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Chronic Stable Angina

In document Board Review From Medscape (Page 60-65)

43. A previously healthy 52-year-old man presents with complaints of intermittent substernal chest dis-comfort. The pain does not radiate. The symptoms occur with exercise, and they are not relieved by rest.

The patient does not have shortness of breath. The resting ECG is normal. You determine that the patient has an intermediate pretest probability of having significant coronary artery disease, and you elect to have him undergo exercise ECG testing to further evaluate his symptoms.

Which of the following findings would be most highly suggestive of significant ischemic heart disease (IHD) on exercise ECG testing?

❏ A. Chest discomfort before completion of the test

❏ B. Hypertension during the test

❏ C. An S3heart sound during the test

❏ D. A 0.5 mm ST segment depression during the test

Key Concept/Objective: To understand the significant positive findings during exercise ECG testing

Recently published guidelines from the American College of Cardiology/American Heart Association/American College of Physicians (ACC/AHA/ACP) recommend exercise ECG as the diagnostic test of choice for the average patient with an intermediate pretest proba-bility of IHD and a normal resting ECG. Exercise-induced falls in blood pressure or the development of an exercise-induced S3heart sound are strongly suggestive of ischemic left ventricular dysfunction. Specific exercise-induced ECG changes include changes 1 mm horizontal or downward-sloping ST segment depression or elevation during or after exer-cise. Exercise-induced changes in lead V5 are most reliable for the diagnosis of IHD.

(Answer: C—An S3heart sound during the test)

44. A 56-year-old man with hypertension presents to your clinic for a routine health maintenance visit. He is asymptomatic and takes only hydrochlorothiazide. His blood pressure is 138/78 mm Hg. His total cho-lesterol level is 190 mg/dl, and his high-density liproprotein (HDL) chocho-lesterol level is 36 mg/dl. He is a nonsmoker. He tells you he is concerned about IHD and that he has read about new methods to detect early disease, including CT imaging. He is interested in this screening test in hope of detecting any dis-ease he may have before it becomes a problem.

How should you advise this patient with regard to electron-beam computed tomography (EBCT)?

❏ A. You should tell him that EBCT is a safe and effective method of detect-ing early coronary artery disease

❏ B. You should recommend this test because it will hopefully alleviate his concerns about IHD

❏ C. You should recommend against this form of testing because his risk of heart disease can be equally well determined by the information already known about him

❏ D. You should recommend against this test because even if the test is neg-ative, he would still have a high likelihood of having significant lesions

Key Concept/Objective: To understand the limitations of new technology in the diagnosis of IHD

Although the sensitivity of EBCT for the diagnosis of significant coronary artery stenosis is high, the specificity of EBCT for significant coronary artery stenosis ranges from only 41% to 76%, yielding many false positive results. To date, no prospective, population-based studies have been performed to investigate a potential association between the calcium score derived from EBCT and the risk of future coronary events, and no studies have shown that screening for IHD with EBCT reduces mortality. Asymptomatic patients for whom EBCT results indicate a potentially high risk of cardiac events may suffer anxiety and unnecessary procedures as a result of the study. The ACC/AHA do not currently rec-ommend EBCT and other imaging procedures, such as magnetic resonance imaging

angiography, in asymptomatic patients. (Answer: C—You should recommend against this form of testing because his risk of heart disease can be equally well determined by the information already known about him)

45. A 61-year-old woman was recently admitted to the hospital with acute coronary syndrome. She was found to have coronary artery disease that is not amenable to revascularization procedures. She is hyper-tensive and has hyperlipidemia. She smokes approximately 1 pack of cigarettes a day. She currently has stable angina. Medical therapy and lifestyle changes are recommended for this patient.

Which of the following statements is true regarding the management of this patient?

