Cardiothoracic Surgery · Supplementary · from Cardiothoracic Surgery

Case 1: Aortic Valve Stenosis Requiring TAVR vs SAVR

Patient Presentation

Demographics: 78-year-old male retired professor of history

Chief Complaint: "I nearly fainted while climbing the stairs to my study last week, and I've been getting more winded over the past few months."

History of Present Illness: Dr. H.M. presents to the cardiothoracic surgery clinic after referral from cardiology for evaluation of severe symptomatic aortic stenosis. He reports a 6-month history of progressive exertional dyspnea, initially noticed while walking uphill or climbing two flights of stairs (previously could walk 3 miles without limitation). Three weeks ago, he experienced a near-syncopal episode while ascending stairs — he felt lightheaded, had graying of vision, and needed to sit down for several minutes. He did not lose consciousness. He also reports exertional chest pressure described as a "heaviness" across his anterior chest during brisk walking, relieved by rest.

His cardiologist performed an echocardiogram that revealed severe aortic stenosis with a trileaflet aortic valve (senile/degenerative calcific AS). He was referred for evaluation for aortic valve replacement. He lives independently, drives, does his own shopping and cooking, and remains intellectually active (writing a book). His primary concern is recovery time and return to his normal activities.

Past Medical History:

• Hypertension (20 years, well-controlled)
• Type 2 diabetes mellitus (12 years, oral agents only)
• Chronic kidney disease stage 3a (eGFR 52 mL/min/1.73m²)
• Atrial fibrillation (paroxysmal, rate-controlled)
• Prior transient ischemic attack (TIA) 3 years ago (no residual deficits)
• Osteoarthritis bilateral knees
• Former smoker (15 pack-years, quit 30 years ago)

Medications:

• Amlodipine 5 mg daily
• Metformin 500 mg BID
• Apixaban 5 mg BID
• Metoprolol succinate 50 mg daily
• Atorvastatin 40 mg daily
• Aspirin 81 mg daily

Social History:

• Non-smoker (quit 30 years ago)
• Rare alcohol (1 glass wine per week)
• Widowed, lives alone in two-story home
• Two adult children locally, supportive
• Retired professor; writing historical biography
• Independent in all ADLs and IADLs; drives regularly

Family History:

• Father: died of aortic aneurysm rupture age 72
• Mother: died of congestive heart failure age 85
• Brother: aortic valve replacement (mechanical) age 68

Physical Examination

• Vital Signs: BP 138/62 mmHg (wide pulse pressure paradoxically preserved due to concurrent AR), HR 72 bpm (irregular), RR 16, SpO2 96% on room air, Temp 36.7°C, BMI 24.6 kg/m²
• General: Well-appearing elderly gentleman, no acute distress at rest; thin habitus
• Cardiovascular:
• Carotid pulses: delayed upstroke bilaterally (pulsus parvus et tardus); carotid bruits absent
• PMI: sustained, laterally displaced to 6th intercostal space, anterior axillary line
• Auscultation: harsh, late-peaking, grade IV/VI crescendo-decrescendo systolic ejection murmur, loudest at right upper sternal border (aortic area), radiating to bilateral carotids and cardiac apex; S2 absent (calcified immobile valve); S4 gallop present; no S3
• Additionally: grade II/VI early diastolic blowing murmur at left sternal border (concurrent mild AR)
• Pulmonary: Fine bibasilar crackles (mild pulmonary congestion); no wheeze
• Extremities: Trace bilateral pedal edema; no clubbing; peripheral pulses palpable but diminished
• Neurological: Alert, oriented, cognitively intact (MMSE 29/30); no focal deficits

Workup and Results

Laboratory Studies:

Imaging/Additional Studies:

• Transthoracic echocardiogram: Severe aortic stenosis — aortic valve area (AVA) 0.7 cm² (severe <1.0 cm²); mean transvalvular gradient 48 mmHg (severe >40 mmHg); peak velocity 4.6 m/s (severe >4.0 m/s); trileaflet valve with heavy calcification; concentric LV hypertrophy (wall thickness 14 mm); LV EF 50% (low-normal); mild aortic regurgitation; mild mitral regurgitation; estimated RVSP 42 mmHg (mild PH); LAVI 42 mL/m² (dilated — diastolic dysfunction)
• Cardiac catheterization: No significant coronary artery disease (mild 30% LAD lesion, non-flow-limiting); confirmed AVA 0.72 cm² on invasive hemodynamics; LVEDP 22 mmHg (elevated)
• CT aorta (gated): Aortic annulus dimensions: perimeter 78.2 mm, area 456 mm²; trileaflet valve with heavy calcification; no bicuspid morphology; ascending aorta 38 mm (not dilated); iliofemoral arteries: minimal calcification, minimum diameter 7.2 mm bilaterally (adequate for transfemoral TAVR access); no abdominal aortic aneurysm
• Frailty assessment: 5-meter gait speed 0.9 m/s (not frail >0.83 m/s); grip strength adequate; no frailty by Fried criteria
• STS Predicted Risk of Mortality (SAVR): 4.2% (intermediate risk)
• EuroSCORE II: 3.8%

Clinical Image

Illustration comparing transcatheter aortic valve replacement (TAVR) via transfemoral approach with surgical aortic valve replacement (SAVR) via sternotomy, showing valve positioning, access routes, and key anatomical considerations. Source: Educational illustration.

