Cardiac Rehabilitation

Critical Review of Coronary Arteries Disease on Cardiac Rehabilitation and Exercise

 

Cardiovascular disease is the single most common, cause of death in the developed world. Of these deaths, nearly half are directly related to coronary artery disease and another 20% results from stroke. From an epidemiological perspective risk factor are characteristic feature of an individual or population that are present early in life and are associated with an increased risk of developing future disease (2001). Heart disease develops slowly over many decades, so its quite common among older adults. For example, among those who dies o coronary artery disease (also known as coronary heart disease [CHD]) in 200, about 85% were 65 years old or above. Additionally, about 58% of the almost 2,200,000 people released from the short stay in hospitals in 200 with “a first listed diagnosis of CHD” were in this age group ( 2003). Unfortunately, of those individuals who have diagnosed heart problems, fewer than 30% participate in organized cardiac rehabilitation programs, and the proportion of eligible women participating is even lowering ( 2003). Many women underestimate the threat coronary artery disease (CAD) poses to their health. Coronary artery Disease is the number one killer of women in the United States. Yet in a recent survey, 50% of women replied that they still considered cancer their biggest health threat. Only 13% cited coronary artery disease as their biggest concern (2004).

It is well established that endothelial dysfunction is presentin coronary artery disease (CAD), although few studies havedetermined the effect of training on peripheral conduit vesselfunction in patients with CAD (2003). When the heart muscle doesn’t get enough blood, it is deprived of oxygen and nutrients. If this situation continues, the heart muscle will be damaged. The amount of damage depends on the location of and the degree of blockage. Angina pectoris and myocardial infarction are two consequences of CAD. Exercise is effective in both preventing and treating coronary artery disease (CAD). The clinical relevance of endothelial dysfunctionhas been further highlighted by recent studies indicating thatendothelial dysfunction is an independent predictor of cardiacevents in patients with and without established coronary arterydisease (2000). Furthermore, interventions such as lipid-loweringand angiotensin-converting enzyme (ACE) inhibitor therapy,which improve cardiovascular mortality and morbidity, are alsoassociated with improved no-mediated vascular function (1999). Regular physical exercise improves endothelium-dependent vasodilationin a number of populations, including those with heart failure ( 1998), Type 2 diabetes (2001), and hypertension (1999).  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 (1997).

Endurance exercise enhances the breakdown of blood clots and decreases the adhesiveness and aggregation of platelets. These factors in turn reduce thrombosis (1996). Another important benefit of exercise is that it helps patients feel better by improving exercise tolerance, symptoms, and sense of well – being (1997). Aerobic exercise does a great job lowering systolic blood pressure, and both aerobic and resistance exercise help reduce diastolic blood pressure.  This makes it much easier for the heart to do its job of pumping blood throughout the body. Both forms of exercise also strengthen the heart muscle making it work much more efficiently (2005).   Psychologically, exercise gives patients self-confidence, reduces depression, and provides a foundation for approaching other behavioral changes such as smoking cessation and weight loss efforts (1997). Doctors can encourage their patients with healthy hearts (no matter what their age or gender) and those with unhealthy hearts (under medical supervision) to start using resistance training along with their aerobic training as an integral part of their heart-disease prevention and / or treatment program (2005).  The following table, by Pollock and Vincent, from The President’s Council on Physical Fitness and Sports Research Digest, is cited in the article entitled ‘ the Importance of exercise and how to prescribe it for your patient’ by   2005. Table 1 helps us better understand the differences in aerobic (cardio) training and resistance training.

Table 1: Comparison of the Effects of Aerobic Endurance Training to Strength (Resistance) Training on Health and fitness Variables

Variable

Aerobic Exercise

Resistance Exercise

Increase bone density

Decreases body fat

Increases muscle mass

Very little effect

Increases strength

Decreases insulin response to glucose

Decrease basal insulin levels

Increases insulin sensitivity

Increases HDL

Very little effect

Decreases resting heart rate

Very little effect

Increases stoke volume of the heart

Very little effect

Decreases diastolic blood pressure

Improves cardio/vascular fitness

Increases endurance time

Improves physical function

Increases basal metabolism

 Resistance training for health.  1996.

