Coronary Artery Disease (CAD) Risk Factors

Atherosclerosis

• Atherosclerosis involves the thickening, loss of elasticity and calcification of arterial walls: this naturally occurs with aging
• Atherosclerosis causes plaque formation in arteries
• Arteriosclerosis and atherosclerosis are conditions that can begin in childhood, progressing asymptomatically into adulthood
• Atherosclerosis is a cause of coronary heart disease (CHD), also known as coronary artery disease (CAD)

Pathophysiology

• Atherosclerosis is a multistep process affecting the inner lining of arteries
• Injury to endothelial cells causes inflammation and immune response
• Endothelial damage stimulates smooth muscle cell growth
• These cells then secrete collagen and fibrous proteins
• Lipids, platelets, and clotting factors accumulate
• Plaque accumulates on artery walls - composed of smooth muscle cells, fibrous proteins, and cholesterol-laden foam cells
• Plaque develops a fibrous cap that calcifies and can tear or rupture
• A blood clot forms on the plaque, either blocking the coronary artery or dislodging into a smaller artery leading to the heart
• The artery can become stenosed (narrowed) by plaque buildup, leading to partial or total occlusion, reduced blood flow, and ischemia in distal areas

Etiology

• Risk factors for atherosclerosis are modifiable and non-modifiable
• Patient education is important to prevent risk factors

Risk Factors That Cannot Be Changed

• Age increases chances of arteriosclerosis and CAD
• Men have increased incidence after age 50, women after menopause
• Black Americans have a higher prevalence
• Men have more risk factors + increased CAD incidence
• CAD risk factors, like hyperlipidemia, have a genetic component

Risk Factors That Can Be Changed

Diabetes Mellitus

• Increases risk of hypertension, obesity, and elevated blood lipids

Hypertension

• Vasoconstriction increases myocardial oxygen demand

Elevated Serum Cholesterol

• Levels above 200 mg/dL increase risk of developing CAD

Elevated Low-Density Lipoprotein (LDL)

• LDL particle number or apolipoprotein B infiltrates arterial walls and rapidly causes damage

Elevated Serum Homocysteine

• Increases CAD risk; intake of food containing folic acid (fruits, green leafy vegetables) reduces homocysteine levels

Excessive Alcohol Use

• Raises blood pressure, increases triglycerides, and causes irregular heartbeats

Obesity

• Increases heart workload and risk of hypertension, diabetes, glucose intolerance, and hyperlipidemia

Sedentary Lifestyle

• Increases obesity, hypertension, and hyperlipidemia

Emotional Stress

• Increases heart workload and risk for hypertension

Tobacco Use/ Secondhand Smoke

• Causes vasoconstriction and increases myocardial oxygen demand.
• Decreases high-density lipoproteins (HDLs)

Diagnostic Tests

• Total cholesterol levels above 200 mg/dL increase risk of CAD and myocardial infarction (MI)
• Elevated LDLs and low HDLs associated with increased CAD risk
• High Lp(a) cholesterol(genetic LDL variation) is a risk factor of premature CAD
• LDL particle number (measured directly or indirectly as apolipoprotein B)is an excellent predictor of MI risk
• Apolipoprotein B particles in LDL-type cholesterol infiltrate arterial walls, rapidly causing damage
• C-reactive protein (CRP) indicates low-grade inflammation in blood vessels and an increased CAD risk
• Elevated blood glucose levels can increase the risk for atherosclerosis
• Radiological studies of the arteries can show narrowed/occluded vessels

Atherosclerosis Summary: Diagnostic Tests

• Cholesterol
• LDL particle number
• Triglycerides
• Arteriogram

Atherosclerosis Summary: Therapeutic Measures

• Low-fat, low-cholesterol diet
• Smoking cessation
• Exercise

Priority Nursing Diagnoses

• Acute pain
• Deficient knowledge

Therapeutic Measures

• A healthy lifestyle, preventing risk factors, medications, and regular physical examinations help control atherosclerosis

Diet

• Plaque in arteries is caused primarily by fatty deposits, so DASH(Dietary Approaches to Stop Hypertension) eating plan is beneficial

Smoking

• Risk of developing CAD is greater in cigarette smokers vs nonsmokers
• Risk increases proportionate to # of cigarettes smoked
• Smoking contributes to a loss of HDL, causes vasoconstriction, leading to angina pectoris and cardiac arrhythmias
• Smoking cessation benefits are dramatic and immediate
• Education about the risks of smoking/effects of exposure to secondhand and thirdhand smoke is important
• Provide information about treatments or smoking cessation programs

