Dietetics is a part of a comprehensive cardiovascular rehabilitation. Therefore, there are high risk factors associated with patients’ poor dietary and lifestyle choices that predispose them to recurrence of the event. There is also a disparity between patients who undergo cardiac rehabilitation programs and those who do not. In trying to answer the question as to why few patients participate in these programs, several cogent reasons have been identified. The issue of how to improve the program attendance is addressed. To curb these risk factors, there is a need for a more comprehensive rehabilitation, which includes exercise training to burn excessive calories. The paper takes a closer look at the exercise routine for cardiac event patients. It addresses safety considerations, intensity, and frequency of exercise and provides recommendation on areas that need more research in the future.
Many works of scientific literature have been reviewed for the purpose of providing recommendations about optimal rehabilitation program for patients who suffered a cardiac event to prevent a recurrence of such event. This includes modes of delivering the prevention program services and discussing areas needing future research. The goal of the research is reduced morbidity and mortality (Taylor et al, 2004).
Participation in Cardiac Rehabilitation Programs
Research has indicated that older adults greatly benefit from cardiac rehabilitation. If the opportunity is missed, it is potentially harmful as the recurrence risk increases. Survival rate is greater among those who attend the rehabilitation program as opposed to those who are not referred to the cardiac rehabilitation program (Suraya, 2006). He also stipulates that those patients who participate in the cardiac rehabilitation not only live longer, but also have a better quality of life being more functional and thereby more productive.
Unfortunately, cardiac rehabilitation programs are not put to use effectively. In United States of America, for instance, it is estimated that 10% to 20% out of approximately two million people eligible for these programs actually enroll (Ades, 2001). Among the key causes of such low attendance is a low referral rate, especially among women, elderly, and patients who come from ethnic minorities. Other similar issues are the lack of motivation in patients to enroll and follow the set of guidelines, lack of indemnity against damage, and inaccessibility of the program due to geographical limitations (Allen et al, 2001).
The medical profession did a poor job of educating the general public on the importance of cardiac rehabilitation. As a result, alternate models preceded the traditional ones, where hospital or community-based centers have been set up, or where home-based nurses provide service. These centers have nurses who play the role of managers, facilitators, and supervisors and monitor patients’ progress (Ceccato et al, 2007). There also are non-physician healthcare providers.
With a majority of people having access to Internet, electronic media became an efficient tool in home-based learning. It offers a comprehensive education on how to lower risk factors and instructions for structured dietary programs (Southerd et al, 2003). However, more research is needed for the purpose of firmly establishing the effectiveness and means of delivering these rehabilitative services.
There are different levels at which the cardiac rehabilitation program participation can be increased. At the organizational level, physicians should be approachable and enthusiastic, with a strong knowledge of cardiovascular rehabilitation topic. Community should be educated about the importance of the cardiac rehabilitation programs in health management and be referred to such programs.
People who are referred, or attend the first sessions and fail to stick to the program should be followed up on. The reasons for withdrawal should be eliminated; people should be provided with transport grants and tailored programs to suit different groups based on gender and age. Amid having so many viable recommendations, very few have been implemented according to the review of 2004.
How it works
Cardiac rehabilitation is a behavioral intervention that has solid theoretical grounds (Ceccato et al, 2007). This theory has been found to be effective in predicting the attendance of cardiac rehabilitation in certain studies (New Zealand Guidelines Group, & National Heart Foundation of New Zealand, 2002). The patients are referred through the invitation letters that outline the benefits of cardiovascular rehabilitation and explain the simplicity of the program. It is highly emphasized that their doctors highly recommend the program. The common sense model theory also has been indicative of having an influence in the program attendance. Better attendance has been noticed among people with adequate knowledge and understanding of their health conditions. Such patients believed that their illness is serious, but can be controlled (French et al, 2006).
