ARTERIOSCLEROTIC HEART DISEASE

ARTERIOSCLEROTIC HEART DISEASE - Felix B. Chang, MD; Alfonso Tafur, MD
BASICS
DESCRIPTION
• Arteriosclerosis is a group of diseases characterized by thickening and loss of elasticity of arterial walls that progressively block coronary arteries and their branches. Arteriosclerosis is the most common form of coronary arteriosclerosis. Process is chronic, occurring over many years, and is the most common cause of cardiovascular disability and death. Other forms of arteriosclerosis include arteriolosclerosis and calcific stenosis, both of which are uncommon in coronary vasculature.
• Subclinical cardiovascular disease (CVD) is defined as a plaque occurrence in carotid arteries with 25% stenosis, ankle-brachial blood pressure index (ABI) 0.9 and, coronary calcification based on Agatston calcium score 200
• Synonym(s): Coronary artery disease; Coronary heart disease; Coronary arteriosclerosis
GENERAL PREVENTION
See "Treatment: General Measures"
EPIDEMIOLOGY
• Leading cause of death in the US and Europe
• Predominant sex: Male > Female
• Predominant age for peak clinical manifestations
- Men: 50-60
- Women: 60-70
• Rare in pregnancy
Incidence
Greatest incidence in geriatric population
Prevalence
Common
RISK FACTORS
• Primary risk factors
- Diabetes mellitus (considered AHD equivalent)
- Male age >45 or female >55
- Family history of premature coronary heart disease (1st degree relative: Male 55 years, female 65 years)
- BP >140/90 or hypertension on medication
- Active cigarette abuse
- HDL cholesterol 40 mg/dL (HDL >60 mg/dL is a negative factor)
• Secondary risk factors
- Elevated LDL cholesterol
- Obesity
ETIOLOGY
• Inflammation including autoimmunity
• Atherosclerosis
• Narrowing of coronary arteries
• Embolism compromising coronary arteries at orifices
• Subintimal atheromas in large and medium vessels
ASSOCIATED CONDITIONS
• Obesity
• Hypertension
• Diabetes
• Hypercholesterolemia

DIAGNOSIS
SIGNS AND SYMPTOMS
• Variable: May remain clinically asymptomatic even in advanced disease states, for example, silent ischemia
• Clinical manifestations
- Substernal chest pain
- Exertional dyspnea
- Orthopnea
- Paroxysmal nocturnal dyspnea
- Cardiac arrhythmias
- Systolic murmur
- Cardiomegaly
- Pedal edema
Physical Exam
• Brachial artery pressures for ABI: When the 2 brachial artery pressures differ by 10 mm Hg or more, the highest brachial artery pressure is used as the denominator. For each lower extremity, the highest pressure (dorsalis pedis or posterior tibial) is used an numerator.
• 5 ABI categories: 0.90 (definite peripheral arterial disease [PAD]); 0.90-0.99 (borderline ABI); 1,00-1,09 (low-normal ABI); 1.10-1.29 (normal ABI); and >1.30 (high ABI)
TESTS
• ECG: Variable; may be normal or may see ST-segment elevation/depression and/or T-wave inversion
• Exercise stress test: Positive
Lab
• Elevated triglycerides
• Elevated total cholesterol
• Elevated LDLs
• Decreased HDLs
• Elevated cholesterol/HDL ratio
• American Heart Association statement currently supports C reactive protein is no more predictive of AHD than traditional risk factors.
Imaging
• Angiography: Narrowed coronary arteries
• Echocardiography: Wall-motion abnormalities
• Pharmacologic stress tests (dobutamine, dipyridamole, adenosine): Positive
• Stress thallium test: Positive
• Noninvasive CAD detection with multislice CT or MRI
Pathological Findings
• Gross: Narrowed coronary arteries
• Micro: Cholesterol plaques on intima of coronary vessels
• Fibrotic subendothelial connective tissue of intima with plaque
TREATMENT
GENERAL MEASURES
• Outpatient for management of risk factors
• Inpatient care for acute ischemic syndromes
• CHC or CHD risk equivalents (10 years risk >20%) has a LDL c goal 100 mg/dL
• Prevention of further disease progression
- Smoking cessation
- Treatment of hypercholesterolemia (diet, drugs)
- Increase HDL (diet, exercise)
- Control of BP (140/90; if DM or renal disease, 130/80) (4)[C)
- Diabetes mellitus treated early and adequately
- Exercise 30-40 minutes 5 times/week (4)[C]
- Prophylactic aspirin
- Stress reduction
- Diet changes
- Weight loss (BMI 25) (4)[C]
• Treatment of complications: Covered elsewhere under individual topics (e.g., angina pectoris, myocardial infarction, heart failure, stroke, and peripheral arterial occlusion)
• Preventive measures can begin early (e.g., proper nutrition, exercise, weight control, smoking deterrent programs).
