Effect of exercise training in supervised cardiac rehabilitation programs on prognostic variables from the exercise tolerance test

A comparison of low and high dose of moderate intensity aerobic exercise on heart rate recovery of the sedentary adults: a pragmatic randomized controlled trial

BACKGROUND

Heart rate recovery (HRR) has been used as a prognostication marker of health. A slower drop in HRR is linked to a higher risk of cardiovascular diseases and all-cause mortality. Since aerobic exercise has been shown to have favorable effects on HRR, we aimed to compare the effects of two different aerobic exercise doses on HRR among a sedentary adult population.

METHODS

A pragmatic randomised controlled trial was conducted on 29 healthy sedentary adults (seven males and 22 females) in a 12-week exercise program. They were randomly assigned to group A (75 min/week, N.=15) or group B (150 min/week, N.=14) of moderate intensity aerobic exercise groups. HRR at 1-minute (HRR1), HRR at 2-minute (HRR2), and peak oxygen uptake (VO<inf>2peak</inf>) were measured pre- and post-intervention.

RESULTS

The improvements of HRR1 and HRR2 were seen in both groups but was only significant (P<0.05) for group A with HRR1, -4.07 bpm (post 24.47±6.42 - pre 20.40±5.51, P=0.018) and HHR2, -3.93 bpm (post 43.40±13.61 - pre 39.47±10.68, P=0.046). Group B showed increment of HRR1, -1.14 bpm (post 21.14±5.35 - pre 20.00±6.30, P=0.286) and HRR2, -2.5 bpm, (post 39.36±8.01 - pre 36.86±9.57, P=0.221). Improvement of the VO<inf>2peak</inf> was only significant in group B with an increment of 1.52±2.61 (P=0.049).

CONCLUSIONS

In conclusion, our study suggests that improvements in heart rate recovery (HRR1 and HRR2) among sedentary healthy adults can be achieved by engaging in moderate intensity exercise at a dose lower than the current recommended guidelines. The lower dose seems to be more attainable and may encourage exercise compliance. Future studies should further explore the effects of different exercise volumes on HRR in a larger sample size and also by controlling for BMI or gender.

Mobile Technology Improves Adherence to Cardiac Rehabilitation: A Propensity Score-Matched Study

Background

Despite its established effectiveness, adherence to cardiac rehabilitation remains suboptimal. The purpose of our study is to examine whether mobile technology improves adherence to cardiac rehabilitation and other outcomes.

Methods and Results

We identified all enrollees of the cardiac rehabilitation program at Boston Medical Center from 2016 to 2019 (n=830). Some enrollees used a mobile technology application that provided a customized list of educational content in a progressive manner, used the patient’s smartphone accelerometer to provide daily step counts, and served as a 2‐way messaging system between the patient and program staff. Adherence to cardiac rehabilitation was defined as the number of attended sessions and completion of the program. Enrollees had a mean age of 59 years; 32% were women, and 42% were Black. Using 3:1 propensity matching for age, sex, race/ethnicity, education, smoking status, transportation time, diagnosis, and baseline depression survey score, we evaluated change in exercise capacity, weight, functional capacity, and nutrition scores. Those in the mobile technology group (n=114) attended a higher number of prescribed sessions (mean 28 versus 22; relative risk, 1.17; 95% CI, 1.04–1.32; P=0.009), were 1.8 times more likely to complete the cardiac rehabilitation program (P=0.01), and had a slightly greater weight loss (pounds) following rehabilitation (−1.71; 95% CI, −0.30 to −3.11; P=0.02) as compared with those in the standard group (n=213); other outcomes were similar between the groups.

Conclusions

In a propensity‐matched, racially diverse population, we found that adjunctive use of mobile technology is significantly associated with improved adherence to cardiac rehabilitation and number of attended sessions.

