Designing Cardiac Rehab Programs

Regular physical activity has been the cornerstone of cardiac rehabilitation programs since their inception. Maintaining a program of structured physical activity appears to favorably affect other components of a successful rehabilitation program, especially in conjunction with a holistic approach to disease management. This approach includes patient assessment, nutritional intervention, psychological counseling, smoking cessation, and management of body weight, blood lipids, blood glucose and blood pressure.

Evidence for the role of exercise in helping manage what are known to be major and emerging risk factors related to coronary artery disease (CAD) comes from numerous studies conducted over the past several years. The recent scientific statement presented be the American Heart Association (AHA) outlines the results from physical activity and exercise studies in relation to cardiac risk factors, as well as the role of exercise in both the prevention and treatment of atherosclerotic cardiovascular disease outcomes.

For most patients, exercise acts to 1) improve dietary compliance, in addition to assisting with weight management; 2) improve psychological state and suppress symptoms of depression following a major coronary event; 3) assist in facilitating long-term smoking cessation by increasing the initial quit rate; 4) decrease total and LDL (bad) cholesterol and raise HDL (good) cholesterol by roughly 4 to 5 percent; 5) assist with blood glucose management by enhancing glucose uptake into muscles; and 6) lower blood pressure by roughly 4 to 8 mmHg (greater response for patients who are hypertensive).

All of these responses and adaptations associated with exercise appear to reduce mortality and the risk of developing future medical complications. Thus, exercise should be strongly recommended to all individuals with known CAD, in addition to those who do not yet have the disease (as a preventive strategy).

While the data presented in the AHA scientific statement, as well as in other studies, largely refer to aerobic exercise, more recent studies have also focused on the role of resistance exercise in a cardiac rehabilitation setting, with promising results. Unfortunately, the overwhelming amount of evidence in favor of aerobic exercise appears to overshadow that of resistance exercise. And, while many programs do incorporate resistance exercise into the overall exercise prescription, the focus of cardiac rehabilitation remains centered around aerobic exercise. However, resistance exercise may have the same effects on CAD patients as on healthy individuals in that it improves muscular strength, endurance and power, as well as favorably affects body composition, blood lipids, blood glucose and psychological state.

Facility readiness to enroll cardiac patients

The immediate outpatient rehabilitation following a major coronary event- such as myocardial infarction (MI); percutaneous trans-luminal coronary intervention; coronary artery bypass surgery (CABG); and sometimes angina, valve disorders, heart transplants, etc.- typically occurs in a medically supervised program lasting 12 weeks (as this is the typical time period for insurance coverage). Following such a period, however, patients are released to begin their “maintenance” program, which should theoretically last for the remainder of their lives. Because these programs are typically not covered by insurance, participants often exercise on their own, away from a medically trained staff, either at home or as a member of a fitness center or corporate wellness program.

Staffing. While personnel who have degrees in exercise-related fields often staff such programs, these professionals may lack specific advanced training and/or certifications that may be commonplace in a medically supervised program. (For a detailed overview of core competencies for healthcare providers working with cardiac patients, refer to the position statement of the American Association of Cardiovascular and Pulmonary Rehabilitation.) It is unlikely that all staff members will posses such advanced training, although it may be appropriate for at least the program director or facility operator to posses such skills, education and clinical experience to serve as a resource for other staff members.

      Medical emergencies. Aside from staffing, some facilities may lack the appropriate equipment and/or procedures needed to adequately handle a medical emergency. Therefore, specific precautions are worth mentioning if a facility knows that higher-risk individuals will be exercising there. Specific guidelines have been presented in a joint position paper by the American College of Sports Medicine (ACSM) and AHA regarding cardiovascular screening, staffing and emergency procedures. Additionally, ACSM and AHA have more recently published a joint position paper in reference to the use of automated external defibrillators (AEDs) in health and fitness facilities. Operators of such facilities are strongly encouraged to read these papers to determine their ability to adequately handle a medical emergency. Upon review of current procedures, changes should be made in an attempt to comply with those recommendations made by both the ACSM and AHA.

      Patient’s health history. To minimize medical complications, a detailed history should be obtained from all patients with known CAD prior to starting an exercise program. This includes obtaining all records from patients’ past cardiac rehabilitation training (if this is the case), including exercise logs, exercise tests, physician reports and clearance, and current and past medication lists. Also, have a detailed interview with each patient concerning symptoms, how the exercise program operates, and what procedures are in place in case of a medical emergency. Learn as mush as possible about patients prior to enrolling them into the program. And educate the patients about what the facility would expect of them during their time exercising (i.e., notify staff of medication changes and changes in symptoms, carrying nitroglycerine when exercising in case of an angina attack, etc.).

      Determine whether patients can progress from a medically monitored cardiac rehab program providing minimal or no formal supervision as described by ACSM. If appropriate, patients should provide consent to participate at the facility, often with the approval of their supervising physician.

Exercise prescription

      With the appropriate patient screening, comfort of the staff and the facility medical emergency plan, a suitable exercise prescription can be written. Often, this may simply be an extension of the exercise prescriptions that were provided to patients upon release from their initial 12 weeks of cardiac rehab, though modified slightly for progression. Discuss exercise physiologist or supervising nurse during the patients’ initial rehab, as this will likely provide more information than simply looking at an exercise log.

      As suggested by both the Centers for Disease Control and Prevention (CDC) and ACSM, health professionals should prescribe exercise programs for 30 minutes or more of moderate-intensity aerobic activity on most, preferably all, days of the week. Of course, more specific prescriptions should be made, which consider the following variables: mode, frequency, duration, intensity and progression. This is true for both aerobic and resistance exercise, as both forms of physical work have their place in cardiac rehabilitation. All of these variables should be considered and explained to the patient when designing the exercise program. For a more detailed overview, refer to the ACSM position stand on exercise for patients with CAD.

