Amount of exercise necessary for the patient with coronary artery disease

Outcome of Cardiac Rehabilitation Following Off-Pump Versus On-Pump Coronary Bypass Surgery

BACKGROUND:

A few studies have compared the cardiac rehabilitation (CR) outcome between those who undergo conventional on-pump bypass surgery and off-pump surgery. We compared this outcome among the patients differentiated by the On-pump and off-pump surgical procedures about cardiovascular variables and psychological status.

METHODS:

This longitudinal study recruited 318 and 102 consecutive patients who had undergone CABG (on-pump surgery, n = 318 and off-pump surgery, n = 102) and been referred to the CR clinic.

RESULTS:

The off-pump surgery patients had more improvement in their metabolic equivalents (METs) value. The physical and mental components of health-related quality of life (QOL) (based on SF-36 questionnaire) as well as depression-anxiety (based on Costello-Comrey Depression and Anxiety Scale) were notably improved in the two study groups after the CR program, while changes in the QOL components scores and also depression-anxiety score were not different between the off-pump and on-pump techniques.

CONCLUSIONS:

Regarding QOL and psychological status, there were no differences in the CR outcome between those who underwent off-pump bypass surgery and those who underwent on-pump surgery; nevertheless, the off-pump technique was superior to the on-pump method on METs improvement following CR.

Motivation, Psychological Distress and Exercise Adherence Following Myocardial Infarction

Fifty patients with myocardial infarction were recruited from a hospital based Cardiac Education and Assessment Program (CEAP) in Sydney, Australia. The Exercise Motivation Inventory-2 (EMI-2) and the Depression, Anxiety and Stress Scale (DASS) were administered prior to commencement in the program and re-administered by telephone interview at 5-month followup. Four exercise adherence measures were completed: attendance, exercise stress test, self-report ratings and a 7-day activity recall interview. There was a 46% adherence rate for MI patients during the hospital based CEAP. Of those individuals who completed CEAP, 91% obtained functional improvement on the exercise stress test. For the 38 patients who were followed-up by telephone interview at 5 months, 71% were exercising according to CEAP prescription. Higher levels of anxiety were associated with lower levels of self-reported exercise adherence. The 3 strongest motivations for exercise in this group of MI patients were all health related; wanting to be free from illness, maintaining good health and recovering from the effects of coronary heart disease. The discussion highlights the implications of these findings for cardiac rehabilitation programs and the need for empirically driven guidelines for measuring exercise adherence.

A systematic review of the effectiveness of qigong exercise in cardiac rehabilitation

The objective of this study was to assess evidence for the efficacy and effectiveness of Chinese qigong exercise in rehabilitative programs among cardiac patients. Thirteen databases were searched through to November 2010, and all controlled clinical trials on Chinese qigong exercise among patients with chronic heart diseases were included. For each included study, data was extracted and validity was assessed. Study quality was evaluated and summarized using both the Jadad Scale and the criteria for levels of evidence. Seven randomized controlled trials (RCTs) and one non-randomized controlled clinical trial (CCT) published between 1988 and 2007 met the inclusion criteria. In total, these studies covered 540 patients with various chronic heart diseases including atrial fibrillation, coronary artery disease, myocardial infarct, valve replacement, and ischemic heart disease. Outcome measures emerged in these studies included subjective outcomes such as symptoms and quality of life; and objective outcomes such as blood pressure, ECG findings, and exercise capacity, physical activity, balance, co-ordination, heart rate, and oxygen uptake. Overall, these studies suggest that Chinese qigong exercise seems to be an optimal option for patients with chronic heart diseases who were unable to engage in other forms of physical activity; however, its efficacy and effectiveness in cardiac rehabilitation programs should be further tested.

