Transforming exercise-based cardiac rehabilitation programs into secondary prevention centers: a national imperative.

Abstract

Cardiac rehabilitation programs should be transforming themselves from cardiac exercise facilities to comprehensive risk-reduction centers. Exercise will always have a place in cardiac rehabilitation. Postcoronary event patients who participate in exercise rehabilitation enjoy lower mortality rates and improved physical and psychological function. 1–3 Furthermore, cardiac rehabilitation exercise is a crucial intervention for older CHD patients striving to maintain physical independence. 4 However, the clinical benefits of exercise can be greatly amplified by strict attention to the measurement and treatment of coronary risk factors and by the attainment of well-defined risk factor goals. 5–9 Individual rehabilitation programs will need to carefully and thoughtfully develop risk factor modules and practice ongoing quality improvement with collection of outcomes data. The days of blindly applying a single exercise intervention over a 36-session period to all patients are all but over. Third-party payors, patients, and referring physicians are appropriately expecting improved clinical outcomes over a relatively short-term follow-up period (2–4 years). These goals can only be attained with a comprehensive, active, and participatory approach to cardiac risk reduction. HISTORICAL PERSPECTIVE Cardiac rehabilitation programs were established in the 1960s and 1970s when hospitalizations for acute myocardial infarction and surgical revascularization were prolonged and deconditioning was extreme. 10 As inpatient reambulation extended into the outpatient period, closely supervised, electrocardiographically monitored exercise programs developed, with physicians on-site to respond to potential cardiac emergencies. The focus was almost exclusively on exercise. These programs were shown to improve functional capacity for patients with coronary heart disease (CHD), and combined randomized-controlled trials (analyzed by meta-analysis) demonstrated a mortality benefit. 1,2 It has since been demonstrated that the acute risk of cardiac rehabilitation exercise is exceedingly low. 11–13 Home-exercise programs have been developed and appear to be safe for low-and moderate-risk patients. 14,15 Cardiac rehabilitation participation criteria have expanded to include patients with percutaneous coronary interventions, recent valvular heart surgery, chronic heart failure, heart transplantation, peripheral arterial disease, and the elderly. 16 By the early 1990s, the benefits of risk factor modification on clinical outcomes in patients with CHD were demonstrated. Randomized-controlled clinical trials that included combinations of exercise, low-fat diets 7,17–19 and lipid-lowering therapy 7,20–22 documented a slowing of the atherosclerotic process and a marked decrease in cardiac events and cardiac hospitalizations. The Stanford Coronary Risk Intervention Project (SCRIP) model is particularly relevant to outpatient cardiac rehabilitation as it provides an example of multi-risk intervention that can be emulated in the cardiac rehabilitation setting. 7,23 Physicians in clinical practice have not been particularly effective in assisting CHD patients to attain well-defined risk factor goals. For example, recent studies have documented that only 9% to 25% of CHD patients in practice settings have met the NCEP guidelines for lipid management 24–29 (Table 1). A significant percentage of patients are not taking preventive medications that have been shown to improve long-term outcomes. 8 In many settings it has been demonstrated that a systematic approach to the measurement and treatment of coronary risk factors is required to attain risk factor goals. The “art” of medicine is less effective than systematic screening and well-defined treatment algorithms.Table 1: UNDERTREATMENT OF HYPERLIPIDEMIA IN PATIENTS WITH CORONARY HEART DISEASECardiac rehabilitation programs and preventive cardiology clinics need to embrace the challenge of secondary prevention. It is our only viable future. We, furthermore, believe that exercise-only programs will find themselves excluded from reimbursement plans for the chronic care of CHD. Certainly, there is a role for exercise to improve functional capacity for the prevention and treatment of cardiac disability and for its preventive effects at the level of the coronary vasculature. 