Exercise

• Increased activity raises HDL levels
• Increased physical activity lowers insulin resistance and facilitates weight loss
• Exercise promotes development of collateral circulation, which allows blood to flow around occlusion sites
• Check with a health-care provider (HCP) before starting an new exercise program

Medications

• Lowering lipid levels is the primary therapy
• Medication is used if dietary control is ineffective, check with doctor
• May take 4-6 weeks before lipid levels respond to medication therapy
• Injectable monoclonal antibodies are used for familial hypercholesterolemia, to treat chromosome 19 defect, can't remove LDL

Medications Used to Lower Lipid Levels: Statins

• First-line medications to reduce LDL by reducing cholesterol synthesis
• Examples: atorvastatin (Lipitor), fluvastatin (Lescol XL), lovastatin (Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor), simvastatin (Zocor)

Statins: Nursing Implications

• Monitor liver function studies
• Monitor for rhabdomyolysis (lethal breakdown of skeletal muscle)

Statins: Teaching Points

• Take medication in the evening when cholesterol synthesis is highest
• Report muscle pain to the health-care provider

Medications Used to Lower Lipid Levels: Fibrates

• Reduce triglycerides
• Examples:clofibrate (Atromid-S), fenofibrate (TriCor), gemfibrozil (Lopid)

Fibrates: Teaching Points

• Take 30 minutes before morning and evening meal
• May increase the effects of anticoagulants and hypoglycemia

Medications Used to Lower Lipid Levels: Niacin

• Prevents conversion of fats into very low LDLs
• Rarely used because of flushing
• Examples: niacin (nicotinic acid), extended-release niacin (Niaspan)

Niacin: Teaching Points

• Take aspirin 30 minutes before taking medication to reduce flushing

Medications Used to Lower Lipid Levels: Cholesterol Absorption Inhibitor

• Inhibits the absorption of cholesterol
• Decreases LDLs and increases HDLs
• Examples: ezetimibe (Zetia)

Cholesterol Absorption Inhibitor: Teaching Points

• Take with liquids and meals
• Take other medications 1 hour before, or 4 hours after

Medications Used to Lower Lipid Levels: Combination Agent

• Examples: Vytorin = ezetimibe (Zetia) + simvastatin (Zocor)

Coronary Artery Disease

• CAD is obstruction of blood flow through coronary arteries to the heart muscle cells.
• Obstruction typically comes from atherosclerosis

Prevention of Coronary Artery Disease

• Risk factors should be changed
• Low-dose aspirin recommended by HCP to prevent thrombus formation
• Million Hearts Initiative meant to prevent 1 million heart attacks/strokes within 5 years
• Priorities to improve cardiovascular health include cholesterol management, self-measured blood pressure monitoring, hypertension control, tobacco cessation, and cardiac rehabilitation

Angina Pectoris

• Angina pectoris is chest pain related to ischemia resulting from a reduction in coronary artery blood flow + oxygen delivery to myocardium
• Angina is a symptom, not a disease

Angina Pectoris Types

Stable Angina

• Occurs with moderate exertion in a recognizable pattern
• Pain is predictable, lasts a few minutes
• Relieved by rest and nitroglycerin

Vasospastic Angina

• Caused by coronary artery spasms and is serious
• Pattern is cyclical, pain occurs at same around the same time each day
• Pain lasts longer than stable angina, occurs with exercise or at rest, and often occurs at night

Microvascular Angina

• Spasms in walls of heart’s tiniest arteries reduce coronary blood flow to cause microvascular angina
• Pain is often severe and long lasting when compared with other types of anginal pain

Angina Pectoris: Signs and Symptoms

• Patients (especially men) often describe anginal chest pain as discomfort, burning, fullness, heaviness, pressure, or squeezing
• Pain radiates to adjacent areas: one or both arms (left arm is common), shoulders, neck, jaw, or back
• Referred pain occurs if pain is present in shoulders neck,jaw,arms, back, not chest
• Patients may describe heaviness in their arms or a feeling of impending doom
• During the episode of pain patient may be pale, diaphoretic, or dyspneic
• Women experience chest pain, jaw pain, or heartburn
• Women exhibit atypical symptoms: shortness of breath, fatigue, nausea, pain described as less severe

Angina Pectoris Diagnostic Tests

• Tests used include electrocardiogram (ECG), exercise stress test, echocardiography, chemical stress testing, cardiac computed tomography (CT), cardiac magnetic resonance imaging (MRI)/magnetic resonance angiogram (MRA), radioisotope imaging, and coronary angiography

