Circulatory and symptomatic effects of physical training in patients with coronary-artery disease and angina pectoris

Progression of Exercise Training in Early Outpatient Cardiac Rehabilitation: AN OFFICIAL STATEMENT FROM THE AMERICAN ASSOCIATION OF CARDIOVASCULAR AND PULMONARY REHABILITATION

Aerobic and resistance exercise training is a cornerstone of early outpatient cardiac rehabilitation (CR) and provides impressive benefits for patients. The components of the exercise prescription for patients with cardiovascular diseases are provided in guideline documents from several professional organizations and include frequency (how many sessions per week); intensity (how hard to exercise); time (duration of the exercise training session); type (modalities of exercise training); volume (the total amount or dose of exercise); and progression (the rate of increasing the dose of exercise). The least discussed, least appreciated, and most challenging component of the exercise prescription for CR health care professionals is the rate of progression of the dose of exercise. One reason for this observation is the heterogeneity of patients who participate in CR. All components of the exercise prescription should be developed specifically for each individual patient. This statement provides an overview of the principles of exercise prescription for patients in CR with special emphasis on the rate of progression. General recommendations for progression are given and patient case examples are provided to illustrate the principles of progression in exercise training.

[Cardiac rehabilitation after coronary artery bypass surgery]

Ischemic heart disease is the leading cause of death worldwide with an increase in the incidence in younger populations. Today revascularization strategies are capable of alleviating acute ischemia and/or chronic ischemia. These can be performed percutaneously or through surgery. Even if we improve myocardial perfusion by these methods, the main determinant in maintaining patency of coronary arteries and bypass is a correctly instituted secondary prevention. This is the main focus of cardiac rehabilitation proposals. Although much has been published about the role of cardiac rehabilitation after percutaneous revascularization, there is little work able to synthesize the current state of cardiac rehabilitation in patients undergoing coronary artery bypass surgery. The aim of this paper is to review the effect of rehabilitation in the return to work, survival, functional capacity, depression and anxiety, as well as compare centralized vs. home rehabilitation in this patient population.

The emperor's tailors: the failure of the medical weight loss paradigm and its causal role in the obesity of America

During the past century, the medical profession has developed a paradigm for the treatment of obesity, which prescribes specific exercise and dietary goals under the umbrella of 'lifestyle change'. It has three components, all of which evolved from origins that had nothing to do with weight control. First, it is individually prescriptive, that is weight loss is considered the responsibility of the individual as contrasted to a societal or group responsibility. Second, it recommends exercise aimed towards structured, or non-functional, activities with a variety of physiological endpoints. Last, dietary goals are defined by calories, exchanges, food groups and various nutritional components. Diets are usually grouped by these goals. This model is unique to America, it is not working and it has also played a causal role in the obesity it is attempting to eliminate. A new model must be developed, which contains an observationally based societal prescription and links activity with functional outcomes and diets, which are food rather than nutritionally based.

Early exercise tests after uncomplicated acute myocardial infarction before early discharge from hospital

As part of an early mobilization and early discharge scheme, 76 consecutive low-risk patients were selected from a population of 298 acute myocardial infarction (AMI) patients, to undergo an exercise test. The test was done on the 7th day after an AMI. The patients were 57 men and 19 women of mean age 57 and 68 years, respectively. Twelve patients were unable to complete the test, but no serious complications were observed. Average heart rate during the highest exercise load (50 W) was 106 beats/min. The following risk indices (RI) were considered abnormal and were looked for during or after exercise: 1) heart rate greater than 125 (n = 12), 2) major ventricular arrhythmias (n = 3), 3) angina pectoris (n = 9), 4) ST deviation of more than 1 mm (n = 11). Two RIs were found in 9 patients during the exercise test which led to prolonged hospitalization. One RI was found in 26 patients (34%). Eighty-eight per cent (n = 36) of the patients with normal exercise test had an uneventful recovery during the six-month observation period, in contrast to 35% (n = 9) of patients with heart rate greater than 125 recovered normally, a significantly lower number (p less than 0.05) than among patients with a normal exercise test. Reinfarction occurred in one patient with normal exercise test and in six (23%) of those with one RI (p less than 0.01) and two of those with two RIs (N.S.). We conclude that a submaximal bicycle exercise test seven days after an AMI is a safe and useful selection instrument for early discharge from hospital as well as a useful predicting instrument of future complications.

Predicting Exercise Training Outcome From Cardiac Rehabilitation

PURPOSE

This study was conducted to identify predictors of training effect after 6 months of supervised exercise for cardiac rehabilitation patients.

METHODS

Data at baseline and after 6 months of supervised exercise from 60 patients with coronary artery disease were used for this study. All the patients exercised 3 days per week for 5 to 9 months. Attendance exceeded 70%. The training effect was independently evaluated by the change in rate-pressure product at a 5-metabolic equivalent (MET) workload (RPP5), and the change in estimated peak METs (METPK) during treadmill testing. Baseline variables were examined to identify predictors of change in RPP5 and METPK separately using multiple linear regression.