Aerobic exercise

      For most patients, beginning a low-volume and low-intensity aerobic exercise program begins immediately (within days) following MI or surgical intervention.

      Mode. The exercise mode in most cardiac rehab settings has traditionally been walking or jogging, as aerobic exercise is best performed using large muscle groups in a mode that is familiar and comfortable for participants. However, due to orthopedic problems that may make walking difficult, or simply for the sake of increasing interest in exercising, several modes may be considered. These include cycling (upright and recumbent), elliptical cross training or stair stepping. To avoid boredom and to improve program effectiveness, it may be best to vary the exercise mode regularly.

      Frequency. The frequency of exercise is best recommended at a minimum of three days per week, and up to six or seven days per week, if possible. Regarding cardio respiratory fitness, additional benefits from more than three to five days per week appear to be minimal. However, more frequent exercise sessions act to increase energy expenditure and to more favorably affect blood glucose regulation, which is particularly important for patients with diabetes or impaired glucose tolerance. With the greater frequency of exercise, alteration in mode becomes more of a concern, and variation between weight-bearing and non-weight-bearing exercise may be considered.

      Duration. Exercise duration should be from 30 to 60 minutes. This may be performed in a continuous manner, or in two to three sessions throughout the day (e.g. 15 minutes before work, 15 minutes before lunch, 15 minutes after dinner). Intermittent sessions appear to work well for individuals who have low functional capacity, and for those with peripheral vascular disease and intermittent claudicating. It simply boils down to what is easiest for the patient to maintain.

      Intensity. Exercise intensity can be measured in several ways. However, in cardiac rehab, it is traditional to use exercise heart rate (HR) as well as rating of perceived exertion (RPE). Because most cardiac rehab patients use medications that alter both their resting and exercise HR (e.g., beta blockers), the typical formulas for calculating HR ranges often do not apply. The best bet would be to obtain the calculated HR prescription from their previous cardiac rehab program. If this is not possible, review their latest exercise test results to determine their maximal and sub-maximal HR responses (make certain that their medications have not changed). The maximal HR determined from the exercise test should allow for determination of a target HR zone, as would normally be done using the HR reserve formula ([max HR-resting HR] x 40-85% + resting HR) or 55 to 90 percent of maximal HR.

      The additional method is to have patients monitor their RPE, which should be maintained between 12 to 15 (somewhat hard to hard). Because RPE does not correspond exactly to HR response, and may differ depending on an individual basis, in particular for individuals who have difficulty monitoring HR.

      Individual programs. While it appears cardio respiratory fitness can be maintained with as little as 30 minutes of moderate-intensity exercise performed three days per week, as with all exercise participants, cardiac patients require more challenging workloads if they are to improve. However, a conservative approach of slow and steady is certainly preferred, and the rate depends greatly on the individual. The ranges provided above for exercise frequency, duration and intensity are wide, and allow for much variation in program design, starting at the lower end for all variables and progressing gradually.

      Follow-up exercise tests should be performed at regular intervals (e.g., every few months during the initial stages of the program) to determine degree of progression, and to allow for a new exercise prescription to be written. In most circumstances, a symptom-limited maximal exercise test under the supervision of a physician would be best. However, sub-maximal tests may also prove useful. Regardless, routine follow-up of patient progress is important to appropriately adjust the exercise workload. The degree and rate of progression is highly individual, and needs to be considered on a per-patient basis.

Resistance exercise

      While more studies are being done each year regarding resistance training programs for patients with CAD, the general exercise prescription endorsed by ACSM for patients in a primary prevention program applies to cardiac patients as well. This consists of the performance of one to two sets of eight to twelve reps for each of eight to 10 separate exercises involving either free weights or machines for all major muscle groups. These are suggested to be performed two to three days per week.

      Most patients (with the exception of those with unstable angina, uncontrolled arrhythmias, uncontrolled hypertension, symptomatic congestive heart failure and severe valve disorders) can receive clearance from the facility staff, in consultation with the patient’s physician. A typical waiting period of four to six weeks following MI, and eight to 12 weeks following surgery is often recommended prior to starting a resistance-training program.

      Patients with a history of CABG surgery need to take special precautions regarding the healing of their sternum incision, and may consider specific exercises aimed at improving their range of motion. Stretching exercises, in particular, can prove helpful, and should be followed as generally prescribed to all fitness clientele (e.g., static stretching while maintaining normal breathing, holding each stretch for 10 to 30 seconds, for three to four reps, performed several days per week).

      As with aerobic exercise, the frequency, volume, intensity and progression of resistance-training sessions should be adjusted on individual basis, as should the baseline exercise prescription. Furthermore, following an initial conditioning period of several weeks, it may be beneficial to adopt a conventional approach involving a split routine in which the entire body would be trained over two to three day period and then the cycle repeated (as opposed to training every body part at every session). This may allow for more recovery, especially if the training volume per muscle group is increased to optimize the training effect. Beyond this, special attention should be given regarding the use of proper form during exercise, in particular the avoidance of a Valsalva maneuver (breath holding) during lifting.

Prescription to exercise

      Based on the available evidence, it appears clear that patients with known CAD can greatly benefit from programs of structured exercise, including both aerobic and resistance training. Furthermore, with the appropriate precautions and instruction, exercise within this patient population is safe, and should be endorsed by healthcare professionals to all those who qualify.   

Written by Richard j. Bloomer