Intensive Cardiac Rehabilitation (ICR): Tolerability and Effectiveness

BACKGROUND: Conventional Cardiac Rehabilitation (CR) involves a 36-session supervised and monitored exercise treatment program in a cardiac rehabilitation facility for patients with an approved cardiac diagnosis, such as chronic angina, recent myocardial infarction (heart attack), cardiac surgery, or recent percutaneous coronary intervention. The exercise sessions generally are one hour each and the treatment period is typically over 12 weeks. Intensive Cardiac Rehabilitation (ICR) includes the 36-session exercise intervention plus 36 one-hour educational sessions on the Pritikin program. These education sessions include one-on-one dietary consultation with a registered dietitian, nutrition workshops and cooking classes led by a registered dietitian, a series of Pritikin videos, and a notebook of Pritikin handouts on various topics, including reading nutrition labels, how to prepare heart-healthy meals, mindfulness, smoking cessation, and the process of atherosclerosis.

Nathan Pritikin started the Pritikin program in the 1970s with the aim of decreasing recurrent cardiovascular disease (CVD) events in humans. The three pillars of the Pritikin lifestyle program are a healthy diet, exercise, and mindfulness. The Pritikin diet emphasizes unprocessed foods that are high in fiber, low in calorie density, and very low in sodium, saturated fat, and cholesterol. Mindfulness includes behavior modification therapies such as smoking cessation and stress management. Since the 1970s, there have been more than 100 publications in scientific, peer-reviewed journals demonstrating the efficacy of this program on improving many traditional cardiac risk factors and biomarkers of cardiac health, as well as preventing and treating CVD. In addition, a low-fat, high fiber diet combined with exercise has been shown to improve markers of nitric oxide bioavailability and fasting insulin concentrations.

Most of these results, however, were derived from studies of patients domiciled at a Pritikin wellness center. Relatively recently, the Pritikin program was approved as a form of ICR in an outpatient setting. The BJC/Washington University School of Medicine Cardiac Rehab program at the Heart Care Institute was the first Cardiac Rehab program in the world to offer an outpatient Pritikin ICR program. Currently, Medicare and some (but not all) third-party insurance companies pay for ICR. Thus, many patients under the age of 65 years are not afforded the potential benefits of ICR.

SPECIFIC AIM: The purpose of this study is to fill in the gaps in knowledge on the tolerability and effectiveness of an outpatient, Pritikin-based ICR program on traditional cardiovascular risk factors, exercise performance, and patient well-being (as assessed by questionnaires), as well as to monitor subsequent clinical events in this outpatient population.

HYPOTHESIS: The hypothesis is that patients in the Intensive Cardiac Rehabilitation (ICR) group will have greater improvements in several cardiovascular risk factors than patients in the conventional Cardiac Rehab (CR) group at the end of 24 sessions.

FUTURE DIRECTIONS: If the results of this study are favorable, then there are several implications for clinical practice. 1) Evidence of the effectiveness and tolerability of outpatient ICR should encourage expanded coverage of ICR so that more cardiac patients may benefit from this treatment in the future. 2) Demonstration of any trends in improvement of outcomes would support the need for a multi-center trial to define the degree to which ICR can help patients and decrease health care-related costs. These questions would be explored in future R34 grants and Patient-Centered Outcomes Research Institute (PCORI) grants.

STUDY OVERVIEW: This is a 2-year, non-randomized study in which the Intensive Cardiac Rehab (ICR) and conventional Cardiac Rehab (CR) treatment programs are already being conducted as part of routine clinical care in a cardiac rehabilitation facility. Many of the assessments to be conducted and the outcome measures of this study are being obtained as part of the existing cardiac rehab programs. Assignment to the ICR or CR group will be according to the referring physician's recommendation and insurance coverage and will occur before study enrollment. The research portion is obtaining permission to include the participants' phenotypic and outcome data in the research study database and analyzing the information in a systematic manner to answer study questions regarding the tolerability and effectiveness of the ICR program. Participants also will be asked to complete additional assessments and questionnaires that are for research purposes only.