RESULTS

A reduction in RPP5 (-23 +/- 33 bpm x mm Hg x 10(2); P<.0001) and an increase in METPK (2.1 +/- 1.7 METs; P<.0001) were found after training. Baseline fitness was the best predictor of training effect. Inverse relations were found between baseline scores and change scores for RPP5 (r=-0.68; P<.001) and METpk (r=-0.39; P=.002). Beta-blocker status also was useful for predicting change in RPP5. No association was found between training effect and age, revascularization status, or exercise-induced ischemia.

CONCLUSIONS

Training effect has limited predictability using baseline variables. No baseline patient characteristics other than high initial fitness were related to reduced training effect. Therefore, patients with clinical characteristics similar to those evaluated in this study can achieve a training effect successfully and are eligible for cardiac rehabilitation. The findings of this study support previous research related to this topic.

The effect of physical activity on endothelial function in man

Endothelial dysfunction occurs early in the atherosclerosis in response to elevated atherosclerotic risk factors, and endothelial dysfunction itself may exacerbate the atherosclerotic process. Treatments that reduce atherosclerotic risk factors also generally improve endothelial function. The present review seeks to summarize the effect of exercise training on endothelial function in human subjects. Cross-sectional studies comparing healthy physically active and inactive subjects as well as longitudinal exercise training studies of healthy individuals show little effect of exercise training on endothelial function. In contrast, both cross-section and longitudinal studies document improved endothelial function with exercise training in subjects with abnormal baseline endothelial function, including the elderly and patients with heart failure or coronary artery disease. Improvements in endothelial function with physical activity may explain some of the benefits of exercise in subjects with, or at risk for, vascular disease.

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.

Assessment of a low-intensity cardiac rehabilitation programme using the six-minute walk test

OBJECTIVE

To examine the utility of the six-minute walk test (6'WT), in assessing the effectiveness of a six-week cardiac rehabilitation programme, of which exercise training was an integral part.

SETTING

Royal Liverpool and Broad Green Hospitals Rehabilitation Unit.

DESIGN

Two hundred and thirty-nine consecutive patients referred for cardiac rehabilitation were allocated to one of two groups. In group A 209 entered and 159 completed the usual rehabilitation programme whilst group B patients (n = 30) acted as a control by deferring entry to the programme for six weeks, continuing only activities of daily living.

OUTCOME MEASURES

Both groups were assessed using the 6'WT, peak expiratory flow rate (PEFR) and isometric grip strength at enrolment and six weeks.

RESULTS

At baseline, groups A and B were demographically identical without significant differences in terms of 6'WT, PEFR or grip strength. Following the study period, group A showed a significant increase in 6'WT from 314.7 +/- 76.2 to 377.3 +/- 78.6 m, in PEFR from 406.9 +/- 115.9 to 437.8 +/- 118.6 litres per minute and in grip strength from 28.8 +/- 9.31 to 30.3 +/- 8.93 kg, all p < 0.001. There were no significant changes in group B.

CONCLUSIONS

The 6'WT proved to be a simple and effective measurement of functional capacity in patients performing cardiac rehabilitation. The clinical programme investigated successfully increased patients' functional capacity as assessed by the 6'WT. Significant improvement in PEFR and grip strength was also demonstrated, compared with a control population.

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.

Effect of myocardial ischaemia on left ventricular function and adaptability to exercise training

PURPOSE

We evaluated the possible interaction between exercise-induced myocardial ischemia and abnormalities in left ventricular function in 72 patients with coronary artery disease at entry and upon discharge from a 6-month exercise training program.

METHODS

Twenty-two patients with myocardial ischemia (MIS) defined by electrocardiographic and radionuclide imaging criteria constituted our experimental group (EG). Fifty patients without MIS were assigned to the control group for exercise training (CG-ET) and 31 healthy subjects to the control group for measures of left ventricular function (CG-LV).

RESULTS

Both groups EG and CG-ET showed significant and comparable increases in peak oxygen uptake (EG: 25.2 +/- 5.1 to 26.9 +/- 5.4 mL x kg(-1) x min(-1), P < 0.02; CG-ET: 25.1 +/- 0.6 to 27.4 +/- 0.7 mL x kg(-1) x min(-1), P < 0.001) after exercise training, but only CG-ET showed significant reductions in heart rate, systolic blood pressure, and rate-pressure product during submaximal exercise. A significant increase in end-diastolic volume contributed to the increase in cardiac output during exercise in patients with MIS. Heart rate or treadmill time at onset of ST segment depression failed to increase as a result of training, and stroke counts and the product of stroke counts and heart rate showed a trend toward a decrease in response to exercise, suggesting progression of disease.

CONCLUSIONS

Patients with myocardial ischemia showed improvements in maximal exercise capacity but failed to elicit physiologic adaptations during submaximal exercise or to increase the threshold for ischemia after exercise training. It is possible that the main emphasis in the management of this type of patient in a cardiac rehabilitation setting should be placed more on coronary risk factor modification to slow progression of disease than on improving cardiovascular efficiency.

The psychology of men and women recovering from coronary artery bypass surgery

BACKGROUND

Little is known about the differences between men's and women's cardiac rehabilitation processes. What helps men during recovery may not necessarily aid women's recovery. Psychosocial variables are known to impact recovery in positive and negative ways. Unfortunately, it is not clear what variables are the most effective predictors of recovery outcomes for men and women.