Brief Vigorous Stair Climbing Effectively Improves Cardiorespiratory Fitness in Patients With Coronary Artery Disease: A Randomized Trial

Background: Cardiac rehabilitation exercise reduces the risk of secondary cardiovascular disease. Interval training is a time-efficient alternative to traditional cardiac rehabilitation exercise and stair climbing is an accessible means. We aimed to assess the effectiveness of a high-intensity interval stair climbing intervention on improving cardiorespiratory fitness (V˙O2peak) compared to standard cardiac rehabilitation care.

Methods: Twenty participants with coronary artery disease (61 ± 7 years, 18 males, two females) were randomly assigned to either traditional moderate-intensity exercise (TRAD) or high-intensity interval stair climbing (STAIR). V˙O2peak was assessed at baseline, following 4 weeks of six supervised exercise sessions and after 8 weeks of ~24 unsupervised exercise sessions. TRAD involved a minimum of 30 min at 60–80%HR_peak, and STAIR consisted of three bouts of six flights of 12 stairs at a self-selected vigorous intensity (~90 s/bout) separated by recovery periods of walking (~90 s). This study was registered as a clinical trial at clinicaltrials.gov (NCT03235674).

Results: Two participants could not complete the trial due to the time commitment of the testing visits, leaving n = 9 in each group who completed the interventions without any adverse events. V˙O2peak increased after supervised and unsupervised training in comparison to baseline for both TRAD [baseline: 22.9 ± 2.5, 4 weeks (supervised): 25.3 ± 4.4, and 12 weeks (unsupervised): 26.5 ± 4.8 mL/kg/min] and STAIR [baseline: 21.4 ± 4.5, 4 weeks (supervised): 23.4 ± 5.6, and 12 weeks (unsupervised): 25 ± 6.2 mL/kg/min; p (time) = 0.03]. During the first 4 weeks of training (supervised) the STAIR vs. TRAD group had a higher %HR_peak (101 ± 1 vs. 89 ± 1%; p ≤ 0.001), across a shorter total exercise time (7.1 ± 0.1 vs. 36.7 ± 1.1 min; p = 0.009). During the subsequent 8 weeks of unsupervised training, %HR_peak was not different (87 ± 8 vs. 96 ± 8%; p = 0.055, mean ± SD) between groups, however, the STAIR group continued to exercise for less time per session (10.0 ± 3.2 vs. 24.2 ± 17.0 min; p = 0.036).

Conclusions: Both brief, vigorous stair climbing, and traditional moderate-intensity exercise are effective in increasing V˙O2peak, in cardiac rehabilitation exercise programmes.

HEART FAILURE, DEPRESSION AND EXERCISE

Introduction: Patients with heart failure have high rates of physical disability, based on self-reported difficulty in performing daily living activities. Depression is also a disease entity that has a high co-morbidity in combination with heart failure. Beyond the usual medical care of heart failure, there is a plethora of research on the contribution of exercise to cardiovascular parameters and to the muscular system of patients with heart failure, its effect on their quality of life and relief of depression symptoms. Purpose: The purpose of this study is to highlight the positive effect of exercise on patients with heart failure experiencing depression. Methodology: The study material consisted of articles on the topic, found in Greek and international databases such as: Google Scholar, Mednet, Pubmed, Medline and the Hellenic Academic Libraries Association (HEAL-Link), using the appropriate keywords: heart failure, depression, exercise programs. Results: Depression affects the clinical course and prognosis of patients with heart failure. The coexistence of depression and chronic heart failure leads to an increase in mortality. The benefits of exercise, therefore, in patients with heart failure and depression have a positive impact on the patients' quality of life by contributing to increasing their functional status, reducing their re-admissions to the hospital and relieving the symptoms of depression. Conclusions: The high incidence of depression in patients with chronic heart failure requires measures to prevent it, such as exercise. Health professionals need to help patients understand their condition and follow therapeutic guidelines, as well as therapeutic exercise, which can improve their lifestyle and behavior, and help them prevent depression symptoms and promote their quality of life.