Major Risk Factors
a) Obesity and state of being overweight
These two relate to the body mass index and are among the top risk factors for heart disease. Only one third of Europe and USA has a desirable body mass index (one that is below 25.0) (Kumanyika, Obarzanek , and Stettler, 2008). To evaluate the relation between extra weight and life expectancy in the United States, one million overweight people were studied. Two hundred thousand deaths have been recorded during the fourteen year follow up.
The Cox model was used, where factors such as educational level, alcohol usage, age, fat consumption, and whether estrogen replacement therapy was used (for women). Men and women with a higher risk of death happened to be white and have the highest body mass index. High body mass index mostly predicted death from cardiovascular events. Heavier people of all age groups were more susceptible to disease, especially white race representatives, but results were not significantly different for black men and women (Calle et al, 2003).
Obesity that has a body mass index that spirals up to or beyond 30.0 is favorably a predisposing factor to atherosclerosis, heart failure, instances of coronary artery diseases, hypertension, and acute coronary syndromes and in others may cause diabetes type 2, which reduces life expectancy. Weight gain in adulthood is an independent factor that is a high risk factor for premature deaths as a result of heart attack.
Obesity is also associated with major adverse cardiovascular events (MACE) in patients with a history of coronary disease(s). Individuals with acute coronary syndromes were found to have a favorable course after the cardiac event. This cardiac event, however, happened seven years earlier, in comparison to individuals who were not obese (Buttner et al, 2007).
In itself, body mass index is used as a predictor of overall mortality rates, where an excess to the optimum of 25.0 increases the risk of mortality by premature death due to cardiovascular problems.
The effects of obesity are that it reduces the level of nitric oxide’s bioavailability; the vascular tone/volume is increased, which causes the stiffening of arteries. In turn, the arterial stiffening increases pulse, pressure, and systoles. Overall, it causes atherogenic vascular phenotype. Similarly, there may be additional independent mechanisms at play such as chronic oxidative stress; the renin-angiotensin system may be locally activated and diminish inflammation. These two last effects originate from the visceral adipose tissues in the abdomen (Hajer, van Haeften, Visseren, 2008).
Despite an individual having a normal body mass index, an increase in the circumference of the waist has been recognized as a possible independent factor predisposing to myocardial infarction (Pischon et al, 2008), where the waist circumference was measured using the narrowest circumference to the torso, which is the midpoint that lies between the lower ribs and the iliac crest (Singh et al, 2007). It could also be measured using the hip circumference horizontally at the level where the lateral extension is largest, of the hips or over the buttocks. Visceral fatty tissues are active endocrine organs and are central in lipids and glucose metabolism. They, therefore, produce a number of hormones and cytokines that cause metabolic syndrome and vascular diseases (Hajer et al, 2008).
Preventing and reducing obesity and excess weight
Laboratory animal studies indicate that caloric restriction has a great impact on the physiological and pathophysiological alterations that are responsible for aging and, in certain species such as mammals, increasing the lifespan. Though it has not been conclusively tested on human beings, caloric restriction plays a part in the attenuation of visceral fat deposits, which, in turn, counters the deleterious effects of obesity.
The protective cardio effect of short-term caloric restriction is mediated by an increase in adiponectin production that is associated with activation of protein kinase (Shimmer et al, 2007). Caloric restriction has specific effects on the heart that reverse aging that is associated with a change in the diastolic function and protects against myocardial fibrosis, high blood pressure, and systemic inflammation.
Recently conducted studies indicated that, in individuals who have type 2 diabetes, prolonged caloric restriction decreased the body mass index. This improved the regulation of glucose, which relates to decreased myocardial triglyceride level, and gradually improved the diastolic heart function (Hammer et al, 2008).
Where weight loss is intended, a patient should reduce five hundred to eight hundred kcal. Physical activity is very important and should be increased and aimed at the loss of approximately one kilogram of his weight per two weeks. In regard to diet, low-carbohydrate diets with vegetable-rich meals are a suitable alternative to low-fat meals. Low-carbohydrate foods lead to an improved blood sugar control. A weight loss through diet has the ability to reverse atherosclerosis to some extent and to regress the carotid vascular wall.
