Exercise conditioning in older coronary patients. Submaximal lactate response and endurance capacity

Cardiac rehabilitation for older adults: current evidence and future potential

INTRODUCTION

Growth of the older adult demographic has resulted in an increased number of older patients with cardiovascular disease (CVD) in combination with comorbid diseases and geriatric syndromes. Cardiac rehabilitation (CR) is utilized to promote recovery and improve outcomes, but remains underutilized, particularly by older adults. CR provides an opportunity to address the distinctive needs of older adults, with focus on CVD as well as geriatric domains that often dominate management and outcomes.

AREAS COVERED

Utility of CR for CVD in older adults as well as pertinent geriatric syndromes (e.g. multimorbidity, frailty, polypharmacy, cognitive decline, psychosocial stress, and diminished function) that affect CVD management.

EXPERT OPINION

Mounting data substantiate the importance of CR as part of recovery for older adults with CVD. The application of CR as a standard therapy is especially important as the combination of CVD and geriatric syndromes catalyzes functional decline and can trigger progressive clinical deterioration and dependency. While benefits of CR for older adults with CVD are already evident, further reengineering of CR is necessary to better address the needs of older candidates who may be frail, especially as remote and hybrid formats of CR are becoming more widespread.

Effectiveness of Home-Based Mobile Guided Cardiac Rehabilitation as Alternative Strategy for Nonparticipation in Clinic-Based Cardiac Rehabilitation Among Elderly Patients in Europe: A Randomized Clinical Trial

Importance

Although nonparticipation in cardiac rehabilitation is known to increase cardiovascular mortality and hospital readmissions, more than half of patients with coronary artery disease in Europe are not participating in cardiac rehabilitation.

Objective

To assess whether a 6-month guided mobile cardiac rehabilitation (MCR) program is an effective therapy for elderly patients who decline participation in cardiac rehabilitation.

Design, Setting, and Participants

Patients were enrolled in this parallel multicenter randomized clinical trial from November 11, 2015, to January 3, 2018, and follow-up was completed on January 17, 2019, in a secondary care system with 6 cardiac institutions across 5 European countries. Researchers assessing primary outcome were masked for group assignment. A total of 4236 patients were identified with a recent diagnosis of acute coronary syndrome, coronary revascularization, or surgical or percutaneous treatment for valvular disease, or documented coronary artery disease, of whom 996 declined to start cardiac rehabilitation. Subsequently, 179 patients who met the inclusion and exclusion criteria consented to participate in the European Study on Effectiveness and Sustainability of Current Cardiac Rehabilitation Programmes in the Elderly trial. Data were analyzed from January 21 to October 11, 2019.

Interventions

Six months of home-based cardiac rehabilitation with telemonitoring and coaching based on motivational interviewing was used to stimulate patients to reach exercise goals. Control patients did not receive any form of cardiac rehabilitation throughout the study period.

Main Outcomes and Measures

The primary outcome parameter was peak oxygen uptake (Vo2peak) after 6 months.

Results

Among 179 patients randomized (145 male [81%]; median age, 72 [range, 65-87] years), 159 (89%) were eligible for primary end point analysis. Follow-up at 1 year was completed for 151 patients (84%). Peak oxygen uptake improved in the MCR group (n = 89) at 6 and 12 months (1.6 [95% CI, 0.9-2.4] mL/kg-1/min-1 and 1.2 [95% CI, 0.4-2.0] mL/kg-1/min-1, respectively), whereas there was no improvement in the control group (n = 90) (+0.2 [95% CI, -0.4 to 0.8] mL/kg-1/min-1 and +0.1 [95% CI, -0.5 to 0.7] mL/kg-1/min-1, respectively). Changes in Vo2peak were greater in the MCR vs control groups at 6 months (+1.2 [95% CI, 0.2 to 2.1] mL/kg-1/min-1) and 12 months (+0.9 [95% CI, 0.05 to 1.8] mL/kg-1/min-1). The incidence of adverse events was low and did not differ between the MCR and control groups.

Conclusions and Relevance

These results suggest that a 6-month home-based MCR program for patients 65 years or older with coronary artery disease or a valvular intervention was safe and beneficial in improving Vo2peak when compared with no cardiac rehabilitation.

Trial Registration

trialregister.nl Identifier: NL5168.

Treatment of the Aged Patients at a Large Cardiac Rehabilitation Center in the Southern Brazil and Some Aspects of Their Dropout from the Therapeutic Programs

AIM

This paper aims to assess the dropout rate in different age groups through the example of the large cardiac rehabilitation centre affiliated with the Institute of Sports Medicine, University of Caxias do Sul.

MATERIAL AND METHODS

A historic cohort study comprising the following groups: Non-Old < 65 (n = 141); Young-Old 65-74 (n = 128); and Middle-Old 75-84 years old (n = 57). The exercise program lasted 48 sessions and dropout was defined as attendance of 50% of sessions or less. Logistic binominal regression was performed to assess the risk of dropout. For all analyses, a two-tailed P value of < 0.05 was used.

RESULTS

The total dropout rate was 38.6%. The Young-Old and Middle-Old groups showed lower dropouts compared to Non-Old patients (p = 0.01). Young-Old has 96% less risk for dropout compared to Non-Old group (adjusted odds ratios = 1.96 [1.16-3.29]). Furthermore, patients underwent the Coronary Artery Bypass Graft showed a lower rate of dropout (p = 0.001). The absence of CABG involved three times more risk of dropout (p = 0.001).

CONCLUSION

The Non-Old and the Middle-Old patients showed higher dropout rates compared to Young-Old. To ensure the best possible rehabilitation and to improve patients´ participation in CR, these programs should be adjusted to the needs of patients in terms of their age.

Whole-body strength training with Huber Motion Lab and traditional strength training in cardiac rehabilitation: A randomized controlled study

BACKGROUND

Isometric strengthening has been rarely studied in patients with coronary heart disease (CHD), mainly because of possible potential side effects and lack of appropriate and reliable devices.

OBJECTIVE

We aimed to compare 2 different modes of resistance training, an isometric mode with the Huber Motion Lab (HML) and traditional strength training (TST), in CHD patients undergoing a cardiac rehabilitation program.