METHODS

Ninety coronary artery bypass graft patients (60 men, 30 women) completed a battery of psychological questionnaires on or after the third day after surgery.

RESULTS

Results showed that women reported significantly more depressive symptoms than men. For women, pain was correlated positively with depressive symptomatology and functional impairment. For men, pain and functional impairment were correlated negatively with social support. In addition, the results of a multiple regression of pain on age, severity of disease, and two psychosocial variables (depressive symptomatology and social support) for the women showed that after controlling for age and severity of disease, depressive symptomatology and social support accounted for a significant 43% increment in the variance in pain. The psychosocial variables accounted for much less variance in pain in men. However, in a multiple regression of functional impairment on the same variables, depressive symptomatology and social support accounted for a significant 14% increment in the variance in pain in men but a nonsignificant increment for the women.

CONCLUSIONS

The results support the notion that psychosocial variables play different roles in the recovery paths of men and women. In consequence, cardiac rehabilitation programs would be more effective with gender-specific tailoring.

Women and cardiac rehabilitation: referral and compliance patterns

Heart disease is the primary killer among American women. Differences in referral for cardiac rehabilitation, as well as compliance rates, have been reported between male and female cardiac patients. This study explored the use of Phase I and Phase II cardiac rehabilitation programs by male and female patients. In particular, the study aimed to investigate the relationship between eligibility and subsequent referral to Phase II cardiac rehabilitation in both men and women, as well as their compliance rates in completing Phase II. In addition, for those patients who never started a Phase II program, their reasons for nonparticipation were explored. Structured patient interviews and chart audits were used to explore cardiac rehabilitation eligibility criteria, referral and completion rates. The sample consisted of 87 patients (46 women and 41 men) who were admitted with a medical diagnosis of angina, myocardial infarction, coronary artery bypass grafting, or valve replacement surgery. Men had higher eligibility rates for Phase I, whereas women had higher eligibility rates for Phase II; more men received a referral for Phase II from their physician than women did. Men had a higher completion rate with Phase II compared with women. For those patients who chose not to start a Phase II program, the most common reasons cited included transportation problems, insurance issues, and having exercise equipment at home. Although women are being referred for cardiac rehabilitation, fewer complete the programs. Continued education is essential to teach women the importance of cardiac rehabilitation to overall recovery and adaptation to an acute cardiac event. In addition, cardiac rehabilitation programs must be structured to meet the unique needs of women and thereby remove obstacles that have prevented higher participation rates by women in the past.

Cardiac rehabilitation: are the potential benefits being realized?

Cardiac rehabilitation or exercise training programmes are provided by many hospitals. This article discusses the evidence supporting the implementation of such facilities and reviews the reality of services in the UK.

Long-term physical exercise and quantitatively assessed human coronary collateral circulation

OBJECTIVES

This prospective, cross-sectional study sought to determine an association between the level of long-term physical activity as well as other clinical and angiographic variables and an index of collateral flow to the vascular region undergoing percutaneous transluminal coronary angioplasty (PTCA).

BACKGROUND

There is limited and conflicting information about the effect of physical exercise on the coronary collateral circulation in humans, partly because previous studies lacked a quantitative means of assessing collateral channels.

METHODS

In 79 patients (mean [+/-SD] age 58 +/- 10 years) with coronary artery disease undergoing PTCA (no transmural myocardial infarction), a coronary collateral flow index was determined as the ratio between the intracoronary (IC) distal flow velocity time integral during (Vi(occl)[cm]) and after (Vi(occl) [cm]) PTCA of the stenosis. Vi(occl)/Vi(occl) was measured by a 0.014-in. Doppler guide wire, from which an IC electrocardiogram (ECG) was also recorded. Patients without ECG ST-T wave changes during PTCA were considered to have sufficient collateral channels (n = 29); those with ST-T wave changes were considered to have insufficient collateral channels (n = 50). The level of long-term physical activity was determined by a structured interview (score from 1 to 4). Univariate and multivariate analyses were used to find associations between physical activity as well as 30 other clinical and angiographic variables and the collateral flow index.

RESULTS

Long-term physical activity during leisure time, but not during work hours, and the severity of the stenosis undergoing PTCA were found to be independently and directly associated with sufficient versus insufficient collateral channels and with Vi(occl) Vi(occl) (leisure time physical activity [LTPA] score 3.3 +/- 0.9 vs. 2.4 +/- 1.0, p = 0.0002; percent diameter stenosis 88 +/- 12% vs. 80 +/- 14%, p = 0.001; Vi(occl)/Vi(occl) = 0.1 +/- 0.1 LTPA score, p = 0.0002 for trend).

CONCLUSIONS

In patients with coronary artery disease, the level of long-term physical activity during leisure time and the severity of the stenosis undergoing PTCA are directly associated with the quantitative degree of collateral flow.

Skeletal muscle and cardiovascular adaptations to exercise conditioning in older coronary patients

BACKGROUND

Older coronary patients suffer from a low functional capacity and high rates of disability. Supervised exercise programs improve aerobic capacity in middle-aged coronary patients by improving both cardiac output and peripheral extraction of oxygen. Physiological adaptations to aerobic conditioning, however, have not been well studied in older coronary patients.

