Health Care Guideline:
Stable Coronary Artery Disease
General Implementation January 1998
Copyright © 1998 by Institute for Clinical Systems Integration
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Work Group Members
Work Group Leader
Greg Lehman, MD, HealthPartners
Adult Medicine
Patricia Burley, RN, Aspen Medical Group
Cardiology
Steve Benton, MD, HealthPartners
Hugh Smith, MD, Mayo Clinic
Family Practice
Dale Duthoy, MD, Family HealthServices Minnesota
Anthony Spagnolo, MD, HealthSystem Minnesota
General Internist
Greg Lehman, MD, HealthPartners
Fritz Arnason, MD, HealthSystem Minnesota
Health Education
Susan M. Hanson, RD, Institute for Research & Education HealthSystem
Minnesota
Pharmaceutics
Peter Marshall, RPh, HealthPartners
Measurement Advisor
Jane Gendron, ICSI
Facilitator
Julie Persoon, RN, ICSI
Adults aged 18 and over who meet the stated guideline criteria as identified in Annotation #1.
Priority Aims For Medical Groups When Using This Guideline
1. Optimize medical therapy through improved selection and education of patients for aspirin and anti-anginal drugs.
Possible measure of accomplishing this aim:
a. Percent of patients with stable CAD who have aspirin use documented in the medical record.
2. Improve patient understanding of disease management.
Possible measure of accomplishing this aim:
a. Percent of patients with stable CAD who report that they know how to use nitroglycerin and when to call 911.
3. Increase the percentage of patients with stable CAD who receive an intervention for modifiable risk factors.
Possible measures of accomplishing this aim:
a. Percent of cigarette-smoking patients with stable CAD who report being advised to quit or being offered help in quitting.
b. Percent of stable CAD patients who have had a lipid profile determination performed within the last three to six months (as recommended in the Lipid Treatment guideline).
Algorithm Annotations
Stable Coronary Artery Disease
1. Patient
with Stable Coronary Artery Disease
2. Perform
Appropriate History, Physical, Labs and Patient Education
3. Non-Atherogenic Causes?
5. Address
Modifiable Risk Factors and Co-Morbib Affectors
6. Assessment Yields High Risk of Adverse
Event
7. Need for Prognostic Testing
8. Patient/EKG Allows
Exercise Electrocardiography?
10. Perform Non-Invasive
Imaging Study
11. Results Yield High Risk of Adverse Event?
12. Initiate/modify medical
therapy
13. Is Medical Treatment Effective?
14. Follow
Regularly to Assess Risk Factors, Profile, Responses to Treatment
15. Worsening in Angina Pattern?
16. Change Suggests Need for Cardiology Referral?
17. Cardiology Consult
and/or Referral
18. Cardiac Catherization?
19. Any Coronary
Artery Lesion Requiring Revascularization?
20. Percutaneous
Transluminal Coronary Angioplasty (PTCA), Coronary Artery Bypass Graft
(CABG) or Other Revascularization Procedures
1. Patient with Stable Coronary Artery Disease
This guideline applies to patients with coronary artery disease either with or without angina. Examples include patients with prior myocardial infarctions, prior revascularization (i.e., PTCA, CABG), angiographically proven coronary atherosclerosis, or reliable non invasive evidence of myocardial ischemia.
A patient presenting with angina must meet the following criteria:
As such the patient may already have undergone some diagnostic workup as a result of a prior presentation of chest pressure, heaviness, and/or pain with or without radiation of the pain and/or shortness of breath. Initial care of such patients falls under the auspices of the Diagnosis of Chest Pain guideline.
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2. Perform Appropriate History, Physical, Labs and Patient Education
A thorough history and physical including medication and compliance are important to confirm diagnosis, assist in risk stratification and to develop a treatment plan. Some important historical points to elicit are:
The physical examination should include a thorough cardiovascular examination as well as evaluation for evidence of hyperlipidemia, hypertension, peripheral vascular disease, congestive heart failure, anemia and thyroid disease.
Initial laboratory studies should include an electrocardiogram and a cholesterol profile (total cholesterol, HDL, calculated LDL and triglycerides). Further tests, based on history and physical examination, may include chest x-ray, hemoglobin, diabetes and thyroid tests, and renal function.
An important aspect to treatment of the stable coronary artery disease patient is education. Education includes helping the patient understand the disease processes, the prognosis, the treatment options and the signs of worsening cardiac ischemia so that prompt medical assistance is sought when necessary and appropriate. The education process may occur in a number of ways among the various medical groups. It may be ongoing, occur in a formal class, and/or be done at the provider visit. Instruction on the proper use of ASA and Nitroglycerin SL, PRN, should be reviewed at this time also.