Table 1: Comparison of the Effects of Aerobic Endurance Training to Strength (Resistance) Training on Health and fitness Variables

Source: 2005

Home exercise as suggested by  1997; are for patients who have mild CAD—those who have documented mild, stable occlusion but who haven’t had a coronary event—and those who have two or more cardiac risk factors should be advised to work gradually toward the exercise goal suggested for all Americans: 30 minutes of moderate activity on most days of the week (see box 1) as Patients who have cardiac risk factors should have a medical evaluation before undertaking a regular exercise program.

BOX 1. Exercise for Mild Coronary artery Disease

Most patients who have mild CAD can exercise safely, but a very small minority may have problems during vigorous activity. High-tech tests don’t always flag the people who will have problems, so—in addition to having the tests that your doctor recommends before you begin—your best bet is to be aware of the warning signs that say, “Stop exercising and call your doctor.” These signs include: (1) abnormal heart rhythm. Irregular heartbeats, called arrhythmias, feel like extra heartbeats or skipped beats. You may also feel dizzy. (2) Chest pain. Pain or pressure in the center of your chest during or after exercise is a signal that your heart isn’t getting enough oxygen. The pain may radiate across your chest or down the left arm. Pain or pressure in your back, throat, or stomach may also be a warning sign. (3) Dizziness. Dizziness during or just after exercise may be a symptom of a serious circulation problem. (4) Fatigue. Unusual tiredness during or after exercise can be a heart-related symptom.

Remember: This information is not intended as a substitute for medical treatment. Before starting an exercise program, consult a physician.

Box 1: Exercise for Mild Coronary Artery Disease

Source:

Advancing age is one risk factor used as a surrogate for atherosclerotic plaque burden. With aging there is a gradual but progressive accumulation of coronary plaques. This accounts for the increasing risk of CAD with advancing age (1997).     

            In recent decades, research has validated the effectiveness of regular exercise as a way to reduce and/or prevent age-related functional decline and reduce the risks of a sedentary lifestyle (1996). Most medical groups recommend regular physical activity (1996). People over age 65 carry the highest load of chronic disease, disability, and healthcare utilization (1998). Though many of these problems are preventable, primary care physicians rarely provide their older patients with an appropriate exercise recommendation that includes an individualized motivational message, a pre-participation evaluation to ensure a safe exercise program, and a tailored exercise prescription (1996).

In 1998, the  issued its first position statement on aging and exercise, in which it recommended strength training for frail older people. says, “We now know that older patients can perform to very high levels, so exercise prescription does not differ for older and younger persons, and training effects for the elderly can exceed those of younger people at the upper end of VO2max.” Exercise is the key to maintaining quality of life, as well as extending the number of years of life expectancy.  It’s never too late to start, and an early start is better. Even 90- and 100-year-olds can do strength training. Physicians need more training in how to make best use of this powerful therapy.  Physicians can successfully encourage increased activity by giving their patients a written exercise prescription along with printed advice on how to design a safe, enjoyable routine. 

Prescribing exercise is like prescribing medications, surgery, or other therapy—it is a thoughtful compromise between potential benefits and side effects. After careful consideration of these factors, the physician and the patient reach an agreement on the most effective plan. Important considerations include the goal of exercise (e.g., osteoporosis prevention, weight loss, strength improvement, marathon training) and patient preferences. Expanding on his or her current exercise habits is a good starting point because choosing activities the patient already enjoys improves adherence (2005).

This goal can be achieved with moderate to vigorous exercise, but it can also be accomplished by engaging in leisure activities that involve lower levels of exercise (1998). Figure 1 illustrates ways to vary the intensity, duration and frequency of activity and still attain an exercise training goal.