Angina Pectoris Therapeutic Measures

• Treatment to prevent anginal attacks involves activity and MI
• May involve weight reduction, a heart-healthy diet, and smoking cessation
• Three major classes of medications: nitrates, beta blockers, and calcium channel blockers, antianginal medication like ranolazine (Ranexa) are used to reduce angina

Angina Pectoris Medications: Nitroglycerine

• Nitroglycerine (NTG) is medication of choice for acute anginal attacks
• For acute use, available sublingually (buccal, powder, spray, tablet) or intravenously in the hospital
• Sublingually administered NTG may relieve chest pain within 1 - 2 minutes
• Long-acting nitrates (oral or topical: ointment, transdermal patch) are for preventing acute chest pain
• Ointment or patch is removed for a 10- to 12-hour nitrate-free period to prevent development of nitrate tolerance

Sublingual Nitroglycerin: Important Points

• Take 2 more doses, 5 minutes apart, if after one tablet and 5 minutes pain is unrelieved or worsens (especially with symptoms of an MI), and call 911
• For angina: Take one NTG tablet. If symptoms aren’t worsening but aren’t relieved, repeat a tablet every 5 minutes up to three tablets total. Call 911 if pain is unresolved after three tablets

Sublingual Nitroglycerin: Important Communication

• Communicate with patients about the danger of combining nitrates with medications for erectile dysfunction, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra)
• These medications dilate blood vessels and may cause a significant drop in blood pressure if used with nitrates

Medications Used to Treat Angina Pectoris: Antiplatelets

• Inhibit platelet activation, adhesion, or procoagulant activity
• Examples: aspirin, clopidogrel (Plavix), ticagrelor (Brilinta)

Antiplatelets: Nursing implications

• Enteric-coated aspirin is beneficial for daily use
• Monitor for bleeding

Medications Used to Treat Angina Pectoris: Beta Blockers

• Decrease heart rate, contractility, and BP to reduce cardiac workload and exertional angina
• Decrease the risk of cardiac death
• Examples: atenolol (Tenormin), metoprolol (Lopressor, Toprol XL)

Beta Blockers: Nursing implications

• Check with HCP before administering medication if pulse is less than 60 bpm or systolic BP is less than 90 mm Hg

Beta Blockers: Teaching points

• Rise slowly
• Abrupt withdrawal may result in diaphoresis, palpitations, headache, and tremors

Medications Used to Treat Angina Pectoris: Calcium Channel Blockers

• Dilate peripheral arteries, decreasing myocardial contractility, depress conduction system, and decrease workload of the heart
• Reduce coronary artery spasms in vasospastic angina
• Examples: amlodipine (Norvasc), diltiazem (Cardizem, Dilacor XR), felodipine (Plendil), verapamil (Calan SR)

Calcium Channel Blockers: Nursing Implications

• Notify HCP before administering medication if pulse is less than 60 bpm or systolic BP is less than 90 mm Hg

Medications Used to Treat Angina Pectoris: Nitrates

• Vasodilate to increase blood flow to coronary arteries and reduce preload and afterload to reduce oxygen consumption of myocardium

Nitrates: Nursing Implications

• Don’t use nitroglycerine with erectile dysfunction medication due to drop in blood pressure
• Document onset, location, type, radiation, and duration of pain
• Monitor blood pressure (BP) pre- and post-administration

Nitrates: Examples

Fast Acting

• Nitroglycerin sublingual powder (GONITOR)
• Nitroglycerin sublingual, buccal (Nitrostat, NitroQuick)
• Nitroglycerin sublingual spray (Nitrolingual, Nitromist)

Long acting

• Nitroglycerin (Transderm Nitro, Nitro-Bid)
• Nitroglycerin patch (Nitro-Dur, Nitrek)
• Isosorbide dinitrate (Isordil)
• Isosorbide mononitrate (Imdur, ISMO)
• Nitroglycerin extended release (Nitro-Time)

Nitrates: Important Considerations

• Wear gloves to protect yourself from hypotension from touching the ointment or patch medication
• Remove patch prior to magnetic resonance imaging and defibrillation
• Remove current transdermal ointment to prevent overdose
• Rotate application sites
• Apply to clean. dry, hairless area daily
• Provide nitrate-free period as prescribed

Anti-Ischemic Agent

• Antianginal agent used as combination therapy for those not responding to other antianginal medication
• Examples: ranolazine (Ranexa)

