Coronary artery bypass grafting indications US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Coronary artery bypass grafting indications. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Coronary artery bypass grafting indications US Medical PG Question 1: A 71-year-old man comes to the physician for a routine health maintenance examination. He feels well. He goes for a 30-minute walk three times a week and does not experience any shortness of breath or chest or leg pain on exertion. He has not had any weakness, numbness, or vision disturbance. He has diabetes that is well controlled with insulin injections. He had smoked one pack of cigarettes every day for 40 years but quit 5 years ago. He appears healthy and well nourished. His temperature is 36.3°C (97.3°F), pulse is 75/min, and blood pressure is 136/78 mm Hg. Physical examination shows normal heart sounds. There are systolic bruits over the neck bilaterally. Physical and neurologic examinations show no other abnormalities. Fasting serum studies show:
Total cholesterol 210 mg/dL
HDL cholesterol 28 mg/dL
LDL cholesterol 154 mg/dL
Triglycerides 140 mg/dL
Glucose 102 mg/dL
Duplex ultrasonography of the carotid arteries shows a 85% stenosis on the left and a 55% stenosis on the right side. Which of the following is the most appropriate next step in management?
- A. Carotid artery stenting
- B. Aspirin therapy only
- C. Bilateral carotid endarterectomy
- D. Left carotid endarterectomy (Correct Answer)
Coronary artery bypass grafting indications Explanation: ***Left carotid endarterectomy***
- The patient has **asymptomatic carotid artery stenosis** with a **left-sided stenosis of 85%**. For asymptomatic patients, carotid endarterectomy is indicated for stenosis between 70% and 99% if the patient has a life expectancy of at least 5 years and the periprocedural stroke and death rate is low (<3%).
- This patient, despite his age, is **active and healthy**, has no neurological deficits, and his comorbidities (well-controlled diabetes, history of smoking but quit 5 years ago) are unlikely to significantly increase surgical risk beyond the benefit of stroke prevention for severe stenosis.
*Carotid artery stenting*
- While carotid artery stenting (CAS) is an alternative to endarterectomy, it is generally preferred in patients who are **high-risk for endarterectomy** due to specific anatomical or medical comorbidities, or in cases of **restenosis after endarterectomy**.
- In asymptomatic patients, **endarterectomy** is generally favored over stenting, especially for stroke prevention, as large trials have shown a slightly higher periprocedural stroke risk with stenting.
*Aspirin therapy only*
- While **aspirin and statin therapy** are crucial for patients with carotid artery disease to reduce cardiovascular events, they are **insufficient as sole treatment** for severe asymptomatic carotid stenosis (85%).
- Medical therapy alone does not provide the same level of stroke risk reduction as interventional approaches for high-grade stenosis.
*Bilateral carotid endarterectomy*
- A **bilateral procedure** is not indicated at this time. The right carotid stenosis is 55%, which in an asymptomatic patient, is typically managed with **medical therapy** rather than surgical intervention.
- Performing endarterectomy on the right side at this time would expose the patient to unnecessary surgical risk without clear benefit for immediate stroke prevention.
Coronary artery bypass grafting indications US Medical PG Question 2: A 41-year-old man presents to his primary care provider because of chest pain with activity for the past 6 months. Past medical history is significant for appendectomy at age 12 and hypertension, and diabetes mellitus type 2 that is poorly controlled. He takes metformin and lisinopril but admits that he is bad at remembering to take them everyday. His father had a heart attack at 41 and 2 stents were placed in his heart. His mother is healthy. He drinks alcohol occasionally and smokes a half of a pack of cigarettes a day. He is a sales executive and describes his work as stressful. Today, the blood pressure is 142/85 and the body mass index (BMI) is 28.5 kg/m2. A coronary angiogram shows > 75% narrowing of the left anterior descending coronary artery. Which of the following is most significant in this patient?
