A 70-year-old man with severe ischemic cardiomyopathy (EF 25%) has recurrent ventricular tachycardia despite optimal medical therapy and ICD placement. Cardiac MRI shows a large anteroseptal scar with viable myocardium in the lateral and inferior walls. He has three-vessel coronary disease. His daughter is advocating for heart transplantation, but he has multiple comorbidities including obesity (BMI 37) and active tobacco use. Evaluate the management priority and rationale.
Q2
A 49-year-old woman with myasthenia gravis undergoes CT chest showing a 5 cm anterior mediastinal mass with irregular borders. Biopsy confirms thymoma (WHO type B2). She has well-controlled myasthenic symptoms on pyridostigmine. Staging shows no distant metastases, but the mass abuts the pericardium without clear invasion. Evaluate the optimal treatment approach.
Q3
A 58-year-old man with coronary artery disease requires CABG. Preoperative angiography shows 90% left main stenosis, 95% proximal LAD stenosis, 80% circumflex stenosis, and chronic total occlusion of the RCA with collaterals. He has diabetes, renal insufficiency (Cr 2.1), and previous stroke. Evaluate the optimal grafting strategy to maximize long-term patency and outcomes.
Q4
A 62-year-old man develops sudden onset of severe chest and back pain. CT angiography shows a Stanford Type B aortic dissection extending from just distal to the left subclavian artery to the iliac bifurcation. Blood pressure is 165/95 mmHg, heart rate 88/min. He has no evidence of malperfusion, rupture, or refractory pain. Analyze the initial management strategy.
Q5
A 68-year-old woman with rheumatic heart disease has severe mitral stenosis (valve area 0.9 cm²) and moderate mitral regurgitation. She is in atrial fibrillation. Echocardiography shows heavily calcified mitral valve leaflets with restricted mobility and moderate subvalvular disease. The left atrium measures 6.2 cm. Analyze the optimal surgical approach.
Cardiothoracic Surgery US Medical PG Practice Questions and MCQs
Question 1: A 70-year-old man with severe ischemic cardiomyopathy (EF 25%) has recurrent ventricular tachycardia despite optimal medical therapy and ICD placement. Cardiac MRI shows a large anteroseptal scar with viable myocardium in the lateral and inferior walls. He has three-vessel coronary disease. His daughter is advocating for heart transplantation, but he has multiple comorbidities including obesity (BMI 37) and active tobacco use. Evaluate the management priority and rationale.
A. Left ventricular assist device as destination therapy
B. Catheter ablation of VT with continued ICD monitoring
C. Cardiac resynchronization therapy upgrade and medication adjustment
D. List for heart transplantation immediately given severe cardiomyopathy
E. CABG with surgical ventricular reconstruction and continued medical optimization (Correct Answer)
Explanation: ***CABG with surgical ventricular reconstruction and continued medical optimization***
- The patient has **three-vessel disease** and **viable myocardium** in the lateral and inferior walls; **CABG** addresses the ischemic substrate and potentially improves **LVEF**.
- **Surgical ventricular reconstruction (SVR)** addresses the large **anteroseptal scar**, reducing left ventricular volume and providing better geometric stability to mitigate **ventricular tachycardia** (VT).
*Left ventricular assist device as destination therapy*
- While **LVAD** is an option for end-stage heart failure, the presence of **active tobacco use** and **obesity** (BMI 37) are significant relative contraindications.
- **Surgical revascularization** is prioritized when significant **viable myocardium** is present and surgical targets are available.
*Catheter ablation of VT with continued ICD monitoring*
- **VT ablation** target-treats the arrhythmia but does not address the underlying **remodelling** or **ischemia** causing the progressive cardiomyopathy.
- Given the **three-vessel disease**, surgical intervention is more comprehensive for long-term prognosis compared to percutaneous ablation alone.
*Cardiac resynchronization therapy upgrade and medication adjustment*
- The patient is already on **optimal medical therapy** with an **ICD**; simple medication adjustment is unlikely to control recurrent VT in the setting of structural scar and ischemia.
- **CRT** provides limited benefit if the primary issue is a large **anteroseptal scar** and **active ischemia** requiring revascularization.
*List for heart transplantation immediately given severe cardiomyopathy*
- Direct listing is contraindicated due to **active tobacco use** and a **BMI >35**, which are standard exclusion criteria for transplant programs.
- Heart transplantation is considered a last resort after maximizing options like **revascularization** and addressing **modifiable risk factors**.
Question 2: A 49-year-old woman with myasthenia gravis undergoes CT chest showing a 5 cm anterior mediastinal mass with irregular borders. Biopsy confirms thymoma (WHO type B2). She has well-controlled myasthenic symptoms on pyridostigmine. Staging shows no distant metastases, but the mass abuts the pericardium without clear invasion. Evaluate the optimal treatment approach.