METHODS AND RESULTS

The effect of a 3-month and a 1-year program of intense aerobic exercise was studied in 60 older coronary patients (mean age, 68 +/- 5 years) beginning 8 +/- 5 weeks after myocardial infarction or coronary bypass surgery. Outcome measures included peak aerobic capacity, cardiac output, arterio-venous oxygen difference, hyperemic calf blood flow, and skeletal muscle fiber morphometry, oxidative enzyme activity, and capillarity. Training results were compared with a sedentary, age- and diagnosis-matched control group (n = 10). Peak aerobic capacity increased in the intervention group at 3 months and at 1 year by 16% and 20%, respectively (both P < .01). Peak exercise cardiac output, hyperemic calf blood flow, and vascular conductance were unaffected by the conditioning protocol. At 3 and 12 months, arteriovenous oxygen difference at peak exercise was increased in the exercise group but not in control subjects. Histochemical analysis of skeletal muscle documented a 34% increase in capillary density and a 23% increase in succinate dehydrogenase activity after 3 months of conditioning (both P < .02). At 12 months, individual fiber area increased by 29% compared with baseline (P < .01).

CONCLUSIONS

Older coronary patients successfully improve peak aerobic capacity after 3 and 12 months of supervised aerobic conditioning compared with control subjects. The mechanism of the increase in peak aerobic capacity is associated almost exclusively with peripheral skeletal muscle adaptations, with no discernible improvements in cardiac output or calf blood flow.

Effects of endurance training on the circadian rhythm of fibrinolysis in men and women

This randomized study compared the fibrinolytic circadian rhythm of healthy older men and older women (average age 66 +/- 5), before and after 6 months of endurance training versus stretching controls. Compared with men, women at baseline had similar rhythms for tissue plasminogen activator (t-PA) activity and plasminogen activator inhibitor 1 (PAI-1) activity, but lower levels of total t-PA antigen. In men (N = 16), endurance training increased VO2max 15% (P < 0.001), while decreasing PAI-1 activity 37% (P = 0.034) and total t-PA antigen 18% (P = 0.0003) between midnight and 6 a.m., but did not affect t-PA activity. In women (N = 9), endurance training increased VO2max 18% (P = 0.003), and increased t-PA activity 20% (P = 0.027) and total t-PA antigen 55% (P = 0.007) between 10 p.m. and 4 a.m., but had no effect on PAI-1 activity. After endurance training there were no significant differences in the fibrinolytic circadian rhythm of men versus women. Six months of nonaerobic stretching had no effect on VO2max or fibrinolysis in men (N = 11) or women (N = 8). This study indicates that potentially favorable changes occur in fibrinolytic factors after endurance training in older men and older women.

Prospective, randomized, placebo-controlled, double-blind, multicenter study of exercise with enoxaparin pretreatment for stable-effort angina

In this double-blind, placebo-controlled, multicenter trial, we examined the combined effects of repeated exercise and intravenous enoxaparin (low-molecular-weight heparin) on treadmill exercise capacity and angiographic collateral growth and compared them with the effect of repeated exercise with placebo. Fifty-two patients with stable-effort angina were randomly assigned to receive one of two doses of enoxaparin (40 or 60 mg) or placebo. In each patient, 20 treadmill exercise sessions were performed with the pretreatment of enoxaparin or placebo for 2 to 3 weeks. Before and after treatment, coronary cineangiography was repeated to evaluate the changes in coronary and collateral circulation. Improvement of rate-pressure product (RPP) at the onset of angina was taken as an index of enhanced collateral flow reserve. Although the mean differences in the magnitude of increase in RPP were not significantly different between the 3 groups, a heterogeneous response was observed: 1620 beats/min.mm Hg in 40 mg (p = 0.12), 3060 beats/min.mm Hg in 60 mg (p = 0.02), and 1090 beats/min.mm Hg in placebo (p = 0.44). The end-points of the exercise test were changed from chest discomfort to leg fatigue or dyspnea in 10 (28%) of 36 enoxaparin-treated patients but in only 1 (6%) of 16 placebo patients (p = value not significant (NS)). Similarly, the extent of coronary and collateral circulation to the completely obstructed coronary artery was increased in 17 (47%) of 36 enoxaparin-treated patients but only in 4 (25%) of 16 placebo patients (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

HIV infection, exercise, and immune function

Decreased physical endurance is viewed by both HIV-infected people and their primary nurses as a major healthcare problem. There is a widespread belief among HIV-infected people that the way to improve their endurance is through exercise. Yet healthcare providers are divided about the role of exercise. This paper presents an overview of decreased endurance as a major problem in this population, with a review of the literature on exercise in healthy and chronically-ill populations, including those with HIV infection, and its effect on immune function.

Angiogenic effects of low molecular weight heparin in patients with stable coronary artery disease: a pilot study

OBJECTIVES

The study was designed to assess the feasibility of conducting a trial to investigate whether exercise and low molecular weight heparin therapy with dalteparin sodium (Fragmin) would improve collateral function to the ischemic myocardium in patients with coronary artery disease.

