In a patient with severe Aortic Stenosis (AS) and Peripheral Arterial Disease (PAD), which procedure should be done first, Aortic Valve Replacement (AVR) or Aorto-femoral bypass?

Management of Severe Aortic Stenosis with Peripheral Arterial Disease: Prioritizing Aortic Valve Replacement

In a patient with severe aortic stenosis (AS) and peripheral arterial disease (PAD), aortic valve replacement (AVR) should be performed first, followed by aorto-femoral bypass. 1

Rationale for Prioritizing AVR

The decision to prioritize AVR over peripheral vascular intervention is based on several important factors:

1. Mortality Risk: Symptomatic severe AS carries an extremely poor prognosis without intervention, with mortality rates exceeding that of untreated PAD. Once symptoms develop in severe AS, survival rates drop dramatically without valve replacement 1.

2. Hemodynamic Stability: Performing aorto-femoral bypass first could lead to hemodynamic instability during surgery in a patient with severe AS due to:

   • Limited cardiac output reserve
   • Inability to increase stroke volume during stress
   • Risk of hypotension during anesthesia and surgery

3. Guideline Support: European and American guidelines provide clear recommendations for prioritizing AVR in patients with severe AS who require non-cardiac surgery 1:

   • In symptomatic patients with severe AS, AVR should be performed before non-cardiac surgery
   • High-risk non-cardiac procedures (like aorto-femoral bypass) should be preceded by AVR in patients with severe AS

Clinical Decision Algorithm

Step 1: Assess AS Severity and Symptoms

• Confirm severe AS (valve area ≤1.0 cm², mean gradient ≥40 mmHg, or jet velocity ≥4.0 m/s) 1
• Document symptoms (dyspnea, angina, syncope)
• If asymptomatic, consider exercise testing to unmask symptoms

Step 2: Evaluate Surgical Risk

• Calculate surgical risk score (STS or EuroSCORE II)
• Consider comorbidities and frailty
• Assess technical feasibility of both procedures

Step 3: Determine AVR Approach

• For low to moderate surgical risk: Surgical AVR
• For high or prohibitive surgical risk: Consider TAVR 1

Step 4: Plan Staged Procedures

• First procedure: AVR (surgical or transcatheter)
• Allow for recovery and stabilization (typically 4-6 weeks)
• Second procedure: Aorto-femoral bypass

Special Considerations

Urgent PAD Scenarios

If the patient has critical limb ischemia requiring urgent intervention:

• Consider balloon aortic valvuloplasty as a bridge to definitive AVR 1
• Perform limited endovascular intervention to stabilize limb perfusion
• Proceed with definitive AVR once stabilized

Transcatheter Options

TAVR may be particularly advantageous in this scenario:

• Faster recovery than surgical AVR
• May allow earlier treatment of PAD
• Requires careful vascular access planning due to concomitant PAD 2

Potential Pitfalls

1. Underestimating AS Severity: Symptoms of AS may be masked by limited mobility from PAD, leading to inappropriate prioritization of vascular surgery 3

2. Vascular Access Challenges: PAD may complicate TAVR access; thorough vascular assessment is essential 4, 2

3. Anticoagulation Management: Carefully plan anticoagulation strategy between procedures to minimize bleeding and thrombotic risks

4. Hemodynamic Instability: If aorto-femoral bypass is performed first, there's significant risk of cardiovascular collapse during surgery due to the fixed cardiac output limitation from severe AS 1

By prioritizing AVR before addressing PAD, you maximize the patient's chances of survival through both procedures while minimizing the risk of catastrophic hemodynamic compromise during the vascular intervention.