DESIGN

We randomly assigned 50 patients to HML or TST. Patients underwent complete blinded evaluation before and after the rehabilitation program, including testing for cardiopulmonary exercise, maximal isometric voluntary contraction, endothelial function and body composition.

RESULTS

After 4 weeks of training (16 sessions), the groups did not differ in body composition, anthropometric characteristics, or endothelial function. With HML, peak power output (P=0.035), maximal heart rate (P<0.01) and gain of force measured in the chest press position (P<0.02) were greater after versus before training.

CONCLUSION

Both protocols appeared to be well tolerated, safe and feasible for these CHD patients. A training protocol involving 6s phases of isometric contractions with 10s of passive recovery on an HML device could be safely implemented in rehabilitation programs for patients with CHD and improve functional outcomes.

Functional Recovery and Exercise Behavior in Men and Women 5 to 6 Years Following Coronary Artery Bypass Graft (CABG) Surgery

Improvement following coronary artery bypass graft (CABG) surgery has been reported to be less in women than men. Relationships between exercise behavior and functional status of men and women 5 to 6 years after CABG have not been examined in a representative patient sample. This study compared the 5- to 6-year recovery in a cohort of 184 patients at the Minnesota site of the Post CABG Biobehavioral Study. Data were collected by telephone interviewand self-administered questionnaires. Results showed that women had lower physical ( p ≤ .004) and social ( p = .001) functioning scores; men were more likely to participate in regular exercise ( p = .01). Exercisers had higher functional status scores. ANCOVA demonstrated that differences in measures of functional status by exercise category were maintained even after controlling for age, sex, and symptom severity ( p ≤ .01). In conclusion, individuals who exercised had more positive functional outcomes 5 to 6 years post-CABG.

Acute Cardiovascular Response to Sign Chi Do Exercise

Safe and gentle exercise may be important for older adults overcoming a sedentary lifestyle. Sign Chi Do (SCD), a novel form of low impact exercise, has shown improved balance and endurance in healthy older adults, and there have been no SCD-related injuries reported. Sedentary older adults are known to have a greater cardiovascular (CV) response to physical activity than those who regularly exercise. However their CV response to SCD is unknown. This study explored the acute CV response of older adults to SCD. Cross-sectional study of 34 sedentary and moderately active adults over age 55 with no previous experience practicing SCD. Participants completed a 10 min session of SCD. CV outcomes of heart rate, blood pressure, rate pressure product were recorded at 0, 5, 10 min of SCD performance, and after 10 min of rest. HR was recorded every minute. There was no difference in CV scores of sedentary and moderately active older adults after a session of SCD-related activity. All CV scores increased at 5 min, were maintained at 10 min, and returned to baseline within 10 min post SCD (p < 0.05). SCD may be a safe way to increase participation in regular exercise by sedentary older adults.

Effects of exercise on cardiovascular performance in the elderly

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

Diagnostic performance of weight loss to predict body fatness improvement in cardiac rehabilitation patients

PURPOSE

To determine the diagnostic performance of weight loss to identify fat mass loss in cardiac rehabilitation (CR) patients.

METHODS

We included consecutive patients enrolled in early outpatient CR who underwent air displacement plethysmography with measurements of height, weight, and waist circumference at initiation and completion of CR. We calculated the accuracy of >1 kg of weight loss to predict a >1 kg loss of fat mass.

RESULTS

We analyzed data from 142 patients (mean age ± SD = 60 ± 12 years), 74% male, 94% non-Hispanic whites, and body mass index (BMI) 29.9 ± 5.1 kg/m. Following 87 ± 49 days and 22 ± 9 CR sessions, there was a small but significant change in weight (-1.3 ± 3.8 kg), BMI (-0.4 ± 1.2 kg/m), fat mass (-2.6 ± 3.9 kg), lean mass (+1.3 ± 1.9 kg), and waist circumference (-4.3 ± 5.1 cm), P < .001 for all. Overall, patients who lost weight consistently lost fat mass, positive predictive value 0.91 (95% CI: 0.83-0.96). However, the negative predictive value of lack of weight loss to exclude fat mass loss was poor, 0.59 (95% CI: 0.52-0.64). Among patients who did not lose weight, waist circumference reduction was modestly predictive of fat mass loss (r = 0.33, P = .004.)

CONCLUSIONS

Although weight loss in CR is indicative of fat mass loss in most patients, absence of weight loss, or even weight gain, would not necessarily rule out fat loss in a significant number of patients attending CR. These findings speak to the importance of body fatness measurements beyond BMI in the CR setting.

Effects of Short-term Exercise Training on Cardiorespiratory Fitness of Male Adults with Myocardial Infarction

[Purpose] The purpose of this study was to determine the effects of short-term exercise training on the cardiorespiratory fitness (CRF) of individuals suffering from myocardial infarction. [Subjects] A total of 60 participants were divided into experimental (EXP; n=30, mean age 56.7 ± 2.8 years, body mass 80.7 ± 10.7 kg, body height 171.9 ± 7.2 cm) and control (CON; n=30, mean age 56.5 ± 3.1 years, body mass 84.4 ± 12.4 kg, body height 171.5 ± 12.4 cm) groups. [Methods] The members of the EXP group took part in an organized daily physical exercise program (Monday through Sunday), for a period of 3 weeks. The exercise program consisted of 60 min daily specialized fitness exercises with an intensity ranging from 55-70% of the maximum heart rate, which was determined by test on a bicycle ergometer. The effects of the exercise were monitored by means of the following parameters: maximum oxygen uptake (VO2peak), resting heart rate, systolic blood pressure and diastolic blood pressure. [Results] The results indicate statistically significant post-exercise improvements in heart rate, relative oxygen uptake and systolic blood pressure, among the members of the EXP group. The results indicate that at the initial measurement of cardiorespiratory fitness no statistically significant differences were found between the groups at the multivariate level (Wilk's λ=0.83), while statistically significant differences in the cardiorespiratory fitness were found at the final measurement (Wil's λ=0.430). [Conclusion] The obtained results indicate that the exercise program, which lasted for a period of 21 days, though shorter in duration than other programs still led to statistically significant changes in the CRF of individuals suffering from MI.