1,2,30–32 However, third-party payors eventually will limit on-site, monitored exercise to all but the highest risk and least functional patients. A system of care that systematically reduces risk in CHD patients by defining and treating hyperlipidemia, by offering successful weight-loss programs and nutritional counseling, by optimizing hypertensive and diabetic care, by recognizing and treating depression, and by optimizing preventive pharmacologic therapies, is the most likely system to be accepted as the standard of care. The concept of cardiac rehabilitation as the site for comprehensive risk-reduction has been recognized by the Cardiac Rehabilitation Clinical Practice Guidelines 16 under its byline “Cardiac Rehabilitation as Secondary Prevention.” The American Heart Association and the Cardiac Rehabilitation Certification program of the American Association of Cardiovascular and Pulmonary Rehabilitation also promote it. 5 The Core Components for Cardiac Rehabilitation/Secondary Prevention were recently published jointly in Circulation5 and in the Journal of Cardiopulmonary Rehabilitation6 and need to be widely embraced (Figure 1).Figure 1.: Risk factor goals (data from Balady et al 5,6). LDL, low-density lipoprotein; HDL, high-density lipoprotein; BP, blood pressure; BMI, body mass index; HBA 1C , glycosylated hemoglobin.How does an exercise-only cardiac rehabilitation program transform to become a comprehensive risk-reduction center? The key components of making a successful transition from an exercise-only program to a comprehensive secondary prevention program are: the adoption of the case-management system of patient management, and the gradual implementation of “risk factor modules.” CASE MANAGEMENT SYSTEM OF CARE Case management is the cornerstone of multiple risk reduction and provides a structural framework for the organization of cardiac rehabilitation programs. It involves the coordination of risk-reduction care for clusters of patients by a single individual, most commonly a nurse or exercise physiologist, with appropriate medical supervision. The inter-relatedness of coronary risk factors demands an integrated approach to management. While lifestyle skills will remain the foundation of risk factor interventions, providing both important metabolic and psychosocial benefits, there also is an important role for concomitant physician-directed pharmacologic therapy. It is in the application of behavioral modification principles and treatment algorithms that case management has been shown to be a safe and effective method of providing multiple risk reduction interventions. Case management for the treatment of CHD is based on: □ Screening to identify persons with disease □ Risk stratification and triage of those identified □ Assignment of individual to a case-manager □ Institution of intensive risk-reduction interventions based on clinical practice guidelines □ Medical surveillance of safety, efficacy, and adherence to risk reduction efforts □ Measurement of medical outcomes and patient satisfaction □ Systematic follow-up and institution of change in therapies as indicated Medical care in the United States in the 21st century is hampered by reimbursement issues, lack of continuity in medical insurance coverage, lack of continuity of healthcare providers, limited time with healthcare providers, and a focus on isolated “chief complaint” physician office visits. On the other hand, disease management is more effective than standard medical care because it is based on integrated approaches and services. Case management provides a model for coronary heart disease management by integrating patient, family, environment, lifestyle, and community. Several recent studies document the relative ineffectiveness of standard physician office visits on the management of CHD risk factors. 24–29 Sueta et al 24 evaluated the degree of treatment of hyperlipidemia in patients with CHD. The authors audited medical charts in 140 predominately cardiovascular practices in the United States. A total of 58,890 outpatient records were reviewed; 83% of patients were diagnosed with CHD. All patients reviewed had at least two office visits recorded in a 12-month period between July 1, 1994 and October 1, 1996. This study revealed a large screening gap with 56% of patients not having a recent LDL-cholesterol (LDL-C) documented, 61% of screened patients not receiving appropriate lipid-lowering therapy, and only 25% of patients at the National Cholesterol Education Program (NCEP II) goal of ≤ 100 mg/dL 30 (Figure 2). Patients with a documented LDL-C in their charts were four times more likely to receive lipid-lowering therapy.Figure 2.: Office-based lipid management in coronary artery disease. Aggregate data n = 48,586. Adapted from Sueta et al. 24The Lipid Treatment Assessment Project (L-TAP) similarly evaluated the percentages of dyslipidemic patients receiving lipid-lowering therapy and achieving LDL-C goals. In this study, Pearson et al 27 targeted the practice patterns of primary care physician where patients with dyslipidemia were regularly seen. Participating physicians completed a survey regarding their own demographic status, professional characteristics, and practice profiles. Awareness and adherence to NCEP II guidelines also were assessed. In L-TAP, the primary outcome measured was the success rate of appropriately screened and stratified patients reaching NCEP II LDL-C levels 9 (Table 1). These results demonstrate that in primary care, as in specialty practice, a large gap exists in the achievement of LDL-C goals as only 18% of CHD patients had reached an LDL-C of < 100 mg/dL. These studies are pivotal in that they demonstrate clearly the need for improved models for healthcare delivery. In contrast, the benefits of case management have been documented in several clinical settings. The Butterworth Health System in Grand Rapids, Michigan reorganized their cardiac rehabilitation program to focus on improvement of long-term patient outcomes using a case-management model. 