BACKGROUND

The severity of myocardial ischemia in patients with coronary artery disease is at least partly dependent on the status of the collateral circulation. Therefore, improvement in collateral function would potentially provide a unique way of alleviating myocardial ischemia. Because the combination of ischemia and heparin has previously been demonstrated to enhance collateral growth, we studied the anti-ischemic effects of combined treatment with dalteparin sodium and exercise-induced ischemia in patients with coronary artery disease.

METHODS

Twenty-three patients with stable coronary artery disease were randomized to receive either subcutaneous dalteparin sodium or placebo for a 4-week period. Patients received either placebo or 10,000 IU of dalteparin sodium by subcutaneous injection once daily for weeks 1 and 2 and 5,000 IU daily for weeks 3 and 4. During the 1st 2 weeks, patients were exercised to ischemia three times a day. At baseline and 4 weeks after treatment, treadmill exercise testing, exercise radionuclide ventriculography and 48-h ambulatory ST segment monitoring were performed.

RESULTS

Eight (80%) of the 10 dalteparin sodium-treated patients compared with 4 (31%) of 13 placebo-treated patients (p < 0.02) had an increased rate-pressure product at the onset of 1 mm of ST segment depression. The duration of exercise to ischemia increased in all patients treated with low molecular weight heparin and in 62% of placebo-treated patients (p < 0.03). The number and duration of episodes of ST segment depression during ambulatory monitoring decreased by 30% and 35%, respectively (p < 0.05), in the dalteparin sodium group but were unchanged in the placebo group. The decrease in left ventricular ejection fraction with exercise was lower in 80% of dalteparin sodium-treated patients compared with 54% of placebo-treated patients (p = 0.06). When all five factors reflecting collateral function were considered together in a multivariate analysis of variance, there was a significant improvement in low molecular weight heparin-treated patients compared with placebo-treated patients (p = 0.014).

CONCLUSIONS

This study provides preliminary evidence suggesting that exercise and low molecular weight heparin therapy with dalteparin sodium lessen myocardial ischemia and that the improvement is likely to be mediated by enhanced collateral function.

Long-term efficacy of heparin exercise treatment for patients with chronic effort angina: evaluation by exercise Tl-201 myocardial scintigraphy

To determine the effects of heparin exercise treatment on the coronary collateral flow reserve, exercise thallium-201 myocardial perfusion images were obtained with the same work-load before and late after heparin exercise treatment (17 +/- 2 months, mean +/- S.E.). In six patients with stable effort angina, to develop the collateral circulation, treadmill exercise was performed 20 times for 2-3 weeks with pretreatment with a single intravenous dose of heparin (5000 IU). The coronary collateral flow reserve was measured quantitatively as a severity score by analysis of exercise thallium-201 myocardial perfusion images. The severity score was decreased from 11,976 +/- 1722 to 5531 +/- 1967 (P < 0.05) long after heparin exercise treatment. The ST segment depression at the time of peak exercise was also decreased from 0.15 +/- 0.02 mV to 0.05 +/- 0.02 mV. In an additional five medically treated patients, these indexes remained unchanged during 18 +/- 3 months of follow-up period. These findings demonstrate that the coronary collateral flow reserve is significantly enhanced with heparin exercise treatment. These preliminary results lend support for heparin exercise treatment as one of the possible therapeutic modalities for treating patients with chronic stable effort angina.

Regular physical exercise and low-fat diet. Effects on progression of coronary artery disease

BACKGROUND

Significant regression of coronary and femoral atherosclerotic lesions has been documented by angiographic studies using aggressive lipid-lowering treatment. This study tested the applicability and effects of intensive physical exercise and low-fat diet on coronary morphology and myocardial perfusion in nonselected patients with stable angina pectoris.

METHODS AND RESULTS

Patients were recruited after routine coronary angiography for stable angina pectoris; they were randomized to an intervention group (n = 56) and a control group on "usual care" (n = 57). Treatment comprised intensive physical exercise in group training sessions (minimum, 2 hr/wk), daily home exercise periods (20 min/d), and low-fat, low-cholesterol diet (American Heart Association recommendation, phase 3). No lipid-lowering agents were prescribed. After 12 months of participation, repeat coronary angiography was performed; relative and minimal diameter reductions of coronary lesions were measured by digital image processing. Change in myocardial perfusion was assessed by 201Tl scintigraphy. In patients participating in the intervention group, body weight decreased by 5% (p less than 0.001), total cholesterol by 10% (p less than 0.001), and triglycerides by 24% (p less than 0.001); high density lipoproteins increased by 3% (p = NS). Physical work capacity improved by 23% (p less than 0.0001), and myocardial oxygen consumption, as estimated from maximal rate-pressure product, by 10% (p less than 0.05). Stress-induced myocardial ischemia decreased concurrently, indicating improvement of myocardial perfusion. Based on minimal lesion diameter, progression of coronary lesions was noted in nine patients (23%), no change in 18 patients (45%), and regression in 13 patients (32%). In the control group, metabolic and hemodynamic variables remained essentially unchanged, whereas progression of coronary lesions was noted in 25 patients (48%), no change in 18 patients (35%), and regression in nine patients (17%). These changes were significantly different from the intervention group (p less than 0.05).