A new strategy for the implementation of an aerobic training session

The objectives were to propose a new strategy for adjusting aerobic training variables based on the eighth American College of Sports Medicine (ACSM) guidelines and maximal aerobic power (&OV0312;O2max) and to establish energy expenditure (EE) recommendations for training, which depend on a subject's body mass (BM). Exclusively based on aerobic training recommendations that are available in the ACSM guidelines, 16 equally partitioned subcategories were created from the slope of a linear regression between the lower (16.4 ml·kg(-1)·min(-1)) and upper (61.2 ml·kg(-1)·min(-1)) limits of VO(2max) percentile tables and all aerobic variables (intensity: 30-85%Reserve, duration: 60-300 min·wk(-1), frequency: 3-5 d·wk(-1), and EE: 1,000-4,000 kcal·wk). ACSM's EE (EE(ACSM)) recommendation was compared to EE based on VO(2max) (EE(Actual)), BM, exercise intensity and duration combined, for five BM categories (60 to 100 kg). The following equations were generated to adjust aerobic training: Intensity (%(Reserve)) = VO(2max) (ml·kg(-1)·min(-1)) × 1.23 + 9.85, Duration (min·wk(-1)) = VO(2max) × 5.36-27.91, Frequency (d·wk(-1) = VO(2max) × 0.044 + 2.27, EE(ACSM) (kcal·wk(-1)) =VO(2max) × 82.61-1,055.29, and EE(Actual) (kcal·wk(-1)) = ([V(O2max) - 3.5] × Intensity + 3.5) × BM (kg)/200 × Frequency. A comparison of EE(ACSM) and EE(Actual) for 5 BM and 3 aerobic fitness categories demonstrated an effect size classification that is equal or superior to "large" in 9 of 15 comparisons, suggesting that EE(ACSM) adjustment is inadequate at least 60% of the time. Despite the need to verify the adequacy of the linear model and perform future cross-sectional and longitudinal studies, the present proposal first provides criteria to adjust aerobic training variables consistent with subject capacity, thus diminishing the risk of the imprecise aerobic prescription.

Cardiac rehabilitation outcomes no different after on-pump versus off-pump coronary artery bypass surgery

PURPOSE

Clinical evidence supports lower morbidity with off-pump coronary revascularization surgery as well as superior short- and mid-term outcomes, equivalent graft patency, and reduced cost. The purpose of this study was to compare cardiac rehabilitation (CR) outcomes between patients undergoing on-pump versus off-pump coronary artery bypass surgery.

METHODS

Data were retrospectively examined for patients who participated in CR between 1996 and 2004. Two hundred ninety-five patients who underwent bypass surgery and completed at least 80% of their 36 required sessions were divided into on-pump and off-pump groups. Pre- and post-CR measures included grip strength, flexibility, energy expended during class, quality of life, and self-efficacy.

RESULTS

Both groups were similar with respect to age, sex, ejection fraction, and mean number of grafts. There were no statistical differences between the on-pump and off-pump groups (P > .05) for weight, abdominal and hip circumferences, grip strength, flexibility, and total energy expenditure. In addition, there were no between-group differences regarding quality of life and self-efficacy. Grip strength, flexibility, and energy expenditure during class improved with CR regardless of the surgical procedure (P = .001). Quality of life (P = .001) and self-efficacy (P = .001) also improved.

CONCLUSIONS

The present data support the concept that although there are clinical advantages to off-pump surgery, there is no benefit over on-pump surgery regarding CR. Subsequently, patients undergoing off-pump surgery should be managed similarly as their on-pump counterparts.