Anti-Ischemic Agent: Nursing Implications

• May not be as effective in women
• Prolongs QT interval on electrocardiogram
• See relevant drug table for statins

Fast-Acting Nitroglycerin: Important Points

• Carry nitroglycerine at all times
• Keep nitroglycerine tablets tightly sealed to protect from heat, light, and moisture
• Replace nitroglycerine tablets as needed or every 6 months
• Use nitroglycerine before an activity known to cause chest pain
• Tingling should be felt under the tongue when sublingual nitroglycerine tablets are used
• Pour sublingual packet of powder under the tongue to dissolve without swallowing
• Do not shake aerosol canister before spraying it on or under the tongue
• Close mouth immediately
• Nitroglycerine may cause lightheadedness: Sit or lie down when taking nitroglycerine, and rise slowly (especially with sublingual spray)
• Nitroglycerine may initially cause a headache.

Important Points on Angina Treatment

• Beta blockers are initial therapy for exertional angina
• They decrease heart rate/contractility and lower blood pressure to reduce heart workload
• Beta blockers are ineffective for coronary artery spasms, so should not be used for vasospastic angina
• Calcium channel blockers dilate coronary arteries and peripheral vessels to increase myocardial oxygen supply and reduce cardiac workload (Are ineffective in relieving acute anginal attacks)
• Antiplatelets prevent cardiovascular events that would occur from blood clots and cause angina
• Statins prevent and treat atherosclerosis because cholesterol and inflammation in artery walls are involved in atherosclerosis development

Angina and Coronary Artery Disease: Data Collection

• Record height, weight, allergies, over-the-counter and prescription medications, use of herbs, and typical diet
• Identify nonmodifiable and modifiable risks for atherosclerosis and CAD
• Check vital signs/oxygen saturation
• Note dyspnea, labored respirations, diaphoresis, nausea, skin color, and temperature
• Document a history of chest pain, fatigue, or activity intolerance
• Note description of anginal pain, factors worsening it, how long the patient has had angina, triggering activities, and how the pain has been relieved in the past

Priority Nursing Diagnoses for Patients With Cardiac Issues

• Acute pain is related to reduced perfusion of coronary arteries: Aim to resolve the pain within 30 minutes
• Deficient knowledge is related to ineffective management of regimen

Nursing Actions for Acute Angina/Cardiac Pain

• Ask the patient to rate pain using a scale, for consistency
• Administer oxygen as ordered, to increase oxygen availability to the myocardium
• Administer fast-acting nitroglycerine (sublingual) as prescribed, to relieve pain
• Notify HCP if pain remains unrelieved after three doses of nitroglycerine (as prescribed) or if vital signs change: Chest pain unrelieved by nitrates (sublingual) may represent MI
• Help the patient to remain calm and provide support: Never leave a patient alone who has chest pain

Acute Coronary Syndromes

• ACS refers to conditions with myocardial ischemia; unstable angina, non-ST-elevation MI (NSTEMI), and ST-elevation MI (STEMI)
• With unstable angina, the ischemia doesn’t cause enough cardiac damage to release cardiac biomarkers
• NSTEMI is caused by a partial coronary artery blockage
• STEMI is caused by a complete blockage of a coronary artery, sometimes there is no obstruction with STEMI

Issues With Ischemia

• Silent Ischemia occurs without pain, can carry great risk due to being undetected
• Older adults, women, hypertension or diabetes most often have silent ischemia
• Sudden cardiac death is cardiac arrest triggered by ventricular arrhythmias or asystole from abrupt occlusion of a coronary artery
• MI requires immediate treatment in order to try to prevent death

Myocardial Infarction

• Heart’s ability requires healthy cardiac muscle
• Acute MI is death of heart muscle cells due to sudden partial or complete ischemic blockage of a coronary artery
• The extent of damage relies on the location and measure of blockage
• The extent of death can be minimized with timely reperfusion techniques

Pathophysiology of Myocardial Infarction

• Ischemic injury evolves over several hours before total necrosis
• The ischemic process is most harmful to the subendocardial area
• This results in depressed myocardial contractility: The body's attempts to compensate with the sympathetic nervous system to increase the heart rate
• Changes in heart rate increase myocardial oxygen demand, furthering the impacts on the myocardium
• Once necrosis takes place, the contractile function of the muscle is lost completely
• the heart has an area zone of ischemia and injury around the necrotic area
• The area of injury is closest to the necrotic area.
• If initiated within the first hour, treatment should be focused on blood supply restoration