The impact of training modalities on the clinical benefits of exercise intervention in patients with cardiovascular disease risk or type 2 diabetes mellitus

Exercise training intervention represents an effective means to reduce adipose tissue mass, improve glycaemic control and increase whole-body oxygen uptake capacity (VO(2peak)) in obesity, metabolic syndrome, type 2 diabetes mellitus (T2DM) and heart disease patients. In this manuscript, we review the impact of different exercise training modalities on clinical benefits of prolonged exercise intervention in these patient (sub)populations. By changing training modalities, significantly greater clinical benefits can be obtained. Greater training frequency and longer programme duration is associated with greater reduction in adipose tissue mass in obesity patients. A greater training frequency (up to 2 days/week) and a longer programme duration (up to 38 weeks) seems to be associated with greater improvements in VO(2peak) in heart disease patients. Longer programme duration and addition of resistance-type exercise further improve glycaemic control in T2DM patients. The first line of evidence seems to indicate that high-intensity interval exercise training has a greater impact on VO(2peak) in heart disease patients and insulin sensitivity in subjects with metabolic syndrome, but not on adipose tissue mass in obese subjects. However, it remains unclear whether addition of resistance-type exercise and continuous higher-intensity endurance-type exercise training are accompanied by greater improvements in VO(2peak) in heart disease patients. Furthermore, the impact of training session duration/volume on adipose tissue mass loss and glycaemic control in obesity and T2DM patients, respectively, is currently unknown. The impact of training frequency on glycaemic control remains to be investigated in T2DM patients.

Intermittent hypoxia increases exercise tolerance in patients at risk for or with mild COPD

The effects of repeated short-term hypoxia on exercise tolerance in patients at risk for, or with mild COPD were investigated. Eighteen patients (10 males, 8 females; 33-72 years) were randomly assigned in a double-blind fashion to receive 15 sessions of intermittent hypoxia (FiO(2): 0.15-0.12) or normoxia within 3 weeks. Three weeks of intermittent hypoxia increased total haemoglobin mass (+4% vs. 0%, p<0.05), total exercise time (+9.7% vs. 0%, p<0.05) and the exercise time to the anaerobic threshold (+13% vs. -7.8%, p<0.05) compared to controls. Changes in the total exercise time were positively related to the changes in total haemoglobin mass (r=0.59, p<0.05) and changes in the time to the anaerobic threshold were positively related to the changes in the lung diffusion capacity for carbon monoxide (r=0.48, p<0.05). Intermittent hypoxia treatment may be a valuable addition to therapy designed to improve exercise tolerance in patients at risk for, or with mild COPD.

Exercise-based cardiac rehabilitation for very old patients (> or =75 years): focus on physical function

Older patients have high rates of physical function impairment and disability following a cardiac event. Exercise training has been shown to favorably affect such limitations, as well as cardiovascular risk factors, symptoms, and mortality post coronary event in middle-aged patients. Aerobic capacity, body strength, quality of life, and physical function are improved with exercise-based cardiac rehabilitation (CR) in patients older than 65 years. However, there have been relatively few studies of the effects of exercise-based CR on physical function recovery in the very old patients (> or =75 years), despite the continuous growth of this segment of the population. After hospitalization for a cardiac event, postacute inpatient CR serves as a bridge between acute care and independent home living for the most disabled older patients. It plays an important role in the physical recovery process, particularly after cardiac surgery. Exercise-based outpatient (phase II) CR, starting early after hospital discharge, is safe in very old patients and studies demonstrate that these patients derive similar benefits from CR, compared with younger patients, regarding physical function improvement. Older patients, however, are less likely than younger cardiac patients to participate in outpatient CR programs. There is a need to find protocols that could increase the referral and participation rates of the frailer and older cardiac patient to exercise-based CR.

Effects of short-term exercise training on symptoms and quality of life in patients with chronic atrial fibrillation

BACKGROUND

A randomised study was conducted to determine if short-term exercise training in patients with chronic atrial fibrillation (AF) might improve symptoms and health-related quality of life (HRQoL).

METHODS

AF patients (64+/-7 years) were randomised to exercise training (n=15) or a 2-month control period (n=15) followed by an exercise training program (ETP). The ETP consisted of 24 training sessions with aerobic exercise and muscle strengthening. A cycle ergometer test, with recording of perceived exertion on the Borg scale, was performed. The participants completed HRQoL questionnaires, the Short-Form 36 (SF-36) and Symptom and Severity Checklist (SSCL), before and after training. Because there were no changes after two months in the control group, pooled data for all patients are presented before and after training.

RESULTS

Four of the eight SF-36 scales improved significantly (p<0.05) following training: physical functioning (82+/-14 pre-ETP, 86+/-10 post-ETP), bodily pain (82+/-17 pre-ETP, 92+/-14 post-ETP), vitality (61+/-14 pre-ETP, 68+/-13 post-ETP) and role-emotional (85+/-28 pre-ETP, 94+/-20 post-ETP). The SF-36 physical component summary scale also increased from 49+/-6 pre-ETP to 52+/-6 post-ETP (p<0.05). Significant improvements were also observed for summary and specific symptom scores of the SSCL. Exercise capacity improved by 41+/-20% and perceived exertion during testing by 1.4 points after training (p<0.05 for both).

CONCLUSIONS

The study demonstrates a significant improvement in HRQoL, symptoms during exercise testing and exercise capacity after a short-term exercise training program in patients with chronic AF.

Cardiac rehabilitation in the elderly: patient selection and outcomes

In Western countries, the aging and improving survival of patients with coronary heart disease are responsible for an increasing number of older adults (65 years of age and older) who are eligible for cardiac rehabilitation. The elderly with coronary heart disease represent a special population with changes induced by aging and lifestyle, comorbidity, cognitive dysfunction, and high risk of disability. Although the elderly account for the majority of cardiac admissions and procedures, studies on cardiac rehabilitation have traditionally focused on younger patients. In aged experimental animals, there is evidence that exercise training is able to improve hemodynamic parameters and biologic markers. Moreover, in older patients, exercise improves functional capacity and reduces myocardial work, similar to that seen in younger patients. As for younger patients, cardiac rehabilitation requires a multidisciplinary approach, including comprehensive assessment, treatment of risk factors and comorbidity, and psychosocial assessment. Cardiac rehabilitation is safe and helpful for elderly coronary patients. Physicians must be encouraged to prescribe cardiac rehabilitation programs for the elderly following major coronary events and coronary revascularization procedures.

