Aortic Stenosis Intervention

Abbreviations

  •  TTE: Trans-Thoracic Echocardiography
  • LVEF: Left Ventricular Ejection Fraction
  • AS: Aortic Stenosis

Introduction

  • Options of fixing stenotic valves include percutaneous vs. open and valvuloplasty vs. replacement
  • Decision should involve a Valve Team and should be individualized to every patient
  • Patient profile and technical factors influence decision
  • Choosing what type of intervention will be the focus of this article. Diagnosing stenotic lesions and medical therapy are discussed elsewhere.

Aortic Stenosis

Diagnosis

  • TTE is indicated to establish diagnosis
  • If low-flow low gradient is suspected, low-dose dobutamine stress testing with echo or cardiac catheterization can be done

Criteria

  • Severe aortic stenosis is diagnosed by:
    • Peak velocity >4 m/s or mean gradient >40 mmHg
    • Typically aortic valve area < 1 cm2 but not required to diagnose
  • Ancillary findings
    • LV diastolic function, LV hypertrophy, and generally normal LVEF, but in late stages EF can drop and LV can dilate

Interventions

  1. Percutaneous Aortic Balloon Dilation
  2. Surgical Aortic Valve Replacement (SAVR)
  3. Transcatheter Aortic Valve Intervention (TAVI)
  4. Ross Procedure
    • Reserved for younger patients
AHA 2020 - Timing of intervention for AS

Percutaneous Aortic Balloon Dilation

  • Mainly used in young patients; limited role in elderly
  • Can be used in patients with severe AS and refractory pulmonary edema or cardiogenic shock as a bridge but less common with availability of TAVI

Prosthetic Valve Choice

  • Choice of AVR should be based on shared decision making involving the Valve Team and the patient

Assess Risk and Frailty

  • Use either STS score or EUROSCORE II to assess risk (note – maybe we could include images of these scores as quick references too? Just a thought)
  • Use ADLs or frailty scores such as the FRAILTY-AVR 4 point score to assess frailty
Afilalo 2017 - FRAILTY-AVR 4 point score
  • High or prohibitive risk patients should go for TAVI or palliation
  • Not high risk:
    • <50 SAVR (mechanical valve)
      • unless contraindication to VKA
    • 50-65 SAVR
      • Mechanical or bioprosthetic valve
      • Highly debated as new bioprosthetic valve more durable
    • 65-80 SAVR or TAVI
    • >80 TAVI (Class 2 SAVR)
AHA 2020 - Choice of SAVR versus TAVI when AVR is indicated for valvular AS

Assess TAVI Suitability

  • TAVI suitability should be assessed by Valve Team
  • Assessment includes valve anatomy, annular size, coronary ostial height (low ostial height precludes TAVI) and vascular access

Decision Making Frameworks

AHA 2020 - Risk Assessment for Surgical Valve Procedures
AHA 2020 - A Simplified Framework With Examples of Factors Favoring SAVR, TAVI, or Palliation Instead of Aortic Valve Intervention

Further Reading

  • 2020 AHA: Guideline for the Management of Patients With Valvular Heart Disease (html) (pdf)
  • Afilalo J, Lauck S, Kim DH, et al. Frailty in Older Adults Undergoing Aortic Valve Replacement: The FRAILTY-AVR Study. J Am Coll Cardiol. 2017; 70(6):689-700. (html) 

Authors

  • Author: Atul Jaidka (MD, FRCPC, Cardiology Fellow)
  • Copy Editor: Megha Shetty (MD Candidate)
  • Last Updated: April 5, 2021
  • Comments or questions please email feedback@cardioguide.ca