The Canadian Association of Cardiac

Transcription

1 Reinventing Cardiac Rehabilitation Outside of acute care institutions, cardiovascular disease is a chronic, inflammatory process; the reduction or elimination of recurrent acute coronary syndromes is a major goal of cardiac rehabilitation programs. The success of disease intervention is derived not only from what interventions or therapies are prescribed, but equally from how they are applied. James A. Stone, MD, PhD, FRCPC, FAACVPR, FACC The Canadian Association of Cardiac Rehabilitation has defined cardiac rehabilitation as, The enhancement and maintenance of cardiovascular health through individualized programs designed to optimize physical, psychological, social, vocational and emotional status. This process includes the facilitation and delivery of secondary prevention through risk factor identification and modification in an effort to prevent disease progression and recurrence of cardiac events. 1 Contemporary cardiac rehabilitation is best thought of as a systemic process of chronic disease care. 2,3 It is a patient-centered care environment in which proactive disease surveillance, rather than reactive, symptom-driven disease care, is the principle mode of service delivery. Within this care setting, cardiac patients are treated to scientifically validated treatment targets, in accordance with national guidelines. In years gone by, cardiac rehabilitation programs were primarily exercise-based, with minimal if any target-driven cardiovascular risk factor or psychosocial interventions. Some physicians came to regard cardiac rehabilitation programs as little more than touchy-feely programs that did nothing to change cardiac outcomes. However, clinical trials and large metaanalyses have consistently demonstrated the positive effects of cardiac rehabilitation programs on both total and cardiac mortality. 4-6 Table 1 Clinical outcomes in cardiac rehabilitations from a meta-analysis 4 Outcome Odds ratio Total mortality* 0.80 (0.61 to 0.93) Cardiac mortality* 0.74 (0.61 to 0.96) Post-myocardial infarction 0.79 (0.50 to 1.09) Post-CABS 0.87 (0.65 to 1.06) Post-PCI 0.81 (0.49 to 1.34) Total cholesterol* mmol/l (-0.63 to -0.11) Triglycerides* mmol/l (-0.39 to -0.07) LDL (-0.53 to -0.12) HDL (-0.53 to -0.12) Systolic blood pressure* -3.2 mmhg (-5.4 to -0.9) Diastolic blood pressure -1.2 mmhg (-2.7 to -0.3) Smoking cessation* 0.64 (0.5 to 0.83) *Significant p < 0.05 CABS: Coronary artery bypass surgery PCI: Percutaneous coronary intervention LDL: Low-density lipoprotein HDL: High-density lipoprotein Perspectives in Cardiology / November/December

2 Table 2 Post-acute coronary syndrome interventions Parameter Physical activity and exercise Weight control Alcohol consumption Tobacco usage Diet and dietary supplements Stress management Psychosocial health Goals Accumulate 30 to 60 minutes of moderate to vigorous-intensity exercise on most preferably all days of the week. Daily caloric balance with the goal of maintaining a BMI of 18.5 kg/m 2 to 24.9 kg/m 2 and a waist circumference of less than 102 cm (40 ) in men and less than 88 cm (36 ) in women. Abstinence or a maximum intake of: Males: 14 standard drinks per week Females: Nine standard drinks per week None or immediate cessation of all forms of tobacco intake. Avoidance of second-hand tobacco smoke. As per Canada s Food Guide to Healthy Eating (Chapter 4), DASH diet ( Omega 3 fatty acid supplements should be considered in high-risk groups. Avoidance or control of depression, anger states, hostility, confrontation, psychosocial and vocational stress. Cardiovascular disease patients and high-risk clients should be evaluated for depression. BMI: Body mass index DASH: Dietary Approaches to Stop Hypertension The science of cardiac rehabilitation Through the use of interventions, such as exercise and risk factor reduction, cardiac rehabilitation programs and services can result in reduced vascular oxidative stress and inflammation, thereby reducing: cardiac mortality, the likelihood of recurrent hospitalizations and the need for repeat revascularization procedures. 3 The most recent meta-analysis of cardiac rehabilitation confirmed the results of clinical trials and four previous meta-analyses regarding the significant reductions in total and cardiac mortality, along with cardiovascular risk factors, realized through participation in cardiac rehabilitation programs (Table 1). In addition, the results of this meta-analysis could find 36 Perspectives in Cardiology / November/December 2005

3 no evidence that the increased use of secondary prevention strategies in more recent trials of cardiac rehabilitation (those published after 1995), such as anti-platelet agents, beta-blockers, statins and angiotensinconverting enzyme (ACE) inhibitors, has diminished or nullified the beneficial effects of exercise training in patients with cardiac disease. This observation suggests that the addition of exercise therapy to the multitude of standard pharmacologic interventions currently recommended and prescribed postacute coronary syndromes can still produce additional patient benefits (Table 2). Risk stratification Current Canadian guidelines recommend that all patients admitted to cardiac rehabilitation programs undergo a systematic admission process, including: a full medical history, a physical examination, a resting electrocardiogram and appropriate laboratory investigations. 3 Table 3 Core elements of cardiac rehabilitation programs 6 Patient referral process Patient assessment - Risk stratification - Exercise stress testing - Risk factor assessment Lifestyle and risk factor modification Nutritional counselling Risk factor assessment - Lipids - Hypertension - Smoking cessation - Diabetes - Psychosocial issues - Weight management, particularly abdominal obesity - Psychosocial management - Physical activity counselling and exercise training Patient education programs - Lifestyle adherence strategies - Medication adherence strategies Outcomes assessment programs - Health outcomes - Educational outcomes - Behavioural outcomes - Service outcomes Continuous quality improvement programs Continuous professional development programs Patients should also undergo formal risk stratification (Figure 1; only the female table is presented). The risk evaluation strategy combines a Framingham risk model 7 validated for cardiac patients in combination with a Duke treadmill score. 8 These two scores are then combined into a recurrent cardiac event risk score to provide an overall estimate of the patient s subsequent cardiac risk. In addition to prognostic information, the recurrent cardiac event risk score also allows for patients to be more cost-effectively assigned to either program supervised, facility-independent exercise, i.e., home exercise (low and some intermediate risk patients) or program supervised, facilitydependent exercise (high-risk patients). Cont d on page 38 About the author... Dr. Stone is a Clinical Associate Professor of Medicine, University of Calgary, Cardiac Wellness Institute of Calgary, Calgary, Alberta. Perspectives in Cardiology / November/December