[Exercise training in cardiac patients: usefulness of the cardiopulmonary exercise test]

Exercise training is currently including in the treatment of coronary arterial disease patients, in patients with left ventricular dysfunction as well as in patients who underwent cardiac transplantation or cardiac surgery. However methods of prescribing exercise-training programs are difficult to determine and must be adapted for each patient Exercise test with gas analysis through the determination of anaerobic threshold may help to understand the physiopathological mechanism related to exercise limitation in these patients. Exercise test may help to precise exercise intensity during cardiac rehabilitation and may assess the benefits on exercise tolerance.

Effects of angiotensin-converting enzyme inhibitor plus irbesartan on maximal and submaximal exercise capacity and neurohumoral activation in patients with congestive heart failure

BACKGROUND

In patients with symptomatic congestive heart failure receiving optimal therapy with an angiotensin-converting enzyme (ACE) inhibitor and a beta-blocker, the impact of using an angiotensin receptor blocker on submaximal exercise capacity and on neurohumoral activation at rest and during stress has not been investigated.

METHODS

Thirty-three patients with congestive heart failure, New York Heart Association II or III symptoms, and left ventricular ejection fraction 25.5% +/- 7.2% treated with an ACE inhibitor and a beta-blocker were recruited. Patients were randomly assigned to receive irbesartan 150 mg per day (n = 22) or a placebo (n = 11) for 6 months. Maximal exercise capacity was assessed using a ramp protocol. Submaximal exercise duration was assessed using a constant load protocol, and plasma norepinephrine and angiotensin II (A-II) were measured in resting state, at 6 minutes, and at peak exercise.

RESULTS

Patients treated with irbesartan presented a 26% increase in submaximal exercise time (+281 seconds, P = .08) whereas exercise duration increased by only 7% in patients treated with a placebo (+128 seconds, P = NS irbesartan vs placebo). Norepinephrine levels increased to a similar extent in both groups, whereas A-II levels did not increase or change in response to therapy.

CONCLUSIONS

Dual A-II suppression with an ACE inhibitor plus irbesartan provides a small but a significant increase in submaximal exercise capacity. This beneficial effect is observed despite no significant changes in maximal exercise capacity, and in resting or exercise-induced increase in neurohumoral activation.

Cardiorespiratory requirements and reproducibility of the six-minute walk test in elderly patients with coronary artery disease

OBJECTIVES

To measure the cardiorespiratory requirements of the six-minute walk test (6MWT), to compare this demand with the symptom-limited exercise test (SLET) at ventilatory threshold and at maximal level in elderly patients with coronary artery disease (CAD), and to assess the reproducibility of the 6MWT in cardiorespiratory exchanges in those patients.

DESIGN

Comparative and reproducibility sample.

SETTING

Cardiac rehabilitation service.

PARTICIPANTS

Twenty-five people with CAD.

INTERVENTIONS

Subjects performed an SLET and a 6MWT. To test 6MWT reproducibility, 9 patients performed 2 repeated 6MWTs.

MAIN OUTCOME MEASURES

The 6MWT cardiorespiratory values, measured with a portable gas analyzer, were compared with the SLET data and with the data from the 2 repeated 6MWTs.

RESULTS

The 6MWT peak oxygen uptake (VO2peak, 14.27+/-2.94 mL.min(-1).kg(-1)) and heart rate (94+/-14 beats/min) did not differ from the SLET values at ventilatory threshold (VO2, 13.4+/-2.65 mL.min(-1).kg(-1); heart rate, 91+/-17 beats/min), whereas the 6MWT ventilation (VEpeak, 36.72+/-10.03 L/min) was higher than the SLET at ventilatory threshold (Ve, 31.54+/-8.93 L/min, P<.03). Maximal 6MWT cardiorespiratory data were lower than the SLET maximal values. Cardiorespiratory values did not differ between the 2 repeated 6MWT (VO2peak, 15.33+/-3.52 mL.min(-1).kg(-1) vs 15.11+/-2.65 mL.min(-1).kg(-1); VEpeak, 39.07+/-12.33 L/min vs 39.07+/-12.13 L/min; heart rate, 95+/-21 beats/min vs 89+/-15 beats/min).

CONCLUSIONS

The 6MWT cardiorespiratory requirement values did not differ from SLET values at ventilatory threshold except for ventilation, and 6MWT values are reproducible in elderly patients with CAD.

Effects of exercise and cardiac rehabilitation on cardiovascular outcomes

Cardiac rehabilitation was originally conceived to counteract the deconditioning and comorbidities associated with prolonged bed rest after a myocardial infarction. Contemporary cardiac rehabilitation has taken a more comprehensive approach, with a broader range of participating patients. Relevant cardiovascular outcomes of cardiac rehabilitation can be classified as primary clinical outcomes, intermediate clinical outcomes, and quality-of-life outcomes. In this article, the effects of exercise training alone and, more importantly, the value of comprehensive cardiac rehabilitation are reviewed from the point of view of individual cardiovascular outcomes.

Aerobic exercise and the post myocardial infarction patient: a review of the literature

Meta analyses of randomized controlled tests of cardiac rehabilitation after myocardial infarction demonstrate that regular exercise reduces the risk of overall mortality and cardiovascular mortality. In patients with established coronary artery disease, exercise is associated with improved activity tolerance, modification of risk factors, and improvement in quality of life. Randomized controlled tests demonstrate that whereas older patients after coronary events are substantially less fit than younger patients, they obtain a similar relative improvement of aerobic capacity with a graded conditioning program. However, older adults are enrolled in such programs at a lower rate than other age groups. Despite similar clinical profiles to men, women are less likely to participate in exercise rehabilitation. In this article we discuss the principles of program development, guidelines for monitoring of patients, and facilitation of exercise programs in the Australian context.