❏ A. Clopidogrel and ticlopidine are equally effective in reducing future cardiovascular events

❏ B. Smoking cessation is as effective as or more effective than any current medical therapy in reducing the risk of future cardiovascular events

❏ C. Patients with chronic stable angina should be placed on statin therapy only if their low-density lipoprotein (LDL) cholesterol level is greater than 100 mg/dl

❏ D. It is clear that patients who walk for at least 1 hour five to seven times a week derive more benefit than patients who walk only for 30 min-utes five to seven times a week

Key Concept/Objective: To understand the management of patients with IHD and chronic stable angina

A systematic review of prospective cohort studies of smokers with IHD found a striking 29% to 36% relative risk reduction in all-cause mortality for patients who were able to quit smoking. The magnitude of the risk reduction for smoking cessation was as great as or greater than that expected to result from use of aspirin, statins, beta blockers, or angiotensin-converting enzyme (ACE) inhibitors. Patients with chronic stable angina should be encouraged to include moderate aerobic activity in their daily lives. Moderate physical activity consists of walking briskly for 30 minutes or more five to seven times a week or the equivalent. There are no studies demonstrating that ticlopidine reduces car-diovascular events in outpatients with chronic stable angina. Results of the Heart Protection Study indicate that all patients with chronic stable angina should be treated with a statin, barring specific allergy. (Answer: B—Smoking cessation is as effective as or more effective than any current medical therapy in reducing the risk of future cardiovascular events)

46. A 72-year-old male patient has long-standing IHD. He has significant angina that is stable but causes him considerable distress and limits his activities of daily living. You hope to improve his anginal symptoms.

For this patient, which of the following statements regarding the management of the symptoms of chronic stable angina is true?

❏ A. Because of bronchospasm, beta blockers are usually not well tolerated in patients with chronic obstructive pulmonary disease

❏ B. Although both beta blockers and calcium channel blockers are effec-tive in the treatment of angina, the combination of these two medi-cines offers little additional benefit

❏ C. Patients with left ventricular systolic dysfunction should never be started on calcium channel blockers because of their negative inotrop-ic effects

❏ D. Nitrates should not be used as treatment for anginal symptoms within 24 hours of taking sildenafil for erectile dysfunction

Key Concept/Objective: Understand the appropriate management of the symptoms of chronic stable angina

Beta blockers are generally well tolerated in patients with chronic obstructive pulmonary disease, although they may exacerbate bronchospasm in patients with severe asthma.

Calcium channel blockers can be used as monotherapy in the treatment of chronic stable angina, although combinations of beta blockers and calcium channel blockers relieve angina more effectively than either agent alone. Calcium channel blockers are con-traindicated in the presence of decompensated congestive heart failure, although the vasoselective dihydropyridine agents amlodipine and felodipine are tolerated in patients with clinically stable left ventricular dysfunction. Nitroglycerin and nitrates should not be used within 24 hours of taking sildenafil or other phosphodiesterase inhibitors used in the treatment of erectile dysfunction, because of the potential for life-threatening hypoten-sion. (Answer: D—Nitrates should not be used as treatment for anginal symptoms within 24 hours of taking sildenafil for erectile dysfunction)

47. A 70-year-old man presents to establish care. His medical history is remarkable for hypertension and a myocardial infarction 3 years ago. His medications include aspirin, 325 mg daily; metoprolol, 100 mg twice daily; and isosorbide mononitrate, 120 mg daily. He reports that when walking more than one block he has substernal chest pressure, which is relieved by rest. He had a cardiac catheterization 2 months ago that showed a left main coronary artery stenosis of 80%, a proximal left anterior descend-ing artery stenosis of 60%, and a 70% stenosis of the first obtuse marginal branch. The left ventricular ejection fraction (LVEF) was estimated at 45%.

Which of the following therapies would be most beneficial for this patient?

❏ A. Continuing the patient's current medication regimen without modification

❏ B. Percutaneous transluminal angioplasty (PCTA)

❏ C. Coronary artery bypass graft (CABG)

❏ D. Enhanced external counterpulsation therapy (EECP)

❏ E. Transmyocardial revascularization procedure (TMR)

Key Concept/Objective: To know the indications for coronary artery bypass surgery

CABG is recommended in patients with any of the following criteria: significant left main coronary artery disease, three-vessel disease (in patients with three-vessel disease, those with LVEF < 50% have the greatest survival benefit), and two-vessel disease with signifi-cant left anterior descending coronary artery involvement or abnormal LV function (LVEF

< 50%). In patients with three-vessel disease and abnormal LVEF, the survival benefit and symptom relief of CABG are superior to those of PCTA or medical therapy. EECP involves leg cuffs that inflate and deflate to augment venous return. This therapy may be helpful in decreasing angina in patients who have refractory angina and are not candidates for revascularization. In TMR, a laser is used to create channels in the myocardium to relieve angina. This procedure has been shown to improve severe refractory angina in patients who could not be treated with conventional revascularization techniques (PCTA or CABG).