Areas Impacted By Myocardial Infarctions

• The left coronary artery supplies the anterior wall (and most of the left ventricle)
• Blockage in this area causes an anterior wall MI which can cause severe loss of left ventricular function leading to severe hemodynamic issues
• The right coronary artery supplies the heart's inferior wall, parts of the atrioventricular node and the sinoatrial node.
• An inferior MI and abnormalities in cardiac conduction can results from an occlusion of the right coronary artery
• A blockage in left circumflex coronary artery results in lateral wall infarction of the left ventricle

Myocardial Infarction: Complications

• Arrhythmias like premature ventricular contractions, ventricular tachycardia/ fibrillation or heart block
• Cardiogenic Shock and heart failure or pulmonary edema and valvular insufficiency

Classic Signs and Symptoms of Myocardial Infarction

• Crushing/vise-like chest pain with radiation to arms/shoulder/hands/neck and throat/lower jaw/teeth/ or back
• General symptoms include: shortness of breath, dizziness, nausea and sweating

Atypical Signs and Symptoms of Myocardial Infarctions

• Absence of chest pain along with fatigue or cramping
• Anxiety or feelings of impending doom and falling
• Some differences are seen in women including increased shortness of breath, fatigue and pain or discomfort in the upper body and/or indigestion

Diagnostic Tests for Myocardial Infarctions

• Electrocardiogram (ECG)
• Serum cardiac troponin
• Serum myoglobin
• Complete blood count (CBC)
• Serum magnesium and potassium
• Vital signs & Oxygen saturation

Therapeutic Measures for Myocardial Infarctions

• Oxygen
• Antiplatelets & anticoagulants: aspirin and heparin
• Nitrates
• Thrombolytics
• Beta blockers
• Statin drugs
• Myocardial revascularization (coronary artery bypass grafting)
• Daily weight and bedrest with use of bedside commode
• Low-sodium diet and cardiac rehabilitation

Myocardial Infarction: Timely Treatment

• Recognize that atypically presented heart attacks may occur and to not ignore the symptom.
• Be aware that medical treatments should be sought as soon as possible since more muscle tissue is lost over time.

Women & Heart Health

• Tend to have acute MI at an older age compared to men
• Higher mortality rate with more complications such as ventricular fibrillation
• More prone to have other symptoms that classic chest pain
• Many also state unusual heart rhythms or a month out period of unusual fatigue

Special Considerations for Geriatric Myocardial Infarction Patients:

• Pain may not be present
• May experience sudden shortness of breath, fainting or restlessness
• Because of more time with collateral circulation, there may be fewer complications with MI

Diagnostic Test Considerations for Myocardial Infarction Patients:

• Medical treatment sought immediately (within 5 mins) for those with chest pain

Treatment Considerations for Myocardial Infarction Patients:

• Medical treatment sought immediately (within 5 mins) for those with chest pain or other atypical symptoms
• Restore blood flow within 90 minutes to prevent further harm

Percutaneous Intervention With Stenting: Therapeutic Action

• Coronary artery stenting with drug-eluting stents is preferred to revascularize for a Cardiac Intervention
• Inhibits smooth muscle cell proliferation to reduce the risk of a narrowed or blocked artery
• Complications with this:Thrombosis, bleeding, or dissection
• Anticoagulant therapy recommended for bleeding risk and stroke

Thrombolytic Therapy Considerations

• Must be started in specific time frame of 1-6 hours before necrosis in order to be effective

Oxygen Considerations

• Routine oxygen isn't beneficial if oxygen levels are normal

Antiplatelet & Anticoagulant Medications

• antiplatelets: aspirin
• anticoagulants: heparin
  • do not give if bleeding risk
  • dose regulated by heparin antifactor

Interventions for Patient with Coronary Artery Disease:

• Heart catheterization in order to check to see if bypass graft is ideal
• Median sternotomy in order to get graft from body and connect to heart.
• Physical therapy is required
• Maintain a minimum 40 min workout exercise routine
• Reduce risks to stay healthy

Surgical Considerations

• A Never Event is a site infection following a surgery such as CABG. Medicare will not fund the costs
• Nursing Diagnoses should be carried out from this data.
• Education about therapeutic regimens include data about diseases, treatment options, diets, etc,

Lifestyle Changes

• Smoking changes and cardiac rehabilitation improves the function and quality of life
• Patients can prevent overexertions with information given to them about how to make informed decisions.
• Patients are often nervous of beginning cardiac rehab, and can utilize stress management techniques