Cardiorespiratory fitness and functional capacity assessed by the 20-meter shuttle walking test in patients with coronary artery disease

OBJECTIVE

To validate the 20-meter shuttle walking test (20MST) in the assessment of maximal oxygen consumption (VO(2)max) and maximal speed in patients with coronary artery disease (CAD).

DESIGN

Single-sample validity study.

SETTING

Cardiac rehabilitation service in France.

PARTICIPANTS

Seventeen men with CAD.

INTERVENTIONS

Subjects underwent a symptom-limited treadmill test (SLTT) in a laboratory, with a speed starting at 2.5km/h and increasing by 0.5km/h every minute, and performed an adapted 20MST in a corridor, with a speed starting at 3km/h and increasing by 1km/h every minute until exhaustion.

MAIN OUTCOME MEASURES

VO(2) measured during the 20MST with the Cosmed K2 telemetric gas analyzer (K2 VO(2)), estimated VO(2) calculated by the Léger equation (Léger VO(2)) from the maximal speed obtained during the 20MST, and VO(2) measured during the SLTT (SLTT VO(2)). Maximal speeds attained on the treadmill and on the 20MST were also compared.

RESULTS

A significant (P<.0001) difference was observed between the Léger estimate of VO(2) and those of K2 VO(2) and SLTT VO(2) (mean +/- standard deviation, 12.28+/-5.90mL. min(-1).kg(-1) vs 23.04+/-7.17 and 22.56+/-6.29mL.min(-1).kg(-1)). No difference was found between the treadmill and the 20MST maximal speeds (6.73+/-0.91km/h, 6.78+/-1.23km/h, respectively). Measured with the Cosmed K2, a significant relationship existed between VO(2) and each speed level (r=.95, P<.0001; VO(2)=4.24x speed-7.37, standard estimation error=2.29mL.min(-1).kg(-1)).

CONCLUSION

Maximal VO(2) and maximal speed measured on the treadmill did not differ significantly from those obtained on the 20MST. The current 20MST equation (Léger equation) was not valid to estimate VO(2) in CAD patients. A modified prediction equation of VO(2) was given and would need a larger number of patients to be generalized.

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

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

Factors associated with cardiac rehabilitation attendance: a systematic review of the literature

BACKGROUND

Many eligible patients fail to attend cardiac rehabilitation courses.

OBJECTIVE

To undertake a systematic literature review of studies that have investigated factors associated with cardiac rehabilitation attendance.

METHODS

Literature published between 1978 and 2001 was searched using the MEDLINE, PSYCINFO and CINAHL computerized databases. Studies were sought that examined course attendance in eligible patient samples. Studies had to include at least one baseline predictor variable.

RESULTS

Fifteen studies were identified and predictor variables were usually categorized as sociodemographic, medical and psychological. Nonattenders are more likely to be older, to have lower income/greater deprivation, to deny the severity of their illness; they are less likely to believe they can influence its outcome or to perceive that their physician recommends cardiac rehabilitation. Job status, gender and health concerns play an indirect role in attendance behaviour. Comparison of results between studies could be influenced by different case-mix, measurement instruments and country of origin.

CONCLUSION

A number of factors predict cardiac rehabilitation attendance and some of these are potentially modifiable.

Women and cardiac rehabilitation after heart surgery: patterns of referral and adherence

This cross-sectional, descriptive study examined patterns of referral of women to cardiac rehabilitation programs after heart surgery, their adherence to those programs, and whether their participation differed according to their age ranges. A Cardiac Rehabilitation Participation questionnaire was mailed to 157 women who were selected from the records of 4 hospitals and 7 physician groups. Of the 157 women, 122 had been referred to a cardiac rehabilitation program. Ten (8.3%) of 122 did not attend the program at all, and 25 (29%) did not attend as often as had been recommended. Women who had bypass surgery were more likely to have been referred than were those who had valvular surgery. Patterns of referral and adherence were similar in older women (66 years or older) to the patterns for women in midlife (32 to 65 years). Study participants indicated that health, convenience, work or time constraints, or personal preferences were factors that most interfered with their attending the programs. Age was not a factor.

Determinants of disability in older coronary patients

BACKGROUND

Patient-reported physical function is a major component of disability determinations and an important contributor to health-related quality of life. Prior studies of coronary disability have shown a surprisingly poor correlation between real-life activity profile and exercise capacity measured on the treadmill. The goal of the current investigation was to evaluate the relative importance of medical factors, sex, fitness-related measures, and psychologic factors as determinants of patient-reported physical function score in older persons with established coronary heart disease (CHD).

METHODS

Determinants of disability were studied in 51 community-dwelling patients >65 years old (71 +/- 5 years, range 65-83 years) with established chronic CHD. Patient-reported physical function score (scaled 0-100) was measured by the Medical Outcomes Study Short Form physical function section. Independent variables included clinical and demographic data, treadmill testing, rest and exercise echocardiography, measures of body composition, strength, aerobic fitness, and a depression score.

RESULTS

Patients with a diagnosis of myocardial infarction had a lower physical function score than did patients with other CHD diagnoses (68 +/- 19 vs 82 +/- 22, P <.05). Univariate predictors of patient-reported physical function score included peak aerobic capacity (R = 0.62), treadmill test duration (R = 0.61), depression score (R = -0.60), handgrip strength (R = 0.42), and comorbidity score (R = -0.39). Peak aerobic capacity (R2 = 0.38) and depression score (cumulative R2 = 0.60) were the best independent predictors of physical function. Women had lower physical function scores than men (64 +/- 22 vs 78 +/- 20, P <.05) despite a similar age, diagnostic distribution, depression score, and comorbidity score. Resting left ventricular ejection fraction was not a predictor of physical function score.

CONCLUSIONS

Peak aerobic capacity and depression score were the best independent predictors of patient-reported physical function score in older coronary patients. These data focus on the potential for exercise training and treatment of mental depression to prevent and treat coronary disability in older coronary patients.