- A. Obesity
- B. Family history
- C. Hypertension
- D. Smoking
- E. Diabetes mellitus (Correct Answer)
Coronary artery bypass grafting indications Explanation: ***Diabetes mellitus***
- **Diabetes mellitus** is a significant risk factor for **atherosclerosis** and contributes to accelerated progression of **coronary artery disease (CAD)**, often leading to more widespread and severe disease.
- Poorly controlled diabetes can cause **endothelial dysfunction**, increasing oxidative stress and inflammation, which are key processes in **plaque formation** and destabilization.
*Obesity*
- **Obesity** (BMI 28.5 kg/m2) is a risk factor for **CAD** but often acts through associated conditions like **hypertension**, **diabetes**, and **dyslipidemia**.
- While it contributes to overall cardiovascular risk, it is less directly pathogenic than diabetes which independently accelerates **atherosclerosis**.
*Family history*
- The patient's father had a **heart attack at 41**, which is a significant risk factor for **early-onset CAD**.
- However, the patient has multiple modifiable risk factors (smoking, hypertension, diabetes) that are independently and more directly contributing to his current presentation.
*Hypertension*
- **Hypertension** (142/85 mmHg) is a major modifiable risk factor that causes **endothelial damage** and promotes **atherosclerosis**.
- While important, the patient's **poorly controlled diabetes mellitus** often creates a more aggressive environment for plaque formation and progression compared to hypertension alone.
*Smoking*
- **Smoking** is a potent, modifiable risk factor that causes direct vascular injury, promotes **thrombogenesis**, and contributes to **atherosclerosis**.
- Although highly detrimental, smoking is one of several significant risk factors; **diabetes mellitus**, with its systemic metabolic impact, can be considered more broadly influential in the severity and diffuse nature of **CAD**.
Coronary artery bypass grafting indications US Medical PG Question 3: A 72-year-old man arrives at the emergency department 30 minutes after developing rapid onset right-sided weakness and decreased sensation on the right side of his body. The patient’s wife also reports that he has had difficulty forming sentences. His wife adds that these symptoms were at their maximum within a few minutes of the incident and began to resolve almost instantaneously. The patient says he had a related episode of painless visual loss in his left eye that resolved after about 10–20 minutes about 3 months ago. His past medical history includes diabetes mellitus type 2 and essential hypertension. The patient reports a 50 pack-year smoking history. His blood pressure is 140/60 mm Hg, and his temperature is 36.5°C (97.7°F). Neurological examination is significant for a subtle weakness of the right hand. A noncontrast CT scan of the head is unremarkable, and a carotid Doppler ultrasound shows 10% stenosis of the right internal carotid artery and 50% stenosis of the left internal carotid artery. Which of the following is the expected change in resistance to blood flow through the stenotic artery most likely responsible for this patient’s current symptoms?
- A. It will double
- B. No change
- C. It will be 8 times greater
- D. It will be 4 times greater
- E. It will be 16 times greater (Correct Answer)
Coronary artery bypass grafting indications Explanation: ***It will be 16 times greater***
- According to **Poiseuille's law**, resistance to blood flow is inversely proportional to the fourth power of the radius (R ∝ 1/r⁴).
- In vascular medicine, **50% stenosis** refers to a 50% reduction in the vessel **diameter**, which also means the radius is reduced by 50% (halved).
- When the radius is halved, resistance increases by a factor of (1/0.5)⁴ = 2⁴ = **16 times**.
- The **left internal carotid artery** with 50% stenosis is responsible for the patient's symptoms (right-sided weakness and aphasia indicate left hemisphere pathology).
*It will be 8 times greater*
- This would occur if the radius were reduced to approximately 63% of its original size (1/0.63⁴ ≈ 8).
- This does not correspond to a 50% stenosis.
*It will double*
- A doubling of resistance would occur if the radius were reduced by approximately 16% (to 84% of original).
- This represents much less severe stenosis than described in this case.
*It will be 4 times greater*
- A four-fold increase would result from reducing the radius by approximately 29% (to 71% of original).
- This would correspond to approximately 30% stenosis by diameter, not 50%.
*No change*
- Any degree of **stenosis** reduces the vessel radius and significantly increases resistance according to Poiseuille's law.
