Stephan D. Fihn, MD
New comprehensive guidelines for the diagnosis and treatment of stable ischemic heart disease have been released by the American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines, along with the American College of Physicians (ACP), American Association for Thoracic Surgery (AATS), Preventive Cardiovascular Nurses Association (PCNA), Society for Cardiovascular Angiography and Interventions (SCAI), and The Society of Thoracic Surgeons (STS). The guidelines are being published in the Journal of the American College of Cardiology and Annals of Internal Medicine and will be available on the ACC Cardiosource website and the SCAI website.
The chairman of the writing committee, Stephan Fihn, provided the following summaries of the key points of the document for professionals and for patients:
a. Management of SIHD, including diagnosis, risk assessment, treatment and follow-up should be based upon strong scientific evidence and the patient’s preferences.
b. All patients who present with angina should be categorized as stable vs. unstable angina. Those with moderate or high risk unstable angina should be treated emergently for acute coronary syndrome.
c. For patients with an interpretable ECG and who are able to exercise, a standard exercise test should be the first choice test for diagnosis of IHD, especially if the likelihood is intermediate (i.e., 10 to 90%). Those who have an uninterpretable ECG and are able to exercise, should undergo an exercise stress with nuclear MPI or echocardiography, particularly if the likelihood of IHD is intermediate to high. For patients unable to exercise, nuclear MPI or echocardiography with pharmacologic stress is recommended.
d. Patients diagnosed with SIHD should undergo assessment of risk for death or complications of IHD. For patients with an interpretable ECG and who are able to exercise, a standard exercise test is also the preferred choice for risk assessment. Those who have an uninterpretable ECG and are able to exercise, should undergo an exercise stress with nuclear MPI or echocardiography, while for patients unable to exercise, nuclear MPI or echocardiography with pharmacologic stress is recommended.
e. Patients with SIHD should generally receive a “package” of Guideline-Directed Medical Therapy (GDMT) that include lifestyle interventions and medications shown to improve outcomes which includes (as appropriate):
- Diet, weight loss and regular physical activity;
- If a smoker, smoking cessation;
- Aspirin 75-162mg daily;
- A statin medication in moderate dosage;
- If hypertensive, antihypertensive medication to achieve a BP <140/90;
- If diabetic, appropriate glycemic control.
f. Patients with angina should receive sublingual nitroglycerin and a beta-blocker. When these are not tolerated or are ineffective, a calcium-channel blocker or long-acting nitrate may be substituted or added.
g. Coronary arteriography should be considered for patients with SIHD whose clinical characteristics and results of noninvasive testing indicate a high likelihood of severe IHD and when the benefits are deemed to exceed risk.
h. The relatively small proportion of patients who have “high-risk” anatomy (e.g., >50% stenosis of the left main coronary artery), revascularization with CABG should be considered to potentially improve survival. Most of the data showing improved survival with surgery compared to medical therapy are several decades old and based on surgical techniques and medical therapies that have advanced considerably. There are no conclusive data demonstrating improved survival following PCI.
i. For the vast majority of patients with SIHD, a trial of GDMT is warranted before consideration of revascularization to improve symptoms. Deferral of revascularization is not associated with worse outcomes.
j. Prior to performing revascularization to improve symptoms, coronary anatomy should be carefully correlated with functional studies to ensure the highest likelihood that lesions responsible for symptoms are targeted.
k. All patients with SIHD should receive careful follow-up to monitor for progression of disease, complications and adherence to therapy. Exercise and imaging studies need not be performed annually and should generally be repeated only when there is a change in clinical status or when clinical features suggest a significant change in risk of death or complications from IHD.
a. Nearly 9 million persons in the U.S. have angina, the most common symptom of IHD and the prevalence is as high as 15-33% among persons over age 60.
b. If you develop chest discomfort or shortness of breath with activity, seek immediate medical attention.
c. The choice of tests to diagnose IHD is complicated and is based upon your symptoms, personal and health characteristics and preferences. If you able to exercise, a standard exercise test is often the first-choice test.
d. If you are found to have IHD, it is important for your physician to assess your risk of a heart attack or other undesirable outcomes. This may require additional exercise or imaging tests.
e. Most patients with IHD should adopt lifestyle changes that include a healthy, low-fat diet; regular exercise and when warranted, weight loss. Other important steps (when applicable): include smoking cessation; good control of high blood pressure; a statin medication to lower LDL (bad) cholesterol; good control of diabetes; daily aspirin; and medications to eliminate chest pain (angina) such as nitroglycerin and beta-blockers. This “package” of activities and medications is called Guideline-Directed Medical Therapy.
f. When angina does not respond to medications, patients may decide with their medical team, to undergo a procedure to improve circulation to the heart. This can be accomplished either with surgery (coronary artery bypass grafting) or with a catheter (PCI – percutaneous coronary intervention). The choice should be based upon the clinical characteristics of the patient and the results of testing including cardiac catherization. Both surgery and PCI are relatively safe and effective in eliminating chest pain BUT surgery improves survival only in a relatively small group of patients with very severe blockages of the left main coronary artery or several arteries, while PCI has not been conclusively shown to improve survival in any group of patients.
g. Patients with SIHD should receive regular medical follow-up from a primary care provider or cardiologist. The purpose is to answer any questions that arise, monitor therapy for effectiveness and possible adverse events, and check for any new complications related to IHD. Annual stress tests are usually not necessary and your provider should determine what tests are necessary and how often they should be performed based upon your personal clinical characteristics.