Coronary Artery Disease and Acute Coronary Syndrome

Description Coronary Artery Disease (CAD) A type of blood vessel disorder that is included in the general category of atherosclerosis

Description Atherosclerosis Can occur in any artery in the body Atheromas (fatty deposits) Preference for the coronary arteries

Description Atherosclerosis Terms to describe the disease process: Arteriosclerotic heart disease (ASHD) Cardiovascular heart disease (CHD) Ischemic heart disease (IHD) CAD

Description Cardiovascular diseases are the major cause of death in the US and Canada Heart attacks are still the leading cause of all cardiovascular disease deaths and deaths in general

Etiology and Pathophysiology Atherosclerosis is the major cause of CAD Characterized by a focal deposit of cholesterol and lipids, primarily within the intimal wall of the artery

Etiology and Pathophysiology Endothelial lining altered as a result of chemical injuries Hyperlipidemia Hypertension

Etiology and Pathophysiology Bacteria and/or viruses may have role in damaging endothelium by causing local inflammation C-reactive protein (CRP) Nonspecific marker of inflammation Increased in many patients with CAD Chronic exposure to CRP triggers the rupture of plaques

Etiology and Pathophysiology Endothelial alteration  Platelets are activated Growth factor stimulates smooth muscle proliferation Cell proliferation entraps lipids, which calcify over time and form an irritant to the endothelium on which platelets adhere and aggregate

Etiology and Pathophysiology Endothelial alteration  Thrombin is generated Fibrin formation and thrombi occur

Response to Endothelial Injury Fig. 33-3

Stages of Development in Atherosclerosis Fig. 33-4

Etiology and Pathophysiology Collateral Circulation Analogous to “detours” around atherosclerotic plaques Occur normally in coronary circulation But collaterals increase in the presence of chronic ischemia When occlusion occurs slowly over a long period, there is a greater chance of adequate collateral circulation developing

Collateral Circulation Fig. 33-5

Risk Factors for Coronary Artery Disease Risk factors can be divided: Unmodifiable risk factors Modifiable risk factors

Risk Factors for Coronary Artery Disease Unmodifiable risk factors: Age Gender Ethnicity Genetic predisposition

Risk Factors for Coronary Artery Disease Modifiable risk factors: Elevated serum lipids Hypertension Smoking Obesity Physical inactivity Diabetes mellitus Stressful lifestyle

Risk Factors for Coronary Artery Disease Health Promotion Identification of high-risk persons Management of high-risk persons Risk factor modification Physical fitness Health education in schools Nutrition (weight control, ↓ fat, ↓ chol intake) Cholesterol-lowering medications

Types of Angina Types of Angina Results when the lack of oxygen supply is temporary and reversible Types of Angina Stable Angina Prinzmetal Angina Unstable Angina

Stable Angina Pectoris Chest pain occurs intermittently over a long period with the same pattern of onset, duration, and intensity of symptoms Can be controlled with medications on an outpatient basis Pain usually lasts 3 to 5 minutes Subsides when the precipitating factor is relieved Pain at rest is unusual

Silent Ischemia

Prinzmetal’s Angina Occurs at rest usually d/t spasm of major coronary artery Spasm may occur in the absence of CAD

Unstable Angina Angina that is: New in onset Occurs at rest Has a worsening pattern Unpredictable Considered to be an acute coronary syndrome Associated with deterioration of a once stable atherosclerotic plaque

Clinical Manifestations Angina Chest pain or discomfort (d/t ischemia) A strange feeling, pressure, or ache in the chest Constrictive, squeezing, heaving, choking, or suffocating sensation Indigestion, burning

However Up to 80% of patients with myocardial ischemia are asymptomatic Associated with diabetes mellitus and hypertension

Location of Chest Pain Fig. 33-12

Diagnostic Studies Angina ECG Coronary angiography Cardiac markers (CK MB, Troponin) Treadmill exercise testing (stress test) Serum lipid levels C-reactive protein (CRP) Nuclear imaging

Collaborative Care Angina Treatment for stable angina:  oxygen demand and/or  oxygen supply Nitrate therapy Stent placement

Collaborative Care Angina Treatment for stable angina: Percutaneous coronary intervention Atherectomy Laser angioplasty Myocardial revascularization (CABG)

Collaborative Care Angina Drug Therapy Antiplatelet aggregation therapy Aspirin: drug of choice (for MI prevention) First line of treatment for angina

Collaborative Care Angina Drug Therapy Nitrates 1st line therapy for treatment of acute anginal symptoms Dilation of vessels

Collaborative Care Angina Drug Therapy -Adrenergic blockers Calcium channel blockers

Collaborative Care Angina Percutaneous coronary intervention Surgical intervention alternative Performed with local anesthesia Ambulatory 24 hours after the procedure

Collaborative Care Angina Stent placement Used to treat abrupt or threatened abrupt closure and restenosis following PCI

Collaborative Care Angina Atherectomy The plaque is shaved off using a type of rotational blade Decreases the incidence of abrupt closure as compared with PCI

Collaborative Care Angina Laser angioplasty Performed with a catheter containing fibers that carry laser energy Used to precisely dissolve the blockage

Collaborative Care Angina Myocardial revascularization (CABG) Primary surgical treatment for CAD Patient with CAD who has failed medical management or has advanced disease is considered a candidate

Clinical Manifestations Myocardial Infarction Pain Severe, immobilizing chest pain not relieved by rest, position change, or nitrate administration The hallmark of an MI

Clinical Manifestations Acute Coronary Syndrome (ACS) Develops when the oxygen supply is prolonged and not immediately reversible

Clinical Manifestations ACS encompasses: Unstable angina Myocardial infarction (MI)

Relationships Among CAD, Stable Angina, and MI Fig. 33-8