Although death rates from cardiovascular disease (CVD) have declined in recent years, CVD continues to be the leading cause of death for women in the United States. In the years between 1997 and 2007, the overall death rate from CVD declined 26.3%; however, the rate of death has been increasing by an average of 1.3% annually between 1997 and 2002, which is statistically significant.¹

Cardiac rehabilitation (CR) involves exercise training, education, counseling regarding risk reduction and lifestyle modification, and, frequently, behavior interventions in patients with cardiac events or chronic cardiac disease. For many women who experience a cardiac event, a structured CR is their first opportunity to become physically active. CR is an important component of multidisciplinary approach for management of the patients with various presentations of coronary heart disease. CR improves functional capacity, recovery, and psychological well-being. It is a class I recommendation endorsed by American Heart Association and American College of Cardiology in treatment of patients with CVD. Moreover, it is a cost-effective intervention following an acute coronary event and chronic heart failure (CHF)^2,3,4 as it improves prognosis by reducing recurrent hospitalization and health-care expenditures, while prolonging life.

In addition to a structured exercise program, components of a CR program often include medical history and physical examination; nutrition counseling; weight, blood pressure, and lipid management; diabetes education; psychosocial evaluation and treatment; and tobacco cessation programs.⁵ The benefits of participation in CR program include improved exercise capacity, improvement in lipid profile, reduction of obesity, prevention or reduction of Type 2 diabetes mellitus, improvement in depression and anxiety, and improvement in overall quality of life.⁶

Despite the role of cardiac rehabilitation having been extensively documented, endorsed, and promoted by a number of health-care organizations for the comprehensive secondary prevention of cardiovascular events, it continues to remain vastly underutilized; much more so in women. They are less likely to be referred for rehabilitation program, and even when referred, are less likely to attend.⁷ The Evidence-Based Guidelines for Cardiovascular Disease Prevention in Women strongly endorse cardiac rehabilitation after a coronary event.⁸ Barriers to participation for women include the lack of financial resources, transportation difficulties, and lack of social and emotional support.

HISTORICAL PERSPECTIVE

Following the clinical description of myocardial infarction by Herrick in 1912, prolonged bed rest up to 2 months was advocated for fear of infarct expansion, aneurysm formation, congestive heart failure, cardiac rupture, and sudden death. Strenuous activities were restricted for prolonged periods, and sometimes indefinitely. Resumption of normal life style was rare.⁹

By late 1940s, Levine and Lown advocated the use of chair therapy as an alternative to prolonged bed rest.¹⁰ It was erroneously believed that the dependent lower extremities resulted in reduced venous return, thereby decreasing the stroke work and cardiac output.¹¹ Early ambulation was defined as 3 to 5 minutes of walking, twice daily, 4 weeks after infarction by Newman et al.¹² This was then tried at 14 days after an acute event.¹³ In 1961, Cain et al recommended the efficacy and safety of early graded activity.¹⁴

Clinicians began to realize that early ambulation following an acute event helped decrease the incidence of pulmonary embolism and deconditioning. Early ambulation was increasingly advocated at earlier intervals, and finally evolved into what we currently define as phase I cardiac rehabilitation. Wenger et al refined the technique and promoted its wide clinical use.¹⁵

INDICATIONS AND CONTRAINDICATIONS

Medicare-Approved Indications

• 
  

  Recent myocardial infarction

  
  
• 
  

  Stable angina

  
  
• 
  

  Coronary angioplasty

  
  
• 
  

  Coronary bypass surgery

  
  
• 
  

  Heart valve surgery

  
  
• 
  

  Heart transplantation or heart/lung transplantation

There are many studies demonstrating the benefit of cardiac rehabilitation in patients with advanced heart failure, and asymptomatic patients at high risk for coronary heart disease, though they are not Medicare-approved indications yet.

Contraindications for Cardiac Rehabilitation

• 
  

  Severe residual angina

  
  
• 
  

  Decompensated heart failure

  
  
• 
  

  Uncontrolled arrhythmias

  
  
• 
  

  Severe ischemia, LV dysfunction, or arrhythmia during exercise testing

  
  
• 
  

  Poorly controlled hypertension

  
  
• 
  

  Hypertensive or any hypotensive systolic blood pressure response to exercise

  
  
• 
  

  Unstable concomitant medical problems (eg, poorly controlled or “brittle” diabetes, diabetes prone to hypoglycemia, ongoing febrile illness, active transplant rejection)

  
  
• 
  

  Active pericarditis

  
  
• 
  

  Severe orthopedic problems

REFERRAL TO CARDIAC REHABILITATION

Risk stratification is typically performed following a cardiac event utilizing a stress test prior to referring a patient to a cardiac rehabilitation program. Either a submaximal stress test or a symptom-limited stress test is utilized. The exercise prescription and surveillance are based on results of exercise testing. These are individualized.

Phases of CR

• 
  

  Phase I (in-hospital phase): The purpose is to provide education and to prevent deconditioning. It prepares patients to return to normal daily activities. In CCU, assisted range of motion should be performed within the first 24 to 48 hours. Low-risk patients are made to sit on a chair and perform self-care activities. On being transferred to the step-down unit, patients should be encouraged to ambulate as tolerated. Walking is resumed with target heart rate of <20 beats above the resting heart rate. This can be started with 5 to 10 minutes of walking each day, with exercise time being gradually increased to 30 minutes daily.

  
  
• 
  

  Phase II (supervised exercise): The purpose of this phase to progressively improve functional capacity, lower risk factors, and prepare patients for return to work. It includes exercises which are performed following dismissal from hospital. It typically lasts 1 week to 3 months following an event. During phase II CR, the BP, heart rate, telemetry, dyspnea scale, Borg scale, and angina scale are all monitored (Figure 7-1).

  
  
• 
  

  Phase III (late outpatient maintenance phase): The purpose of this phase is continued patient education, risk factor modification, and improved functional status. This phase is unsupervised and should ideally last lifetime (Figure 7-2).

Cardiac rehabilitation/secondary prevention (SP) programs are expected to deliver patient-centered care services provided by a multidisciplinary team of health-care providers. Communication between these disciplines is critical.

The American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) has defined core components to assure the provision of high-quality care within evidence-based guidelines. Initially introduced as performance measures in 2007, these components were established with the support of the American Heart Association and The American College of Cardiology.¹⁹

Initially, all patients starting a CR program should have a comprehensive clinical examination, including assessment of risk stratification for adverse events. Assessment continues to guide an individual’s treatment plan including determination of a risk factor profile, interventions, goal setting, and on-going evaluation (Figure 7-3). While planning and implementing CR for women, one needs to consider that women are more likely to be older; have clustering of comorbidities such as hypertension, diabetes, hypercholesterolemia, obesity, heart failure, as well as lower exercise and functional capacity compared to male patients; and may therefore carry a higher cardiac risk as a CR population. Beyond the impact of the cardiac disease, older women in particular are more likely to experience activity limitations and other exercise-limiting comorbid conditions such as arthritis, osteoporosis, and urinary incontinence. At recruitment to CR, women typically score lower in health-related quality of life and they are more likely to be diagnosed with depressive disorders and higher scores of anxiety.

Essential care components include the following steps:

• 
  

  Tobacco cessation as an ultimate goal utilizing behavioral interventions, pharmaceuticals, referral to a tobacco cessation program, and on-going support as needed.

  
  
• 
  

  Hypertension management utilizing frequent and repeated blood pressure measurements; assessment of medication compliance, sodium intake, patient’s understanding of the complexity of factors affecting blood pressure; and empowering patients to become active partners in blood pressure control through education and self- monitoring. Collaboration with the patient’s physician is important.

  
  
• 
  

  Individual assessment of optimal lipid control. This also includes collaboration with the patient’s physician as well as a dietician. Education should include target lipid goals and the importance of treatment compliance and lifestyle modifications.

  
  
• 
  

  Assessment of current physical activity levels, with return to or establishment of safely meeting the goal of 30 to 60 minutes of activity most days of the week. On-going evaluation of ECG- monitored exercise training sessions and hemodynamic response allows safe progression of exercise prescription. Behavioral counseling is part of the education related to this goal.

  
  
• 
  

  Each participant should be evaluated for body weight and composition to guide in a collaborative effort for weight management. Besides, nutritional and dietary habits should be assessed as a baseline for nutritional counseling as well as behavioral intervention.

  
  
• 
  

  A diagnosis of diabetes mellitus directs us to focus on assessment and management of blood glucose levels. Monitoring of blood glucose levels around physical activities allows for opportunity to educate patients regarding self-management techniques. Collaboration with the patient’s physician and other practitioners is often necessary to achieve optimal diabetes management.

Screening for depression should be an integral part of the initial assessment for CR/SP program participants. Because of its high prevalence in cardiac patients and its identification as an independent risk factor for cardiac mortality after an acute myocardial infarction or unstable angina, cannot be ignored. The opportunity to bridge cardiac care and mental health through communication with physicians and appropriate referral promotes psychosocial well being, which is critical to optimizing patient outcomes.²⁰

Most recently, an update published in 2010 describes core competencies for health-care professionals working in CR/SP programs that address the necessary knowledge and skill sets in order to meet the requirements of the core components.²¹

The recommended time between an event and the start of an exercise program is typically 6 weeks following a coronary artery bypass surgery, 4 weeks after an acute myocardial infarction, and 3 weeks after a percutaneous coronary intervention. Exercise prescription is individualized and is typically based on the results of a submaximal or a symptom-limited stress test for prognostic, diagnostic, and therapeutic purposes. Exercise testing carries a predictive value for mortality. In addition to mortality, the stress test will stratify the patient’s risk for cardiac events during exercise participation.^22,23

Both aerobic and strength training aspects are recommended. Isotonic, rhythmic, and aerobic exercise using large muscle groups such as walking, jogging, swimming, and cycling is preferred. Strength training at least twice a week is recommended after participating in endurance training for several weeks. The calorie expenditure and a positive influence on risk factors is less with strength training than with endurance training; however, the resultant increased muscle mass correlates with the increased strength and functional mobility. High-intensity isometric exercises should be avoided because of the resultant increase in afterload.

Strength training should be avoided in patients with congestive heart failure, uncontrolled arrhythmias, systolic blood pressure >160 mm Hg, diastolic blood pressure >100 mm Hg, severe valvular disease, or unstable angina.²⁴

The components of exercise prescription typically include the following:

• 
  

  Mode: Recommend the type that requires the use of large muscle groups and aerobic exercises. Low-impact activities are typically recommended due to lesser risk of physical injury. The mode or modes of exercise chosen should be enjoyable and simple to carry out to maximize compliance.

  
  
• 
  

  Frequency: Typically performed 3 to 5 times a week, to achieve a significant improvement in functional capacity.

  
  
• 
  

  Content and duration:

  
  
  
  
  1. 
     

     Warm-up: Usually lasts 5 to 10 minutes. These include stretching, flexibility movements, and aerobic activity that gradually increases the heart rate into the target range. This gradual increment in oxygen demand minimizes the risk of exercise-related cardiovascular complications.

     
     
  2. 
     

     Conditioning or training phase: This usually lasts a minimum of 20 minutes, and preferably lasts 30 to 45 minutes of continuous or discontinuous aerobic activity.

     
     
  3. 
     

     Cool-down: Usually lasts 5 to 10 minutes. This involves low-intensity exercise and permits a gradual recovery from the conditioning phase. Omission of cool-down can result in a transient decrease in venous return, reducing coronary blood flow while heart rate and myocardial oxygen consumption remain high.

  
  
• 
  

  Intensity: This ranges from 40% to 85% of functional capacity (VO_2max), which corresponds to 55% to 90% of maximal heart rate. Categorized using the percent HR_max as light (<60%), moderate (60%-79%), and heavy (80%).

  
  
• 
  

  Supervision: Low-risk patients may initially benefit from medically supervised ECG-monitored exercise (6-12 sessions), which help to reassure the patient about the safety of the program. Self-monitored, home-based exercise programs also have been shown to be effective and safe in these patients and result in better rates of adherence when compared to group-based programs.