Strength of evidence for this recommendation: C
Consideration may be given to starting the patient on a multivitamin with folate and/or Vitamin E.
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Aortic stenosis is a significant source of all non-atherogenic causes of stable coronary artery disease. This and any other non-atherogenic causes are considered to be outside the scope of this clinical guideline.
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5. Address Modifiable Risk Factors and Co-Morbid Affectors
Co-morbid conditions that could affect myocardial ischemia may include hypertension, anemia, thyroid disease, hypoxemia and others.
The modifiable risk factors for coronary heart disease need to be evaluated in a patient with stable coronary artery disease. These include smoking, inappropriate activity, stress, hyperlipidemia, obesity, hypertension and diabetes mellitus. Intervention involving any risk factor pertinent to the patient is encouraged. Intervention includes education, goal setting, and follow-up as necessary.
5a. Smoking:
Cigarette smoking may cause an acute cardiac ischemic event, and may interfere with the efficacy of antianginal medications.
Please refer to Tobacco Use Prevention and Cessation for Adults and Mature Adolescents for recommendations regarding smoking cessation.
5b. Inappropriate Activity Level:
An important aspect of the provider's role is to counsel patients in the kind of work they can do, in their leisure activities, eating habits, vacation plans and the like. Modify strenuous activities if they constantly and repeatedly produce angina. The patient with stable coronary artery disease should avoid excess fatigue and exhaustion. Exercise can be an important adjunct to modification of risk factors such as hypertension, hyperlipidemia and obesity. In addition, it can enhance an individual's perception of their quality of life. However, caution needs to be utilized to avoid consistent reproduction of ischemic symptoms and/or situations that may precipitate ischemic complications. Education is critical in achieving these goals.
5c. Stress:
Psychophysiologic stress is a notable feature of the relationship between myocardial ischemia and the patient's daily environment.
5d. Hyperlipidemia:
A fasting cholesterol fractionation should be evaluated for age-appropriate patients with stable coronary artery disease. Such patients should be viewed as secondary prevention patients and treated aggressively. For those patients determined at risk because of their blood lipid levels, a referral to a Registered Dietitian (RD) or trained professional should be made along with any medical intervention the provider feels is necessary. Management of hyperlipidemia should be age appropriate.
Please refer to the Lipids Treatment in Adults Guideline for recommendations on cholesterol lowering.
5e. Obesity:
Although obesity is not an independent risk factor, it is reasonable to advise patients to assume a healthy body weight which will positively impact the treatment of such co-morbid conditions as hypertension, diabetes mellitus and hyperlipidemia.
5f. Hypertension:
General measures include the treatment of hypertension, which is not only a risk factor for development and progression of atherosclerosis but also causes cardiac hypertrophy, augments myocardial oxygen requirements, and thereby intensifies myocardial ischemia in patients with obstructive coronary disease.
Please refer to the Hypertension Diagnosis and Treatment Guideline for recommendations regarding blood pressure management.
5g. Diabetes:
Diabetes should be optimally controlled.
Please refer to the Management of Type 2 Diabetes Mellitus guideline for recommendations regarding management of diabetes.
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6. Assessment Yields High Risk of Adverse Event?
Some individuals are considered to be at high risk of infarction and/or death based upon history, physical examination and initial lab values. Those individuals presenting with severe symptoms, symptoms of peripheral vascular disease, or symptoms of left ventricular dysfunction should be referred to a cardiologist if not precluded by other medical conditions.
7. Need for Prognostic Testing?
Prognostic testing is appropriate for patients in whom risk determination remains unclear after the above evaluations have been completed, or by the cardiologist when cardiac catheterization is deemed inappropriate. Prognostic testing may precede or follow an initial course of pharmacological therapy.
8. Patient/EKG Allows Exercise Electrocardiography?
In exercise electrocardiography (Masters 2-Step Test, Graded Exercise Test, Bicycle Test, Ergometry), sensitivity may be reduced for many patients. Such patients include those unable to reach the level of exercise required for near maximal effort, such as:
Reduced specificity may be seen in patients with abnormal baseline EKG changes, such as tkóse taking digitalis medications, and patients with Left Ventricular Hypertrophy or Left Bundle Branch Block patterns.
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10. Perform Non-Invasive Imaging Study
A non-invasive imaging study such as myocardial perfusion scintigraphy or stress echocardiography should best meet the patient's needs while providing the most clinical utility and cost-effectiveness within the provider's institution. Selection of an imaging study may best be accomplished via discussion with the cardiologist or imaging expert.