 

 

 

 

 

FIGURE  1 : Exercise Training Protocols

The circles illustrate variations in intensity, duration and frequency of exercise. The circle at the upper left displays the basic model, with equal frequency, intensity and duration of exercise. The upper right circle displays a protocol of greater intensity, with shorter duration and less frequency of exercise; the lower left circle shows a protocol with greater duration and less frequency and intensity; and the lower right circle shows a protocol with greater frequency, shorter duration and less intensity.

Figure 1: Exercise Training Protocols

Source: 1998

Cardiac Rehabilitation is defined in the review of2000, as inpatient, outpatient or community – based intervention that is applied to a cardiac patient population. The intervention must include some for of exercise training. The following comparisons have been made: (1) exercise training alone and usual care vs. care alone (exercise only vs. usual care). (2) Exercise training in addition to psychological and / or educational interventions vs. usual care alone (comprehensive cardiac rehabilitation vs. usual care.)

This systematic review has allowed analysis of an increased number of patients from approximately 4500 in earlier meta-analyses to 8440 (7683 contributing to the total mortality outcome).The pooled effect estimate for total mortality for the exercise only intervention shows a 27% reduction in all cause mortality (random effects model OR 0.73 95% confidence interval 0.54 to 0.98). Comprehensive cardiac rehabilitation reduced all cause mortality, but to a lesser degree (OR 0.87 95% confidence interval 0.71 to 1.05). Total cardiac mortality was reduced by 31% (random effects model OR 0.69 95% confidence interval 0.51 to 0.94) and 26% (random effects model OR 0.74 95% confidence interval 0.57 to 0.96) in the exercise only and comprehensive cardiac rehabilitation groups respectively. We found no evidence of an effect of the interventions on the occurrence of non-fatal myocardial infarction. There was a significant net reduction in total cholesterol (pooled WMD random effects model -0.57 mmol/l 95% confidence interval -0.83 to -0.31) and LDL (pooled WMD random effects model -0.51 mmol/l 95% confidence interval-0.82 -0.19) in the comprehensive cardiac rehabilitation group.

It has been recommended that every district hospital which treats patients with heart disease should provide a cardiac rehabilitationservice, and that individual programmes should evaluate theiroutcome and a standard format of audit could be agreed nationallyto allow comparison (1997). However, the provision of cardiac rehabilitationis still a neglected topic in some centers and it is likely thatthere is considerable potential to improve the quality of careand to reduce undesirable variations in service provision.

Strategies for cardiac rehabilitation have changed over recent years. Currently, less emphasis is being placed on office or hospital visits for electrocardiographic (ECG) monitoring and supervised group programs. Many patients are unable to participate in such programs because of travel considerations, expense or inconvenience. Consequently, more patients are being managed individually through home programs. These programs involve aggressive coronary risk modification with specific emphasis on smoking cessation, lipid control, blood pressure control and physical activity (1998).

Home exercise programs without telephone monitoring are also being used by cardiologists and primary care physicians for patients who have been evaluated with an exercise test. Such individual programs should, however, include periodic face-to-face physician counseling. Patients assigned to these programs are predominantly those at low risk according to American Heart Association (AHA) criteria (Table 2), (  1998); who show no evidence of left ventricular dysfunction, high-grade arrhythmias, unstable angina pectoris or other medical problems that could be of concern in home exercise.

 

Table 2: – Risk Criteria for Exercise

New York Heart Association class 1 or 2

Exercise Capacity over ^METs (>=21 mL per kg per minute oxygen consumed)

No evidence of Heart Failure

Free of angina or ischemia at rest or with exercise

Appropriate increase in blood pressure with exercise

No sequential ectopic ventricular ectopy ( three or more beats in a row)

Ability to satisfactory self – monitor exercise intensity

MET=metabolic equivalent.