Cardiac rehabilitation in the elderly

BACKGROUND

Although patients >/=65 years old account for the majority of cardiac admissions and procedures in the United States, studies of cardiac rehabilitation have traditionally focused on younger patients. Only recently has the effectiveness of cardiac rehabilitation in the elderly population begun to receive more attention.

METHODS

We present a comprehensive literature review of studies that have looked specifically at the effectiveness of cardiac rehabilitation in the elderly. We discuss the methodologic limitations of studies to date, compare outcomes among elderly rehabilitation patients with those of younger patients, and examine barriers to participation among the elderly.

RESULTS

The majority of studies published to date have been small observational case series. Despite these limitations, these studies generally show consistent improvements in exercise capacity, cardiac risk factors, and quality-of-life parameters in elderly cardiac rehabilitation patients. These benefits appear to be similar to those seen in younger patients. In spite of this, participation rates among the elderly are low, primarily because of less aggressive referral.

CONCLUSIONS

Although further studies are necessary, the current literature shows that cardiac rehabilitation is associated with improved outcomes after a cardiac event, regardless of age. However, innovative recommendation and referral strategies are needed because few elderly patients actually enroll.

The benefits of exercise in geriatric women

Women 65 years of age and older are the fastest growing segment of the population. As women age, physical inactivity is the leading cause of morbidity and mortality due to coronary heart disease, diabetes mellitus, and hypertension. There is also a loss of both physiologic and psychological capabilities that contributes to an overall reduction in function and independent living. Regular physical activity in geriatric women has been shown to reduce cardiovascular morbidity and all-cause mortality. Further research needs to be done to evaluate the role of regular physical activity in the management of diabetes and hyperlipidemia.

Exercise rehabilitation of older patients with cardiovascular disease

As the population of elderly patients with cardiovascular disease continues to increase, much research needs to be done with the goal of maintaining physical functioning and personal independence in this population. It is of particular importance to determine whether training programs can improve physical functioning in the most severely disabled older coronary patients. Effects of cardiac rehabilitation programs on other outcome measures, including psychosocial outcomes, lipid levels, insulin levels, and body composition require better study. Finally, the economic benefits of cardiac rehabilitation in the older coronary patients has received little attention, although early reports are promising. In summary, the older population with coronary disease is characterized by high rates of disability. Exercise training has been demonstrated to be safe and to improve strength, aerobic fitness capacity, endurance and physical function. It remains to be seen whether exercise training can reverse or prevent disability in a broad population of older patients with cardiovascular disease. If successful, cardiac rehabilitation programs will pay great medical, social, and economic dividends in this population.

Exercise rehabilitation for cardiac patients: a beneficial but underused therapy

Exercise-based cardiac rehabilitation is currently underused, even though exercise is one of the few nonsurgical interventions that can make heart disease patients feel better physically and mentally. Benefits include increased muscle strength, lowered heart rate, increased stroke volume, and increased submaximal and maximal working capacity. Patients in cardiac rehabilitation programs, however, often do not exercise enough to obtain maximal benefit. Programs should ideally be initiated under supervision to provide the correct regimen and requisite vigorous activity. Subsequent moderate exercise regimens can be done at home. All patients should engage in lifelong maintenance programs.

Cardiac rehabilitation and secondary prevention programs for elderly cardiac patients

The utility of cardiac rehabilitation for elderly cardiac patients is controversial, and cost, logistic barriers, and encumbering comorbidities often seem disproportionate. Many clinicians view the emphasis of cardiac rehabilitation on behavior modification and risk-factor reduction as irrelevant for very old adults and consider pure exercise programs as appropriate alternatives. The strong rationale for cardiac rehabilitation and secondary prevention is elucidated, and available corroborating data are presented. The benefits of exercise prescription in cardiac rehabilitation and synchronized risk-factor reduction are pertinent to aging and age-related heart disease, including coronary heart disease and heart failure.

Exercise training and peripheral vascular disease

BACKGROUND

Conservative management is advocated as a treatment of choice for patients with intermittent claudication. This is a review of the mechanisms behind the improvement following an exercise rehabilitation programme.

METHODS

All Medline articles from the National Library of Medicine, USA containing the text words 'claudication' or 'peripheral vascular disease' and 'exercise' were reviewed. Cross-referencing from relevant articles was carried out.

RESULTS AND CONCLUSION

The poor physical status of a patient with intermittent claudication is not solely due to a reduction in blood flow to the lower limbs; associated factors, such as metabolic inefficiency, poor cardiorespiratory reserve and exercise-induced inflammation contribute. An exercise programme frequently improves both the physical aspect and quality of life, and the success of such exercise is multifactorial. An increase in the blood flow to the lower extremity is uncommon. Other factors, such as a redistribution of blood flow, changes in oxidative capacity of the skeletal muscles and greater utilization of oxygen, occur and the associated metabolic dysfunction of the skeletal muscles is rectified. Following exercise training, blood rheology improves and exercise-induced inflammation is ameliorated; cardiorespiratory status also benefits and the oxygen cost of exercise decreases.

Development of a servo-controller of heart rate using a cycle ergometer

In exercise training, precise control of exercise intensity would maximize the training efficacy while minimizing risks. To adjust work rate, heart rate (HR) has been used as a measure of exercise intensity. Thus, we developed a servo-controller of HR using a cycle ergometer. After estimating the transfer function from work rate to HR, we optimized feedback parameters for achieving a quick and stable HR response by means of a computer simulation. We then examined the performance of the servo-controller of HR in 55 healthy volunteers. We set the target HR at 60% and 75% of the age-predicted maximum HR. Times required for HR to reach 90% of the target HR were 136 +/- 33 and 137 +/-22s in the respective protocols. Standard deviations of the steady-state difference between the target and measured HRs were 2.5 +/- 0.6 and 3.8 +/- 1.1 beats/min. We conclude that the developed servo-controller makes it possible to precisely regulate HR and, thereby, exercise intensity.

Determinants of exercise tolerance after acute myocardial infarction in older persons

OBJECTIVES

Exercise tolerance is reduced with advancing age. Identification of potentially reversible determinants of the age-related decrement in exercise tolerance, which remain largely unexplored in older subjects and in patients recovering from a recent myocardial infarction (MI), may have useful therapeutic implications. The objective of this study was to identify the independent determinants of exercise tolerance in older patients with a recent MI.