Cardiac risk of coronary patients after reintegration into occupations with heavy physical exertion

The job related reintegration of patients with coronary artery disease (CAD) is a central part of cardiac rehabilitation. However, specific occupational demands like jobs with heavy physical exertion (> 6 METs) could increase the cardiovascular risk because the relative risk for acute myocardial infarction (MI) and cardiac death is temporarily elevated after vigorous exertion ("hazard period"). Thus, in 2001 any male patient with proven CAD who performed a job with heavy exertion until the occurrence of an index event (MI/ACS, any interventional or surgical revascularization measure) received a questionnaire after an average of 20 months. Complete data were available in 108 from 119 included patients (90.8%), aged 51.8+/-7.8 years. Ejection fraction was 61.5+/-13.1% and the functional capacity at the time of hospital discharge averaged 130.1+/-31.2 W. 75% of the patients had a previous MI and 59.3% underwent bypass surgery. During follow-up the previous job with heavy exertion was performed over a cumulated time of 74 years. The aim of the study was to compare the observed and the expected incidence of MI and cardiac death with and without job performance. The expected ("basal") risk for MI and cardiac death without heavy physical exertion was determined from pooled study results and assumed to be 5.2% per year. The combined risk due to performing an occupation with strenuous exertion can be calculated from time periods with and without working hours and amounts to 11.9%. There could be expected 0.119 . 74=8.8 cardiac events related to the job. In contrast, 5 MIs (4 NSTEMI, 1 STEMI) were observed (6.8%). The relative risk for an expected event compared to the basal risk without heavy exertion was 2.3 (95% CI: 0.7-7.4). The relative risk for the observed cardiac events amounts to 1.3 (95% CI: 0.4-4.8). The lower observed risk is probably due to the high grade of physical fitness in this patient group. In spite of several limitations, our study showed no convincing evidence for increasing the cardiac risk of patients with CAD performing occupations with heavy physical exertion. Because of the importance of this prognostic finding, a representative and prospective study is strongly required.

Exercise prescription using resting heart rate plus 20 or perceived exertion in cardiac rehabilitation

PURPOSE

For patients starting a cardiac rehabilitation program, exercise intensity often is set 20 beats per minute above the standing resting heart rate (RHR+20) or in a range of 11 to 13 on Borg's Scale for Rating of Perceived Exertion (RPE 11-13). The purpose of this study was to determine the actual exercise intensity, expressed as a percentage of peak oxygen uptake reserve (%VO2R) using these techniques.

METHODS

For this study, 11 new referrals to a phase 2 cardiac rehabilitation program voluntarily underwent a symptom-limited exercise test and a field test that consisted of self-paced over-the-ground walking for 10 minutes at levels corresponding to RPE 11-13 and RHR+20. During both tests, gas exchange data were obtained via the Cosmed K4b and heart rate via the Polar monitor.

RESULTS

The mean %VO2R at RHR+20 (41.8 +/- 12.3%) and RPE 11-13 (71 +/- 15.3% mL.kg.min) were significantly different. Exercise at RHR+20 resulted in 4 of the 11 patients (36%) exercising at less than 40% VO2R, 6 of the patients (55%) exercising at 40% to 60% VO2R, and 1 of the patients (9%) exercising at more than 60% VO2R. Exercise at RPE 11-13 resulted in 1 of the 11 patients (9%) exercising at less than 40% VO2R, 1 of the patients at exercising at 40% to 60% VO2R (9%), and 9 of the patients (82%) exercising at more than 60% VO2R.

CONCLUSIONS

The results of this study indicate that using RHR+20 or RPE 11-13 to prescribe exercise intensity during over-the-ground walking for phase 2 cardiac rehabilitation patients results in substantial intersubject variability and raises questions about the safety and efficacy of these approaches.

Is brisk walking an adequate aerobic training stimulus for cardiac patients?

