospitalization or all-cause mortality.

RESULTS

A total of 292 patients had history of AF, with a mean age of 68 ± 9 years old, 76% of which were males. The median predicted baseline fitness of AF patients was significantly lower compared to non-AF patients (103% vs 122%, P < 0.001, respectively). Prominent improvement was achieved in the majority of the patients in both groups (64% among AF patients and 63% among those without AF). Median improvement in fitness between stress tests was significantly higher in patients with AF (124% vs 110%, P < 0.001, respectively). Among AF patients, high baseline fitness was associated with a lower event rates (HR 0.40; 95%CI 0.23-0.70; P = 0.001). Moreover, prominent improvement during CR showed a protective effect (HR 0.83; 95% CI 0.69-0.99; P = 0.04).

CONCLUSION

In patients with AF participating in CR program, low fitness levels at baseline EST are associated with increased risk of total mortality or cardiovascular hospitalization during long-term follow-up. Improvement on follow-up EST diminishes the risk.

Is Cardiorespiratory Fitness Related to Cardiometabolic Health and All-Cause Mortality Risk in Patients with Coronary Heart Disease? A CARE CR Study

Background

Higher cardiorespiratory fitness (CRF) is associated with lower morbidity and mortality in patients with coronary heart disease (CHD). The mechanisms for this are not fully understood. A more favourable cardiometabolic risk factor profile may be responsible; however, few studies have comprehensively evaluated cardiometabolic risk factors in relation to CRF amongst patients with CHD. We aimed to explore differences in cardiometabolic risk and 5-year all-cause mortality risk in patients with CHD who have low, moderate, and high levels of CRF.

Methods

Patients with CHD underwent maximal cardiopulmonary exercise testing, echocardiogram, carotid intima-media thickness measurement, spirometry, and dual X-ray absorptiometry assessment. Full blood count, biochemical lipid profiles, high-sensitivity (hs) C-reactive protein, and NT-proBNP were analysed. Patients were defined as having low, moderate, or high CRF based on established prognostic thresholds.

Results

Seventy patients with CHD (age 63.1 ± 10.0 years, 86% male) were recruited. Patients with low CRF had a lower ventilatory anaerobic threshold, peak oxygen pulse, post-exercise heart rate recovery, and poor ventilatory efficiency. The low CRF group also had higher NT pro-BNP, hs-CRP, non-fasting glucose concentrations, and lower haemoglobin and haematocrit. Five-year mortality risk (CALIBER risk score) was also greatest in the lowest CRF group (14.9%).

Conclusions

Practitioners should interpret low CRF as an important clinical risk factor associated with adverse cardiometabolic health and poor prognosis, study registry; www.researchregistry.com.

CARE CR-Cardiovascular and cardiorespiratory Adaptations to Routine Exercise-based Cardiac Rehabilitation: a study protocol for a community-based controlled study with criterion methods

INTRODUCTION

Cardiac rehabilitation (CR) reduces all-cause and cardiovascular mortality in patients with coronary heart disease (CHD). Much of this improvement has been attributed to the beneficial effects of structured exercise training. However, UK-based studies have not confirmed this. Improvements in survival and cardiovascular health are associated with concurrent improvements in cardiorespiratory fitness (CRF). It is therefore concerning that estimated CRF improvements resulting from UK-based CR are approximately one-third of those reported in international literature. Modest improvements in CRF suggest that UK CR exercise training programmes may require optimisation if long-term survival is to be improved. However, contemporary UK studies lack control data or use estimates of CRF change. Cardiovascular and cardiorespiratory Adaptations to Routine Exercise-based CR is a longitudinal, observational, controlled study designed to assess the short-term and long-term effect of CR on CRF, as well cardiovascular and cardiometabolic health.

METHODS AND ANALYSIS

Patients will be recruited following referral to their local CR programme and will either participate in a routine, low-to-moderate intensity, 8-week (16 sessions) exercise-based CR programme or freely abstain from supervised exercise. Initial assessment will be conducted prior to exercise training, or approximately 2 weeks after referral to CR if exercise training is declined. Reassessment will coincide with completion of exercise training or 10 weeks after initial assessment for control participants. Participants will receive a final follow-up 12 months after recruitment. The primary outcome will be peak oxygen consumption determined using maximal cardiopulmonary exercise testing. Secondary outcomes will include changes in subclinical atherosclerosis (carotid intima-media thickness and plaque characteristics), body composition (dual X-ray absorptiometry) and cardiometabolic biomarkers.

ETHICS AND DISSEMINATION

Ethical approval for this non-randomised controlled study has been obtained from the Humber Bridge NHS Research Ethics Committee-Yorkshire and the Humber on the 27th September 2013, (12/YH/0278). Results will be presented at national conferences and published in peer-reviewed journals.

CHA2DS2-VASc score and exercise capacity of patients with coronary artery disease participating in cardiac rehabilitation programs

BACKGROUND

Exercise based cardiac rehabilitation improves prognosis and quality of life in patients with coronary artery disease. We aimed to investigate whether the CHA2DS2-VASc score may be a predictor of improvement in exercise capacity in acute coronary syndrome (ACS) patients participating in a cardiac rehabilitation program.

METHODS

Included were patients following a hospital admission due to ACS and were subsequently referred for an exercise based cardiac rehabilitation during 2010-2015. Participants were divided into three groups of low (1-2), intermediate (3) and high (4≤) CHA2DS2-VASc score. Exercise capacity was evaluated by a treadmill stress test at baseline and following 9 months. The primary endpoint was the percent of patients who achieved at least 25% improvement in exercise capacity.

