This article was written in collaboration with Dr. Chip Lavie.
In the US, it is estimated that approximately 800,000 new and 200,000 recurrent myocardial infarctions occur each year. The prevalence of coronary artery disease and heart failure is increasing. Each year, over 950,000 patients undergo percutaneous coronary angioplasty, 400,000 patients undergo coronary bypass surgery, and 500,000 patients are discharged with a new diagnosis of heart failure.
What is Cardiac Rehabilitation and Secondary Prevention?
Cardiac rehabilitation and secondary prevention services are comprehensive, long-term programs involving medical evaluation, prescribed exercise, cardiac risk factor modification, education, and counseling. These programs are designed to reduce the physiological and psychological effects of cardiac illness, reduce the risk of cardiac death and re-infarction, improve cardiac symptoms, and stabilize and sometimes reverse the process of atherosclerosis while enhancing the well-being of the patients. While exercise training is at the core of cardiac rehabilitation, other important components include optimization of cardiovascular risk factors, fostering a cardiac healthy and active lifestyle, reducing disability, and increasing the ability to return to work more quickly.
Who Benefits from Cardiac Rehabilitation and Secondary Prevention?
Patients who undergo a revascularization procedure such as percutaneous coronary angioplasty (PCI) or coronary artery bypass (CABG).
Patients with exertional stable angina on medical therapy.
Patients with a heart valve replacement either for aortic or mitral valve disease.
Patients with a new diagnosis of chronic heart failure with a step-change in clinical presentation.
Patients who have undergone a procedure for implantation of a cardiac defibrillator (ICD) or cardiac resynchronization (BiV with or without ICD) for chronic heart failure.
Patients with a heart transplant and LVAD.
Patients with peripheral vascular disease (PVD) reduce limb symptoms, improve exercise capacity and lessen disability and decrease cardiovascular events.
What is the Exercise Prescription for a Cardiac Rehabilitation/Secondary Prevention Program?
Rehabilitation programs vary in intensity and duration. Formal rehabilitation is predominantly provided to supervised groups in outpatient hospital clinics, starting 1-4 weeks after PCI or myocardial infarction and 4-6 weeks after surgery (CABG or valve surgery).
The exercise prescription follows the ACSM/AHA/AACVPR guidelines tailoring the exercise programs to enhance all levels of physical abilities in a safe environment. These involve four main types of activities: aerobic exercise, muscle strengthening, bone strengthening, stretching, and flexibility. Before starting an exercise program, patients with coronary disease should be clinically stable. Patients should be advised to aim for >20 min/day of mostly vigorous activity, although less exercise still has some effects. The training schedule is adapted according to disease severity, frailty, and baseline exercise capacity. Patients can be started in moderate-intensity continuous training, which can be progressed in duration than in intensity.
During cardiac rehabilitation, a documented and individualized exercise prescription for aerobic and resistance training is based on initial evaluation, risk stratification, patient goals, and resources.
Aerobic exercise can vary from 2-5 days per week, at 50-80% of capacity, from 30 to 60 min, using walking on a treadmill, cycling, rowing, climbing stairs, arm ergometry, or others.
Resistance exercise can vary from 2-3 days per week, 8-15 repetitions per muscle group with 1-3 sets of 6-10 different upper and lower body exercises (20-30 min) using elastic bands, free weights, wall pulleys, or weight machines. Warm-up, cool-down, and flexibility exercises are included in every session. The exercise prescription is updated continuously according to the patient’s condition. The formal exercise regimen is supplemented with at-home activities that include at least 30 minutes of moderate activity for more than 5 days per week.
What are the Other Components of the Cardiac Rehabilitation/Secondary Prevention Program?
Nutritional counseling is important to assess eating habits and prescribe specific dietary modifications aimed at reducing saturated fats and cholesterol. Medical professionals will also educate and counsel patients and family members regarding dietary goals and how to attain them.
Lipid management is integrated into these discussions to achieve LDL cholesterol levels of less than 70. The importance of statin therapy and adherence to treatment as well as a healthy lifestyle is emphasized.