DESIGN, SETTING, AND PARTICIPANTS

Data is from baseline assessment of 265 post-MI patients (age range 45-85 years) enrolled in the Cardiac Rehabilitation in Advanced Age randomized, controlled trial. Patients with major comorbidities or severe MI complications were excluded from the trial. Exercise tolerance was determined from symptom-limited exercise testing and expressed as total work capacity (TWC, kg.m) or peak oxygen consumption (VO2peak, mL/kg/min). The associations between both TWC and VO2peak and baseline demographic, social, clinical, and neuropsychological variables and an index of health-related quality of life were determined with univariate and multivariate analysis.

RESULTS

With univariate analysis, TWC decreased by 1285 kg.m per decade of increasing age between 45 and 85 years of age. With multivariate analysis, TWC decreased by 922 kg.m per decade. Increasing age (P < .001), female gender (P < .001), a small body surface area (P < .001), a low level of usual physical exercise before MI (P < .002), and the presence of post-MI depressive symptoms (P < .024) were independently associated with a lower TWC. The same factors, in addition to a small arm muscle area (P < .002), were also independently associated with a lower VO2peak.

CONCLUSIONS

Age per se accounts for approximately 70% of the age-related decay in TWC or VO2peak. However, the inclusion of modifiable factors such as physical exercise and depression in the prediction model reinforces the importance of a multidimensional approach to the evaluation and treatment of older patients with a recent MI.

Effects of exercise and cardiac rehabilitation on cardiovascular outcomes

Comprehensive cardiac rehabilitation for coronary patients includes a systematic approach to the measurement and treatment of coronary risk factors, along with the better-known exercise training component. Studies of exercise and nutritional interventions in patients with coronary heart disease have documented improved primary outcomes of decreased morbidity and mortality, decreased symptoms, and fewer cardiac rehospitalizations. Quality of life, depression scores, and physical functioning are improved after rehabilitation.

Development of a servo-controller of heart rate using a treadmill

Although treadmill exercise involves a more familiar range of motions and is thus more physiological in terms of daily activity than cycle ergometer exercise, difficulties in controlling the exercise intensity have limited its utility. As heart rate (HR) has been used as a measure of exercise intensity, controlling HR should allow for the proper control of exercise intensity during treadmill exercise. Thus, a servo-controller framework was applied to regulate HR during treadmill exercise. After estimating an averaged transfer function from speed command to HR, feedback parameters were optimized via a computer simulation in order to achieve a quick and stable HR response. The performance of the servo-controller of HR was then examined in 10 healthy subjects. Standard deviations of the steady-state difference between the target and measured HRs were 2.7+/-0.9 and 5.0+/-1.4 beats/min in the stepwise and ramp target HR protocols, respectively. The rise time to reach 90% of the target HR was 93+/-20 s in the stepwise protocol. It was concluded that a treadmill implemented with a negative feedback mechanism made it possible to precisely regulate HR and thus exercise intensity.

Cardiac rehabilitation in older coronary patients

The majority of patients presenting with acute coronary disease or undergoing coronary revascularization procedures are older than age 65. Disability rates are very high in these patient populations, particularly in women, the older-old, and patients with clinical manifestations of angina pectoris or chronic heart failure. The presence of mental depression is also an important determinant of poor physical functioning. Cardiac rehabilitation has been demonstrated to safely increase aerobic capacity, muscular strength, and endurance in older coronary populations.

Aims, design and enrollment rate of the Cardiac Rehabilitation in Advanced Age (CR-AGE) randomized, controlled trial

Data regarding the efficacy of cardiac rehabilitation after acute myocardial infarction in advanced age are limited, and are derived from either controlled but non randomized trials, or observational studies. Several aspects of cardiac rehabilitation after myocardial infarction in advanced age, including its effectiveness on exercise tolerance and health-related quality of life, as well as the feasibility of rehabilitation programs, need clarification. The objectives of this randomized, controlled trial, Cardiac Rehabilitation in Advanced Age (CR-AGE), are to examine the effects of an 8-week comprehensive cardiac rehabilitation intervention, comparing 1) supervised outpatient, hospital-based cardiac rehabilitation, 2) home-based cardiac rehabilitation, and 3) usual care in each of three groups of post-myocardial infarction patients, 45-65, 66-75, and 76-85 years of age. The primary objective of the trial is to evaluate the change in physical fitness in each age group assessed by total work capacity at the end of the intervention, and during follow-up over both the medium- (6 months) and the long-term (1 and 2 years). Secondary objectives of the trial include an examination of the feasibility of cardiac rehabilitation in older patients, as well as the determination of the following: exercise complication rates; changes in peak oxygen consumption; changes in other outcome measures, such as health-related quality of life, prevalence of anxiety and depressive symptoms, fluid intelligence, body composition and mass index; incidence of new cardiac and non-cardiac events; and utilization rates of health care services. Enrollment in the CR-AGE trial is expected to be completed within the first half of 1998.

Cardiac rehabilitation in the elderly

Rehabilitation for patients with heart disease consists of exercise training, behavioral interventions, counseling, and education with the goal of improving physiologic and psychosocial status. The Cardiac Rehabilitation Clinical Practice Guidelines, recently published in the United States, list the most substantial benefits of cardiac rehabilitation as an improvement in exercise tolerance, symptoms, blood lipid levels, and psychosocial well-being, and a reduction in cigarette smoking, stress, and mortality. With the evidence-base on the elderly in the Guidelines derived from 1 non-randomized controlled trial and 7 observational studies, the efficacy and effectiveness of cardiac rehabilitation is based almost exclusively on data generated on young and middle-aged males. We have located an additional 10 randomized and 2 non-randomized controlled trials published since the Guidelines, but only one provided age-specific data. The elderly are the fastest growing segment of the population, and may be more responsive to the effects of cardiac rehabilitation as they often have greater initial disability and less independence than younger patients. While referral of elderly persons to cardiac rehabilitation services appears safe and warranted in the secondary prevention of heart disease, the lack of rigorous scientific evidence has created an important clinical research and clinical policy vacuum which urgently needs to be filled.

