An Update on Pharmacologic Treatment of Chronic Stable Angina

It is estimated that more than 6 million Americans suffer from chest pain and discomfort. The American Heart Association (AHA) estimates that in the United States there are 400,000 newly diagnosed stable angina cases each year. Furthermore, it is estimated that the annual costs associated with chronic stable angina are measured in the 10s of billions of dollars.¹

Recently, the AHA, in association with the American College of Cardiology (ACC), published updated guidelines for the management of patients with chronic stable angina. Treatment of asymptomatic patients?ie, patients with silent ischemia showing abnormal noninvasive test results or patients with known coronary artery disease (CAD)?also are included in these guidelines.¹

Recommendation Classifications and Levels of Evidence

The customary ACC/AHA classifications (I, IIa, IIb, and III) and levels of evidence (A, B, and C) are used in these guidelines:

• Class I: Conditions for which there is evidence or general agreement that a given procedure or treatment is useful and effective
• Class II: Conditions for which there is conflicting evidence or a divergence of opinion about the usefulness/efficacy of a procedure or treatmentClass IIa:Weight of evidence/opinion is in favor of usefulness/ efficacyClass IIb: Usefulness/efficacy is less well established by evidence/opinion
• Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful
• Level of evidence high (A): The data were derived from multiple randomized clinical trials with large numbers of patients.
• Level of evidence intermediate (B): The data were derived from a limited number of randomized trials with small numbers of patients, careful analyses of nonrandomized studies, or observational registries.
• Level of evidence low (C): Expert consensus was the primary basis for the recommendation.

Treatment of Patients with Chronic Stable Angina

The Table includes a comparison of the old and new guidelines. The modifications are indicated in bold.

Treatment of Asymptomatic Patients

Treatment of asymptomatic patients is an addition; it was not included in the old guidelines.

Class I

• Aspirin in the absence of contraindications in patients with prior myocardial infarction (MI) (level of evidence: A)
• Beta-blockers as initial therapy in the absence of contraindications in patients with prior MI (level of evidence: B)
• Lipid-lowering therapy in patients with documented CAD and low-density lipoprotein (LDL) cholesterol >130 mg/dL, with a target LDL of <100 mg/dL (level of evidence: A)
• ACE inhibitor in patients with CAD who also have diabetes and/or systolic dysfunction (level of evidence: A)

Class IIa

• Aspirin in the absence of contraindications in patients without prior MI (level of evidence: B)
• Beta-blockers as initial therapy in the absence of contraindications in patients without prior MI (level of evidence: C)
• Lipid-lowering therapy in patients with documented CAD and LDL cholesterol of 100 to 129 mg/dL, with a target LDL of 100 mg/dL (level of evidence: C)
• ACE inhibitor in all patients with diabetes who do not have contraindications due to severe renal disease (level of evidence: B)
• Recommendations for pharmacotherapy to prevent MI and death in asymptomatic patients are included here.

Coronary Disease Risk Factors and Evidence That Treatment Can Reduce the Risk for Coronary Disease Events

The following are recommendations for the treatment of risk factors.

Class I

• Treatment of hypertension according to Joint National Conference VI guidelines (level of evidence: A)
• Smoking-cessation therapy (level of evidence: B)
• Management of diabetes (level of evidence: C)
• Comprehensive cardiac rehabilitation program (including exercise) (level of evidence: B)
• LDL-lowering therapy for patients with documented or suspected CAD and LDL cholesterol D130 mg/dL, with a target LDL of <100 mg/dL (level of evidence: A)
• Weight reduction for obese patients in the presence of hypertension, hyperlipidemia, or diabetes mellitus (level of evidence: C)

Class IIa

• For patients with documented or suspected CAD and LDL cholesterol 100 to 129 mg/dL, several therapeutic options are available: (level of evidence: B) a. Lifestyle and/or drug therapies to lower LDL to <100 mg/dL (level of evidence: B) b. Weight reduction and increased physical activity for persons with the metabolic syndrome (level of evidence: B) c. Institution of treatment of other lipid or nonlipid risk factors; consideration of use of nicotinic acid or fibric acid for elevated triglycerides or low HDL cholesterol (level of evidence: B)
• Therapy to lower non-HDL cholesterol in patients with documented or suspected CAD and triglycerides of >200 mg/dL, with a target non-HDL cholesterol of <130 mg/dL (level of evidence: B)
• Weight reduction for obese patients in the absence of hypertension, hyperlipidemia, or diabetes mellitus (level of evidence: C)
• Folate therapy for patients with elevated homocysteine levels (level of evidence: C)
• Identification and appropriate treatment of clinical depression to improve CAD outcomes (level of evidence: C)
• Intervention directed at psychosocial stress reduction (level of evidence: C)

Class III

• Initiation of hormone replacement therapy in postmenopausal women for the purpose of reducing cardiovascular risk (level of evidence: A)
• Vitamin C and E supplementation (level of evidence: A)
• Chelation therapy (level of evidence: C)
• Garlic (level of evidence: C)
• Acupuncture (level of evidence: C)
• Coenzyme Q (level of evidence: C)

Summary

The new guidelines have treatment strategies for adult patients with symptomatic and asymptomatic chronic stable angina. Changes include the use of beta-blockers for more patients, the use of ACE inhibitors, comments on the dose of aspirin, changes to lipid-lowering therapy, and the inclusion of treatment for asymptomatic chronic stable angina patients.

For a list of references, send a stamped, self-addressed envelope to: References Department, Attn. D. Ryan, Pharmacy Times, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to: dryan@mwc.com.