RESULTS

The 597 patients included in the study had a mean age of 65.5±9.3 years and consisted of 22.5% women. The primary endpoint of at least 25% improvement in exercise capacity following 9 months of cardiac rehabilitation occurred more frequently in patients in the high CHA2DS2-VASc group compared to the intermediate and low CHA2DS2-VASc score groups (47.3, 29.9 and 36.1% in the high, intermediate and low CHA2DS2-VASc score groups respectively, P=0.002).

CONCLUSION

The CHA2DS2-VASc score may serve as a predictor of exercise capacity improvement. Its use for tailoring specific cardiac rehabilitation programs for ACS patients may yield further improvement in functional capacity and better utilization of resources.

Estimated peak functional capacity: an accurate method for assessing change in peak oxygen consumption after cardiac rehabilitation?

OBJECTIVE

Cardiopulmonary exercise testing (CPET) is the 'gold standard' method of determining VO_2peak . When CPET is unavailable, VO_2peak may be estimated from treadmill or cycle ergometer workloads and expressed as estimated metabolic equivalents (METs). Cardiac rehabilitation (CR) programmes use estimated VO_2peak (METs) to report changes in cardiorespiratory fitness (CRF). However, the accuracy of determining changes in VO_2peak based on estimated functional capacity is not known.

METHODS

A total of 27 patients with coronary heart disease (88·9% male; age 59·5 ± 10·0 years, body mass index 29·6 ± 3·8 kg m^-2 ) performed maximal CPET before and after an exercise-based CR intervention. VO_2peak was directly determined using ventilatory gas exchange data and was also estimated using the American College of Sports Medicine (ACSM) leg cycling equation. Agreement between changes in directly determined VO_2peak and estimated VO_2peak was evaluated using Bland-Altman limits of agreement (LoA) and intraclass correlation coefficients.

RESULTS

Directly determined VO_2peak did not increase following CR (0·5 ml kg^-1 min^-1 (2·7%); P = 0·332). Estimated VO_2peak increased significantly (0·4 METs; 1·4 ml kg^-1  min^-1 ; 6·7%; P = 0·006). The mean bias for estimated VO_2peak versus directly determined VO_2peak was 0·7 ml kg^-1  min^-1 (LoA -4·7 to 5·9 ml  kg^-1  min^-1 ). Aerobic efficiency (ΔVO₂ /ΔWR slope) was significantly associated with estimated VO_2peak measurement error.

CONCLUSION

Change in estimated VO_2peak derived from the ACSM leg cycling equation is not an accurate surrogate for directly determined changes in VO_2peak . Our findings show poor agreement between estimates of VO_2peak and directly determined VO_2peak . Applying estimates of VO_2peak to determine CRF change may over-estimate the efficacy of CR and lead to a different interpretation of study findings.

Exercise dose and all-cause mortality within extended cardiac rehabilitation: a cohort study

Aims

To investigate the relationship between exercise participation, exercise ‘dose’ expressed as metabolic equivalent (MET) hours (h) per week, and prognosis in individuals attending an extended, community-based exercise rehabilitation programme.

Methods

Cohort study of 435 participants undertaking exercise-based cardiac rehabilitation (CR) in Leeds, West Yorkshire, UK between 1994 and 2006, followed up to 1 November 2013. MET intensity of supervised exercise was estimated utilising serial submaximal exercise test results and corresponding exercise prescriptions. Programme participation was routinely monitored. Cox regression analysis including time-varying and propensity score adjustment was applied to identify predictors of long-term, all-cause mortality across exercise dose and programme duration groups.

Results

There were 133 events (31%) during a median follow-up of 14 years (range, 1.2 to 18.9 years). The significant univariate association between exercise dose and all-cause mortality was attenuated following multivariable adjustment for other predictors, including duration in the programme. Longer-term adherence to supervised exercise training (>36 months) was associated with a 33% lower mortality risk (multivariate-adjusted HR: 0.67; 95% CI: 0.47 to 0.97; p=0.033) compared with all lesser durations of CR (3, 12, 36 months), even after adjustment for baseline fitness, comorbidities and survivor bias.

Conclusion

Exercise dose (MET-h per week) appears less important than long-term adherence to supervised exercise for the reduction of long-term mortality risk. Extended, supervised CR programmes within the community may play a key role in promoting long-term exercise maintenance and other secondary prevention therapies for survival benefit.

Effects of exercise-based cardiac rehabilitation on cardiorespiratory fitness: A meta-analysis of UK studies

BACKGROUND

Exercise-based cardiac rehabilitation can promote meaningful improvements in cardiorespiratory fitness (fitness) but the magnitude of such improvements varies according to local characteristics of exercise programmes. We aimed to determine if cardiac rehabilitation (CR), as practised in the United Kingdom (UK), could promote meaningful changes in fitness and to identify programme characteristics which may moderate these changes.

METHODS

Electronic and manual searches to identify UK CR studies reporting fitness at baseline and follow up. Change in fitness (Δfitness) was expressed as mean difference (95% CI) and effect size (ES). A random effects model was used to calculate the mean estimate for change in Δfitness. Between-group heterogeneity was quantified (Q) and investigated using planned sub-group analyses.

RESULTS

We identified n=11 studies containing 16 patient groups (n=1 578) which used the incremental shuttle walking test (ISWT) (distance walked) to assess fitness. The overall mean estimate for Δfitness showed a significant increase in distance walked (ES=0.48, P<0.001), but this estimate was highly heterogeneous (Q=77.1, P<0.001, I(2)=81%). Sub-group analyses showed significantly greater ES (Q=3.94, P=0.046) for Δfitness in patients prescribed n>12 exercise sessions compared with those receiving n≤12 sessions.

CONCLUSION

We found significant increases in fitness (based on ISWT) in patients attending exercise-based CR in the UK. However, UK studies provide approximately one-third of the exercise "dose", and produce gains in fitness less than half the magnitude reported in international studies.