CONCLUSIONS

In patients participating in regular physical exercise and low-fat diet, coronary artery disease progresses at a slower pace compared with a control group on usual care.

Referral patterns and exercise response in the rehabilitation of female coronary patients aged greater than or equal to 62 years

Gender-related differences in cardiac rehabilitation referral patterns and response to an aerobic conditioning program were examined in 226 hospitalized older coronary patients (aged greater than or equal to 62 years). Overall, the outpatient cardiac rehabilitation participation rate in this population was 21%. Older women were less likely to enter cardiac rehabilitation than were older men (15 vs 25%; p = 0.06), despite similar clinical profiles. This was explained primarily by a greater likelihood of primary physicians to strongly recommend cardiac rehabilitation to men. Before conditioning, women who entered cardiac rehabilitation were less fit than were men; peak oxygen consumption was 18% lower in women (16 +/- 5 vs 20 +/- 5 ml/kg/min; p = 0.02). However, both groups improved aerobic capacity similarly in response to a 12-week aerobic conditioning program, with maximal oxygen consumption increasing by 17% in women and by 19% in men. Thus, older female coronary patients are less likely to be referred for cardiac rehabilitation, despite a similar clinical profile and improvement in functional capacity from the training component.

Comparison of the clinical profile and outcome of women and men in cardiac rehabilitation

Few data are available regarding the outcome of women in cardiac rehabilitation. To determine whether women differ from men in clinical profile and outcome, 225 consecutive patients were prospectively evaluated in an urban, multidisciplinary, exercise-based cardiac rehabilitation program. Among the 51 women (age 56 +/- 10) and 174 men (age 54 +/- 10), most were: white (84%), married (64%), employed (63%), had had myocardial infarction or revascularization, or both (66%), and traveled less than 10 miles to the program (92%). Risk profiles revealed obesity in 48% (mean Metropolitan Relative Weight = 124 +/- 22%), hypertension in 47%, smoking in 23%, diabetes in 16%, and mean cholesterol of 236 +/- 45 mg/dl. Compared with men, more women were nonwhite, unemployed, unmarried, hypertensive or diabetic (p less than 0.0001) and had higher cholesterol (p less than 0.01). Compliance rates were similar for women (51%) and men (63%) (p = not significant). Univariate predictors of program noncompliance differed between women and men. Initial exercise capacity was less for women than for men, but both groups achieved a similar training effect. Women increased their exercise time by 31% and peak METs by 30%, whereas men showed a 21% increase in exercise time and 16% increase in peak METs achieved (p less than 0.001). Thus, in this cardiac rehabilitation program, women have a less favorable risk factor profile and differ from men with regard to baseline demographics and predictors of program completion. Women, however, have similar rates of compliance and achieve the same improvement in functional capacity with training.

Blood coagulability and fibrinolytic activity before and after physical training during the recovery phase of acute myocardial infarction

The effects of physical training on hemostatic parameters were evaluated in 56 postmyocardial infarction (MI) patients before and after one month of systematic physical training and in 30 control post-MI patients, who did not undergo such training. There were no significant changes in prothrombin time (PT) and alpha 1-antitrypsin (alpha 1AT) at the beginning and end of the study in either group. Levels of fibrinogen, Factor VIII: C (VIII:C) and von Wildebrand antigen (vWf:Ag), and activities of ATIII and plasminogen (Plg) were significantly decreased in the group with physical training (p less than 0.05), while values were unchanged in the control group. Hematocrit, platelet counts, and alpha 2-plasmin inhibitor (alpha 2PI) activities also decreased in the physical training group (p less than 0.05). In contrast, these variables increased in the control group (p less than 0.05). Activated partial thromboplastin time (aPTT) tended to be prolonged in the group with physical training, while it was shortened in the control group. In a subset of 20 patients with physical training, resting levels of plasmin-alpha 2PI complex (PIC), thrombin-antithrombin III complex (TAT), protein-C (P-C:Ag), plasminogen activator inhibitor-1 (PAI-1), VII:C, and P-C activities had significantly decreased after one month of physical training (p less than 0.05), although tissue plasminogen activator activities remained unchanged. Physical training appeared to suppress coagulability as indicated by the decrease in fibrinogen, VIII:C, vWf:Ag, VII:C, and TAT, and prolongation of aPTT. The decrease in plasminogen, t-PA:Ag, alpha 2PI, PAI-1, and PIC after physical training may result from the decreased coagulability. In conclusion, physical training appears to induce a suppression of the coagulation system in patients in the recovery phase of MI.

