coronary artery disease (CAD)

facts about CAD

→ most common type of CV disease

→leading cause of death in US

→ pts may be asymptomatic or develop chronic stable angina

→ may evolve to more serious conditions of unstable angina and MI

what is CAD?

the narrowing or obstruction of one or more coronary arteries

caused by atherosclerosis

atherosclerosis

accumulation of lipid-containing plaque in the arteries

plaque hardens over time→ hardening of the arteries

can occur in any artery

→ individuals with this condition are high stroke risk

stage 1 of atherosclerosis→ chronic inflammation and injury

chronic injury and inflammation lead to a damaged endothelial lining of the artery

no longer able to repair self immediately

lipoproteins carry cholesterol and other lipids into the arterial intima

stage 2 of atherosclerosis → development of the fatty streak

earliest form of atherosclerosis

these are lipid-filled smooth muscle cells

appear in coronary arteries by age 20

stage 3 of atherosclerosis→ fibrous plaque formation

plaques can form on one side of the artery or in a circular fashion involving the entire artery lumen

may begin to develop by age 30

increase with age

stage 4 of atherosclerosis→ plaque disruption

dangerous stage

development of a complicated lesion

platelets aggregate and create a thrombus

high risk for MI

effects of CAD on perfusion

perfusion depends on the heart’s ability to generate enough cardiac output to distribute blood to all body tissues

significant CAD negatively affects heart function; impaired CO and decreased perfusion

collateral circulation

arterial anastomoses within coronary circulation

allows for an alternative supply of coronary blood flow during an episode of acute or chronic ischemia

collateral circulation can improve cardiac outcomes →still able to get blood flow

non-modifiable risk factors CAD

increasing age

biologic sex

ethnicity→ highest incidence among Black males

family history of heart disease

genetic predisposition

Heart disease in women

leading cause of death in women in the US

incidence increases after menopause

atypical symptoms of heart disease

• fatigue, weakness, SOB, upper back pain, nausea, indigestion, lightheadedness, palpitations, and anxiety

high rate of delay in treatment/ HCP identification

modifiable risk factors for CAD

elevated lipid levels

hypertension > 120/80

tobacco use

diabetes

physical inactivity

metabolic syndrome

obesity

cholesterol

necessary for building cells, production of certain hormones, & aids in digestive process

cholesterol comes from sources

• naturally produced by the liver, obtained from animal sources

too much circulating cholesterol increases risk of CAD

triglycerides & lipoproteins

triglycerides→ main storage form of lipids, aid in transportation of cholesterol throughout body

high-density lipoproteins (HDL)→ good cholesterol, remove cholesterol

low-density lipoproteins (LDL) → bad cholesterol, hold onto cholesterol

hypertension & tobacco use

HTN more common in postmenopausal women

stretched vessel walls from high blood pressure cause endothelial injury and increase risk for developing atherosclerosis

tobacco use is a major risk factor of CAD

causes vasoconstriction

affects endothelial function increase risk of atherosclerosis and blood clots

diabetes

major modifiable risk factor

incidence of CAD increases

manifestations of CAD seen earlier

aim to keep HbA1c <7% (3 month BS, life of a RBC)

physical inactivity

lack of physical activity increases risk of developing CAD

physical activity promotes lipid metabolism, increased HDL production, decrease risk of thrombus formation, and decreases workload on the heart

obesity & metabolic syndrome

death rate higher in obese patients

metabolic syndrome is a cluster of risk factors for CAD

Must have 3/5:

• central obesity

• hypertension

• hypertriglyceridemia

• low HDL levels

• high fasting glucose levels

CAD manifestations

asymptomatic

chest pain

palpitations

cold sweats

dyspnea

syncope

cough or hemoptysis

excessive fatigue

diagnostic testing

electrocardiogram (ECG)→ ST depression/ T wave inversion; STEMI

lipid panel→ cholesterol, triglyceridides, HDL, LDL

stress test→ nuclear vs treadmill

cardiac catheterization→ shows presence and extent of atheroclerotic plaques in coronary arteries

percutaneous transluminal coronary angioplasty (PTCA)

coronary artery bypass grafting (CABG)

lipid panel

cholesterol→ (<200 mg/dL)

triglycerides→ (male: 20-160; female: 35-155 mg/dL)

HDL→ (male: >45mg/dL; female >55 mg/dL)

LDL→ (<130 mg/dL)

identifying and managing high risk pts

Identifying

• thorough health hx (fam hx, current/past medical problems, meds, diet, level of activity, job)

• complete physical assessment

Managing

recommend preventative measures, maintain ideal body weight, adequate physical exercise, reduce saturated fat intake, avoid tobacco/substance abuse

physical activity guidelines

30-60 min/day of moderate aerobic activity or 15-30 min/day of high intensity aerobic activity with strength training 2days/week

FITT

F→ frequency: perform physical activity on most days of the week

I→ intensity: HR determines activity intensity

T→ types of activity: regular, rhythmic, and repetitive using large muscles

T→ time: should be at least 30 min, may vary among individuals

nutrition therapy

focus on lowering LDL levels

choose foods low in saturated fat and cholesterol

• lean meats, fat-free/low fat dairy; mono/poly unsaturated fats

increase complex carbs

• whole grains, fruit, veggies

consume omega 3-fatty acids

• fatty fish (salmon, mackerel, tuna

avoid simple sugars

• sweet treats, fruity drinks, soda, white flour

decrease sodium intake

• recommended <1500 mg/day, educate where hidden sodium is in foods

fibric acid derivatives

Fenofibrate (Tricor), Gemfibrozil (Lopid)

purpose: decrease triglycerides & LDL, increase HDL

side effects: increase liver enzymes myopathy, rhabdomyolysis

nursing considerations: increase effects of Coumadin, may increase adverse effects of statin when used together, myopathy

statins

Atorvastatin (Lipitor), Pravastatin (Pravachol), Rosuvastin (Crestor), Simvastatin (Zocor)

purpose: block synthesis of cholesterol, decrease triglycerides and LDL

side effects: increase liver enzymes, myopathy, rhabdomyolysis

nursing considerations: monitor liver enzymes, given in evening

Niacin

Niacin (NIaspan)

purpose: decrease triglycerides& LDL, increase HDL

side effects: flushing and itching on upper torso and face; GI upset orthostatic hypotension

nursing considerations: taking Aspirin 30 min before drug may decrease flushing, take with food

omega -3 fatty acid

Omega-3 acid ethyl esters (Lovaza)

purpose: decrease triglycerides, increase HDL

side effects: anaphylaxis (fish allergy), taste changes, GI problems

Nursing considerations: increase coumadin effects, take with meals, do not open or dissolve capsules