- A 50% stenosis causing a 16-fold increase in resistance can critically reduce blood flow, especially during periods of increased demand or reduced perfusion pressure, leading to **TIA** symptoms as seen in this patient.
Coronary artery bypass grafting indications US Medical PG Question 4: A 57-year-old man presents to his primary care provider because of chest pain for the past 3 weeks. The chest pain occurs after climbing more than 2 flight of stairs or walking for more than 10 minutes and resolves with rest. He is obese, has a history of type 2 diabetes mellitus, and has smoked 15-20 cigarettes a day for the past 25 years. His father died from a myocardial infarction at 52 years of age. Vital signs reveal a temperature of 36.7 °C (98.06°F), a blood pressure of 145/93 mm Hg, and a heart rate of 85/min. The physical examination is unremarkable. Which of the following best represents the most likely etiology of the patient’s condition?
- A. Hypertrophy of the interventricular septum
- B. Multivessel atherosclerotic disease with or without a nonocclusive thrombus
- C. Intermittent coronary vasospasm with or without coronary atherosclerosis
- D. Fixed, atherosclerotic coronary stenosis (> 70%) (Correct Answer)
- E. Sudden disruption of an atheromatous plaque, with a resulting occlusive thrombus
Coronary artery bypass grafting indications Explanation: ***Fixed, atherosclerotic coronary stenosis (> 70%)***
- The patient's presentation with **exertional chest pain** that resolves with rest (stable angina), along with multiple **cardiovascular risk factors** (obesity, type 2 diabetes mellitus, smoking, family history of early MI, hypertension), strongly points towards **stable ischemic heart disease**.
- This clinical picture is typically caused by a **fixed, hemodynamically significant stenosis** in one or more coronary arteries, usually greater than 70%, that limits blood flow during increased demand.
*Multivessel atherosclerotic disease with or without a nonocclusive thrombus*
- While the patient likely has **multivessel atherosclerosis**, the phrase "with or without a nonocclusive thrombus" leans towards **unstable angina** or NSTEMI, which typically involves a sudden change in symptoms or rest angina.
- The patient's symptoms are **stable and reproducible** with exertion, resolving with rest, which is characteristic of stable angina rather than a thrombotic event.
*Sudden disruption of an atheromatous plaque, with a resulting occlusive thrombus*
- This mechanism describes an **acute coronary syndrome (ACS)**, such as an **ST-elevation myocardial infarction (STEMI)** or **non-ST-elevation myocardial infarction (NSTEMI)**.
- ACS typically presents with new-onset, worsening, or rest angina, which is different from the stable, exertional pattern described in the patient.
*Intermittent coronary vasospasm with or without coronary atherosclerosis*
- **Coronary vasospasm** (e.g., Prinzmetal angina) typically causes chest pain that occurs **at rest**, often at night or in the early morning, and is not necessarily related to exertion.
- While the patient could have underlying atherosclerosis, the **predictable exertional nature** of his symptoms makes vasospasm less likely as the primary etiology.
*Hypertrophy of the interventricular septum*
- **Interventricular septal hypertrophy** is characteristic of **hypertrophic cardiomyopathy (HCM)**, which can cause exertional chest pain due to outflow tract obstruction or myocardial ischemia.
- However, HCM is less likely to be the primary etiology in a 57-year-old with multiple classic **atherosclerotic risk factors** and no mention of a heart murmur or family history of HCM.
Coronary artery bypass grafting indications US Medical PG Question 5: A 55-year-old man comes to the emergency department because of left-sided chest pain and difficulty breathing for the past 30 minutes. His pulse is 88/min. He is pale and anxious. Serum studies show increased cardiac enzymes. An ECG shows ST-elevations in leads I, aVL, and V5-V6. A percutaneous coronary intervention is performed. In order to localize the site of the lesion, the catheter must pass through which of the following structures?