A. Thymectomy with possible en bloc pericardial resection, followed by adjuvant radiation (Correct Answer)
B. Increase immunosuppression then delayed surgery in 6 months
C. Radiation therapy alone to preserve myasthenia control
D. Immediate thymectomy followed by observation
E. Neoadjuvant chemotherapy, then thymectomy and adjuvant radiation
Explanation: ***Thymectomy with possible en bloc pericardial resection, followed by adjuvant radiation***
- Complete **surgical resection (R0)** is the cornerstone of treatment for **WHO type B2 thymomas**, especially when the mass is resectable despite abutting local structures like the **pericardium**.
- **Adjuvant radiation** is indicated for **Masaoka Stage II/III** disease or high-risk B2 histology to minimize the risk of **local recurrence**.
*Increase immunosuppression then delayed surgery in 6 months*
- Delaying surgery for a 5 cm **potentially invasive thymoma** allows for tumor progression and increases the risk of higher-stage disease.
- **Myasthenia gravis** symptoms are already **well-controlled**, making immediate surgical intervention safe and the preferred priority.
*Radiation therapy alone to preserve myasthenia control*
- **Radiation alone** is not a curative intent treatment for resectable thymoma and is usually reserved for **unresectable** or medically unfit patients.
- Thymectomy is actually a therapeutic part of managing **myasthenia gravis**, often leading to symptomatic improvement or remission.
*Immediate thymectomy followed by observation*
- Observation alone after surgery is insufficient for **B2 thymomas** that show irregular borders or high-risk features like **pericardial involvement**.
- The size over 5 cm and contact with the **pericardium** (Stage IIb/III) necessitate **postoperative radiotherapy** to improve oncologic outcomes.
*Neoadjuvant chemotherapy, then thymectomy and adjuvant radiation*
- **Neoadjuvant chemotherapy** is typically reserved for tumors deemed **primarily unresectable** on imaging, which is not the case here.
- Since the mass only **abuts** the pericardium and has no distant metastases, it is considered **upfront resectable**.
Question 3: A 58-year-old man with coronary artery disease requires CABG. Preoperative angiography shows 90% left main stenosis, 95% proximal LAD stenosis, 80% circumflex stenosis, and chronic total occlusion of the RCA with collaterals. He has diabetes, renal insufficiency (Cr 2.1), and previous stroke. Evaluate the optimal grafting strategy to maximize long-term patency and outcomes.
A. Bilateral internal mammary arteries with supplemental vein grafts
B. Off-pump CABG with sequential vein grafts only
C. LIMA to LAD, radial artery to circumflex, vein graft to RCA (Correct Answer)
D. All saphenous vein grafts to minimize operative time
E. LIMA to LAD, saphenous vein grafts to remaining vessels
Explanation: ***LIMA to LAD, radial artery to circumflex, vein graft to RCA***
- The **LIMA-to-LAD** graft is the gold standard, providing the best long-term patency and survival outcomes in multi-vessel **CABG**.
- Using a **radial artery** for the circumflex system (high-grade stenosis) offers superior patency over vein grafts while avoiding the high risk of **sternal wound infection** associated with **BIMA** in diabetic patients.
*Bilateral internal mammary arteries with supplemental vein grafts*
- While **BIMA** provides excellent patency, it is associated with a significantly increased risk of **sternal dehiscence** and infection in patients with **Diabetes Mellitus**.
- The benefit of a second arterial graft is better achieved with the **radial artery** in this high-risk comorbid profile.
*Off-pump CABG with sequential vein grafts only*
- **Sequential vein grafts** have lower long-term patency compared to arterial conduits and do not capitalize on the survival benefit of the **LIMA-to-LAD**.
- Off-pump surgery might reduce some risks but using only vein grafts is suboptimal for a 58-year-old with **long-term** survival goals.
*All saphenous vein grafts to minimize operative time*
- **Saphenous vein grafts (SVG)** have much higher failure rates (approx. 50% at 10 years) compared to **internal mammary arteries**.
- Minimizing operative time does not justify the poor long-term clinical outcomes and higher **re-intervention rates** associated with an all-SVG strategy.
*LIMA to LAD, saphenous vein grafts to remaining vessels*
- This is a standard approach, but the addition of a second arterial conduit like the **radial artery** is preferred for younger patients with high-grade stenosis to maximize **patency**.
- In the setting of **90% left main** and **80% circumflex** stenosis, the radial artery is more durable than a vein graft for the circumflex target.
Question 4: A 62-year-old man develops sudden onset of severe chest and back pain. CT angiography shows a Stanford Type B aortic dissection extending from just distal to the left subclavian artery to the iliac bifurcation. Blood pressure is 165/95 mmHg, heart rate 88/min. He has no evidence of malperfusion, rupture, or refractory pain. Analyze the initial management strategy.