Gender differences in cardiac rehabilitation

It is now widely recognized that comprehensive cardiac rehabilitation has substantial benefits in patients with cardiovascular disease. Despite the fact that cardiovascular disease is the leading cause of death for women in the United States with more than 250,000 deaths each year, most studies of cardiac rehabilitation have not included a substantial number of women. By making cardiac rehabilitation programs more responsive to the needs and goals of female coronary patients, participation rates and compliance rates should increase with a favorable impact on morbidity, mortality, and quality of life for women with cardiovascular diseases.

Exercise and rehabilitation in women. Indications and outcomes

Women have been shown to improve their cardiovascular risk profiles with increasing levels of physical activity and physical fitness. All-cause mortality is lower among more fit women, but reductions in cardiovascular death rates have not been established, owing to the limited number and size of existing studies. Because older women are at greater risk for cardiac events and are the least likely to engage in regular physical activity, concerted effort should be made to increase the proportion of older women who participate in regular physical activity. Attention to concerns raised by older, sedentary women and development of personalized programs that proceed gradually in intensity and duration and avoid high-impact activities should improve the likelihood of initiation and continuation of greater activity levels. Cardiac rehabilitation programs are under-used by women. Personal and social barriers have been identified as well as the potential for referral bias. Reduction in cardiovascular risk levels and improvements in exercise capacity have been demonstrated for women who do participate. Approaches that meet the needs of older women may require considerable alteration from the standard program established for middle-aged men. Yet women may have the most to gain from participation in multidisciplinary, personalized rehabilitation programs.

Loss of cardiovascular adaptations after physical inactivity

The main objective of this article is to focus on the loss of cardiovascular adaptations after cessation of exercise. A brief description of the nature of adaptive changes to chronic exercise is given to provide a background and understanding of physiologic mechanisms underlying cardiovascular adaptations to exercise training and their clinical implications.

Randomized trial of a hospital-based exercise training program after acute myocardial infarction: cardiac autonomic effects

OBJECTIVES

This study sought to determine whether a moderate intensity supervised exercise training program, performed immediately after an uncomplicated acute myocardial infarction, improves recovery in cardiac autonomic function compared with standard advice about activity at home.

BACKGROUND

Exercise training has beneficial effects on cardiac autonomic function and may improve prognosis after acute myocardial infarction.

METHODS

Thirty-nine male and 10 female patients, mean (+/-SE) age 57 +/- 1 years, with an uncomplicated acute myocardial infarction were randomized to either a 6-week moderate intensity supervised hospital-based exercise training program (exercise group) or to an unsupervised low intensity home walking program (control group). Outcome measures included changes in baroreflex sensitivity (phenylephrine bolus method) and heart rate variability (24-h Holter monitoring) and the endurance time at 85% of peak oxygen consumption.

RESULTS

At baseline, there were no significant differences in left ventricular ejection fraction (57 +/- 2% vs. 53 +/- 2%), frequency of anterior infarction (27% vs. 18%) and peak creatine kinase (1,256 +/- 170 vs. 2,599 +/- 295 IU) between the exercise and control groups. Baroreflex sensitivity (10.5 +/- 1.0 vs. 8.4 +/- 1.2 ms/mm Hg) and time domain measures of heart rate variability were also similar. After completion of the program, the exercise group exercised for a median of 15 min (interquartile range 12 to 25) at a workload of 104 +/- 7 W compared with 7 min (interquartile range 3.5 to 12) at a workload of 89 +/- 8 W in the control group (p < 0.01). There were significant (p < 0.001) improvements in baroreflex sensitivity and heart rate variability for the 49 patients combined but no differences between the exercise and control groups. Baroreflex sensitivity improved by 3.4 +/- 1.0 and 1.7 +/- 1.0 ms/mm Hg and the standard deviation of 24-h RR intervals by 36 +/- 6 and 40 +/- 10 ms, respectively (p > 0.1).

CONCLUSIONS

A hospital-based exercise training program increased endurance capacity but did not improve recovery of cardiovascular antonomic function after uncomplicated acute myocardial infarction.

Exercise training in patients with severe congestive heart failure: enhancing peak aerobic capacity while minimizing the increase in ventricular wall stress

OBJECTIVES

The aims of the study were to 1) assess the effects of 12 weeks of exercise training at low work loads (i.e., corresponding to < or = 50% of peak oxygen consumption [Vo2]) on peak Vo2 and hyperemic calf blood flow in patients with severe congestive heart failure; and 2) evaluate left ventricular diastolic pressure and wall stress during exercise performed at work loads corresponding to < or = 50% and 70% to 80% of peak Vo2.

BACKGROUND

Whether the benefits of exercise training can be achieved at work loads that result in lower left ventricular diastolic wall stress than those associated with conventional work loads is unknown in patients with severe congestive heart failure.

METHODS

Sixteen patients with severe congestive heart failure trained at low work loads for 1 h/day, four times a week, for 12 weeks. Peak Vo2 and calf and forearm reactive hyperemia were measured before and during training. Nine of the 16 patients underwent right heart catheterization and echocardiography during bicycle exercise at low and conventional work loads (i.e., 50% and 70% to 80% of peak Vo2, respectively).

RESULTS

The increase in left ventricular diastolic wall stress was substantially lower during exercise at low work loads than during exercise at conventional work loads, (i.e., [mean +/- SEM] 23.3 +/- 7.4 vs. 69.6 +/- 8.1 dynes/cm2 (p < 0.001). After 6 and 12 weeks of training, peak Vo2 increased from 11.5 +/- 0.4 to 14.0 +/- 0.5 and 15.0 +/- 0.5 ml/kg per min, respectively (p < 0.0001 vs. baseline for both). Peak reactive hyperemia significantly increased in the calf but not in the forearm. The increases in peak Vo2 and calf peak reactive hyperemia correlated closely (r = 0.61, p < 0.02).

CONCLUSIONS

In patients with severe congestive heart failure, peak Vo2 is enhanced by exercise training at work loads that result in smaller increases in left ventricular diastolic wall stress than those observed at conventional work loads.