33 The new model included the use of referral pathways, education sessions, and intervention by social workers as indicated. In addition, they added regular phone call follow-up to assess effectiveness of risk-reduction interventions. At 1 year, 77% of patients were on lipid-lowering medications, 78% reported exercising at least 3 days per week, and 66% of prior smokers reported smoking cessation. Although these results are based on self-report, the model of care deserves close attention. Two key studies, the MULTIFIT Study 34 and the SCRIP study 7 demonstrated the powerful impact of case management. MULTIFIT is a case-management program for men and women hospitalized with acute myocardial infarction in Northern California. This study randomized patients to special risk reduction intervention by nurse case managers versus usual care. The special intervention patients received education and counseling regarding smoking cessation, regular physical activity, and nutrition. Medical management, such as lipid-lowering therapy, was instituted as indicated for risk factors not controlled by lifestyle change. Much of the intervention was mediated via phone and mail contact. The special intervention group showed greater improvement at 6 months and 1 year in functional capacity, rates of smoking cessation and changes in LDL-C compared with the usual care group. This case management system subsequently was adopted by the Kaiser Permanente Health Care System. The SCRIP study was a randomized-controlled clinical trial funded by the National Institutes of Health to evaluate the efficacy of physician-directed, nurse coordinated multi-risk factor intervention, in men and women with CHD. 7 Outcome measures included quantitative coronary arteriography, risk factor measures, rehospitalization rates, and rates of recurrent coronary events. This study used nurse case-managers to supervise and coordinate care. The case managers worked with a team of nutritionists, psychologists, and physicians to provide clinical and lifestyle interventions, striving to attain nationally recognized goals for risk factor reduction. 8 The study was conducted over a 4-year period and demonstrated both clinical and angiographic benefits (Table 2). The intervention group demonstrated a reduction of hospitalizations and clinical coronary events. Angiographic benefits included both less progression and greater stabilization of plaque in the intervention group compared with the usual care group.Table 2: STANFORD CORONARY RISK INTERVENTION PROJECT (SCRIP) RESULTS 7Fonarow et al 35 recently published the results of the Cardiac Hospitalization Atherosclerosis Management Program (CHAMP). In this study, the investigators evaluated the efficacy of a case management approach to discharge planning for persons admitted to the UCLA Medical Center with a diagnosis of CAD or other vascular diseases (Figure 3). The study followed a case management approach emphasizing the appropriate use of aspirin, cholesterol lowering agents, beta-adrenergic blocking agents, and angiotensin-converting enzyme inhibitors (ACE-I). These interventions were applied in conjunction with outpatient exercise, nutrition, and smoking cessation counseling. At completion of the study, utilization of beta blockers, ACE-I, aspirin, and lipid-lowering agents were all significantly increased (Tables 3 and 4). There also was a significant increase in the percentage of patients achieving a LDL-C ≤ 100 mg/dL (58% versus 6%, P < 0.001) and a reduction in recurrent myocardial infarction and 1-year mortality.Table 3: CHAMP MEDICATION UTILIZATION RATES AT DISCHARGETable 4: CHAMP MEDICATION UTILIZATION RATES AND LDL LEVELS AT 1 YEAR POST-HOSPITAL DISCHARGEFigure 3.: Cardiac Hospitalization Atherosclerosis Management Program algorithm for patients with evident atherosclerosis. Reprinted from Fonarow et al. 35 © 2001, with permission from Excerpta Medical Inc.In summary, these data support the efficacy of the case-management model of healthcare regarding long-term adherence to risk-reduction efforts both in the acute and chronic care setting. Case management must be instituted in existing cardiac rehabilitation programs, where, for example, selected qualified staff are each assigned specific patients to serve as their case manager. Assignments can be made to individual case managers on an alternating basis as consecutive patients are admitted to the program, or on the basis of staff specialization, disease severity or patient complexity. Risk Factor Modules From the point of view of implementing multi-risk reduction in the cardiac rehabilitation setting, modules of care need to be organized for each individual risk factor. The case-manager can then refer individual patients to selected modules based upon their baseline screening values. Beyond screening for a risk factor, setting up a module requires an integrated system of care that includes staffing, an education component, counseling of lifestyle interventions including nutrition and exercise, with long-term follow-up of the risk factor measure. For selected risk factors such as hyperlipidemia or hypertension, initiation, modification, and monitoring of pharmacologic therapy by the medical director in concert with the referring physician is also a consideration. Hyperlipidemia Module Exercise alone has relatively modest effects on improving the lipid profile in CHD patients. 