Diagnosis

Severe Symptomatic Degenerative Calcific Aortic Stenosis (Trileaflet) — NYHA Class III, Intermediate Surgical Risk

Key Diagnostic Criteria:

• Severe AS by all echocardiographic criteria: AVA <1.0 cm², mean gradient >40 mmHg, peak velocity >4.0 m/s
• Symptomatic: exertional dyspnea (NYHA III), exertional near-syncope, exertional angina
• Confirmed by invasive hemodynamic assessment
• No significant coronary artery disease requiring concurrent CABG
• STS score 4.2% — intermediate surgical risk

Treatment Plan

1. Heart Team discussion (multidisciplinary — mandatory for valve intervention decisions):

• Cardiothoracic surgeon, interventional cardiologist, imaging cardiologist, cardiac anesthesiologist, geriatrician
• Decision: TAVR recommended based on: age 78, intermediate surgical risk, favorable transfemoral anatomy, trileaflet valve, no concurrent CABG indication, patient preference for faster recovery
• SAVR would also be reasonable and was discussed; advantages of SAVR include: longer-term durability data, ability to address concurrent pathology, lower rates of paravalvular leak and permanent pacemaker
• Shared decision-making with patient: patient prefers TAVR given faster recovery, desire to continue writing project, living alone

1. Pre-procedural optimization:

• Discontinue apixaban 48 hours pre-procedure
• Discontinue metformin morning of procedure
• Hold aspirin; continue metoprolol
• Dental clearance (endocarditis prevention)
• Pre-hydration protocol for CKD (N-acetylcysteine + isotonic bicarbonate before contrast)

1. TAVR procedure plan:

• Transfemoral approach (bilateral femoral arteries adequate at 7.2 mm)
• Valve sizing: 26 mm self-expanding or balloon-expandable prosthesis based on CT annular dimensions
• General anesthesia vs. conscious sedation (center-dependent; patient preference considered)
• Intra-procedural TEE for valve positioning and assessment of paravalvular leak

1. Post-procedural management:

• ICU monitoring 12-24 hours; telemetry for 48 hours
• Serial ECGs monitoring for conduction disturbances (new LBBB, high-degree AV block — pacemaker needed in ~10-20% post-TAVR)
• Echocardiogram before discharge: assess prosthetic valve function, paravalvular leak
• Dual antiplatelet therapy: aspirin 81 mg + clopidogrel 75 mg for 3-6 months, then aspirin alone (or resume apixaban for atrial fibrillation with aspirin only — per recent trial data favoring OAC monotherapy)
• Anticipated discharge: day 2-3 post-procedure
• Cardiac rehabilitation referral

1. Long-term follow-up:

• Echocardiogram at 30 days, 1 year, and annually thereafter
• Endocarditis prophylaxis for dental procedures (lifelong)
• Monitor for structural valve deterioration (estimated bioprosthetic valve durability: 10-15+ years with current-generation TAVR valves)
• Annual assessment of conduction system (delayed pacemaker requirement can occur)

Key Learning Points

• Severe aortic stenosis is defined by AVA <1.0 cm², mean gradient >40 mmHg, and peak velocity >4.0 m/s; once symptoms develop (the classic triad of angina, syncope, and heart failure), prognosis without intervention is poor (2-year mortality ~50%)
• The Heart Team approach is mandated by guidelines for all valve intervention decisions; TAVR and SAVR are both Class I recommendations for symptomatic severe AS, with the choice influenced by surgical risk, anatomy, age, durability considerations, and patient preferences
• TAVR has become the dominant approach for patients aged >65 with intermediate or higher surgical risk; randomized trials (PARTNER 3, Evolut Low Risk) have shown non-inferiority or superiority of TAVR even in low-risk patients, though long-term durability data beyond 5-10 years is still maturing
• Key TAVR-specific complications include paravalvular leak (2-5%), new permanent pacemaker requirement (10-20% depending on valve type), stroke (1-3%), and vascular access complications; SAVR has higher rates of bleeding, atrial fibrillation, and prolonged recovery
• Frailty assessment is critical in elderly patients: the STS score alone may underestimate risk in frail patients; gait speed, grip strength, cognitive function, and nutritional status should inform the Heart Team decision

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