Estimation of Heart Rate Recovery after StairClimbing Using aWrist-Worn Device

Heart rate recovery (HRR) after physical exercise is a convenient method to assess cardiovascular autonomic function. Since stair climbing is a common daily activity, usually followed by a slow walking or rest, this type of activity can be considered as an alternative HRR test. The present study explores the feasibility to estimate HRR parameters after stair climbing using a wrist-worn device with embedded photoplethysmography and barometric pressure sensors. A custom-made wrist-worn device, capable of acquiring heart rate and altitude, was used to estimate the time-constant of exponential decay τ, the short-term time constant S, and the decay of heart rate in 1 min D. Fifty-four healthy volunteers were instructed to climb the stairs at three different climbing rates. When compared to the reference electrocardiogram, the absolute and percentage errors were found to be ≤ 21.0 s (≤ 52.7%) for τ, ≤ 0.14 (≤ 19.2%) for S, and ≤ 7.16 bpm (≤ 20.7%) for D in 75% of recovery phases available for analysis. The proposed approach to monitoring HRR parameters in an unobtrusive way may complement information provided by personal health monitoring devices (e.g., weight loss, physical activity), as well as have clinical relevance when evaluating the efficiency of cardiac rehabilitation program outside the clinical setting.

Assessment of the prognostic utility of the FIT treadmill score in coronary artery disease patients undergoing cardiac rehabilitation

Introduction: Cardiovascular fitness is an important goal in cardiac rehabilitation (CR) programs and is predictive of outcomes. We sought to determine the utility of a novel clinical treadmill score in determining prognosis of coronary artery disease (CAD) patients after CR. Methods: Demographic, clinical and exercise data of 262 patients (mean age 55.8 ± 10.1 years) who completed an outpatient CR program were analyzed. The FIT treadmill score was determined prior to program initiation and after completion. Patients were classified according to risk category using the FIT scores after CR completion and were followed up for the occurrence of 10 year all cause mortality. Results: On median follow up of 10.3 years, 52 patients died. An improvement of the FIT treadmill score by 18.2 points was associated with a 21% reduction in mortality (multivariate-adjusted Hazard Ratio 0.79, 95% CI 0.56-1.08, P≤0.05). Kaplan-Meier survival curves showed increased occurrence of mortality in the high-risk group. After adjustment for confounders a high-risk FIT score category on exit (HR: 2.7, 95% CI 1.41-5.17, P≤0.05) was predictive of increased mortality. Both an improvement in the FIT score (AUC=0.81) and the FIT score category on exit (AUC=0.92) had good discrimination in predicting mortality. Conclusion: The FIT treadmill score is predictive of all cause mortality in patients with CAD undergoing CR. An improvement in the FIT score after CR is associated with improved survival. The FIT score may be a useful prognostic marker of overall cardiovascular fitness and successful outcome for patients who participate in CR programs.

Heart Rate Recovery as a Novel Test for Predicting Cardiac Involvement in Beta-Thalassemia Major

BACKGROUND

Abnormal heart rate recovery (HRR) is predictive of cardiac mortality. Autonomic abnormalities in beta-thalassemia major (TM) patients have been reported in previous studies. However, the importance of low HRR in exercise stress test in TM patients has not yet been ascertained. Therefore, this study will be the first of its kind in the literature.

METHODS

Exercise stress test was performed on 56 TM patients who were being treated at the Thalassemia Center of our hospital, along with 46 non-TM iron deficiency anemia (IDA) patients as a control group. Values for HHR were recorded at 1, 2, 3, 4 and 5 min, and HRR was calculated by the difference of heart rate at peak exercise and at a specific time interval following the onset of recovery.

RESULTS

All HRR values were found to be lower in TM patients compared to those in the IDA group. Exercise capacity [metabolic equivalents (METs)] was also found to be low in these patients (p < 0.001) as well. Total exercise time was significantly lower in the TM group compared to the IDA group (8.40 ± 1.7 min vs. 11.17 ± 1.51 min, p < 0.001). Exercise capacity (METs) was also lower in the TM group compared to the IDA group. Mean T2* value was 28.3 ± 13.7 ms in TM patients on magnetic resonance imaging (MRI). In addition, there are 18 TM patients with T2* value was < 20 ms.

