Coronary Artery Disease (CAD)
Summary
Coronary artery disease (CAD) is the leading cause of death in the United States. As plaque accumulates in the coronary arteries, blood flow to the heart decreases. The location of these blockages, the specific coronary arteries affected, and the number of lesions all influence the timing and severity of blood flow restriction. A rapidly occurring occlusion in the proximal left main coronary artery can lead to sudden death if not promptly treated. In contrast, a slowly progressing, diffuse lesion in a distal segment of the right coronary artery may remain asymptomatic and never cause significant effects.
Classic symptoms such as chest pain, shortness of breath, and diaphoresis often prompt patients to seek medical attention. The initial evaluation includes troponin testing and an EKG, while the definitive diagnosis is made through coronary angiography. Treatment is guided by findings from cardiac catheterization.
Key Terms
- Atherosclerosis
- mostly substances of cholesterol, fatty acids, cellular waste products, calcium and fibrin builds up inside of arteries as plaque. The arterial wall becomes thick and hard because of the plaques. The process and result is atherosclerosis.
- Plaque
- buildup of cholesterol, fatty substances, cellular waste products, calcium and fibrin in the arteries
- Lesion
- in the context of CAD, refers to a spot within the coronary artery that is constricted due to plaque buildup
- GDMT
- goal directed medical therapy.
- Angina
- CCD
- Chronic Coronary Artery Disease
Epidemiology
- Leading cause of death worldwide.
- Prevalence increases with age.
- More common in males, though risk increases in postmenopausal females.
- Demographics
- Black (non hispanic) > Asian > Pacific Islander > Hispanic > White > American Indian / Alaskan Native
- Major risk factors: hypertension, hyperlipidemia, smoking, diabetes, and family history.
Etiology
- Atherosclerosis is the primary cause, leading to plaque buildup in coronary arteries.
- Risk factors include modifiable (e.g., smoking, diet) and non-modifiable (e.g., age, genetics) factors.
- Other rare causes: coronary artery spasm, congenital abnormalities, and vasculitis.
Pathophysiology
- Plaque buildup
- Plaque buildup in coronary arteries reduces blood flow to the myocardium
- Plaque rupture can lead to thrombosis and acute coronary syndromes.
- imbalance between oxygen supply and demand.
- Stable angina results from partial occlusion and increased oxygen demand.
- Unstable angina or myocardial infarction occurs with plaque rupture and thrombosis.
- Prolonged ischemia leads to myocardial cell death.
History of Present Illness
- Range of Sx
- Silent Ischemia
- Stable Angina
- Acute Coronary Syndrome (ACS)
- Unstable Angina
- Non-ST Elevation Myocardial Infarction (NSTEMI)
- ST Elevation Myocardial Infarction (STEMI)
- Myocardial Infarction
- Sudden Cardiac Death
- Typical chest pain: substernal discomfort, pressure, or tightness.
- Radiation to the left arm, neck, or jaw.
- Associated symptoms: dyspnea, diaphoresis, nausea, and fatigue.
- Exacerbated by exertion or stress; relieved by rest or nitroglycerin.
- Consider atypical symptoms in females, diabetics, and the elderly (e.g., fatigue or shortness of breath).
Physical Examination
- May be normal in stable cases.
- Signs of ischemia: diaphoresis, pallor, tachycardia.
- Evidence of heart failure: jugular venous distension, peripheral edema, rales on lung auscultation.
- Presence of carotid bruits or diminished peripheral pulses indicates generalized atherosclerosis.
Diagnostics
- Gold Standard: Coronary Angiography
- Electrocardiogram (ECG): ST changes, T-wave inversion, or Q waves.
- Cardiac biomarkers: elevated troponin and CK-MB in myocardial infarction.
- Stress testing: identifies ischemia with exercise or pharmacologic agents.
- Non-invasive imaging: coronary CT angiography or echocardiography for functional assessment.
Treatment
- Lifestyle Modification: Smoking cessation, healthy diet, regular exercise, weight management.
- Medical Therapy:
- Antiplatelet agents (e.g., aspirin, clopidogrel).
- Beta-blockers to reduce myocardial oxygen demand.
- Statins for lipid management.
- Nitrates for symptomatic relief.
- ACE inhibitors or ARBs for patients with heart failure or diabetes.
- Revascularization:
- Percutaneous coronary intervention (PCI) with stent placement.
- Coronary artery bypass grafting (CABG) for severe multi-vessel disease.
Treatment Comparrison PCI vs. CABG
|
PCI |
CABG |
Primary Indications |
- Single or dual-vessel disease.
- STEMI
- Unstable angina or NSTEMI w/ suitable anatomy.
|
- Multi-vessel disease, especially with diabetes or ↓ LV funx.
- Left main coronary artery disease.
- Complex coronary anatomy (e.g., SYNTAX score >22).
|
Procedure |
Minimally invasive, performed via catheterization. |
Invasive, requiring open-heart surgery and grafting. |
Recovery Time |
Faster recovery (1-2 days in the hospital). |
Longer recovery (5-7 days in the hospital; weeks at home). |
Durability |
- Effective for 5-10 years depending on stent type and patient adherence.
- Higher likelihood of requiring repeat interventions.
|
- Grafts typically last 10-15 years or longer.
- Lower risk of repeat interventions compared to PCI.
|
Risks |
- Bleeding or hematoma at the catheter site.
- Stent thrombosis or restenosis.
- Allergic reaction to contrast dye.
|
- Increased risk of stroke compared to PCI.
- Infection, bleeding, or graft failure.
- Higher initial procedural risk.
|
Outcomes |
- Good outcomes for single-vessel disease.
- Lower long-term survival rates in complex disease compared to CABG.
|
- Superior survival rates in multi-vessel disease and diabetic patients.
- Better long-term outcomes for complex cases.
|
Knowledge Check
- Upon workup for coronary artery disease, which pt's should receive stress test vs. coronary angiography?
References
- American Heart Association. About atherosclerosis. Heart.org. https://www.heart.org/en/health-topics/cholesterol/about-cholesterol/atherosclerosis. Published 2025. Accessed January 25, 2025.
- Virani SS, Newby LK, Arnold SV, et al. 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines [published correction appears in Circulation. 2023 Sep 26;148(13):e148. doi: 10.1161/CIR.0000000000001183] [published correction appears in Circulation. 2023 Dec 5;148(23):e186. doi: 10.1161/CIR.0000000000001195]. Circulation. 2023;148(9):e9-e119. doi:10.1161/CIR.0000000000001168
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