Hypertension management is an important core measure, and blood pressure is assessed with each visit. Lifestyle modification includes exercise, weight management, salt restriction and substitution, and a diet rich in potassium. Drug therapy in patients with heart failure and diabetes is monitored in combination with primary care physicians or cardiologists.
Smoking cessation is another core measure, and readiness to quit is supported by individual education and supplemented by self-learning materials. To help the smoker, a quit date is set and appropriate treatment strategies are implemented. Some may include a formal smoking cessation program for group or individual counseling, while others may involve pharmacological support as needed in concert with the primary care physician.
Weight management is provided by measuring and following the weight and waist circumference. A combined diet, exercise, and behavioral program are designed to reduce caloric intake, maintain appropriate intake of nutrients and fibers, and increase energy expenditure.
Psychosocial management includes counseling and adjustment to heart disease, stress management, and health-related lifestyle changes.
As part of physical activity counseling, goals are set to increase physical activity to 30 minutes per day for greater than 5 days per week, starting with low-impact aerobic exercise and progressively increasing in intensity.
How Does Cardiac Rehabilitation/Secondary Prevention Help?
A meta-analysis of 47 randomized clinical trials that included over 10,000 patients showed that cardiac rehabilitation reduced the overall mortality by 13% and cardiovascular mortality by 26%. The exercise-based Cardiac Rehabilitation reduces mortality in patients with coronary artery disease by 36% to 63%. The STABILITY study demonstrated that more exercise was related to lower mortality. Two hours of brisk walking per week reduce the cardiovascular event rate by 50%. Interestingly, those at high risk (older, smokers, hypercholesterolemia, diabetes, and PVD (peripheral vascular disease) or elevated troponin or NT-proBNP benefited the most. Regarding exercise intensity, vigorous exercise limited by dyspnea was most effective. An exercise time of 20 min/day over a year was associated with more event-free survival, reduced hospitalizations, and fewer repeat coronary interventions.
In a review of studies that included over 4,000 patients with heart failure, cardiac rehabilitation reduced the risk of hospitalization for heart failure by 39%.
Patients who attend 36 sessions of cardiac rehab have a 47% lower risk of death than those who attend only 1 session!
An observational study of 635 patients with coronary heart disease reported improvement in anxiety and depression after cardiac rehab. Studies also have reported improvements in systolic blood pressure, body mass index, serum triglycerides, total cholesterol, and blood glucose.
Cardiac rehabilitation can relieve the symptoms of chest pain and shortness of breath, improve heart function and build healthy habits.
What are the Barriers to Cardiac Rehabilitation?
Even with all the benefits of cardiac rehabilitation, most eligible patients still do not receive the treatment. From the “Get with the Guidelines” registry, 85% of patients recovering from an acute myocardial infarction get referred to cardiac rehab, 60% of patients who undergo PCI get a referral, and only 10% of patients with heart failure get referred. Furthermore, only about 50% of patients referred to cardiac rehab actually enroll in the program. In addition, the completion rate is sub-optimal. If participation was improved to 70%, it is estimated that approximately 25,000 deaths and 180,000 hospitalizations could be prevented each year.
The greatest predictor of participation is the strength of the physician’s recommendation, particularly if we can reduce the interval between hospital discharge and cardiac rehab program orientation.
There are many socioeconomic barriers to enrolling in cardiac rehabilitation: health plan coverage, copay, patient’s commitment to follow through, and travel. It is important for us to create a culture where cardiac rehabilitation is viewed by the provider and health care system with the same importance as any other interventions proven to be beneficial and save lives. The cardiologist and cardiac surgeon should make the referral at the time of discharge.
It is important to create easy and workable solutions to address financial barriers to cardiac rehab enrollment for patients.
Work and family commitments, location/travel distance, and operational hours complicate cardiac rehabilitation enrollment. In tertiary programs, partnering with community hospital-based programs closer to home for patients can help with enrollment.
When available, virtual CR programs or home-based CR that deliver the same comprehensive components as in-center programs have been demonstrated to be as effective for low-risk populations.
This article was written in collaboration with Dr. Chip Lavie.