36,37 The most prominent effect is an improvement of HDL-cholesterol on the order of 8% to 10%, or roughly an increase of 3 to 4 mg/dL over as short as a 3-month training period. While this seems subtle in absolute terms, an improvement of this magnitude using the pharmacologic agent gemfibrozil in CHD patients with an isolated low HDL-cholesterol was recently associated with a 22% decrease in major coronary events over a 5-year period. 38 Cardiac rehabilitation exercise also is associated with a 20% decrease in fasting triglyceride levels for patients whose baseline values are above 200 mg/dL. 35 On the other hand, in the absence of significant weight loss, LDL-C effects of exercise are minimal. Nutritional counseling and dietary change can result in LDL-C reductions that usually do not exceed 10%. Accordingly, most patients with CHD and LDL-C elevations will need to be treated with pharmacologic lipid-lowering agents to reach lipid goals, while lifestyle measures are implemented. The cardiac rehabilitation baseline screening evaluation should include a full fasting lipid profile taken either before coronary revascularization or at least 1 month after an acute coronary event. The rehabilitation program should then participate actively in attaining lipid goals. This includes both nutritional counseling (by nutritionists or trained nurses) weight loss when indicated, and pharmacologic therapy. If well-recognized lipid-lowering algorithms recommend lipid-lowering therapy, 9 the medical director of the program, in communication with the primary physician, should institute lipid-lowering therapy. Using such a model in a quality improvement project at the University of Vermont, the application of appropriate lipid-lowering therapy was tripled (compared with a control group), with the intervention group attaining significantly lower lipid values. 39 At cardiac rehabilitation completion, a repeat lipid profile should be obtained and re-assessment of therapy and long-term goal attainment can be performed. Obesity Module Obesity is highly prevalent in cardiac rehabilitation populations with rates of overweight (body mass index > 25 kg/m 2 ) ranging from 70% to 88%. 40,41 Obesity (body mass index > 30) is present in 35% to 53% of patients. In CHD patients, obesity is associated with very high prevalences of lipid abnormalities, hypertension, insulin resistance, type II diabetes, and clotting abnormalities. 40 Conversely, weight loss in CHD patients acts as a multi-risk intervention. 42 Lipid abnormalities improve along with improvements in blood pressure and glucose control. 42,43 In the cardiac rehabilitation setting, substantial weight loss does not occur with exercise alone. 37 A targeted weight loss intervention is required. A behaviorally based weight reduction program has been described and incorporated into the cardiac rehabilitation setting. 44–46 It is delivered in 12 to 16 weekly group sessions and incorporates the behavioral concepts of daily caloric goals (500 kcal deficit per day yields a 1 lb weight loss per week), dietary records, stimulus control, problem solving, social support, and relapse prevention training. 44,45 It is coordinated by a nutritionist or a cardiac rehabilitation nurse. At the University of Vermont such a program, coordinated by a nurse clinician, has resulted in an average weight loss of 9 to 10 lbs over an 11-week period with a significant decrease in serum cholesterol levels. 46 Cardiac rehabilitation programs should provide, in one form or another, an effective weight loss program for obese patients as part of the cardiac rehabilitation/preventive cardiology experience. Alternatively, patients may be referred to affiliated weight management programs or dieticians. Simply recommending weight loss does not result in any sustained benefit. While physicians play an important role in motivating patients to lose weight they generally do not possess the skills, nor have the time, to accomplish weight loss on a systematic basis. Hypertension Module Hypertension is highly prevalent among individuals with coronary artery disease, noted in 30% to 38% of patients with myocardial infarction enrolled in large clinical trials. 47 Hypertension has been reported to be present in 47% to 65% of consecutive patients enrolled in cardiac rehabilitation programs. 