Management of Stable Angina Pectoris Bushra Abdul Hadi

Angina Pectoris Classic angina is characterized by substernal squeezing chest pain, occurring with stress and relieved with rest or nitroglycerin. May radiate down the left arm May be associated with nausea, vomiting, or diaphoresis.

Angina

Stable Angina Classification Exertional Variant Anginal Equivalent Syndrome Prinzmetal’s Angina Syndrome-X Silent Ischemia

Angina: Exertional Coronary artery obstructions are not sufficient to result in resting myocardial ischemia. However, when myocardial demand increases, ischemia results.

Angina: Variant Angina Transient impairment of coronary blood supply by vasospasm or platelet aggregation Majority of patients have an atherosclerotic plaque Generalized arterial hypersensitivity Long term prognosis very good

Angina: Anginal Equivalent Syndrome Patient’s with exertional dyspnea rather than exertional chest pain Caused by exercise induced left ventricular dysfunction

Angina: Prinzmetal’s Angina Spasm of a large coronary artery Transmural ischemia ST-Segment elevation at rest or with exercise Not very common

Angina: Syndrome X Typical, exertional angina with positive exercise stress test Anatomically normal coronary arteries Reduced capacity of vasodilation in microvasculature Long term prognosis very good Calcium channel blockers and beta blockers effective

Angina: Silent Ischemia Very common More episodes of silent than painful ischemia in the same patient Difficult to diagnose Holter monitor Exercise testing

Angina: Treatment Goals Feel better Live longer

Angina: Prognosis Left ventricular function Number of coronary arteries with significant stenosis Extent of jeoporized myocardium

Stable Angina Risk stratification Noninvasive testing Cardiac catheterization

Stable Angina Evaluation of LV Function Physical exam CXR Echocardiogram

Stable Angina Evaluation of Ischemia History Baseline Electrocardiogram Exercise Testing

CCSC Angina Classification Class I Class II Class III Class IV Angina only with extreme exertion Angina with walking 1 to 2 blocks Angina with walking 1 block Angina with minimal activity

Stable Angina Exercise Testing The goal of exercise testing is to induce a controlled, temporary ischemic state during clinical and ECG observation

Angina: Exercise Testing

Angina: Exercise Testing High Risk Patients Significant ST-segment depression at low levels of exercise and/or heart rate<130 Fall in systolic blood pressure Diminished exercise capacity Complex ventricular ectopy at low level of exercise

Angina: Exercise Testing Low Risk Group CASS Registry: 7 year survival Less than 1 mm ST depression in Stage III of Bruce Protocol Annual mortality: 1.3% JACC 1986;8:741-8

ECG Treadmill EST in Women Higher false-positive rate Reduces procedures without loss of diagnostic accuracy Only 30% of women need be referred for further testing

Stable Angina Guidelines for Nuclear EST Diagnosis/prognosis for CAD Non-diagnostic EST Abnormal resting ECG Negative EST with continued chest pain Intermediate probability of disease

Stable Angina Guidelines for Nuclear EST Defined CAD Post infarct risk stratification Risk stratification to determine need for revascularization ( viability study )

Stable Angina Dipyridamole Nuclear EST Near equivalent sensitivity/specificity with symptom-limited nuclear EST Most useful in patients who cannot exercise Major contraindication is severe bronchospastic lung disease ( consider Dobutamine study )

Appropriateness of Radionuclide Exercise Testing Retrospective analysis of 1092 patients 64% of tests ordered by cardiologists were indicated 30% of tests ordered by non-cardiologists were indicated Excessive charges from non-indicates tests were $1,082,400 Am J Card 1996;77:139-42

Stable Angina Stress Echo Ischemia may cause wall motion abnormalities, no rise of fall in LVEF Sensitivity/specificity same as nuclear testing May be better in women

Stress Echo vs. Nuclear Stress

Exercise Testing Contraindications MI—impending or acute Unstable angina Acute myocarditis/pericarditis Acute systemic illness Severe aortic stenosis Congestive heart failure Severe hypertension Uncontrolled cardiac arrhythmias

Stable Angina Non-Invasive Evaluation

Cardiac Catheterization Indications Suspicion of multi-vessel CAD Determine if CABG/PTCA feasible Rule out CAD in patients with persistent/disabling chest pain and equivocal/normal noninvasive testing

Risk Factor Modification Hypertension Smoking Dyslipidemia Diabetes Mellitus Obesity Stress Homocysteine

Stable Angina Treatment Options

Medical Treatment

Stable Angina Current Pharmacotherapy Beta-blockers Calcium channel blockers Nitrates Aspirin Statins ? ACE inhibitors

Stable Angina Considerations when Choosing a Drug Effect on myocardium Effect on cardiac conduction system Effect on coronary/systemic arteries Effect on venous capitance system Circadian rhytm