CONCLUSIONS

This study found that TM was independently associated with low HRR. Such a condition is an indicator of autonomic dysfunction in TM patients, since abnormal HRR is related to impaired autonomic response. In addition, impaired HRR may be a marker of early cardiac involvement in patients, whose T2* value is high on MRI. Modifying HRR with a cardiac rehabilitation program in TM patients with impaired HRR is a field open for further investigation.

Exercise training-induced modification in autonomic nervous system: An update for cardiac patients

Patients with cardiovascular disease show autonomic dysfunction, including sympathetic activation and vagal withdrawal, which leads to fatal events. This review aims to place sympathovagal balance as an essential element to be considered in management for cardiovascular disease patients who benefit from a cardiac rehabilitation program. Many studies showed that exercise training, as non-pharmacologic treatment, plays an important role in enhancing sympathovagal balance and could normalize levels of markers of sympathetic flow measured by microneurography, heart rate variability or plasma catecholamine levels. This alteration positively affects prognosis with cardiovascular disease. In general, cardiac rehabilitation programs include moderate-intensity and continuous aerobic exercise. Other forms of activities such as high-intensity interval training, breathing exercises, relaxation and transcutaneous electrical stimulation can improve sympathovagal balance and should be implemented in cardiac rehabilitation programs. Currently, the exercise training programs in cardiac rehabilitation are individualized to optimize health outcomes. The sports science concept of the heart rate variability (HRV)-vagal index used to manage exercise sessions (for a goal of performance) could be implemented in cardiac rehabilitation to improve cardiovascular fitness and autonomic nervous system function.

Prognostic value of the post-training oxygen uptake efficiency slope in patients with coronary artery disease

BACKGROUND

Peak oxygen uptake is an independent predictor of mortality in patients with coronary artery disease (CAD). However, patients with CAD are not always capable of reaching peak effort, and therefore submaximal gas exchange variables such as the oxygen uptake efficiency slope (OUES) have been introduced. Baseline exercise capacity as expressed by OUES provides prognostic information and this parameter responds to training. Therefore, we aimed to assess the prognostic value of post-training OUES in patients with CAD.

METHODS

We included 960 patients with CAD (age 60.6 ± 9.5 years; 853 males) who completed a cardiac rehabilitation program between 2000 and 2011. The OUES was calculated before and after cardiac rehabilitation and information on mortality was obtained. The relationships of post-training OUES with all-cause and cardiovascular (CV) mortality was assessed by Cox proportional hazards regression analyses. Receiver operator characteristic curve analysis was performed in order to obtain the optimal cut-off value.

RESULTS

During 7.37 ± 3.20 years of follow-up (range: 0.45-13.75 years), 108 patients died, among whom 47 died due to CV reasons. The post-training OUES was related to all-cause (hazard ratio: 0.50, p < 0.001) and CV (hazard ratio: 0.40, p < 0.001) mortality. When significant covariates, including baseline OUES, were entered into the Cox regression analysis, post-training OUES remained related to all-cause and CV mortality (hazard ratio: 0.40, p < 0.01 and 0.26, p < 0.01, respectively). In addition, the change in OUES due to exercise training was positively related to mortality (hazard ratio: 0.49, p < 0.01).

CONCLUSION

Post-training OUES has stronger prognostic value compared to baseline OUES. The lack of improvement in exercise capacity expressed by OUES after an exercise training program relates to a worse prognosis and can help distinguish patients with favorable and unfavorable prognoses.

Long-term Exercise Adherence After High-intensity Interval Training in Cardiac Rehabilitation: A Randomized Study

BACKGROUND AND PURPOSE

Exercise adherence in general is reported to be problematic after cardiac rehabilitation. Additionally, vigorous exercise is associated with impaired exercise adherence. As high-intensity interval training (HIT) is frequently used as a therapy to patients with coronary artery disease in cardiac rehabilitation, the objective was to assess long-term exercise adherence following an HIT cardiac rehabilitation programme.

METHODS

A multicentre randomized study was carried out. Eligible participants were adults who had previously attended a 12-week HIT cardiac rehabilitation programme, as either a home-based or hospital-based HIT (treadmill exercise or group exercise). The primary outcome was change in peak oxygen uptake; secondary outcomes were self-reported and objectively measured physical activity.

RESULTS

Out of 83 eligible participants, 76 were available for assessment (68 men/8 women, mean age 59 (8) years) at a one-year follow-up. Peak oxygen uptake was significantly elevated above baseline values, (treadmill exercise: 35.8 (6.4) vs. 37.4 (7.4) ml kg(-1)  min(-1) , group exercise: 32.7 (6.5) vs. 34.1 (5.8) ml kg(-1)  min(-1) and home-based exercise: 34.5 (4.9) vs. 36.7 (5.8) ml kg(-1)  min(-1) at baseline and follow-up, respectively), with no significant differences between groups. The majority of the participants (>90%) met the recommended daily level of 30 minutes of moderate physical activity. The home-based group showed a strong trend towards increased physical activity compared with the hospital-based groups.

DISCUSSION

The results from this study have shown that both home-based and hospital-based HIT in cardiac rehabilitation induce promising long-term exercise adherence, with maintenance of peak oxygen uptake significantly above baseline values at a one-year follow-up. The implication for physiotherapy practice is that HIT in cardiac rehabilitation induces satisfactory long-term exercise adherence.

Improvements in heart rate recovery among women after cardiac rehabilitation completion

BACKGROUND

Heart rate recovery (HRR) after exercise cessation is thought to reflect the rate of reestablishment of parasympathetic tone. Relatively little research has focused on improved HRR in women after completing cardiac rehabilitation (CR) exercise training.

OBJECTIVE

We examined the influence of exercise training on HRR in women completing a traditional CR program and in women completing a CR program tailored for women.

METHODS

A 2-group randomized clinical trial compared HRR between 99 women completing a traditional 12-week CR program and 137 women completing a tailored CR program. Immediately upon completion of a symptom-limited graded exercise test, HRR was measured at 1 through 6 minutes.

RESULTS

Compared with baseline, improvement in 1-minute HRR (HRR1) was similar (P = 0.777) between the tailored (mean [SD], 17.5 [11] to 19.1 [12]) and the traditional CR program (15.7 [9.0] to 16.9 [9.5]). The amount of change in the 2-minute HRR (HRR2) for the tailored (30 [13] to 32.8 [14.6]) and traditional programs (28.3 [12.8] to 31.2 [13.7]) also was not different (P = 0.391). Similar results were observed for HRR at 3 through 6 minutes. Given these comparable improvements of the 2 programs, in the full cohort, the factors independently predictive of post-CR HRR1, in rank order, were baseline HRR1 (part correlation, 0.35; P < 0.001); peak exercise capacity, estimated as metabolic equivalents (METs; 0.24, P < 0.001); anxiety (-0.17, P = 0.001); and age (-0.13, P = 0.016). The factors independently associated with post-CR HRR2 were baseline HRR2 (0.44, P < 0.001), peak METs (0.21, P < 0.001), and insulin use (-0.10, P = 0.041).

CONCLUSIONS

One to 6 minutes after exercise cessation, HRR was significantly improved among the women completing both CR programs. The modifiable factors positively associated with HRR1 included peak METs and lower anxiety, whereas HRR2 was associated with insulin administration and peak METs. Additional research on HRR after exercise training in women is warranted.

Physiological and exercise capacity improvements in women completing cardiac rehabilitation

PURPOSE

The objective of this study was to examine the improvements in physiological outcomes, including exercise capacity, in women completing a 12-week gender-specific (tailored) compared with a traditional cardiac rehabilitation (CR) program.

METHODS

A 2-group randomized clinical trial compared symptom limited graded exercise test (SL-GXT), lipid, and anthropometric parameters among 99 women completing a traditional 12-week CR program with 137 women completing a tailored CR program.

RESULTS

Compared with baseline, improvement in estimated peak metabolic equivalents (METs) was similar (P = .159) between the tailored (6.0 ± 2.7-7.6 ± 2.8) and the traditional CR programs (5.6 ± 2.3-7.1 ± 2.8). The amount of change in SL-GXT, anthropometric parameters, lipid profiles, and peak treadmill time from baseline to post-CR were also similar between the 2 groups. Given comparable improvements of the 2 CR programs, in the full cohort, factors independently associated with post-CR METs, in rank order, included baseline METs (part correlation = 0.44, P < .001), perceived physical functioning (0.24, P < .001), waist circumference (-0.10, P = .006), and age (-0.11, P = .004). Factors independently associated with post-CR treadmill time included baseline treadmill time (part correlation = 0.42, P < .001), perceived physical functioning (0.30, P < .001), waist circumference (-0.12, P = .002), and age (-0.10, P 5.006).

CONCLUSIONS

Exercise capacity was significantly improved among women completing both CR programs. In the context of CR, modifiable factors positively associated with post-CR exercise capacity included reduced waist circumference and improved physical functioning. Future research on strategies for reducing abdominal obesity and improving perceived physical functioning and exercise capacity among women attending CR is warranted.

Lifestyle risk reduction interventions in atrial fibrillation: a systematic review

BACKGROUND

The burden of atrial fibrillation (AF) is escalating even though it is potentially modifiable. Affected persons, at high risk of stroke and death, are typically not targeted for risk reduction. We aimed to determine if risk-factor interventions can improve physical functioning, health-related quality of life (HRQoL) and cardiovascular risk in AF.

METHODS

We conducted a systematic review of clinical trials evaluating lifestyle and biomedical risk reduction interventions in AF patients. Trials were identified by searching electronic databases, reference lists and grey literature. Trials were included if conducted by a health professional, and reported changes in multiple risk factor levels or HRQoL.

RESULTS

Five trials, solely exercise based, were identified (166 participants): two randomised controlled trials, one quasi-experimental and two pre-post designs. Exercise capacity improved after 2-12 months in the intervention group in all trials. This was assessed by maximal oxygen uptake (two trials, 2.5-5.4 ml/kg/min (17-32%) improvement, p < 0.02); six-minute walking distance (one trial, 114 m (27%) improvement, p < 0.001); cumulated work (one trial, 564 W/min (37%) improvement, p < 0.001) and incremental exercise testing (one trial, 11 m/min (10%) improvement, p = 0.05). Three trials evaluated heart rate (HR), demonstrating HR reduction at rest (7-13 bpm, p < 0.05) and during exercise (9 bpm, p < 0.05). Two trials measured HRQoL, both reporting significant improvements in SF-36 physical summary scores.

CONCLUSIONS

Literature suggests risk reduction interventions for AF can improve exercise levels, HRQoL and reduce HR, but the evidence base is small, methodologically compromised and focused on physical functioning. High-quality research in this area is required in order to help the multitudes of people living with AF.

Segurança da intervenção fisioterápica precoce após o infarto agudo do miocárdio

INTRODUÇÃO: A fisioterapia na fase I da reabilitação cardiovascular (FTCV) pode ser iniciada de 12 a 24 horas após o infarto agudo do miocárdio (IAM), no entanto, é comum o repouso prolongado no leito em razão do receio de instabilização do paciente. OBJETIVOS: Avaliar as respostas autonômicas e hemodinâmicas de pacientes pós-IAM submetidos ao primeiro dia de protocolo de FTCV fase I, bem como sua segurança. MATERIAIS E MÉTODOS: Foram estudados 51 pacientes com primeiro IAM não complicado, 55 ± 11 anos, 76% homens. Foram submetidos ao primeiro dia do protocolo de FTCV fase I, em média 24 horas pós-IAM. A frequência cardíaca (FC) instantânea e os intervalos R-R do ECG foram captados pelo monitor de FC (Polar®S810i) e a pressão arterial (PA) aferida pelo método auscultatório. A variabilidade da FC foi analisada nos domínios do tempo (RMSSD e RMSM dos iR-R em ms) e da frequência. A densidade espectral de potência foi expressa em unidades absolutas (ms²/Hz) e normalizada (un) para as bandas de baixa (BF) e alta frequência (AF) e pela razão BF/AF. RESULTADOS: O índice RMSSD, a AF e a AFun apresentaram redução na execução dos exercícios em relação ao repouso pré e pós-exercício (p < 0,05), a BFun e a razão BF/AF aumentaram (p < 0,05). A FC e a PA sistólica apresentaram aumento durante a execução dos exercícios em relação ao repouso (p < 0,05). Não foi observado qualquer sinal e/ou sintoma de intolerância ao esforço. CONCLUSÕES: O exercício realizado foi eficaz, pois promoveu alterações hemodinâmicas e na modulação autonômica nesses pacientes, sem ocasionar qualquer intercorrência clínica.

Changes in cardiorespiratory fitness in cardiac rehabilitation patients: a meta-analysis

BACKGROUND/OBJECTIVES

Improving patients' cardiorespiratory fitness is an important therapeutic outcome in cardiac rehabilitation. The ability of cardiac rehabilitation to reduce mortality and morbidity has been evidenced through several meta-analyses. Whether cardiac rehabilitation can increase cardiorespiratory fitness and which factors may influence such gains are less well quantified.

METHODS

We performed detailed literature searches of electronic databases and manually searched papers concerning changes in cardiorespiratory fitness in cardiac rehabilitation patients. We performed random-effects meta-analysis of mean improvements in cardiorespiratory fitness and subgroup analyses to determine potential sources of heterogeneity.

RESULTS

Data from 31 studies produced 48 groups (n=3827) with a mean improvement of 1.55 (95% CI 1.21-1.89) METs, (p<0.001); equivalent to standardised effect size of ES=0.97 (95% CI 0.80-1.13). As this value was highly heterogeneous (Q=852, p<0.001) we performed subgroup analyses on the effect size data. Gains in fitness were highest in patients receiving >36 exercise sessions in studies where fitness was assessed using the Naughton Protocol. Patient characteristics associated with the highest fitness gains were age (being young) and sex (being male training in a male-only exercise group). Changes in fitness were unrelated to programme type (comprehensive or exercise-only), duration or study design. There was no association with patient's baseline fitness levels.

CONCLUSION

This is the first meta-analysis of changes in cardiovascular fitness in cardiac rehabilitation patients and shows clinically significant improvements in a large sample of patients from a variety of rehabilitation programmes. This analysis helps describe the characteristics of cardiac rehabilitation programmes which can increase patients' cardiorespiratory fitness.

Impact of exercise on heart rate recovery

BACKGROUND

Abnormal heart rate recovery (HRR) has been shown to predict mortality. Although small studies have found that HRR can be improved with cardiac rehabilitation, it is unknown whether an improvement would affect mortality. The aim of this study was to determine whether HRR could be improved with cardiac rehabilitation and whether it would be predictive of mortality.

METHODS AND RESULTS

We evaluated 1070 consecutive patients who underwent exercise stress testing before and after completion of a phase 2 cardiac rehabilitation program. Heart rate recovery, defined as the difference between heart rate at peak exercise and exactly 1 minute into the recovery period, and mortality were followed up as the primary end points. Of 544 patients with abnormal baseline HRR, 225 (41%) had normal HRR after rehabilitation. Of the entire cohort, 197 patients (18%) died. Among patients with an abnormal HRR at baseline, failure to normalize after rehabilitation predicted a higher mortality (P<0.001). After multivariable adjustment, the presence of an abnormal HRR at exit was predictive of death in all patients (hazard ratio, 2.15; 95% confidence interval 1.43-3.25). Patients with abnormal HRR at baseline who normalized afterward had survival rates similar to those of the group with normal HRR at baseline and after cardiac rehabilitation (P=0.143).

CONCLUSIONS

Heart rate recovery improved after phase 2 cardiac rehabilitation in the overall cohort. There was a strong association of abnormal HRR at exit with all-cause mortality. Patients with abnormal HRR at baseline who normalized HRR with exercise had a mortality similar to that of individuals with baseline normal HRR.

Relationship between changes in heart rate recovery after cardiac rehabilitation on cardiovascular mortality in patients with myocardial infarction

BACKGROUND

Heart rate recovery (HRR) at predischarge exercise stress test predicts all-cause mortality in patients with myocardial infarction (MI), but the relationship between improvement in HRR with exercise training and clinical outcomes remains unclear.

OBJECTIVE

The purpose of this study was to evaluate the effect of change in HRR after exercise training on clinical outcomes in MI patients.

METHODS

The study included 386 consecutive patients with recent MI who were enrolled into our cardiac rehabilitation program. All patients underwent symptom-limited treadmill testing at baseline and after exercise training, and were prospectively followed-up in the outpatient clinic.

RESULTS

Treadmill testing revealed significant improvement in HRR after 8 weeks of exercise training (17.5 +/- 10.0 bpm to 19.0 +/- 12.3 bpm, P = .011). After follow-up of 79 +/- 41 months, 40 (10.4%) patients died of cardiac events. Multivariate Cox regression analysis revealed that diabetes (hazard ratio [HR] 2.28, 95% confidence interval [CI] 1.01-5.19, P = .049), statin use (HR 0.36, 95% CI 0.16-0.80, P = .012), baseline resting heart rate > or =65 bpm (HR 5.37, 95% CI 1.33-21.61, P = .018), post-training HRR <12 bpm (HR 2.49, 95% CI 1.10-5.63, P = .028), left ventricular ejection fraction < or =30% (HR 4.70, 95% CI 1.34-16.46, P = .016), and exercise capacity < or =4 metabolic equivalents (HR 3.63, 95% CI 1.17-11.28, P = .026) were independent predictors of cardiac death. Patients who failed to improve HRR from <12 bpm to > or =12 bpm after exercise training had significantly higher mortality (HR 6.2, 95% CI 1.3-29.2, P = .022).

CONCLUSION

Exercise training improved HRR in patients with recent MI, and patients with HRR increased to > or =12 bpm had better cardiac survival.

Prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation

BACKGROUND

The prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation (OCR) is not well established.

METHODS

2146 consecutive patients undergoing symptom-limited cycle exercise testing at OCR entry, of whom 1853 (86%) also had a test at end of OCR, were followed for a median of 33 months.

RESULTS

All-cause and cardiovascular annual mortality rates were 1.2% and 0.8%, respectively. At OCR entry, older age, diabetes, lower left ventricular ejection fraction (LVEF), calcium channel blocker use, and lower workload [hazard ratio (HR) 2.38 if < or = 105 W; p<0.001] were independent predictors of death. Diabetes, diuretic use, and lower workload [HR 3.53 if < or = 105 W; p=0.001] were independently associated with cardiovascular death. At end of OCR, older age, lower LVEF, lower workload (HR 2.34 if <140 W; p=0.009), and lower increase in peak heart rate from entry to end of OCR (HR 2.46 if <4 bpm; p=0.002) were independently associated with all-cause mortality. Older age, lower LVEF, lower increase in systolic blood pressure (HR 2.97 if <54 mm Hg; p=0.02), and lower increase in peak heart from entry to end of OCR (HR 2.72 if <4 bpm; p=0.013) were independently associated with cardiovascular mortality. Failure to undergo a test at end of OCR was an additional independent predictor of all-cause (HR 2.51; p<0.001) and cardiovascular mortality (HR 2.56; p=0.003).

CONCLUSION

Symptom-limited cycle exercise testing prior to and after OCR provides important prognostic information.