Management of Severe Aortic Stenosis Including Post-Stenosis Dilation
For patients with severe aortic stenosis, transcatheter aortic valve replacement (TAVR) is recommended for those unsuitable for surgery, while surgical aortic valve replacement (SAVR) remains appropriate for younger, low-risk patients, with the choice between approaches determined by surgical risk, age, and anatomical considerations. 1
Diagnostic Approach for Severe Aortic Stenosis
Severe aortic stenosis is defined as:
- Peak aortic valve velocity ≥4 m/sec or mean gradient ≥40 mmHg
- Aortic valve area (AVA) ≤1.0 cm² (or indexed AVA ≤0.6 cm²/m²) 1
For patients with reduced LVEF and low-flow, low-gradient aortic stenosis:
- Low-dose dobutamine stress echocardiography should be performed to differentiate true severe AS from pseudo-severe AS 2
- This helps identify patients with severe stenosis and low flow due to reduced stroke volume 2
Treatment Algorithm Based on Surgical Risk
High or Extreme Surgical Risk (STS-PROM ≥8%)
- TAVR is the recommended intervention 1
- Shows significant mortality benefit compared to medical treatment alone 3
- At 2 years, TAVR reduces mortality (43.3% vs 68.0%) and cardiac death (31.0% vs 62.4%) compared to standard therapy 3
Intermediate Surgical Risk (STS-PROM 3-10%)
- Either TAVR or SAVR may be appropriate 1
- Decision should consider:
- Age
- Frailty
- Comorbidities
- Valve anatomy (bicuspid vs tricuspid)
- Coronary disease complexity
Low Surgical Risk and Younger Patients (<75 years)
- SAVR is generally preferred due to established long-term durability 1, 4
- TAVR has limited long-term data in young, low-risk patients 4
Special Considerations
Asymptomatic Severe Aortic Stenosis
AVR is recommended in asymptomatic patients with:
- LVEF <50%
- Very severe AS (Vmax ≥5 m/sec or mean gradient ≥60 mmHg)
- Abnormal exercise stress test
- Rapid progression
- High-risk profession requiring physical performance 1
Without intervention, asymptomatic severe AS has poor outcomes with survival rates of only 67%, 56%, and 38% at 1,2, and 5 years respectively 5
Concomitant Coronary Artery Disease
- SAVR with CABG is appropriate for all risk categories
- For intermediate/high-risk patients with less complex coronary disease, catheter-based approaches may be considered 1
Comparison of TAVR vs SAVR
TAVR Benefits
- Less invasive procedure
- Shorter hospital stay
- Faster recovery
- Lower risk of bleeding and atrial fibrillation 1
TAVR Risks
- Higher rates of paravalvular leak
- Increased need for permanent pacemaker implantation
- Higher stroke rates (13.8% vs 5.5% at 2 years) 3
- Limited long-term durability data 1
SAVR Benefits
- Established long-term durability
- Lower rates of paravalvular leak and pacemaker implantation 1
- Better option for patients with small aortic annulus (≤19 mm) 1
Post-Stenosis Dilation and Balloon Valvuloplasty
Balloon aortic valvuloplasty:
- Not recommended as standalone therapy for severe AS due to limited durability
- May be considered as a bridge to definitive therapy in hemodynamically unstable patients
- Can be used as palliative therapy in patients with limited life expectancy (<1 year) or severe dementia 1
Common Pitfalls to Avoid
Delaying intervention in symptomatic patients:
Misclassifying patients as "asymptomatic":
- Many patients reduce activity to avoid symptoms
- Exercise testing can unmask symptoms in seemingly asymptomatic patients
Overlooking low-flow, low-gradient AS:
- Can be missed if only valve area or gradient is assessed
- Requires comprehensive evaluation including dobutamine stress echo 2
Failing to use a Heart Team approach:
- Optimal treatment requires multidisciplinary evaluation considering patient risk factors, valve characteristics, and comorbidities 1
Medical therapy alone does not alter the natural history of severe AS, and valve replacement remains the only treatment shown to improve survival in symptomatic patients 6, 7.