Cardiac rehabilitation participation predicts lower rehospitalization costs

The effect of participation in cardiac rehabilitation on medical costs was determined by measuring hospitalization charges for cardiac admissions over a 3-year period in 580 post-coronary event patients (58% after coronary bypass surgery, 42% after myocardial infarction), of whom 230 entered a cardiac rehabilitation program and 350 did not. Baseline left ventricular ejection fraction was similar in entrants and nonentrants (59.9% vs 59.5%). Over the 1 to 46-month follow-up period (mean 21 months), per capita hospitalization charges for participants in cardiac rehabilitation were $739 lower than charges for nonparticipants ($1197 +/- 3911 vs $1936 +/- 5459, p = 0.022). This was due to both a lower incidence of hospitalizations and lower charges per hospitalization. Inasmuch as groups differed with regard to age, sex, diagnostic category, and smoking status, data were adjusted for these baseline differences by means of analysis of covariance. Rehospitalization charges remained significantly higher in nonparticipants (p = 0.015). Because physician charges were not measured, the cost differential between groups is underestimated. Results of this study show an association between participation in comprehensive cardiac rehabilitation and lowered cardiac rehospitalization costs in the years after an acute coronary event.

Effects of daily high-intensity exercise on myocardial perfusion in angina pectoris

Forty male patients with chronic stable angina pectoris and no prior myocardial infarction were studied by planar thallium scintigraphy with use of circumferential profile analysis. Ischemic defects were assessed by measuring degrees of circumference involved and area of defect. Data were collected for 3 vascular regions in each of 3 views (anterior, 45 degrees and 65 degrees left anterior oblique projection). Patients were then randomized to exercise and control groups, the former training for a period of 1 year using the Canadian Airforce plan for physical fitness. After 1 year, both groups were restudied. Exercise training produced a 34% reduction in degrees of ischemia overall (p less than 0.02), the most significant change being seen on the anterior view (72 degrees +/- 59 degrees before vs 30 degrees +/- 35 degrees after training). Regional analysis showed markedly improved perfusion anterolaterally and apically on the anterior view and anteroseptally on the 65 degrees left anterior oblique view. These improvements support the hypothesis that exercise training improves myocardial perfusion by enhanced collateral function.

Exercise as a coronary protective factor

Exercise has multiple beneficial actions, both in normal subjects and in patients with coronary artery disease, which can be cardioprotective. Apart from reducing known risk factors and protecting against their deleterious effects, exercise also reduces the risk of coronary artery disease by increasing cardiovascular fitness. The exact contribution of each of these mechanisms in reducing coronary artery disease morbidity and mortality is unclear. Although fitness may be desirable, much of the cardioprotection can be achieved through increased leisure time and recreational physical activity. The risk-benefit ratio is very much in favor of moderate intensity exercise. Even in the absence of a controlled trial, the available evidence suggests that efforts to encourage physical activity are justified.

Heparin exercise treatment following percutaneous transluminal coronary angioplasty in a patient with effort angina

A 63-year-old female with chronic stable effort angina underwent percutaneous transluminal coronary angioplasty (PTCA) for a donating coronary artery of the collateral circulation to the jeopardized region. Because of the inefficacy of the procedure in increasing the collateral flow reserve, the patient was then put on an exercise regimen and also received heparin pretreatment. Her exercise tolerance improved remarkably with the development of improved collateral circulation.

Antianginal efficacy of exercise training: a comparison with beta blockade

Forty men with chronic stable angina and no prior myocardial infarction were studied. Exercise tolerance testing was carried out off treatment and after beta blockade. beta Blockers were stopped and the patients were randomised to a control group and a study group of patients who undertook a one year high intensity training programme. The groups were then restudied. Submaximum heart rate was reduced by 13 beats per minute by training and by 23 beats per minute by atenolol. Training increased the maximum heart rate by 10 beats per minute and atenolol reduced it by 29 beats per minute. The double produce ST threshold was increased from 183 to 205 by training but reduced to 143 by atenolol. Maximum ST depression was similarly reduced by both training and atenolol. As a result of the effects on maximum heart rate, training produced a greater improvement in exercise tolerance than atenolol with a treadmill time increased from 741 seconds to 1272 seconds with training compared with 974 seconds with atenolol. Other variables were similarly affected. Thus the antianginal efficacy of exercise training is as good as that achieved by beta blockade and represents an alternative to such treatment.

Cardiovascular rehabilitation: status, 1990

Cardiovascular rehabilitation is defined as the process of development and maintenance of a desirable level of physical, social, and psychologic functioning after the onset of a cardiovascular illness. Patient education, counseling, nutritional guidance, and exercise training play prominent roles in the process of rehabilitation. Benefits from cardiac rehabilitation include improved exercise capacity and decreased symptoms of angina pectoris, dyspnea, claudication, and fatigue. Recent pooled data regarding exercise training after myocardial infarction demonstrated a 20 to 25% reduction in mortality and major cardiac events. Exercise training may result in an improvement in systemic oxygen transport, a reduction in the myocardial oxygen requirement for a given amount of external work, and a decrease in the extent of myocardial ischemia during physical activity. The efficacy of modification of risk factors in reducing the progression of coronary artery disease and future morbidity and mortality has been established. Herein we review the history, current practice and results, and future challenges of cardiovascular rehabilitation.