11. Results Yield High Risk of Adverse Event?
Exercise and electrocardiography prognostic imaging studies may yield results that indicate high, intermediate/indeterminate or low risk of adverse clinical events. The presence of high risk should lead to a cardiology consultation unless the patient is not considered to be a potential candidate for revascularization. Those with intermediate/indeterminate risk assessment may benefit from cardiology consultation and/or further non-invasive imaging if only an exercise electrocardiogram has been performed. Low risk patients can generally be managed medically with a good prognostic expectation. Low risk patients may benefit from angiography if the diagnosis remains unclear; however, angiography is unlikely to alter outcome in these patients.
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12. Initiate/Modify Medical Therapy
12a. Initiate One ASA Daily and SL NTG PRN
The use of daily aspirin is strongly recommended unless there are medical contraindications. In mild stable coronary artery disease patients drug therapy may be limited to short-acting sublingual nitrates on an "as needed" basis, or prophylactically in situations known to cause angina. Use of lower dosage strengths (i.e., 0.3 mg) may be associated with a lesser incidence of side effects such as headache or hypotension in susceptible individuals.
12b. Does Patient Need Daily Maintenance Therapy?
The decision to initiate daily drug therapy on a patient with coronary artery disease is based upon the symptom complex of the patient in combination with findings from the history, physical, lab and prognostic testing. The use of a beta blocker may be indicated in asymptomatic patients with recent myocardial infarction. The use of ACE-inhibitors has been demonstrated to be beneficial in certain subsets of patients with left ventricular systolic dysfunction including that caused by myocardial infarction.
12c. Beta Blocking Agent Appropriate?
Beta blockers are now widely recommended as first line or monotherapy for patients with stable coronary artery disease. Clinical benefits, that is, a reduction in symptoms, are most apparent in patients with exertional angina. Select drugs without intrinsic sympathomimetic activity. Avoid abrupt withdrawal of all beta blockers.
12d. Long-Acting Nitrates Appropriate?
If the provider is unable to prescribe beta blockers as first line therapy, nitrates are the preferred alternative first line therapy because of efficacy and low cost. In fact, sublingual NTG can be used prophylactically prior to activities or circumstances that would be likely to precipitate angina.
12e. Calcium Channel Blocker Appropriate?
For patients who are unable to take beta blockers or long acting nitrates, the use of calcium channel blockers has been shown to be clinically effective. Dihydropyridines as monotherapy may exacerbate angina.
12g. Prescribe Combination Therapy
12h. Combination Therapy Effective?
If after several attempts at adjusting the medications a therapeutic combination is not achieved for the patient, a cardiology consult and/or referral may be appropriate.
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13. Is Medical Treatment Effective?
Effectiveness of pharmacologic treatment is measured by whether the anginal pain is controlled within the definition of stable coronary artery disease as stated in Annotation #1.
14. Follow Regularly to Assess Risk Factors, Profile, Responses to Treatment
Although there is no consensus in the literature regarding frequency of follow-up, ongoing management needs and follow-up should be individualized.
15. Worsening in Angina Pattern?
A new occurrence of angina or a worsening in the chronic stable angina pattern is considered to occur when:
16. Change Suggests Need for Cardiology Referral?
When such change is no longer managed by alterations in the pharmacologics prescribed, it may be appropriate to consult on and/or refer the patient to a cardiologist.
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17. Cardiology
consult and/or referral
18. Cardiac catheterization?
19. Any coronary
artery lesion requiring revascularization?
20. Percutaneous Transluminal Coronary Angioplasty (PTCA), Coronary Artery Bypass Graft (CABG) or other Revascularization Procedures
The relative survival benefit of CABG compared with medical therapy is enhanced by an increase in absolute number of severely narrowed coronary arteries, the degree of left ventricular systolic dysfunction and the magnitude of myocardial ischemia.
To date no survival benefit has been documented with PTCA in stable coronary artery disease. Several investigations are ongoing to evaluate PTCA versus surgical revascularization in coronary artery disease. PTCA is an alternative to medical therapy in patients with clinical evidence of ischemia and with angiographically suitable lesions. PTCA is presently limited in its usefulness by restenosis.
In selected patients who meet criteria for CABG but who have co-morbidities that increase the operative risk, PTCA may be a reasonable treatment alternative to either bypass surgery or medical treatment.
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Grade A: Conclusion based on a randomized, controlled trial that has been published in a peer-reviewed journal.
Grade B: Conclusion based on one of the following study types published in a peer-reviewed journal (but not on a randomized, controlled trial):
Grade C: Conclusion based on one of the following (but not on any studies of the types mentioned above):
Other Guidelines Referenced Within This Guideline
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