For the patient described here, CABG is the preferred procedure. (Answer: C—Coronary artery bypass graft [CABG])

48. A 65-year-old woman presents to the emergency department with anterior chest pain that has been radi-ating to her left arm for the past 10 minutes. She had just run one block to catch a bus before she called the paramedics. Her pain was quickly relieved by two sublingual nitroglycerin tablets given by the para-medics. She said she has had similar pain with exertion over the past 3 years and has been using her hus-band's nitroglycerin occasionally. Her medical history is remarkable for diabetes. Her only medication is glyburide, 5 mg daily. Her blood pressure is 110/60 mm Hg; pulse, 80 beats/min; and respirations, 20 breaths/min. Examination reveals a moderately obese woman in no apparent distress. Heart rate and rhythm are regular, without murmur, and the lungs are clear to auscultation.

Which of the following medications should not be used to treat this patient's angina?

❏ A. Metoprolol extended release, 100 mg p.o., q.d.

❏ B. Aspirin, 325 mg p.o., q.d.

❏ C. Nifedipine, 20 mg p.o., t.i.d.

❏ D. Isosorbide dinitrate, 10 mg p.o., t.i.d.

❏ E. Nitroglycerin sublingual, 0.4 mg, q. 5 min, p.r.n. chest discomfort

Key Concept/Objective: To understand the agents used in the pharmacologic treatment of angina Although not an antianginal, aspirin, 75 to 325 mg daily, should be used in all patients who have angina without specific contraindications, because it has been shown to reduce the risk of adverse cardiovascular events by 33%. Beta blockers, such as metoprolol, are the cornerstone of angina treatment because they are the only antianginals shown to reduce the risk of death and myocardial infarction. Diabetes and use of hypoglycemic medica-tions are not contraindicamedica-tions to beta-blocker therapy, because there is no increase in hypoglycemic events or hypoglycemic unawareness with the use of beta blockers. Nitrates, such as isosorbide dinitrate and nitroglycerin, are effective antianginals, but they do not reduce the risk of cardiac events or death. Calcium channel blockers are effective antiang-inals. Short-acting agents such as immediate-release nifedipine may increase the risk of vascular events and are associated with hypotension, and therefore, they should be avoid-ed. If calcium channel blockers are used, those agents with a long half-life or slow-release formulations should be used. (Answer: C—Nifedipine, 20 mg p.o., t.i.d.)

49. A 72-year-old man with a history of myocardial infarction 10 years ago and angina presents with com-plaints of recurrent chest pain, which he has been experiencing over the past 4 months. This pain is ret-rosternal, is brought on by exertion, and is relieved by rest. The patient has been taking aspirin, long-acting diltiazem, simvastatin, atenolol, and isosorbide dinitrate at maximal doses. His blood pressure is 130/80 mm Hg; pulse, 62 beats/min; and respirations, 16 breaths/min. Physical examination is normal.

ECG shows normal sinus rhythm, with left bundle branch block.

Which of the following tests would be most useful in the evaluation of this patient's angina?

❏ A. Exercise treadmill ECG

❏ B. Exercise treadmill cardiac nuclear imaging

❏ C. Exercise treadmill echocardiography

❏ D. Dobutamine echocardiography

❏ E. Cardiac catheterization

Key Concept/Objective: To understand the modalities available for diagnostic testing and the utility of these tests in various patients

This patient has known coronary artery disease and angina that is refractory to maximal medical management. The diagnosis of angina is firmly established with high probability because this patient has known coronary artery disease and typical symptoms. The patient's baseline ECG has left bundle branch block, and therefore, exercise stress testing is not interpretable. Exercise treadmill cardiac nuclear imaging, exercise treadmill echocar-diography, and pharmacologic stress echocardiography all have higher specificity and sen-sitivity than conventional exercise tolerance testing and give information about function-al anatomy. However, the most useful test for this patient would be cardiac catheterization, because he has symptoms despite maximal medical management, is therefore highly like-ly to need revascularization, and needs to have his cardiac vascular anatomy defined with cardiac catheterization. (Answer: E—Cardiac catheterization)