Personal preferences are used to make considerations in tailoring diet, and, therefore, it becomes easier for people to maintain the new lifestyle (Shai et al, 2008).
The composition of diet is of less importance as compared to participation in the weight counseling sessions. Other factors are those that are intrinsic, such as behavioral factors and motivation to change, that give the patient motivation to follow the chosen macronutrient composition of the food he or she takes (Sacks et al, 2009).
It has also been stipulated that obesity as a societal problem is difficult to deal with since social conditions favor obesity (Katan, 2009). Prevalence of obesity and excess weight in people is a threat to society. To achieve positive impact, it is important that they are addressed at early stage.
Intensive nutritional education and behavioral interventions help patients take low-fat foods and low cholesterol intake. This results in significant improvement in the lipid levels, which, therefore, is essential in comprehensive cardiac rehabilitation.
Poor lifestyle habits such as smoking should be discouraged for patients who have had a cardiovascular event and also as a preventative measure. Ceding smoking is of great importance to cardiovascular patients, as smoking, according to the study made by the University of Wisconsin Medical School, puts the patients at high risk if continued after the cardiac event. In this study, the prevalence of smoking was studied among cardiac rehabilitation patients, to find patients at high risk of event recidivism for the continued use of nicotine.
A patient who has suffered a cardiac event and who was referred to outpatient cardiac rehabilitation was at a lower risk of recidivism as opposed to the patients who were not referred. Smoking leads to poor health and disease manifestation recurrence. Outpatient cardiac rehabilitation enables nurses and other healthcare providers to monitor their patients and determine high risks and modify lifestyle to protect against them.
Conducted studies have shown that moderate red wine intake after a myocardial infraction reduces the risk of cardiovascular morbidity and mortality subsequently after the first event (Kloner & Rezkalla, 2007). This is attributed to the polyphenol and oligomeric content that has a favorable effect on the endothelial function (Corder et al, 2006). However, patient with heart failure are discouraged in any consumption use of alcohol due to the risk of arterial fibrillation and improvement of prognosis.
Women experience the same effects of low alcohol intake due to a lower gastric alcohol dehydrogenase. This effect in women is mitigated by an increased risk of breast cancer. However, there are dangers of excessive alcohol intake that are associated with ischemic stroke for male patients who consume more than two servings of alcohol per day (Mukamal et al, 2005).
Exercise for Cardiovascular Patients
In cardiac rehabilitation, exercise training refers to a series of exercises that are repeated and monitored or where the intensity and frequency of the exercises is adjusted over time. It is mainly based on aerobic or dynamic exercises that are designed to improve the physic. These exercises may also include resistance training such as muscular effort that is aimed at increasing the strength of muscles.
Safety has to be carefully considered in cardiac rehabilitation exercise programs, where they should be supervised medically and directed by a physician using well established guidelines. Risk stratification procedures are carried out to determine cardiovascular patients who are exposed to risk for exercise-related cardiac events. These are people who have recently been implanted with stents and who need extra intensive cardiac monitoring to complement medical supervision.
Effects of exercise
Exercises and physical activities that are done regularly, such as climbing stairs or working around the house, are essential and greatly improve the physical fitness of a cardiovascular event patient. Rehabilitative and well-supervised exercises within a period of three to six months have been reported to increase patients’ oxygen uptake peak by 11% to 36%, having the highest improvement in deconditioned individuals.
An improved individual’s physical fitness enhances his quality of life and enables elderly patients to live independently. Keeping a cardiovascular patient under an exercise training program helps in reducing the sub maximal heart rate, his or her systole blood pressure, and the rate-pressure product, which reduces myocardial oxygen needs during carrying out various activities.