- A. Left coronary artery → left circumflex artery (Correct Answer)
- B. Right coronary artery → posterior descending artery
- C. Left coronary artery → left anterior descending artery
- D. Right coronary artery → right marginal artery
- E. Left coronary artery → posterior descending artery
Coronary artery bypass grafting indications Explanation: ***Left coronary artery → left circumflex artery***
- **ST-elevations** in leads I, aVL, and V5-V6 are indicative of a **lateral myocardial infarction**.
- The **left circumflex artery** primarily supplies the lateral wall of the left ventricle.
*Right coronary artery → posterior descending artery*
- The **posterior descending artery** (PDA) typically supplies the inferior wall and posterior interventricular septum.
- An occlusion here would cause **ST-elevations** in leads II, III, and aVF, which is not seen in this case.
*Left coronary artery → left anterior descending artery*
- The **left anterior descending** (LAD) artery supplies the anterior wall and apex of the left ventricle.
- Occlusion of the LAD would typically cause **ST-elevations** in leads V1-V4, indicating an anterior MI.
*Right coronary artery → right marginal artery*
- The **right marginal artery** is a branch of the right coronary artery and supplies part of the right ventricle.
- Occlusion here would primarily affect the **right ventricle**, and is not typically associated with the given ECG changes.
*Left coronary artery → posterior descending artery*
- While the **posterior descending artery** can sometimes originate from the left circumflex artery (**left dominant circulation**), it primarily supplies the inferior wall.
- The observed ECG changes in leads I, aVL, and V5-V6 are characteristic of a **lateral wall infarct**, which is supplied by the left circumflex artery.
Coronary artery bypass grafting indications US Medical PG Question 6: A 62-year-old man with a past medical history of previous myocardial infarction, angina, hypertension, hyperlipidemia, diabetes mellitus, peripheral vascular disease, and below knee amputation has developed new chest pain. His medication includes insulin, hydrochlorothiazide, lisinopril, metoprolol, daily aspirin, atorvastatin, and nitroglycerin as needed. His vitals include: blood pressure 135/87 mm Hg, pulse 52/min, and respirations 17/min. Coronary arteriography shows a reduced ejection fraction, a 65% stenosis of the left anterior descending artery, and a 75% stenosis of the left circumflex artery. Which of the following is the recommended treatment for the patient?
- A. Increased beta blocker dosage
- B. Coronary artery bypass grafting (CABG) (Correct Answer)
- C. Angioplasty with stent placement
- D. Extended release nitrate therapy
- E. Heparin
Coronary artery bypass grafting indications Explanation: ***Coronary artery bypass grafting (CABG)***
- This patient has complex **multivessel coronary artery disease** (LAD and circumflex stenosis) with a **reduced ejection fraction** and a history of multiple comorbidities, making CABG the preferred revascularization strategy for improved outcomes.
- CABG offers a more complete revascularization in patients with significant disease burden and reduced left ventricular function, leading to better long-term survival and symptom relief compared to PCI in this population.
*Increased beta blocker dosage*
- The patient's current heart rate is 52/min, which is already at the lower end of the target range for beta-blocker therapy in cardiac patients, and further increasing the dose could lead to **bradycardia** and worsening symptoms.
- While beta-blockers are crucial for managing angina and improving outcomes post-MI, increasing the dose wouldn't address the underlying anatomical severe multi-vessel coronary artery disease.
*Angioplasty with stent placement*
- Although PCI (angioplasty with stent placement) can be used for coronary stenosis, in patients with **multivessel disease**, **reduced ejection fraction**, and **diabetes mellitus**, CABG generally offers superior long-term results and survival benefits.
- The complexity of the lesions (65% LAD, 75% circumflex) in a patient with significant comorbidities and extensive atherosclerotic disease makes PCI a less optimal choice here.
*Extended release nitrate therapy*
- Nitrates primarily provide **symptomatic relief** by causing vasodilation, but they do not address the severe underlying coronary stenoses or improve long-term outcomes in patients with complex, multivessel disease.
- The patient is already on PRN nitroglycerin, and while extended-release nitrates could help with angina, they are not a definitive treatment for significant arterial blockages requiring revascularization.