Diet
• Low fat: 20-30 g of fat per day
• Weight-loss diet, if obesity a problem
• Increase soluble fiber.
Activity
Exercise may be helpful in preventing clinical coronary disease and useful for therapeutic measures; 30-40 minutes 3 times/week.
MEDICATION (DRUGS)
First Line
• Aspirin/ASA: 160-325 mg/d (clopidogrel if ASA is contraindicated; some data reflect both beneficial if history of acute coronary syndrome)
• ACE Inhibitors in all with increased risk factors, DM, or know CAD
• Cholesterol-lowering agents
- HMG-CoA reductase inhibitors (dose varies with product): atorvastatin (10-80 mg PO once daily), fluvastatin (20-80 mg/d), lovastatin (10-80 mg/d), pravastatin (10-80 mg/d), simvastatin (20-40 mg once daily), rosuvastatin (5-40 mg once daily)
• Statins also have anti-inflammatory and immunomodulatory effects by reducing monocyte adhesion to EC and endothelial secretion of cytokines and MHC call II expression.
• -3 Acid ethyl esters2-4 g EPA+DHA daily
• To increase HDL cholesterol
- Niacin: 2-6 g/d in divided doses (efficacious, but restricted by side effects)
• Gemfibrozil : 600 mg 2 b.i.d.
• Fenofibrate: 67-200 mg/d
• Probucol: 500 mg 2 b.i.d.
• Colesevelam: 3.75-4.375 g/d
• Ezetimibe: 10 mg/d
• Contraindications: Refer to manufacturer's literature.
• Precautions: Slow-release form of niacin may be linked to hepatotoxicity. Refer to manufacturer's literature.
• Significant possible interactions: Refer to manufacturer's literature.
Second Line
Ticlopidine, Dipyridamole, Clopidogrelantiplatelet activity
FOLLOW-UP
When starting HMG-CoA reductase inhibitors monitor LFT initially, follow-up ~12 weeks after starting therapy, then annually or more frequently if it is indicated.
PROGNOSIS
Guardedly favorable. Many risk factors can be modified.
COMPLICATIONS
• Myocardial infarction
• Ventricular fibrillation
• CHF
• Angina pectoris
• Sudden cardiac death
PATIENT MONITORING
• Monitor cholesterol and triglyceride levels.
• Encourage participation in other preventive programs (weight loss, smoking cessation).
REFERENCES
1. Dewey M, Teige R, Schanapauff D, et al. Noninvasive detection of coronary artery stenoses with multislice computed tomography or magnetic resonance imaging. Ann Intern Med. 2006;145:407-415.
2. Zouridakis E, Avanzas P, Arroyo-Espliquero R, et al. Markers of inflammation and rapid coronary artery disease progression in patient with stable angina pectoris. Circulation. 2004;28:110(13): 1747-1753.
3. Doria A, Sherer Y, Meroni P, et al. Inflammation and accelerated atherosclerosis: Basic mechanisms. Rheum Dis Clin N Am. 2005;31:355-362.
4. Smith SC, et al. AHA/ACC guidelines for preventing heart attack and death in patients with atherosclerotic cardiovascular disease: 2001 updateA statement for healthcare professionals from the American Heart Association and the American College of Cardiology. J Am Coll Cardiol. 2001;38:1581-1583.
ADDITIONAL READING
Knoflach M, Maryl B, Mayerl C. et al. Atherosclerosis is a paradigmatic disease or the elderly: Role of the immune system. Immunol Allergy Clin N Am. 2003;23:117-132.
MISCELLANEOUS
See also: Angina; Atherosclerosis; Myocardial Infarction