Meeting the Challenges Facing Low Cardiac Rehab Referral and Participation Rates

Cardiac rehabilitation (CR) is an intervention that has a long and well-documented history of benefiting patients who have experienced a cardiac event.^1,2 These benefits include improvements in functional capacity, quality of life, and morbidity and mortality.^1-4 Reductions in morbidity and mortality with CR are equivalent to many of the best available pharmacologic and invasive interventions.^5,6 Decades of research have shown that the numerous physiological adaptations following rehabilitation that underlie improvements in exercise capacity have met the fundamental scientific tenet of replication. These adaptations include changes in skeletal muscle metabolism that enhance aerobic potential, improved endothelial function leading to enhanced oxygen delivery to the muscle, improved skeletal muscle function and strength, and optimal autonomic nervous system balance.⁷ Today, CR represents more than an exercise program; it typically includes core components that aim to optimize risk reduction, foster healthy behaviors and compliance with these behaviors, reduce disability, and promote an active lifestyle for patients with cardiovascular disease (CVD). Regular participation in exercise has at least some favorable effect on virtually all the major risk factors for cardiovascular disease.^7,8 The spectrum of patients demonstrating benefits from CR has expanded in recent years; in addition to post-myocardial infarction (MI) patients, this spectrum includes patients post-percutaneous coronary intervention (PCI), heart failure, cardiac transplantation, cardiac resynchronization therapy, heart valve repair or replacement, and those receiving implantable cardiac defibrillators (ICD). Finally, CR has been shown to be cost-effective⁹; this is generally in contrast to PCI, which is less cost-effective than maximal medical therapy and generally has not been shown to improve mortality.^5,10-12

Several meta-analyses have underscored the marked reductions in morbidity and mortality following participation in CR. The most recent included 47 studies with 10,794 patients following MI, PCI, coronary artery bypass graft, or who had known coronary artery disease. Compared to those receiving usual care, those randomized to exercise-based CR had a 13% reduction in all-cause mortality, a 26% reduction in cardiovascular mortality, and a 31% reduction in hospital admissions.³ Given the well-documented benefits of participation in CR, it is surprising how few eligible patients are referred to CR. A number of recent surveys have reported referral rates in the order of 20%.^13,14 The underutilization of CR is particularly apparent in women, those with low socioeconomic status, African Americans, and the elderly¹³, groups that are significantly more likely to die within 5 years following a first MI.¹⁵ This occurs despite many scientific statements, commentaries, guidelines, and performance measures directed toward increasing referral and participation rates for CR.^{1,2,7,8,13,16-19} These include evidence-based guidelines from the American Heart Association and the American College of Cardiology Foundation.¹⁹ The latter document has given a Class-I-level recommendation (signifying a treatment that should be performed or administered) for referral to CR in those groups of patients mentioned above. Yet CR participation and referral has not increased over the last decade; a time during which invasive interventions (largely PCI) have skyrocketed¹⁵, despite the observation that PCI does not improve outcomes.^11,12,20

So why isn't there greater participation and referral for cardiac rehabilitation? The just-published Scientific Statement from the American Heart Association (AHA) highlights some of the reasons.²¹ First, the benefits of CR are greatly under-appreciated in both the public and the medical community. Greater efforts are needed to educate health care providers and the public regarding the benefits of CR. Second, several recent investigations have outlined the barriers to CR referral and participation, including availability of programs, perception of its value, and public policy.^13,14,16,17 Efforts must be made to overcome these barriers. Another barrier is the perception that CR is an exercise-only treatment, rather than a multidisciplinary intervention (including risk factor management, physical activity counseling/training, and psychosocial counseling). A better understanding of the spectrum of benefits from CR would likely enhance its status among health care providers and health care systems. Perhaps the most important impediment to CR referral is lack of reimbursement. While insurance coverage clearly needs to be expanded to include a broader spectrum of patients who are known to benefit from CR, this barrier is in part due to the erroneous perception that CR is not covered by most insurance companies or Medicare. In fact, the Centers for Medicare and Medicaid Services (CMS) recently increased reimbursement rates for hospital-based CR. Finally, new delivery models that are more inclusive for more eligible patients must be embraced. For low-risk patients (which includes the vast majority of patients appropriate for CR), home-based programs have been shown to be more cost-effective and to be comparable in safety and efficacy as more traditional center-based programs.^22,23 Other less traditional but effective methods include community programs and case management during home rehabilitation by CR staff, which typically includes the use of activity surveillance devices (pedometers, heart rate monitors, accelerometers, and activity logs) along with frequent phone, internet, transtelephonic ECG monitoring or some combination of these.^8,16

In the past, referral for CR has frequently been the responsibility of the physician, who largely due to time constraints and lack of awareness of its value, has generally not been as strong an advocate for CR as other allied health professionals.¹⁸ The new AHA advisory more specifically characterizes the roles of these allied health care professionals in both the acute care and home-health settings to improve outpatient CR referrals and participation.²¹ Nurses frequently have immediate and direct contact with the patient and therefore have a pivotal role following a cardiac event or procedure. Since being referred while in the hospital and the patient perceiving the need for CR are both strong predictors of CR participation (odds ratios >6 and >13, respectively)²⁴, these two factors are most easily addressed by the nurse during inpatient hospitalization. Similarly, the inpatient physical therapist has a role in advocating for CR because they often evaluate the patient's functional capabilities, determine discharge status and placement on discharge, and can reinforce education regarding the importance of CR. The clinical exercise physiologist may be involved in the inpatient and/or outpatient program, and provides expertise related to exercise prescription, exercise training, and education. Their frequent contact with patients can help ensure that all eligible patients are referred to the outpatient program prior to discharge. Registered dietitians have a critical role as part of the multidisciplinary CR team; nutrition therapy and counseling is an essential component of the secondary prevention of CVD. Dietitians in the inpatient setting are thus in an important position to educate patients on the value of CR. By encouraging patients to participate in outpatient CR, the dietitian can help patients achieve their long-term nutritional goals. Importantly, the physician must be supportive since it has been demonstrated that physician endorsement of CR is a critical factor in achieving higher rates of referral and enrollment, and direct physician encouragement to patients has been shown to markedly improve enrollment.²⁵ Finally, all of these health professionals should routinely recommend exercise to their patients because it has fundamental benefits to each of these subspecialties (e.g.' weight loss, mental health, exercise tolerance).

Exercise training and secondary prevention in appropriate patients is a well-established, safe, and comparatively inexpensive intervention that increases exercise capacity, reduces symptoms, and improves outcomes in patients with CVD. The new AHA Scientific Advisory underscores the fact that many health care professionals have a role in enhancing the proportion of eligible patients who are referred and participate in CR. Educating these health care professionals, other health care providers, patients, families, and health care systems regarding the indisputable benefits of multidisciplinary CR will go a long way toward broadening the proportion of patients who receive these benefits. A goal of the recent AACVPR/AHA/ACC Task Force on Performance Measures in Cardiac Rehabilitation¹⁹ was, in effect, to make referral to CR as common as giving medications to patients with heart disease. As outlined in this new AHA advisory, making this happen will require the combined efforts of health care professionals, the implementation of novel approaches (automated discharge sets, education, home and community programs), inclusion of CR in performance measures, and a greater focus on underserved populations.