Walking is the most common aerobic training modality utilized in cardiac rehabilitation programs. However, it remains unclear whether or not brisk walking is of a sufficient intensity to improve aerobic fitness in this population. In this study, we investigated whether men and women with coronary artery disease can achieve an exercise intensity that is sufficient to induce a training effect, ie, a training heart rate (THR), defined as >/= 70% of measured maximal heart rate (HRmax), via brisk walking on a flat surface. One hundred forty-two outpatient volunteers from the William Beaumont Hospital Cardiac Rehabilitation Program (Royal Oak, MI) and the University of Wisconsin-La Crosse Exercise and Health Program (La Crosse, WI) were asked to walk one mile as briskly as possible on measured tracks. Heart rate was monitored throughout the walk via radiotelemetry. The percentage of patients within each gender and phase of rehabilitation who attained a THR were assessed using peak or symptom-limited exercise testing to determine the HRmax. All of the women and 90% of the men achieved a THR, averaging 85 +/- 8% and 79 +/- 10% of HRmax, respectively (mean +/- SD). There was no difference in the percentage of phase II or phase III cardiac rehabilitation program patients who achieved a THR. These findings suggest that brisk walking is of a sufficient intensity to elicit a THR in all but the most highly fit patients with coronary disease. Thus, physicians and allied health professionals can prescribe brisk walking on a flat surface to their cardiac patients with confidence that this intensity will achieve cardiorespiratory and health benefits.

Cardiovascular stress during a contemporary stroke rehabilitation program: is the intensity adequate to induce a training effect?

OBJECTIVES

To investigate the level of cardiovascular stress of physical therapy (PT) and occupational therapy (OT) sessions of a contemporary stroke rehabilitation program and to identify therapeutic activities that elicit heart rate responses adequate to induce a training effect.

DESIGN

A descriptive, longitudinal study with heart rate and activity monitoring of PT and OT sessions at biweekly intervals, 2 to 14 weeks poststroke.

SETTING

An acute inpatient stroke unit and inpatient and outpatient stroke rehabilitation units.

PARTICIPANTS

A consecutive sample of 20 patients with ischemic stroke who participated in inpatient and outpatient stroke rehabilitation.

INTERVENTION

Observation of routine PT and OT sessions for patients poststroke without influencing the extent and content of the sessions.

MAIN OUTCOME MEASURE

Time per session in which heart rate was within the calculated target heart rate zone.

RESULTS

Time per PT session spent in target heart rate zone was low (2.8+/-0.9 min), and per OT session was negligible (0.7+/-0.2 min) over the course of rehabilitation.

CONCLUSIONS

The PT and OT sessions between 2 and 14 weeks poststroke did not elicit adequate cardiovascular stress to induce a training effect.

The validity of the Computer Science and Applications activity monitor for use in coronary artery disease patients during level walking

The principal aim of the present study was to examine the validity of the Computer Science and Applications (CSA) activity monitor during level walking in coronary artery disease (CAD) patients. As a secondary aim, we evaluated the usefulness of two previously published energy expenditure (EE) prediction equations. Thirty-four subjects (29 men and five women), all with diagnosed CAD, volunteered to participate. Oxygen uptake (VO2) was measured by indirect calorimetry during walking on a motorized treadmill at three different speeds (3.2, 4.8 and 6.4 km h-1). Physical activity was measured simultaneously using the CSA activity monitor, secured directly to the skin on the lower back (i.e. lumbar vertebrae 4-5) with an elastic belt. The mean (+/- SD) activity counts were 1208 +/- 429, 3258 +/- 753 and 5351 +/- 876 counts min-1, at the three speeds, respectively (P < 0.001). Activity counts were significantly correlated to speed (r = 0.92; P < 0.001), VO2 (ml kg-1 min-1; r = 0.87; P < 0.001) and EE (kcal min-1; r = 0.85, P < 0.001). A stepwise linear regression analysis showed that activity counts and body weight together explained 75% of the variation in EE. Predicted EE from previously published equations differed significantly when used in this group of CAD patients. In conclusion, the CSA activity monitor is a valid instrument for assessing the intensity of physical activity during treadmill walking in CAD patients. Energy expenditure can be predicted from body weight and activity counts.

How much exercise is enough for the coronary patient?