Information from Fletcher  Pollock ML. Exercise standards. A statement for healthcare professionals from the American Heart Association Writing Group. Circulation 1995

Table 2:  – Risk Criteria for Exercise

Source: 1998

Exercise training for patients with stable CAD is now generallyaccepted as a non – pharmacological intervention to improve functionalcapacity and provide risk factor modification, although themechanisms responsible for the salutary effects of exerciseare not fully understood (2001). Improvement in endothelialand vascular function may explain, in part, the beneficial effectsof exercise training on functional capacity and cardiovascular outcomes. Despite its importance, few studies have examinedthe effect of exercise training on endothelial function inpatients with CAD; one study found coronary endothelium-dependentdilation to be improved ( 2000). whereas another found a 10-wkprogram of leg exercise to increase flow-mediated dilation (FMD)significantly in the posterior tibial artery but insignificantlyin the brachial artery ( 2002). In view of this and laboratory’sprevious study finding FMD to be increased in the brachialartery by lower body exercise training (2001). In 2003, the research group of Walsh, et al; studied a groupof patients with stable CAD. The findings of their study is that The findings of this study provide further evidence for the beneficial effect of an exercise training program on endothelium-dependentvascular function in patients with stable CAD undergoing routinemanagement. Furthermore, the benefit is not limited to the vasculature of the trained muscle bed, because changes in the brachial artery were observed as a result of lower limb exercise. Exercise training-mediated improvement in vascular endothelial function may, in part, explain the cardiovascular mortalityand morbidity benefits attributed to exercise in the CAD population.

In summary, exercise is an effective strategy for preventing heart disease, and it is a beneficial, low-cost, pleasure-giving treatment without the side effects of drugs or the risks, pain, and expense of surgery. The future of cardiac rehabilitation will include greater emphasis on primary prevention measures in the families of patients with established cardiovascular disease (1997). The patient is the central actor in the cardiac rehabilitation programme, since involving patients is a prerequisite for success. The Cardiac Rehabilitation Unit tailors the programme to the needs and resources of each patient based on individual discussions between the patients and health professionals. The patient’s family members (primarily spouses) play an important role in cardiac rehabilitation at  Hospital and are involved as resource people in the overall rehabilitation. Studies indicate that patients with good family support are more likely to maintain participation in cardiac rehabilitation and changes in lifestyle than patients without such support ( 2002). In addition, family members often feel powerless and anxious in connection with the illness of close family and have an independent need for support in coping with the early phase of acute illness in their family (1999). Physicians are finding out how important the patient’s significant others can be in fostering compliance with health interventions, including exercise. Because primary care physicians themselves have such an impact on behavior patterns, in this context they are among their patients’ significant others. Primary care providers who steer their CAD patients toward home exercise or cardiac rehabilitation and support their exercise efforts will be instrumental in ensuring that more patients will benefit from the cardiac effects of exercise. Cardiac patients who have been actively involved in rehabilitation programs have lower overall and cardiovascular mortality rates and a lower rate of sudden death. With these measures, you may be able to stop the disease and improve the quality and length of your life. However, many people must take medications for the rest of their lives, and a smaller portion requires surgical treatment to improve blood flow to heart muscle.

 In this paper, we mentioned CAD affects women greatly with a low prognosis -Women are more likely to die of a first myocardial infarction (1996). Women experience more long-term disability (1999). Women have more comorbidity (because they are usually older on presentation). Barriers to physical activity in women must be considered that includes lack of leisure time because of household and care-taking responsibilities, comorbid conditions such as arthritis, and lack of appropriate programs and access to facilities. Lack of access is especially severe among low-income women, who have the highest rates of obesity and cardiovascular morbidity and mortality. Even a walking program can be difficult and dangerous in a neighborhood where the streets are not safe (2001). These particulars must be considered that they may be given appropriate intervention regarding with their health status needs.

As alluded to in an editorial in Heart, (1999) the keys to improving cardiac rehabilitation are individual assessment, carefulformulation of treatment, effective delivery, and systematicevaluation.

 

 

 

 

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