*Heparin*
- Heparin is an **anticoagulant** that may be used as part of initial management of acute coronary syndromes, but it provides only temporary stabilization and does not address the **definitive need for revascularization**.
- While anticoagulation plays a role in acute management, this patient requires **definitive anatomical correction** of his multivessel disease with significant stenoses, which only surgical or percutaneous revascularization can provide, with CABG being superior given his clinical profile.
Coronary artery bypass grafting indications US Medical PG Question 7: Four days after undergoing a craniotomy and evacuation of a subdural hematoma, a 56-year-old man has severe pain and swelling of his right leg. He has chills and nausea. He has type 2 diabetes mellitus and chronic kidney disease, and was started on hemodialysis 2 years ago. Prior to admission, his medications were insulin, enalapril, atorvastatin, and sevelamer. His temperature is 38.3°C (101°F), pulse is 110/min, and blood pressure is 130/80 mm Hg. Examination shows a swollen, warm, and erythematous right calf. Dorsiflexion of the right foot causes severe pain in the right calf. The peripheral pulses are palpated bilaterally. Cardiopulmonary examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10.1 g/dL
Leukocyte count 11,800/mm3
Platelet count 230,000/mm3
Serum
Glucose 87 mg/dL
Creatinine 1.9 mg/dL
Which of the following is the most appropriate next step in treatment?
- A. Urokinase therapy
- B. Iliac stenting
- C. Warfarin therapy
- D. Unfractionated heparin therapy (Correct Answer)
- E. Inferior vena cava filter
Coronary artery bypass grafting indications Explanation: ***Unfractionated heparin therapy***
- The patient presents with classic symptoms of **deep vein thrombosis (DVT)**, including unilateral leg pain, swelling, warmth, erythema, and a positive Homan's sign (pain on dorsiflexion). The recent craniotomy places him at high risk for DVT.
- **Unfractionated heparin is the anticoagulant of choice** for this patient due to TWO critical factors:
1. **Recent craniotomy (4 days ago)**: Requires a rapidly reversible anticoagulant in case of intracranial bleeding; UFH can be reversed with protamine sulfate
2. **Chronic kidney disease on hemodialysis**: Low molecular weight heparin (LMWH) is contraindicated in severe renal failure (CrCl <30 mL/min) as it is renally eliminated and increases bleeding risk. UFH is not renally cleared and can be monitored with aPTT.
*Urokinase therapy*
- **Urokinase is a thrombolytic agent** used to dissolve existing clots, primarily in cases of massive pulmonary embolism or severe DVT with limb-threatening ischemia (phlegmasia cerulea dolens).
- Given the patient's **recent craniotomy and subdural hematoma evacuation**, thrombolytic therapy is **absolutely contraindicated** due to very high risk of intracranial hemorrhage. Recent neurosurgery is a contraindication for at least 2-4 weeks.
*Iliac stenting*
- **Iliac vein stenting** is a procedure typically used to treat chronic **iliac vein compression** (e.g., May-Thurner syndrome) or chronic post-thrombotic obstruction.
- This is an **acute DVT presentation** (4 days post-op) with no indication of chronic iliac vein compression or obstruction. Stenting has no role in acute DVT management.
*Warfarin therapy*
- **Warfarin is an oral anticoagulant** used for long-term DVT treatment but has a **delayed onset of action** (requires 5-7 days to reach therapeutic INR).
- It is **not suitable for acute initial treatment** of DVT, especially in a patient requiring rapid anticoagulation. Warfarin must be overlapped with parenteral anticoagulation (heparin) initially.
- Additionally, warfarin dosing is complex in dialysis patients due to altered vitamin K metabolism.
*Inferior vena cava filter*
- An **IVC filter** is indicated for patients with DVT who have an **absolute contraindication to anticoagulation** (e.g., active bleeding, recent hemorrhagic stroke) or who develop recurrent thromboembolism despite adequate anticoagulation.
- This patient **does not have a contraindication to anticoagulation**. While he had recent neurosurgery, unfractionated heparin is safe to use with careful monitoring and is rapidly reversible if needed.
