What is the recommended treatment for severe aortic stenosis?

Treatment of Severe Aortic Stenosis

Aortic valve replacement (AVR) is the recommended treatment for severe aortic stenosis, with the choice between transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) depending on patient characteristics including age, surgical risk, and comorbidities. 1, 2

Patient Assessment and Treatment Algorithm

Step 1: Confirm Severe Aortic Stenosis

• Severe AS defined as:
  • Aortic valve area (AVA) ≤1.0 cm² or indexed AVA ≤0.6 cm²/m²
  • Peak velocity ≥4.0 m/s or mean gradient ≥40 mmHg 2

Step 2: Evaluate Symptoms

• Symptomatic Severe AS:

  • Immediate intervention (AVR) is strongly recommended regardless of surgical risk 1, 2
  • Delaying intervention in symptomatic patients significantly worsens prognosis with average survival of only 2-3 years without treatment 2
  • Symptoms include exertional dyspnea, heart failure, angina, syncope, or presyncope 1

• Asymptomatic Severe AS:

  • AVR is recommended if:
    • Left ventricular ejection fraction (LVEF) <50% 1
    • Very severe AS (Vmax ≥5 m/sec or mean gradient ≥60 mmHg) 1
    • Rapid progression (increase in Vmax >0.3 m/s/year) 1
    • Abnormal exercise test 1
  • Recent evidence shows early TAVR is superior to clinical surveillance in reducing death, stroke, or unplanned hospitalization 3

Step 3: Determine Type of Intervention (TAVR vs. SAVR)

Age-Based Recommendations:

• <65 years: SAVR preferred
• 65-75 years: SAVR generally preferred over TAVR

• 80 years: TAVR preferred 1

Surgical Risk Assessment:

• High surgical risk (STS-PROM >8%): TAVR recommended
• Intermediate or low surgical risk: Either TAVR or SAVR based on individual factors 1, 2

Special Considerations:

• Patients undergoing other cardiac surgery: AVR is appropriate 1
• Low-flow, low-gradient AS with reduced LVEF: Dobutamine stress echocardiography to confirm true severe AS, then AVR if confirmed 1

Step 4: Valve Selection (If SAVR chosen)

• Age <50 years: Mechanical valve
• Age 50-60 years: Mechanical valve preferred over bioprosthetic
• Age 60-65 years: Either mechanical or bioprosthetic
• Age >65 years: Bioprosthetic valve 1

Evidence Strength and Outcomes

The recommendation for AVR in symptomatic severe AS is supported by strong evidence showing dramatic improvement in survival (90% vs 38% 5-year survival) compared to conservative management 2, 4.

For inoperable patients, TAVR significantly reduces mortality compared to standard therapy (43.3% vs 68.0% at 2 years) 5.

Important Considerations and Pitfalls

1. Misclassification of Symptoms: Patients may reduce activity to avoid symptoms. Thorough assessment including exercise testing may be necessary 2.

2. Low-Flow, Low-Gradient AS: Requires careful evaluation with dobutamine stress echocardiography to differentiate true severe AS from pseudosevere AS 1, 2.

3. Non-Cardiac Surgery: Patients with severe AS requiring non-cardiac surgery should be evaluated for AVR prior to surgery. TAVR may be a safe alternative for high-risk patients 6.

4. Heart Team Approach: Treatment decisions should involve a multidisciplinary heart team, especially for complex cases 2.

5. Follow-up for Conservatively Managed Patients: If AVR is deferred, regular follow-up with echocardiography every 6-12 months is essential 2.

The evidence clearly demonstrates that AVR improves survival in both symptomatic and asymptomatic patients with severe aortic stenosis, with the specific approach (TAVR vs. SAVR) tailored based on patient characteristics and surgical risk.