Beta-Blockers Decrease myocardial oxygen consumption Blunt exercise response Beta-one drugs have theoretical advantage Try to avoid drugs with intrinsic sympathomimetic activity First line therapy in all patients with angina if possible

Beta-Blockers

Beta Blockers Side Effects Bronchospasm Diminished exercise capacity Negative inotropy Sexual dysfunction Bradyarrhythmia Masking of hypoglycemia Increased claudication Hair loss

Beta Blockers Common Available Agents Propranolol Atenolol Metoprolol Nadolol Timolol

Calcium Channel Blockers Mechanisms of Action Arterial dilation/after-load reduction Coronary arterial vasodilation Prevention of coronary vasoconstriction Enhancement of coronary collateral flow Improved subendocardial perfusion Slowing of heart rate with diltiazem, verapamil

Calcium Channel Blockers Mechanisms of Action

Calcium Channel Blockers Side Effects Palpitations Headache Ankle edema Gingival hyperplasia

Calcium Channel Blockers Available Agents Verapamil Diltiazem Nifedipine Nicardipine Amlodipine Felodipine Nisoldipine Bepridil

Stable Angina Treatment Options

Nitrates Mechanisms of Action Nitric oxide has been identified as endothelium-derived relaxing factor Organic nitrates are therapeutic precursors of endothelium-derived relaxing factor

Nitrates Mechanisms of Action Venous vasodilation/pre-load reduction Arterial dilation/after-load reduction Coronary arterial vasodilation Prevention of coronary vasoconstriction Enhancement of coronary collateral flow Antiplatelet and antithrombotic effects

Nitrates Reducing Tolerance Smaller doses Less frequent dosing Avoidance of long-acting formulations unless a prolonged nitrate-free interval is provided Build-in a nitrate-free interval o 8-12 hours

Nitrates Side Effects Headache Flushing Palpitations Tolerance

To provide optimal benefit to patients, clinicians must use nitroglycerin more systematically and critically than they have before W. Frischman

Nitrates Common Available Agents Isorbide dinitrate Isorbide mononitrate Long-acting transdermal patches Nitroglycerin sl

Stable Angina Treatment Options CABG

Stable Angina Results of CABG 65% remain symptom-free at ten years 85% remain free of fatal/nonfatal MI at ten years Mortality of 2-3% yearly over ten years 2.5% incidence of perioperative MI

CABG vs. Medical Rx Three major randomized trials A. VACS B. ECSS C. CASS Improved mortality in CABG group A. L-main CAD B. 3-vessel CAD, esp. with decreased EF C. LAD disease, severe angina, decreased EF

Stable Angina: CABG “Nevertheless, bypass grafting remains a palliative procedure, as is every known treatment for coronary disease, and it assure permanent freedom neither from symptoms nor from a fatal coronary event…” Hull R. Tex Hrt Jnl 1989;16:

Stable Angina Treatment Options PTCA

PTCA vs. Medical Management Review of six major trials Greater symptomatic benefit in PTCA group No change in mortality or rates of MI Higher rate of CABG in PTCA group BMJ 2000(Jul);321:73-77.

PTCA vs Medical Management Multivessel Disease

Stable Angina Results of PTCA 80% or greater success rate 1% mortality 3-5% emergency CABG ( prior to stenting ) 4% acute MI

CABG vs PTCA Multivessel Disease Review of six major randomized trials Most patients had preserved LVEF No differences in mortality or combined endpoint of death and nonfatal MI Second revascularization procedure more likely in first year after PTCA Surgery patients more likely to be angina free at one year

CABG vs. PTCA Multivessel Disease Most patients had 2-vessel CAD, preserved LVEF, and “suitable” anatomy

CABG vs. PTCA BARI Trial Subset of Diabetic Patients A. Five-year survival better in CABG group B. Increased incidence of MI at eight years C. More women, hypertension, CHF, and severe concomitant noncardiac disease D. More multi-vessel disease, significant lesions, and distal lesions

Stable Angina: 1-Vessel CAD Therapeutic Strategies Initiate pharmacologic treatment A. Nearly half of patients will become asymptomatic PTCA preferred alternative if medical therapy does not relieve angina or causes adverse effects

Stable Angina: 2-Vessel CAD Therapeutic Strategies Initial medical management in patients with mild ischemic symptoms and normal LV function Revascularization in patients who fail medical therapy Selection of PTCA vs. CABG depends on coronary anatomy, LV function, need for complete revascularization, and patient preference

Stable Angina: 3-Vessel CAD Therapeutic Strategies CABG in patients with left-main disease or 3-vessel CAD and decreased LVEF PTCA or medical management an alternative in patients with 3-vessel CAD, mild symptoms, and preserved LVEF

Chronic Angia: Reading List Gersh BJ, Solomon AJ. Management of chronic stable angina: medical therapy, PTCA, and CABG. Ann Internal Med 1998(FEB);128: