CSC Case Studies & Practical Application 3 — Questions and Answers
Question 1: A 72-year-old man with DM and CKD (eGFR 28) presents for elective PCI. He is on metformin. How should his metformin be managed peri-procedurally?
- Continue metformin without change
- Hold metformin 48 hours before contrast and restart only after reassessing renal function (Correct answer)
- Switch permanently to insulin before the procedure
- Increase metformin dose to prevent contrast nephropathy
Correct answer: Hold metformin 48 hours before contrast and restart only after reassessing renal function
Metformin should be withheld 48 hours before contrast administration and restarted only after confirming stable renal function due to risk of lactic acidosis.
Question 2: A 50-year-old man presents with progressive exertional dyspnea. Echo shows severe mitral stenosis with MVA 0.9 cm², mean gradient 14 mmHg, pliable non-calcified leaflets, and mild MR. Wilkins score is 7. What is the treatment of choice?
- Mitral valve replacement
- Percutaneous mitral balloon valvotomy (PMBV) (Correct answer)
- Medical therapy with diuretics
- Mitral valve repair with ring annuloplasty
Correct answer: Percutaneous mitral balloon valvotomy (PMBV)
A Wilkins score ≤8 with favorable anatomy (pliable leaflets, minimal MR, no significant calcification) makes PMBV the preferred intervention for severe MS.
Question 3: A 66-year-old woman with AF and CHA₂DS₂-VASc score of 5 is on warfarin. She requires elective hip replacement. Her cardiologist considers bridging therapy. What is the current recommendation?
- Bridge with therapeutic LMWH perioperatively
- Stop warfarin 5 days before; no bridging needed (Correct answer)
- Continue warfarin throughout surgery
- Switch to aspirin 2 weeks before surgery
Correct answer: Stop warfarin 5 days before; no bridging needed
The BRIDGE trial showed that forgoing heparin bridging in AF patients on warfarin undergoing elective surgery did not increase thromboembolism risk and reduced bleeding.
Question 4: A 34-year-old pregnant woman (28 weeks) with known severe MS and worsening pulmonary edema despite diuretics is evaluated. Echo confirms MVA 0.8 cm². What is the safest definitive intervention?
- Emergency cesarean section followed by MVR
- Percutaneous mitral balloon valvotomy with radiation shielding (Correct answer)
- Closed commissurotomy under general anesthesia
- Continue medical therapy until delivery
Correct answer: Percutaneous mitral balloon valvotomy with radiation shielding
PMBV is preferred for pregnant women with severe symptomatic MS refractory to medical therapy, with abdominal shielding to minimize fetal radiation exposure.
Question 5: A 78-year-old man with severe HFrEF (EF 20%) on optimal GDMT presents with worsening dyspnea at rest and recurrent hospitalizations. He is not a transplant candidate. What device therapy should be considered?
- BiV pacing without ICD
- Destination therapy LVAD (Correct answer)
- Implantable hemodynamic monitor only
- Cardiac contractility modulation device
Correct answer: Destination therapy LVAD
Destination therapy LVAD is indicated for advanced HFrEF patients ineligible for transplant who remain severely symptomatic on optimal medical therapy.
Question 6: A 60-year-old man has an EF of 30% and LBBB with QRS 155 ms despite maximal GDMT. He has NYHA class III symptoms. What intervention is most likely to improve his outcomes?
- Optimize beta-blocker dose only
- Cardiac resynchronization therapy (CRT) with or without defibrillator (Correct answer)
- Permanent pacemaker for rate control
- Catheter ablation of LBBB
Correct answer: Cardiac resynchronization therapy (CRT) with or without defibrillator
CRT is strongly indicated (Class I) in patients with EF ≤35%, LBBB morphology, QRS ≥150 ms, and NYHA class II–IV symptoms on GDMT.
Question 7: A 55-year-old woman undergoes elective TAVR and develops complete heart block immediately after valve deployment. What is the appropriate next step?
- Observe for 24 hours before any action
- Administer IV atropine and discharge
- Place a temporary transvenous pacemaker and evaluate for permanent pacemaker need (Correct answer)
- Perform immediate valve explantation
Correct answer: Place a temporary transvenous pacemaker and evaluate for permanent pacemaker need
Complete heart block post-TAVR requires immediate temporary pacing, with permanent pacemaker implantation if conduction does not recover, typically within 24–72 hours.
CSC Case Studies & Practical Application 3
A 72-year-old man with DM and CKD (eGFR 28) presents for elective PCI.
He is on metformin.
How should his metformin be managed peri-procedurally?