Prescribing exercise for cardiac patients is comparable in many ways to prescribing medications; that is, one recommends an optimal dosage according to individual needs and limitations. For in-patients, simple exposure to orthostatic or gravitational stress can obviate much of the deterioration in exercise tolerance that normally follows a cardiovascular event or intervention. On the other hand, the continuum of exercise therapy for outpatients may range from brisk walking to marathon running. Upper body and resistance training also have been shown to be safe and effective for clinically stable patients. Moderate intensity exercise training can produce beneficial changes in functional capacity, cardiac function, coronary risk factors, psychosocial well being, and possibly improve survival in patients with coronary artery disease. These findings may be especially relevant for the previously sedentary patient, in whom the subjective discomfort of vigorous exercise may serve as a deterrent to long-term compliance with physical training. (c) 2000 by CHF, Inc.

Physical activity and exercise training prescriptions for patients

The dominant outcome from exercise prescription is an increase in various markers of exercise capacity. A very large group of studies have demonstrated that the VO2max is increased in response to exercise performed according to well-accepted principles of exercise prescription. Other markers of exercise capacity, such as the VT, also improve substantially following exercise training. Finally, improvement in exercise capacity is generally related to improved quality of life, particularly in patients with exercise capacity limited by various disease processes. Beyond the specific physiologic gains from training, exercise contributes to a better overall clinical outcome. Although there are few data conclusively demonstrating that exercise independently causes favorable changes in other risk factors, it should be recognized that exercise can contribute indirectly to modulation of other risk factors. Exercise represents positive health advice. Since most of our other recommendations to patients are in the nature of negative advice (e.g., don't smoke, don't eat high-fat foods), and since people are infamous for ignoring negative advice, the value of using a positive recommendation that may indirectly lead the patient to discontinue bad behaviors can hardly be overstated.

Exercise performance and training in patients with implantable cardioverter-defibrillators and coronary heart disease

The aim of this preliminary study was to compare exercise performance and the effect of exercise training in cardiac patients with and without an implantable cardioverter-defibrillator (ICD). There are few data on exercise performance and on the effect of exercise training in patients with an ICD. Data in patients with an ICD (n = 8) were compared with those from a matched control group (n = 16). Patients performed maximal cycle-ergometer testing before and after 3 months of exercise training. All patients had to stop the exercise test for reasons of exhaustion. The predetermined heart rate threshold in ICD patients, set at the detection rate of the ICD minus 30 beats/min, was not reached. Before training, peak oxygen uptake was not different in the ICD patients compared with the control group (21.0 +/- 6.9 vs 21.9 +/- 5.0 ml oxygen standard temperature pressure dry/min/kg). Exercise training increased peak oxygen uptake to a similar extent in both groups, 20% and 24%, respectively. One ICD patient developed uneventful ventricular tachycardia at the end of the post-training exercise test, and another during training. Thus, exercise performance and the favorable response to a 3-month exercise training program are comparable in patients with ICD and matched control patients. However, tachyarrhythmias may occur during exercise testing or training and require special attention. Selected patients with ICD can be encouraged to participate in medically supervised exercise training programs. The results of this study should be confirmed with additional studies on larger numbers of subjects.

Physical activity for the chronically ill and disabled

Exercise prescription principles for persons without chronic disease and/or disability are based on well developed scientific information. While there are varied objectives for being physically active, including enhancing physical fitness, promoting health by reducing the risk for chronic disease and ensuring safety during exercise participation, the essence of the exercise prescription is based on individual interests, health needs and clinical status, and therefore the aforementioned goals do not always carry equal weight. In the same manner, the principles of exercise prescription for persons with chronic disease and/or disability should place more emphasis on the patient's clinical status and, as a result, the exercise mode, intensity, frequency and duration are usually modified according to their clinical condition. Presently, these exercise prescription principles have been scientifically defined for clients with coronary heart disease. However, other diseases and/or disabilities have been studied less (e.g. renal failure, cancer, chronic fatigue syndrome, cerebral palsy). This article reviews these issues with specific reference to persons with chronic diseases and disabilities.

