Written by Jeffrey Roitman, Ed.D., FACSM and Thomas P. LaFontaine, Ph.D., FACSM
Cardiovascular Rehabilitation (CVR) is now a multifaceted intervention program designed tohalt or reverse the progression of atherosclerosis (clogged arteries) and to reduce morbidity and mortality. CVR programs are no longer just exercise programs, but should also include comprehensive, evidence-based interventions to decrease risk of recurrent events, control symptoms, and, above all, to influence health behavior changes that lower risk factors.
History of cardiovascular rehabilitation The interest in lifestyle intervention in cardiovascular disease dates back to the 1950s, when Ancel Keys, a noted scientist, published an article in Circulation discussing such things as excess caloric intake and obesity, “animal fat,” and dietary cholesterol, and their relationship to atherosclerosis. Another significant study of aggressive lifestyle intervention for secondary prevention was published in the 1980s, and almost all subsequent studies of lifestyle intervention since have shown that secondary prevention with lifestyle, particularly “aggressive” lifestyle change, is significantly more effective than any “usual care” option. In fact, it is equally effective as almost any pharmacological and or invasive intervention.
Through the 1980s and 1990s, CVR evolved into an individualized, programmatic approach aimed at lifestyle and risk factor management. The ideal CVR program should take direct aim at reducing the risk for progression of the atherosclerotic process and future cardiac events. Active and aggressive control of lipids, blood pressure, diabetes, stress, nutrition, weight loss, and smoking cessation have all become part of CVR, accompanying exercise in the management of cardiovascular disease risk factors.
Diagnosis and reduction
The most common diagnosis for patients entering CVR is coronary artery disease (CAD), and most patients have had an angioplasty and/or coronary stenting or bypass surgery. In 2006, the Centers for Medicaid and Medicare expanded the eligible diagnoses for CVR to include stable angina pectoris, myocardial infarction, percutaneous coronary angioplasty, coronary artery stenting, heart valve repair or replacement, and heart transplant or combined heart-lung transplant.
The benefits of CVR for reducing the risk of mortality and morbidity in people with CAD are well documented. Among others, certain studies have demonstrated decreased mortality rates in CVR participants ranging from 12 percent to more than 72 percent.
Change in lifestyle, including aerobic exercise, low-fat/high-fiber diet, and weight loss improve risk factors for patients with CAD. Additionally, the American College of Sports Medicine states that exercising for at least 30 minutes five days per week improves blood lipids, blood pressure, and insulin resistance and can reduce the risk and incidence of type 2 diabetes.
Effects of exercise
“Sub-acute” effects of exercise are neither acute effects (during exercise), nor chronic effects (long-term), but rather they occur subsequent to a single bout of moderate-to-vigorous exercise. They subside with time and can be maintained only with repetition of more exercise or activity. Importantly, the sub-acute effects of exercise are bestowed on those with and without heart disease. Since they occur between bouts of exercise, it is necessary to repeat the exercise or activity on a daily basis to sustain them.
Among the known effects of exercise are positive changes in the function of arteries, decreases in the inflammation that is part of many chronic diseases, increases in cells that function to renew the linings of arteries and many metabolic improvements that make cholesterol and other blood fats improve. Many of these changes are thought to occur after single exercise sessions, thus it makes daily exercise crucial for optimal results. The importance of both the known chronic effects of exercise, as well as the increasingly recognized sub-acute effects is to provide more support for the recommendation that persons with CAD should engage in daily moderate intensity exercise (or activity) of 30 or more minutes per session. Optimal targets for lifestyle intervention and risk factors have been published.
Recent developments in cardiac rehabilitation Recently, the state of CVR has been addressed in two important documents. The American College of Cardiology and the American Heart Association jointly published a set of “Performance Measures” related to CVR. The following introductory statement is significant: “Occasionally, the evidence supporting a particular structural aspect or process of care is so strong that failure to perform such actions reduces the likelihood that optimal patient outcomes will occur.” This statement is profoundly positive about the importance of CVR and its place in patient care, as well as the effectiveness of a comprehensive secondary prevention program in achieving optimal outcomes for patients with CVD. Second, Circulation published a study about the utilization of CVR programs, showing that the average utilization in patients with myocardial infarction and bypass surgery was 13.9 percent and 31 percent, respectively. Additionally, the utilization rates for men and women were 22.1 percent and 14.3 percent, respectively. Thus, it appears that under-utilization for proven, effective therapy for CVR is the standard, not the exception.
The current state of CVR is extremely bright when outcomes and prevention are considered. However, utilization and referral rates leave much to be desired. Outcomes are clearly improved in participants, but optimal secondary prevention is unlikely without referral and utilization.
The exercise professional must be aware that those with CAD are appearing en masse in health and fitness clubs, in community centers and recreation programs and for personal training. Exercise professionals must be prepared and knowledgeable about both the disease process and the rehabilitation process to fully serve this population.
View the full summer 2008 issue of the ACSM Fit Society® Page online.