What are the criteria for aortic valve replacement?

Criteria for Aortic Valve Replacement

Aortic valve replacement is strongly recommended for all patients with symptomatic severe aortic stenosis regardless of surgical risk, as delaying intervention significantly worsens prognosis with average survival of only 2-3 years without treatment. 1

Definition of Severe Aortic Stenosis

Severe aortic stenosis is defined by:

• 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 1

Indications for Aortic Valve Replacement

Symptomatic Severe AS

• Immediate intervention is indicated for all patients with symptomatic severe AS regardless of surgical risk 2, 1
• Symptoms include:
  • Exertional dyspnea
  • Heart failure
  • Angina
  • Syncope or presyncope 1

Asymptomatic Severe AS

Aortic valve replacement is indicated in asymptomatic patients with:

• Left ventricular ejection fraction (LVEF) <50% 2, 1
• Very severe AS (Vmax ≥5 m/sec or mean gradient ≥60 mmHg) 2, 1
• Rapid progression (increase in Vmax >0.3 m/s/year) 1
• Abnormal exercise test (exercise-induced symptoms, limited exercise capacity, or abnormal blood pressure response) 2, 1
• AVA <1.0 cm² (even without symptoms) as this independently predicts poor outcomes 3

Low-Flow, Low-Gradient Severe AS

• For patients with AVA ≤1.0 cm² with low flow and low gradient:
  • With reduced LVEF: Dobutamine stress echocardiography is recommended to confirm true severe AS 1
  • With preserved LVEF: Evidence of severe valve calcification supports AVR 2
  • AVR is appropriate when clinical, hemodynamic, and anatomic data support valve obstruction as the cause of symptoms 2

Concomitant Cardiac Surgery

• AVR is appropriate for patients with severe AS undergoing other cardiac surgery 1

Treatment Selection: TAVR vs. SAVR

The choice between transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) depends on:

Age-Based Recommendations

• Age >80: TAVR recommended 1
• Age <65: SAVR generally preferred 1
• Age 65-80: Consider individual factors 1

Surgical Risk Assessment

• High or extreme surgical risk (STS-PROM ≥8%): TAVR recommended 2, 1, 4
• Intermediate surgical risk (STS-PROM 3-10%): Either TAVR or SAVR, based on individual factors 2, 1
• Low surgical risk (STS-PROM <3%): SAVR traditionally preferred, but TAVR is increasingly considered 2

Special Considerations

Heart Team Approach

• A multidisciplinary Heart Team should determine optimal treatment strategy, considering:
  • Patient risk factors
  • Valve characteristics
  • Comorbidities 2, 1

Contraindications to Intervention

• Limited life expectancy (<1 year)
• Severe dementia
• In these cases, medical therapy is appropriate, and palliative balloon valvuloplasty may be considered 1

Timing of Intervention

• Recent evidence supports early SAVR in asymptomatic patients with severe AS, as it reduces a composite of all-cause death, acute myocardial infarction, stroke, and heart failure hospitalization compared to conservative treatment 5
• Early intervention in asymptomatic patients with AVA <1.0 cm² should be considered due to excess mortality risk even without symptoms 3

Monitoring Asymptomatic Patients

For asymptomatic patients with severe AS who are managed conservatively:

• Serial Doppler echocardiography every 6-12 months
• Patient education about symptom recognition
• Prompt reporting of new symptoms 1

Pitfalls and Caveats

• Misclassifying patients as "asymptomatic" can lead to reduced activity and overlooked high-risk features 1
• Low-gradient severe AS is common (67% of severe AS cases) and should not be dismissed 3
• AVA <1.0 cm² predicts unfavorable outcomes regardless of symptoms or gradient 3
• Despite clear benefits, AVR is underutilized in community practice (performed in only 45% of eligible patients) 3

Aortic valve replacement significantly improves survival (90% vs 38% 5-year survival) in symptomatic patients with severe AS and should be pursued promptly when indicated 1.