Predictors of referral to cardiac rehabilitation and cardiac exercise self-efficacy

Cardiac rehabilitation (CR) has known benefits after myocardial infarction (MI) or coronary artery bypass surgery (CABG). Yet, only a small percentage of patients are referred for outpatient CR after hospital discharge. This study investigates patient characteristics related to referral to CR and cardiac exercise self-efficacy, a salient predictor of health behavior change and maintenance. Two hundred nineteen patients enrolled in the study. Of the 185 patients who were CR candidates, 74 were referred to CR. Logistic regression analysis was used to identify variables related to CR referral. Results indicate that patient characteristics of having had fewer MIs or CABGs, having attended CR in the past, and being less physically active during leisure time are related to an increased likelihood of being referred to CR. Multiple regression analysis indicates that leisure physical activity is a predictor of cardiac exercise self-efficacy. Implications for nurses who recruit patients for CR are discussed.

Exercise for coronary artery disease: a cornerstone of comprehensive treatment

Exercise is effective in both preventing and treating coronary artery disease (CAD). Exercise improves cardiovascular efficiency and, in combination with other measures such as medication use, diet changes, and smoking cessation, may arrest or reverse atherosclerosis. Exercise prescriptions will vary according to disease level or risk, but the basic principle (physiologic evaluation followed by moderate exercise as tolerated) is the same for treatment or prevention. Most patients should work toward at least 20 to 30 minutes of moderate aerobic exercise three or more times a week.

Condicionamento físico aplicado a doenças cardiovasculares

Tendo em vista a relevância da prevenção das doenças cardiovasculares, este artigo visa discutir alguns aspectos relativos à prevenção cardíaca primária e secundária a partir de um programa de condicionamento físico especializado. A prática da atividade física regular é utilizada tanto para a prevenção como para a reabilitação das doenças cardiovasculares. Um bom programa de condicionamento físico produz alterações fisiológicas crônicas nos sistemas cardiovascular e neurovegetativo e na secreção hormonal, constituindo expressivas modificações no que diz respeito à prevenção, estabilização e até regressão do quadro degenerativo das cardiopatias. A supervisão do paciente durante a sessão de condicionamento físico é essencial, pois a incidência de complicações cardiovasculares é maior nestes, quando comparados com adultos aparentemente saudáveis; com isso, a segurança e a qualidade do programa ficam salvaguardadas. Um aspecto muito importante é a necessidade da prescrição de exercício individualizada, tanto na prevenção primária como nas três fases de prevenção secundária. Essa prescrição deve respeitar os princípios do treinamento físico e os componentes básicos do programa: freqüência e duração, que são valores absolutos, e a intensidade, que é o fator crítico da prescrição, pois é relativa e envolve fatores como diferença entre os sexos, nível de aptidão física e idade

Exercise training and heparin pretreatment in patients with coronary artery disease

The purpose of this study was to evaluate whether combined treatment with a cardiovascular exercise rehabilitation program and low doses of heparin can induce changes in ergometric parameters of ischemia in patients with coronary artery disease (CAD). Heparin may potentiate the development of new vessels promoted by ischemia and therefore may produce important clinical improvement. Thirty-six patients with stable CAD and evidence of myocardial ischemia on exercise testing were randomized into three groups: a control group (n = 11) received the usual medical treatment; another group (n = 11) underwent three exercise sessions per week during 12 weeks; and a third group (n = 14) undertook this exercise program and also received calcium heparin 12,500 IU subcutaneously 20 to 30 minutes before each exercise session. Pretreatment and posttreatment exercise tests were compared. Patients who underwent the rehabilitation program had an increase in exercise duration and workload at the onset of 1 mm ST-segment depression, but only patients who received calcium heparin showed a significant increase in rate-pressure product at the ST-segment ischemic threshold (p = 0.035). This result suggests that higher levels of myocardial oxygen consumption were now tolerated, a change that may be related to an improvement in myocardial perfusion.