With improved physical fitness, patients with advanced coronary artery disease, who normally experience myocardial ischemia when performing physically exerting tasks, are able to perform those tasks at an increased intensity.
Further, resistance training strengthens the muscles, which reduces the rate pressure product associated with myocardial events. An improved cardiorespiratory endurance in training reduces the rate of subsequent fatal and non-fatal cardiovascular events without dependence on other risk factors.
There is a reduced rate of initial cardiac heart disease for people who are physically active. This is a biological plausible heart protection through physical activities, where exercise of moderate intensity is regularly done. Having this as a premise, it is logical to say that inactivity is an eminent risk factor in cardiovascular events.
Meta-analyses of small studies have been vital in the analysis of exercise as a comprehensive part of cardiac rehabilitation programs and its impact on the rates of morbidity and mortality in patients with cardiovascular events. The Agency for Healthcare Policy and Research indicated a significant decrease in the cardiac events and overall mortality for patients who have undergone and completed the cardiac rehabilitation programs as compared to those patients who did not undergo cardiac rehabilitative exercises.
As a part of a comprehensive cardiovascular rehabilitation program, it has been proven to slow progression and/or reduce coronary atherosclerosis severity. An increase in blood flow mediates a shear stress on the arterial walls during the exercise, which improves the endothelial function. Such endothelial functions include synthesis and release of nitric oxide and determine the duration of the biochemical compound’s life. Nitric oxide is essential in maintaining an endothelium dependent vasodilatation, inhibiting multiple processes that are required in atherogenesis and thrombosis. This is demonstrated by Hambrecht on the significant endothelium dependent dilation of the arteries in patients who have had cardiac event and have undergone only four weeks of endurance exercise training.
The physical activity results in moderate body weight loss for most patients. It also promotes a reduction in patient’s blood pressure and serum triglycerides. Patients also have increased high-density lipoprotein cholesterol and an improved insulin sensitivity, which, in turn, controls glucose and homeostasis that reduces the risk of suffering from type 2 diabetes.
Intensity of exercise training
The intensity of exercise for persons who have had a cardiac event can be divided into three categories, namely:
+ Low intensity training;
+ Moderate intensity training;
+ High intensity training.
A patient is assigned into any of the category either according to symptoms, Borg’s scale (Singh, 2007), or according to heart rate. The categorizations, however, should not be on the basis of metabolic equivalent levels without consideration of age and severity of each patient’s illness.
Low-intensity exercise is generally acceptable for almost all patients. Elderly and those with actual heart failure can perform low-intensity exercises. This category has little risk and needs minimal supervision. However, in instances of disabled patients and patients with congestive heart failure, low-intensity training needs monitoring.
Moderate-intensity exercise is also fairly acceptable for most patients. It is difficult to incorporate on the long-term basis into patients’ day-to-day activities and also can case musculoskeletal injury in older patients. It is not recommended for patients with heart failure, unless it is done under careful supervision.
High-intensity exercise is only allowed for a very small percentage of cardiovascular patients. It acts as barrier to participation in the cardiac rehabilitative program, especially for middle-aged and elderly women, elderly men, and obese people. Patients with heart failure or those who have impaired left ventricular function are not within the capacity to undertake this training unless prior testing is done to determine the safety. This type of training requires monitoring and is difficult to incorporate into the life of the patient. It is a preferred activity for people like young males and is essential for rapid reconditioning of patients who have physically demanding jobs.
Many of the cardiac rehabilitative program centers offer moderate-intensity training while high-intensity exercise training is used as a means of achieving regained fitness within a short span of time. It is demanding in relation to costs and resource. High-intensity training is therefore limited, with smaller appeal to patients.
Frequency and duration of the exercise
In United States of America, most authorities recommend supervised exercise intensity for moderate and high-intensity exercise three times a week for twelve weeks. It is also preferable that the exercises are not done within consecutive days. This duration recommendations are based on the fact that physical working capacity improvement reaches plateau during the tenth to the twenty first week of the exercise training program.