- IVC filters have significant complications (thrombosis, filter migration, IVC perforation) and should be avoided when anticoagulation is feasible.
Coronary artery bypass grafting indications US Medical PG Question 8: A 59-year-old patient comes to the emergency department accompanied by his wife because of severe right leg pain and numbness. His condition suddenly started an hour ago. His wife says that he has a heart rhythm problem for which he takes a blood thinner, but he is not compliant with his medications. He has smoked 10–15 cigarettes daily for the past 15 years. His temperature is 36.9°C (98.42°F), blood pressure is 140/90 mm Hg, and pulse is 85/min and irregular. On physical examination, the patient is anxious and his right leg is cool and pale. Palpation of the popliteal fossa shows a weaker popliteal pulse on the right side compared to the left side. Which of the following is the best initial step in the management of this patient's condition?
- A. Urgent assessment for amputation or revascularization (Correct Answer)
- B. Decompressive laminectomy
- C. Oral acetaminophen and topical capsaicin
- D. Arthroscopic synovectomy
- E. Cilostazol
Coronary artery bypass grafting indications Explanation: ***Urgent assessment for amputation or revascularization***
- The patient presents with classic signs of **acute limb ischemia** (severe pain, numbness, coolness, pallor, and diminished pulse) in the setting of chronic atrial fibrillation and medication non-compliance, indicating an **embolic event**.
- **Immediate surgical consultation** for revascularization and limb salvage is critical to prevent irreversible tissue damage and potential amputation.
*Decompressive laminectomy*
- This procedure is indicated for conditions like **spinal stenosis** or **herniated disc** causing nerve root compression, typically presenting with radicular pain, weakness, or sensory deficits.
- The patient's acute onset of symptoms, limb ischemia signs, and irregular pulse are not consistent with a spinal compressive neuropathy.
*Oral acetaminophen and topical capsaicin*
- These are **palliative treatments** for pain that is typically chronic and less severe, such as osteoarthritis or neuropathic pain.
- They are entirely inadequate for the management of **acute limb ischemia**, which requires urgent intervention to restore blood flow.
*Arthroscopic synovectomy*
- This is a surgical procedure to remove inflamed synovial tissue from a joint, typically performed for conditions like **rheumatoid arthritis** or other inflammatory arthropathies that have not responded to medical management.
- It is irrelevant to the management of acute vascular compromise of a limb.
*Cilostazol*
- **Cilostazol** is a phosphodiesterase inhibitor used in the long-term management of **intermittent claudication** due to peripheral artery disease to improve walking distance and reduce symptoms.
- It has no role in the acute treatment of **severe limb ischemia**, which is an emergency requiring immediate revascularization, not a medication for chronic symptoms.
Coronary artery bypass grafting indications US Medical PG Question 9: A 62-year-old man presents to the emergency department with sudden onset of severe left leg pain accompanied by numbness and weakness. His medical history is remarkable for hypertension and hyperlipidemia. His vital signs include a blood pressure of 155/92 mm Hg, a temperature of 37.1°C (98.7°F), and an irregular pulse of 92/min. Physical examination reveals absent left popliteal and posterior tibial pulses. His left leg is noticeably cold and pale. There is no significant tissue compromise, nerve damage, or sensory loss. Which of the following will most likely be required for this patient's condition?
- A. Antibiotics
- B. Warfarin
- C. Fasciotomy
- D. Amputation
- E. Thromboembolectomy (Correct Answer)
Coronary artery bypass grafting indications Explanation: ***Thromboembolectomy***
- The sudden onset of severe leg pain, numbness, and weakness with absent pulses, a cold, pale limb, and an irregular pulse suggests **acute limb ischemia** likely due to an **arterial embolus**, which requires emergent surgical removal.
- Given the symptoms and history of an irregular pulse (suggesting possible atrial fibrillation), a thromboembolectomy is the most appropriate first-line treatment to restore blood flow and prevent permanent damage.