4 Step 1 Calculation of progression of disease score (PDS) Women Total cholesterol level, mmol/l High-density lipoprotein cholesterol < > < Lipid score Systolic blood pressure (SBP), mmhg < SBP score Smoker No 0 Yes 3 Smoker Score Diabetes No 0 Yes 3 Diabetes score Women with documented cardiovascular disease (CVD) Risk factor Risk points Age group, year Age score Total risk points = Age score + lipid score + SBP score + smoker score + diabetes score Mean two-year risk score in women with CVD Total risk Two-year CVD Age (years) Probability points event (%) probability (%) PDS < < < PDS Low risk 2.5% per year Intermediate risk 5% per year High risk > 5 % per year Step 2 Calculation of disease prognosis score (DPS) risk of exercise-associated adverse events 1. Calculate the Duke treadmill score (DTS) DTS = exercise time - (5 x maximal ST depression) - (4 x angina index) 2. Determine the disease prognosis score (DPS) 9 Event risk Duke treadmill Disease prognosis score score Where: Exercise time = Minutes on the Bruce protocol ST depression = Maximal recorded ST depression Treadmill angina index. 0 = No angina 1 = Non-limiting angina 2 = Limiting angina Low risk % per year Intermediate risk + 4 to % per year High risk % per year Step 3 Integrate the DPS and the PDS to determine the recurrent cardiac event risk score Progression of disease score 1 Disease Low risk Intermediate High risk prognosis score risk Figure 1. Risk stratification for women. The recurrent cardiac event score can be used to determine the exercise training setting. Low-risk and intermediate-risk persons are appropriate for program-associated, facility-dependent exercise. High-risk persons should be assigned to programbased, facility-dependent exercise. High Intermediate risk High risk High risk Intermediate Low risk Intermediate risk High risk Low Low risk Low risk Intermediate risk Cont d on page 40

5 Program formats Unfortunately, only a minority of patients are referred for cardiac rehabilitation following hospitalization for acute coronary syndromes. 3 Programs with the best referral and patient attendance rates utilize practitioner independent referral processes, such as automatic referral. Following their initial assessment, medical consultation and risk stratification, patients are given their individualized exercise prescriptions and risk factor treatment programs and enrolled in exercise classes. Even if they are going to participate in program supervised, facility-independent exercise, most programs have patients attend a few exercise classes to ensure appropriate exercise knowledge. Programs are usually three to six months in Take-home message Cardiac rehabilitation programs reduce total and cardiac mortality compared to usual care. Cardiac rehabilitation programs provide an environment of proactive disease surveillance in order to minimize or eliminate recurrent cardiac events. Cardiac rehabilitation can assist busy primarycare and other physicians in the management of their cardiac patients by ensuring adherence to national guidelines in the treatment of cardiovascular risk factors. Most patients with established cardiac disease should be referred for cardiac rehabilitation either by their specialist, primary-care physician or nurse practitioner.

6 duration, with patients attending exercise classes one to three times per week. Contemporary programs provide an extensive array of patient-care services (Table 3) and will both manage and advise referring physicians regarding their patient s status. PCard References 1. Stone JA, Arthur HM, Austford L, et al: Canadian Guidelines for Cardiac Rehabilitation and Cardiovascular Disease Prevention. CACR, Winnipeg, p Stone JA: Current concepts in cardiac rehabilitation. Int Sport Med J 2002; 3(1): Stone JA, Arthur HM: Executive Summary: Canadian Guidelines for Cardiac Rehabilitation and Cardiovascular Disease Prevention. Can J Cardiol 2005: In Press. 4. Taylor RS, Brown A, Ebrahim S, et al: Exercise-based rehabilitation for patients with coronary heart disease: Systematic review and meta-analysis of randomized controlled trials. Am J Med 2004; 116(10): Sdringola S, Nakagawa K, Nakagawa R, et al: Combined intense lifestyle and pharmacologic lipid treatment further reduce coronary events and myocardial perfusion abnormalities compared with usual-care cholesterol-lowering drugs in coronary artery disease. J Am Coll Cardiol 2003; 41(2): Brown A, Taylor R, Noorani H, et al: Exercise-based cardiac rehabilitation programs for coronary artery disease: A systematic clinical and economic review. Canadian Coordinating Office for Health Technology Assessment Technology, Ottawa, Report no.34: p. iii. 7. Califf RM, Armstrong PW, Carver JR, et al: Task force 5: Stratification of patients into high, medium, and low risk groups for purposes of risk factor management. J Am Coll Cardiol 1996; 27(5): Villella M, Villella A, Santoro L, et al: Ergometric score systems after myocardial infarction: Prognostic performance of the Duke Treadmill Score, Veterans Administration Medical Center Score, and of a novel score system, GISSI-2 Index, in a cohort of survivors of acute myocardial infarction. Am Heart J 2003; 145(3): Mark DB, Shaw L, Harrel FE Jr, et al: Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease. N Engl J Med 1991; 325(12):