A. Medical management with beta-blockers and blood pressure control (Correct Answer)
B. Fenestration procedure to improve distal perfusion
C. Observation in ICU without antihypertensive therapy
D. Emergent open surgical repair with graft replacement
E. Immediate thoracic endovascular aortic repair (TEVAR)
Explanation: ***Medical management with beta-blockers and blood pressure control***
- **Stanford Type B** aortic dissections that are **uncomplicated** (no malperfusion, rupture, or refractory pain) are primarily managed through **aggressive blood pressure** and **heart rate** control.
- **Beta-blockers** are the first-line treatment to reduce **dP/dt** (the rate of pressure rise), which decreases **aortic wall shear stress** and limits the extension of the dissection.
*Fenestration procedure to improve distal perfusion*
- This procedure is specifically indicated for **malperfusion syndrome** where the dissection creates a false lumen that compresses the true lumen supplying vital organs.
- Since this patient has **no evidence of malperfusion**, performing a fenestration at this stage is not clinically indicated or necessary.
*Observation in ICU without antihypertensive therapy*
- Simple observation is insufficient because uncontrolled hypertension and high shear stress increase the risk of **aortic rupture** and **aneurysmal expansion**.
- Rigid management aiming for a **systolic blood pressure** of 100–120 mmHg and a **heart rate** below 60/min is the mandatory gold standard.
*Emergent open surgical repair with graft replacement*
- **Open surgical repair** for Type B dissection is associated with high **morbidity and mortality** rates and is generally avoided in the acute phase unless complications like rupture occur.
- Unlike Type A dissections, which require **emergent surgery**, uncomplicated Type B dissections have better outcomes with **non-operative medical therapy**.
*Immediate thoracic endovascular aortic repair (TEVAR)*
- While TEVAR is the treatment of choice for **complicated** Type B dissections, immediate intervention is not recommended for stable patients without high-risk features.
- Clinical trials (such as **INSTEAD**) suggest that routine early TEVAR for uncomplicated cases does not improve **short-term survival** compared to optimal medical management.
Question 5: A 68-year-old woman with rheumatic heart disease has severe mitral stenosis (valve area 0.9 cm²) and moderate mitral regurgitation. She is in atrial fibrillation. Echocardiography shows heavily calcified mitral valve leaflets with restricted mobility and moderate subvalvular disease. The left atrium measures 6.2 cm. Analyze the optimal surgical approach.
A. Mitral valve repair with annuloplasty
B. Medical management with rate control only
C. Mitral valve replacement with mechanical valve plus Maze procedure (Correct Answer)
D. Percutaneous mitral balloon valvuloplasty
E. Mitral valve replacement with bioprosthetic valve
Explanation: ***Mitral valve replacement with mechanical valve plus Maze procedure***
- The patient has **heavily calcified leaflets**, restricted mobility, and **moderate subvalvular disease**, which makes the valve unsuitable for repair or balloon dilation; **mitral valve replacement (MVR)** is the required intervention.
- Given the presence of **atrial fibrillation** and a significantly enlarged left atrium (6.2 cm), a concomitant **Maze procedure** is indicated to restore sinus rhythm and reduce thromboembolic risk.
*Mitral valve repair with annuloplasty*
- **Mitral valve repair** is rarely feasible in rheumatic mitral stenosis with extensive **calcification** and subvalvular thickening, as the underlying tissue is too diseased to function normally.
- Repair is primarily the treatment of choice for **degenerative mitral regurgitation**, not for severe, calcified rheumatic stenosis.
*Medical management with rate control only*
- With a **mitral valve area of 0.9 cm²** (severe stenosis) and moderate regurgitation, the patient is at high risk for heart failure and secondary pulmonary hypertension.
- Medical management alone does not address the **mechanical obstruction** and is associated with poor long-term outcomes compared to surgical intervention.
*Percutaneous mitral balloon valvuloplasty*
- This procedure is contraindicated when there is **moderate mitral regurgitation** and a high **Wilkins score** (heavily calcified, immobile leaflets and subvalvular disease).
- Attempting valvuloplasty in this setting significantly increases the risk of creating severe, acute **mitral regurgitation** requiring emergency surgery.
*Mitral valve replacement with bioprosthetic valve*
- While bioprosthetic valves avoid long-term anticoagulation, they have limited durability; however, the patient is already in **atrial fibrillation**, which mandates lifelong **anticoagulation** regardless of valve type.
- A **mechanical valve** is often preferred in younger or middle-aged patients already requiring warfarin to provide a more durable solution without the risk of structural valve deterioration.