48 The etiology of hypertension in 90% to 95% of cases is not known. However, the cardiac rehabilitation staff can effectively work with the patient’s primary care physician to evaluate and manage this important modifiable risk factor. Pertinent medical history includes a focus on dietary sodium intake, alcohol consumption, caloric intake and expenditure, and correction of physical inactivity. Anti-hypertensive medication type, dosage, and timing also should be reviewed and recorded. A high percentage of CHD patients already will be taking beta-adrenergic blocking agents or ACE-I medications, due to their well-known preventive benefits. 8 Thus, hypertension is at least partly treated in most CHD patients referred to cardiac rehabilitation. The initial physical examination for patients with hypertension should include the following: □ Two or more blood pressure measurements separated by 2 minutes with the patient either supine or seated, and after standing for at least 2 minutes □ Verification in the contralateral arm (if values are different, the higher value should be used) Cardiac rehabilitation program staff can greatly assist the primary care physician in the treatment and surveillance of patients with hypertension. 49 Lifestyle modifications are the foundation for treatment of hypertension and complement pharmacologic therapy when prescribed. 50,51 Cohort studies have demonstrated that regular physical activity prevents the development of hypertension. 52 In mildly hypertensive men short-term physical activity decreases blood pressure for 8 to 12 hours after exercise, and average blood pressure is lower on exercise than on non-exercise days. 53 In hypertensive black men, moderate physical activity performed for 16 to 32 weeks yielded a decrease in diastolic blood pressure, which is sustained even after reduction in antihypertensive medications. In addition, there is a significant decrease in left ventricular hypertrophy as early as 16 weeks after the initiation of exercise. 54 The treatment goals for hypertension are detailed by JNC VI 50 and outlined in Table 2. 5,6 Poor adherence to long-term treatment, both lifestyle modifications and pharmacologic therapy, has been identified as the major reason for inadequate control of high blood pressure. Cardiac rehabilitation provides patient education and support aimed at improving patient understanding of specific therapies and treatment goals, adjusting the therapeutic interventions to patients’ lifestyle, and enhancing family or other social support. They may improve long-term adherence to treatment schedules, and blood pressure control. Diabetes Module Physical activity has beneficial effects on both glucose metabolism and insulin sensitivity. These include increased sensitivity to insulin, decreased production of glucose by the liver, larger number of muscle cells which use more glucose than adipose tissue, and reduced obesity. 55 Patients with diabetes in cardiac rehabilitation programs require special attention, particularly if they are taking exogenous insulin or oral hypoglycemic medication. The patient history should include details regarding type, dose, and timing of diabetes medications. This is important particularly when insulin is part of the treatment regimen. The occurrence and description of previous episodes of hypoglycemia are important to note. Patients should be counseled regarding the effect of exercise on blood glucose levels and the possibility of hypoglycemia, which may occur up to several hours after the exercise session. Therefore, recognition and treatment of hypoglycemic episodes should be reviewed with diabetic patients. Because diabetic patients are prone to leg and foot wounds that may interfere with or be aggravated by exercise, the initial medical evaluation should include an examination of the lower extremities. Patients should be advised to wear thick protective white-cotton socks and well-fitting supportive footwear during exercise. Blood glucose levels should be checked periodically before and after exercise to provide an assessment of that individual’s response to exercise. Blood glucose levels of < 80 and > 300 mg/dL should preclude exercise at that time. The results of blood glucose monitoring may indicate the need for a modification of the insulin and/or oral hypoglycemic regimen. 55 Smoking Cessation Module Cigarette smoking cessation is associated with a marked decrease in coronary event rates in coronary patients. 56,57 The best results with smoking cessation after a coronary event have been obtained with a physician-recommended, nurse-managed intervention that takes place in hospital, during the acute hospitalization. 34,58 The intervention is aimed at relapse prevention and includes teaching of behavioral skills. These include stimulus control, dealing with high-risk situations, relaxation training, provision of nicotine replacement supplements when necessary, and long-term telephone contact. At 1 year, in one study, cessation rates were significantly increased from 32% in controls, to 61% with the intervention. 