Richard A. Lange, MD, MBA

1. Can a patient with new-onset chest pain have chronic stable angina?

    The term “chronic stable angina” refers to angina that has been stable in frequency and severity for at least 2 months and with which the episodes are provoked by exertion or stress of similar intensity. Chronic stable angina is the initial manifestation of coronary artery disease (CAD) in about half of patients; the other half initially experience unstable angina, myocardial infarction (MI), or sudden death.

2. What causes chronic stable angina?

    Angina occurs when myocardial oxygen supply is inadequate to meet the metabolic demands of the heart, thereby causing myocardial ischemia. This is usually caused by increased oxygen demands (i.e., increase in heart rate, blood pressure, or myocardial contractility) that cannot be met by a concomitant increase in coronary arterial blood flow, due to narrowing or occlusion of one or more coronary arteries.

3. How is chronic stable angina classified or graded?

    The most commonly used system is the Canadian Cardiovascular Society system, in which angina is graded on a scale of I to IV. These grades and this system are described in Table 16-1. This grading system is useful for evaluating functional limitation, treatment efficacy, and stability of symptoms over time.

4. What tests should be obtained in the patient with newly diagnosed angina?

    After a careful history and physical examination, the laboratory tests for the patient with suspected angina should include a measurement of hemoglobin, hemoglobin A1c, fasting lipids (i.e., serum concentrations of total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, and calculated low-density lipoprotein (LDL) cholesterol), and a 12-lead electrocardiogram (ECG).

5. What are the goals of treatment in the patient with chronic stable angina?

6. What therapies improve symptoms?

7. What is the initial approach to the patient with chronic stable angina?

    The initial approach should be focused on eliminating unhealthy behaviors such as smoking and effectively promoting lifestyle changes that reduce CV risk, such as maintaining a healthy weight, engaging in physical activity, and adopting a healthy diet. In addition, annual influenza vaccination reduces mortality (by approximately 35%) and morbidity in patients with underlying CAD. Tight glycemic control was thought to be important in the diabetic, but this approach actually increases the risk of CV death and complications.

8. What is first-line drug therapy for the treatment of stable angina?

    When considering medications, β-blockers decrease myocardial oxygen demands by reducing heart rate, myocardial contractility, and blood pressure. They are first-line therapy in the treatment of chronic CAD, as they delay the onset of angina and increase exercise capacity in subjects with stable angina.

9. Is any β-blocker better than the others?

    Although the various β-blockers have different properties (i.e., cardioselectivity, vasodilating actions, concomitant α-adrenergic inhibition, and partial β-agonist activity [Table 16-2]), they appear to have similar efficacy in patients with chronic stable angina. β-blockers prevent reinfarction and improve survival in survivors of MI, but such benefits have not been demonstrated in patients with chronic CAD without previous MI.

10. What is the proper dose of β-blocker?

    The dose of β-blocker is titrated to achieve a resting heart rate of 55 to 60 beats per minute and an increase in heart rate during exercise that does not exceed 75% of the heart rate response associated with the onset of ischemia. β-blockers are contraindicated in the presence of severe bradycardia, high-degree atrioventricular block, sinus node dysfunction, and uncompensated heart failure. They are also contraindicated in the patient with vasospastic angina, in whom they may worsen angina as a result of unopposed α-adrenergic stimulation; calcium channel blockers are preferred in these patients.

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