*Antibiotics*
- Antibiotics are used to treat **bacterial infections** and are not indicated for acute limb ischemia caused by a vascular occlusion.
- There are no signs of infection present, such as fever, redness, or purulent discharge, that would warrant antibiotic therapy.
*Warfarin*
- Warfarin is an **anticoagulant** used for long-term prevention of clot formation, particularly in conditions like atrial fibrillation or deep vein thrombosis.
- While anticoagulation may eventually be part of management to prevent future events, it is insufficient as immediate therapy for an acute, established arterial embolus causing critical limb ischemia.
*Fasciotomy*
- Fasciotomy is performed to relieve **compartment syndrome**, which occurs when increased pressure within a muscle compartment compromises circulation and nerve function.
- While compartment syndrome can be a complication of reperfusion after prolonged ischemia, it is not the primary treatment for the initial arterial occlusion; the first step is to restore blood flow to prevent the need for it.
*Amputation*
- Amputation is a last resort considered when the limb is **irreversibly ischemic** and non-viable, or when revascularization attempts have failed and there is extensive tissue necrosis or infection.
- In this case, there is no significant tissue compromise or nerve damage mentioned, indicating that the limb is still salvageable with timely intervention.
Coronary artery bypass grafting indications US Medical PG Question 10: A 79-year-old man is brought to the emergency department after he noted the abrupt onset of weakness accompanied by decreased sensation on his left side. His symptoms developed rapidly, peaked within 1 minute, and began to spontaneously resolve 10 minutes later. Upon arrival in the emergency room 40 minutes after the initial onset of symptoms, they had largely resolved. The patient has essential hypertension, type 2 diabetes mellitus, chronic obstructive pulmonary disease, and a 50 pack-year smoking history. He also had an ST-elevation myocardial infarction 3 years ago. His brain CT scan without contrast is reported as normal. Carotid duplex ultrasonography reveals 90% stenosis of the right internal carotid. His transthoracic echocardiogram does not reveal any intracardiac abnormalities. Which of the following interventions is most appropriate for this patient's condition?
- A. Carotid stenting (Correct Answer)
- B. Warfarin
- C. Low molecular weight heparin
- D. Hypercoagulability studies
- E. Aspirin and clopidogrel
Coronary artery bypass grafting indications Explanation: ***Carotid stenting***
- The patient experienced a **transient ischemic attack (TIA)** with **90% stenosis of the right internal carotid artery**, which is a high-grade stenosis.
- **Carotid revascularization** is highly recommended for symptomatic patients with **high-grade carotid stenosis** (70–99%) to prevent future strokes.
- Both **carotid endarterectomy (CEA)** and **carotid stenting** are acceptable options. In this elderly patient (79 years) with significant comorbidities (COPD, prior MI, 50 pack-year smoking history), **carotid stenting** may be preferred as it avoids the surgical risks of general anesthesia and neck dissection.
*Warfarin*
- **Warfarin** is primarily used for preventing strokes in patients with **atrial fibrillation** or mechanical heart valves.
- It is **not the first-line treatment** for stroke prevention directly caused by symptomatic carotid artery stenosis.
*Low molecular weight heparin*
- **Low molecular weight heparin (LMWH)** is typically used for acute treatment of **deep vein thrombosis** and **pulmonary embolism**, or in certain acute coronary syndromes.
- It does not address the underlying **structural issue of severe carotid stenosis** for long-term stroke prevention.
*Hypercoagulability studies*
- While hypercoagulability can cause strokes, the patient's symptoms are clearly attributed to **severe carotid stenosis**.
- These studies are usually reserved for patients with strokes of **unexplained etiology**, especially younger patients, or those with unusual clot locations.
*Aspirin and clopidogrel*
- **Dual antiplatelet therapy (aspirin and clopidogrel)** is often used after a TIA or minor stroke, but typically for a limited duration (e.g., 21-90 days), and it is an adjunct to revascularization in severe carotid stenosis.
- Although important for **secondary stroke prevention**, it does not address the critical **90% carotid stenosis** that warrants revascularization.
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