If high-intensity exercise training is done beyond half an hour, there is an increased risk of musculoskeletal injury. Where exercise is done frequently without alternating the exercise days, such musculoskeletal injury risk is also increased. Training thrice a week for twelve weeks culminates to thirty six training sessions. All these sessions are done under electrocardiographic monitoring using telemetry or other methods such as limited defibrillator paddles, which are seen as the basis for funding the rehabilitation centers. This, however, should also be geared towards recognizing and detailing an insurance funding for monitored programs that do not use the electrocardiographic monitoring, which currently is minimally recognized by insurance companies.
Home-based exercise programs
These exercise programs are well-recommended for patients who for some reason cannot attend the group sessions. It is also recommended for patients who take part in the group session program, as a complementary. Certain studies compared home exercise and that of hospital ambulatory group exercise (Singh et al, 2007, and Naparstek et al, 2010). These studies indicate the advantages of physical work and its psychosocial result that is achieved by randomly placing patients in hospital-based programs. Even though home-based exercise reduces the patients’ travel time, patients in home-based exercises also need careful health condition assessment prior to exercise prescription is given, especially if they are to do moderate or high-intensity training. In some instances, patients, who have equipments such as a cycle ergo meter at home and are in constant communication with nurses in the rehabilitation programs for electrocardiographic transmissions within the comfort of their homes, are able to carry out prescribed exercises. However, where prescribed exercise is low-intensity, telephone monitoring is unnecessary for a majority of patients. It is expensive and needs constant supervision through telephone and can end up with failure, where patients lack motivation to exercise train on their own. Home-based patients should be educated on how to monitor themselves by use of their heart rates during the exercise training or monitoring the level of breathing symptoms using the Borg scale. They should also be lectured about their recommended level of training, frequency, and duration of the exercise. These exercises also are inclusive of low-intensity training and can be achieved with physical activity on a daily basis, such as a daily walk.
There is great need to evaluate and determine the efficacy and safety of the various approaches that are designed for the purpose of increasing the number of referrals made, accessibility of these programs, delivery of cardiovascular rehabilitative programs, and improving attendance.
Due to a continued increase of medical costs, there is a demand from the third-party payers for evidence of cost effectiveness and other cost-related healthcare benefits of services and procedures. Few studies have been done to deduce that cardiac rehabilitation and other secondary preventive programs as being cost-effective. More studies should be done to compare the costs of the traditional supervised programs and those that are home-based. This has to be measured in regard to which one of the two has higher capacity to improve the functional ability, independency, quality of life, decrease risk of recidivism.
More research should also be geared towards studying the contribution of endurance and resistance exercise to modification of risk factors in patients and their effects on pathophysiological processes in atherogenesis, myocardial ischemia, and coronary thrombosis. Exercise training dose response should also be researched and determined.
The effects of a comprehensive lifestyle modification in many cases have been overlooked as a secondary prevention mechanism. More studies are also needed to help clarify benefits of lifestyle modification. The cardiac rehabilitative centers should be holistically–oriented and include lifestyle management services such as nutritional advice, weight loss centers, and also psychosocial support for patients such as those with type 2 diabetes.
A review of scientific literature discloses patients who suffered cardiovascular events and experienced fast recovery as a result of physical exercise. Modification of risk factors is also crucial and is aided by exercises too. There is a great difference between patients who attend the cardiac rehabilitative programs and those that do not participate in the program. Education on the dietary matters helps in modification of the patient’s lifestyle and reduction of obesity, which are predisposing factors to cardiac disease. This reduces the risk of recurrence.
Patients who participate in the cardiac rehabilitation programs have increased life expectancy, quality of life, personal independence and are at a lower risk of hospitalization due to recidivism, as opposed to patients who do not undergo the rehabilitative program and continue to engage in high risk factors, such as smoking and bad dietary habits.