Six year follow up of a consecutive series of patients presenting to the coronary care unit with acute chest pain: prognostic importance of the electrocardiogram

In a retrospective 6 year follow up data were obtained for 536 of 566 (95%) consecutive patients admitted to a coronary care unit with acute chest pain. Their diagnoses were acute myocardial infarction in 290 (54%), myocardial ischaemia in 164 (31%), pericarditis in 16 (3%), and non-cardiac in 66 (12%). Six year mortality was 36%, 24%, 0%, and 16% respectively. In patients with acute myocardial infarction a higher mortality rate during follow up was associated with a higher than average age, a higher than average creatine kinase, previous myocardial infarction, Q wave infarction, and the presence of reciprocal changes. The presence of reciprocal changes was associated with higher than average concentration of serum creatine kinase, indicating more extensive infarction. Infarction complicated by ventricular fibrillation or left bundle branch block was associated with a higher death rate. The electrocardiogram recorded at the time of acute myocardial infarction contains much useful prognostic information.

Physiological effects of short-term training after myocardial infarction

The effects of a period of 4 weeks training on treadmill exercise performance were evaluated in 27 patients, mean +/- SD age 55 +/- 7 years, who had previously suffered a myocardial infarction (17 Q-wave) 3-24 months (mean 11 +/- 8). To ensure comparability of exercise levels only patients who obtained their predicted maximal heart rate in the initial test were included. All trained 3-4 hours daily 5 days a week at an average maximal intensity of 85% of their initial peak heart rate. They performed 2 maximal exercise tests before and 1 after the training course. Maximal oxygen consumption was 28.1 +/- 5.3 and 28.8 +/- 6.5 ml/kg/minute (NS) before, and increased by 16% to 33.4 +/- 7.2 after training (P less than 0.01). Treadmill exercise distance was 510 +/- 153 and 559 +/- 163 meters (10% increase, P less than 0.01) before, and increased by 14% to 638 +/- 156 after (P less than 0.01). Heart rate, ratio of respiratory gas exchange, and breathing frequency remained unchanged in all three tests at maximal exercise, but were significantly lower at identical submaximal levels after training, while the respiratory tidal volume increased. Resting heart rate decreased by 12% after (P less than 0.01). Thus, aerobic exercise performance is improved by short-term training after myocardial infarction. By the longitudinal design of the study, and the maximal initial exercise test, this physiological improvement can be differentiated from that of increased motivation, and of increased treadmill exercise distance due to improved exercise technique.

Electrocardiographic findings in male veteran endurance athletes

Twenty male veteran endurance runners and 20 controls underwent resting, exercise, and ambulatory electrocardiography. Four athletes and three controls satisfied voltage criteria for left ventricular hypertrophy. The PR interval was longer in the athletes and they had longer mean (SD) treadmill exercise times (19 (4) v 16 (2) min) than the controls. Four athletes but no controls had greater than 2 mm downsloping ST segment depression during exercise. During 48 hour ambulatory electrocardiography the athletes had a consistently lower heart rate but maintained a circadian variation. Profound bradycardia (less than 35 beats/min) occurred in eight athletes but only one control. Eight athletes and two controls had asystolic pauses ranging from 1.8 to 15 seconds. Six athletes had first degree heart block, four had Mobitz II second degree block, and three had complete heart block. Most conduction abnormalities occurred at night and resolved during exercise. Ventricular ectopic activity was not significantly different between the groups. Thus heart block patterns and profound bradycardia are more frequent in older athletes than their youthful counterparts.

Does Exercise Improve Coronary Collateralization? A New Look at an Old Belief

In brief: An alternative route for blood supply in the heart-ie, coronary collateral vessels-can save the life of a person with coronary artery disease. Debate continues as to whether exercise training accelerates the growth of collateral vessels. Animal research has produced positive results, but studies of humans have been disappointing, largely because of problems in experimental design and methodology. Advances in technology-such as further refinements in radionuclide exercise testing methods-may help provide answers to this intriguing question.

Impaired fibrinolytic response to exercise in type II diabetes: effects of exercise and physical training

We studied the effects of exercise and physical training on coagulation parameters and fibrinolytic activity in 16 sedentary non-insulin-dependent diabetics and nine control subjects matched for prior physical activity. Parameters were measured at rest and after 30 minutes of bicycle exercise at 70% to 75% of maximal oxygen uptake before and after 6 weeks of thrice-weekly physical training. In the untrained state, fibrinolytic activity was impaired in diabetics compared with controls (1.26 +/- 0.19 v 2.20 +/- 0.34 U; P less than .03), and resting levels of plasma fibrinogen (329 +/- 21 v 266 +/- 17 mg/dL; P less than .01) and the prothrombin time (PT) maximal velocity (Vmax) (4.9 +/- 0.5 v 2.9 +/- 0.5; P less than .05) were increased. The activated partial thromboplastin time (APTT) Vmax was also increased but this did not reach statistical significance (3.6 +/- 0.2 v 2.3 +/- 0.5; P less than 0.10). Activation of fibrinolysis occurred following exercise in both groups but the peak activity and increment were less in diabetics. Physical training for 6 weeks had no effect on plasma fibrinogen levels but significantly improved the resting and postexercise APTT Vmax and resting fibrinolytic activity in diabetics. The exercise-induced increment in fibrinolytic activity following training remained depressed compared with normal controls. The changes in APTT Vmax correlated with changes in the indices of blood glucose control. The relevance of these findings to possible antiatherogenic effects of exercise and the mechanism by which exercise produces these effects remain to be established.