50. A 60-year-old man with complaints of substernal chest pressure, brought on only by vigorous activity and relieved by rest, returns for a follow-up appointment. He takes no medications and has smoked one pack of cigarettes a day for 40 years. His blood pressure is 120/70 mm Hg; pulse, 75 beats/min; and respirations, 16. Examination reveals a thin man in no distress. Heart examination reveals a regular rhythm, with no murmurs. Jugular venous pressure is estimated at 5 cm, lungs are clear to auscultation, and extremities are without edema. The patient had an exercise treadmill thallium study that showed a small reversible defect, which prompted cardiac catheterization. This revealed a 70% stenosis of the circumflex artery. His ejection fraction was estimated at 60%. His serum LDL cholesterol is 120 mg/dl, and HDL cholesterol is 35 mg/dl.

Which of the following measures would not be appropriate in this setting?

❏ A. Atorvastatin, 80 mg p.o., q.d.

❏ B. Nitroglycerin, 0.4 mg sublingual, p.r.n. chest pain

❏ C. Coronary artery bypass graft (CABG)

❏ D. Ramipril, 10 mg p.o., q.d.

❏ E. Atenolol, 50 mg p.o., q.d.

Key Concept/Objective: To understand the management of single-vessel and two-vessel coronary artery disease (CAD)

Patients who have one- or two-vessel CAD without significant proximal left anterior descending artery stenosis, who have mild symptoms or have not received adequate antianginal therapy, and who have a small area of reversible ischemia do not benefit from revascularization with CABG or PCTA. Patients with known CAD should be treated to achieve a target LDL < 100 mg/dl. Beta blockers are effective antianginals and reduce mor-tality. Nitrates are useful as antianginals but do not alter mormor-tality. Ramipril, 10 mg daily, was studied in the HOPE trial1and was found to significantly reduce the risks of death, myocardial infarction, and stroke. The patients in that study were older than 55 years, had known cerebrovasular disease or diabetes, had one cardiovascular risk factor (e.g., smok-ing, hypertension, hyperlipidemia), and did not have heart failure or known low ejection fraction. (Answer: C—Coronary artery bypass graft [CABG])

1. Yusuf S, Sleight P, Pogue J, et al: Effects of an angiotensin-converting- enzyme inhibitor, ramipril, on cardiovas-cular events in high-risk patients: The Heart Outcomes Prevention Evaluation Study Investigators. N Engl J Med 342:145, 2000

51. A 70-year-old man presents to his physician with complaints of chest tightness. The sensation is sub-sternal, is brought on by exertion, and is relieved by rest. He is able to walk several blocks before he notes chest pressure. His medical history is remarkable only for hypertension and hyperlipidemia. His med-ications are hydrochlorothiazide, 25 mg daily, and aspirin, 325 mg daily.

Which of the following statements is true for this patient regarding exercise treadmill testing?

❏ A. It is helpful to rule out angina

❏ B. It is helpful to establish the diagnosis of angina

❏ C. It is helpful to either establish or exclude the diagnosis of angina

❏ D. It is helpful to neither establish nor exclude the diagnosis of angina

❏ E. It will not give any prognostic information about morbidity

Key Concept/Objective: To understand the pretest probability of angina and the effect of diag-nostic testing on the posttest probability of angina

In this male patient, who is older than 65 years and has typical angina, the pretest proba-bility of significant coronary atherosclerosis is 93% to 97%. Exercise treadmill ECG has limited sensitivity and specificity. Therefore, the posttest probability after a positive or a negative test is only a few percentage points different from the pretest probability in a patient such as this one, who has a high pretest probability of coronary artery disease. In this patient, then, exercise treadmill testing (ETT) is not helpful for diagnosing angina (sus-picion was sufficiently high before a test was conducted), nor is it helpful in excluding the diagnosis (because a negative test would most likely be a false negative). Exercise testing is most useful for diagnosing coronary artery disease in patients with an intermediate pretest probability (e.g., 20% to 80%). The ETT does provide useful information about the severi-ty of disease and prognosis. (Answer: D—It is helpful to neither establish nor exclude the diagnosis of angina)

For more information, see Sutton PR, Fihn SD: 1 Cardiovascular Medicine: IX Chronic Stable Angina. ACP Medicine Online (www.acpmedicine.com). Dale DC, Federman DD, Eds.

WebMD Inc., New York, December 2004

In document Board Review From Medscape (Page 60-65)