58 In the outpatient cardiac rehabilitation setting, the identification of smokers and family members who smoke is the first step of the treatment program. Smoking experts generally recommend a stepped care approach to smoking cessation. 59,60 These steps include: □ Providing a firm, unequivocal message regarding the importance of quitting □ Determining if the patient is willing to quit, and if not, providing some guidance toward making this decision □ Determining the best quitting method such as a group program or individual counseling □ Planning for problems associated with withdrawal, such as increased eating or increased stress, by instituting behavioral strategies □ Utilizing pharmacological therapies as indicated 60 □ Setting a quit date to formalize the commitment □ Providing additional support as needed, such as encouraging regular exercise, modifying intake of alcohol, and providing a means to enhance social support □ Providing follow-up to support relapse prevention and to acknowledge successes The ability of cardiac rehabilitation programs to reach families and social environments allows for a broader and more effective means of achieving successful smoking cessation than in an office setting. Mental Depression Module Assessment of psychosocial function is necessary to achieve successful rehabilitation of the cardiac patient. Evaluation of emotional status should raise the following questions: □ Is there evidence of posttraumatic stress disorder? □ What is the patient’s perception of his or her health status and family attitudes toward their illness? □ Is the patient mourning the loss of a previous, albeit perceived healthy heart or is the patient clinically depressed? Of note, moderate to severe depression occurs in 16% to 22% of post-myocardial infarction patients. 61,62 Such levels of depression are associated with increased medical morbidity and mortality. 63 Moreover, depressed patients after myocardial infarction are more likely to experience social problems, report more stress, and are less likely to return to work than those who are not depressed. 64 The physiological mechanisms that link depression to adverse medical outcomes are not yet clear, but may be related in part to increased sympathetic and decreased vagal tone. The latter have been shown to increase the risk for myocardial infarction, arrhythmias and sudden cardiac death. 61,64 It should be noted that participation in cardiac rehabilitation with a stress management series of seminars is associated with an overall decrease in depression score and improved clinical outcomes, particularly for patients with high baseline depression scores. 3,65 Thus, the importance of diagnosing and treating depression in cardiac patients is now being recognized as an essential part of comprehensive cardiac rehabilitation and secondary prevention. Recognizing depression may be difficult in that depressive symptoms, such as fatigue, also are common manifestations of cardiac disease. In addition, many patients may be reluctant to report depressive symptoms and conversely, many healthcare providers may be hesitant to ask about such symptoms. Thus, routine screening mechanisms should be implemented as part of the initial evaluation for patients entering cardiac rehabilitation/secondary prevention programs. These should include an initial patient interview in which signs and symptoms, as well as a history of depression should be sought. A variety of brief questionnaires and interview forms are also available to assist in this screening process. These include the Beck Depression Inventory 66 which is a 21-item self-report questionnaire on which a score of ≥ 10 is suggestive at least mild to moderate depression and the Geriatric Depression Questionnaire, a 15-item instrument, where a score of ≥ 5 suggests depression. 67 If significant depression is uncovered, then a treatment strategy must be established. This should be done in concert with the patient’s primary healthcare provider. Referral liaisons with psychiatrists, psychologists, or other behavioral specialists should be considered to assist with evaluation and management of these patients, particularly if symptoms do not improve after participation in group exercise and stress management. Challenges and Future Directions Exercise will always have a place in cardiac rehabilitation, but the challenge before us is to put in place effective programs for risk factor management. Individual programs will need to carefully and thoughtfully develop risk factor modules and practice ongoing quality improvement with collection of outcomes data. Patients, referring physicians, and third-party payors are expecting improved clinical outcomes over a relatively short-term period of 2 to 4 years. These goals can only be attained if each and every program focuses on attaining risk factor goals with a comprehensive and participatory approach to CHD management. Acknowledgment The authors thank Philip Greenland, MD, for his helpful comments.