What are the indications for Transcatheter Aortic Valve Replacement (TAVR)?

Indications for Transcatheter Aortic Valve Replacement (TAVR)

TAVR is recommended for patients with severe, symptomatic, calcific stenosis of a trileaflet aortic valve who have prohibitive surgical risk and suitable aortic/vascular anatomy with predicted survival >12 months. 1

Patient Selection Criteria

Severe Aortic Stenosis Definition

• Aortic valve area ≤1.0 cm² OR
• Aortic valve index ≤0.6 cm²/m² OR
• Mean gradient ≥40 mm Hg OR
• Aortic jet velocity ≥4.0 m/s
• With calcified, reduced systolic motion of valve leaflets 1

Risk Stratification

1. Prohibitive Surgical Risk (Class I recommendation):

   • Estimated ≥50% risk of mortality or irreversible morbidity at 30 days with surgery 1
   • Other factors qualifying as prohibitive risk:
     • Frailty
     • Prior radiation therapy
     • Porcelain aorta
     • Severe hepatic or pulmonary disease 1

2. High Surgical Risk (Class IIa recommendation):

   • STS score ≥8% 1
   • Other anatomic factors increasing surgical risk 1
   • Significant frailty 1

3. Intermediate Risk (expanded indication):

   • More recent evidence supports TAVR in intermediate-risk patients 2

4. Low Risk (emerging indication):

   • Early evidence shows promising outcomes in low-risk patients 3
   • Zero mortality and zero disabling stroke at 30 days in low-risk TAVR patients 3

Anatomical Requirements

• Suitable aortic annulus size for available TAVR devices
• Adequate vascular access (femoral, iliac, subclavian, or axillary) or suitability for apical approach 1
• Appropriate valve plane to coronary ostium height 1

Contraindications for TAVR

Absolute Contraindications

• Absence of a "heart team" and no cardiac surgery on-site
• Life expectancy <1 year
• Unlikely improvement in quality of life due to comorbidities
• Severe primary disease of other valves requiring surgical treatment
• Inadequate annulus size (<18 mm, >29 mm)
• Thrombus in left ventricle
• Active endocarditis
• High risk of coronary ostium obstruction
• Mobile thrombi in ascending aorta or arch
• Inadequate vascular access for chosen approach 1

Relative Contraindications

• Bicuspid or non-calcified valves
• Untreated coronary artery disease requiring revascularization
• Hemodynamic instability
• LVEF <20%
• Severe pulmonary disease (for transapical approach) 1

Decision-Making Algorithm

1. Confirm severe symptomatic aortic stenosis

   • Echocardiographic criteria met
   • Presence of symptoms (dyspnea, angina, syncope, heart failure)

2. Assess surgical risk

   • Calculate STS score
   • Evaluate for frailty, porcelain aorta, prior chest radiation, severe comorbidities
   • Determine risk category: prohibitive, high, intermediate, or low

3. Evaluate anatomical suitability

   • Assess aortic annulus size and valve morphology
   • Evaluate vascular access options
   • Measure coronary height and assess risk of coronary obstruction

4. Heart Team evaluation

   • Multidisciplinary team including cardiologists, cardiac surgeons, imaging specialists
   • Consensus decision on optimal approach (TAVR vs. SAVR)

5. Determine expected post-procedure survival

   • Must be >12 months to justify TAVR procedure 1

Procedural Considerations

• TAVR should only be performed in hospitals with cardiac surgery on-site 1
• A Heart Valve Team approach is mandatory for optimal patient selection 1
• Careful pre-procedural imaging is essential for device selection and procedural planning 4

Potential Complications

• Mortality (3-5%)
• Stroke (6-7%)
• Vascular access complications (17%)
• Pacemaker insertion (2-9% with Sapien, 19-43% with CoreValve)
• Paravalvular aortic regurgitation
• Acute kidney injury
• Coronary occlusion, valve embolization, or aortic rupture 1

Key Pitfalls to Avoid

1. Inappropriate patient selection:

   • Selecting patients with life expectancy <12 months
   • Choosing TAVR when severe disease of other valves requires surgical intervention

2. Inadequate anatomical assessment:

   • Failing to properly size the aortic annulus
   • Missing high-risk features for coronary obstruction

3. Ignoring contraindications:

   • Proceeding with TAVR in patients with active endocarditis
   • Performing TAVR without cardiac surgical backup

4. Underestimating comorbidities:

   • Not accounting for frailty and its impact on outcomes
   • Overlooking cognitive impairment that may affect recovery

TAVR has revolutionized the management of severe aortic stenosis, particularly in patients at prohibitive or high surgical risk. With expanding evidence, its application is growing to include intermediate and potentially low-risk patients. Careful patient selection through a Heart Team approach remains essential to optimize outcomes and minimize complications.