What is the recommended approach for aortic valve replacement in a patient with a bicuspid aortic valve?

Aortic Valve Replacement in Bicuspid Aortic Valve

When performing aortic valve replacement (AVR) in patients with bicuspid aortic valve (BAV), you should replace the ascending aorta if its diameter exceeds 4.5 cm, and for isolated aortic disease without valve dysfunction, intervene at 5.5 cm (or 5.0 cm with risk factors). 1

Valve Replacement Strategy

Valve Type Selection

For patients under 60 years of age, mechanical valves provide superior long-term survival compared to bioprosthetic valves. 2, 3

• In patients aged 50-59 years undergoing AVR, mechanical valves showed a 15% survival advantage at 15 years compared to bioprosthetic valves 3
• For all patients ≤60 years, mechanical AVR demonstrated independent risk-adjusted survival benefit over bioprosthetic AVR with 12-year follow-up data 2
• Mechanical valves carry higher bleeding risk but lower reoperation rates (HR 3.05 for reoperation with bioprosthetic valves) 4
• Stroke risk is equivalent between valve types 4

Valve Repair Considerations

For BAV with aortic regurgitation, valve repair with or without root remodeling is preferable when the valve is not severely fibrotic or calcified. 1

• Valve-sparing operations yield excellent results in Heart Valve Centers of Excellence for patients without severely deformed or dysfunctional valves 1
• For stenotic bicuspid valves with dilated aortic root, composite valve grafts (mechanical or biological) are the standard approach 1

Ascending Aorta Management

Concomitant Aortic Replacement During AVR

Replace the ascending aorta when its diameter exceeds 4.5 cm in patients undergoing AVR for severe aortic stenosis or regurgitation. 1

• This threshold applies regardless of whether stenosis or regurgitation is the primary indication 1
• The 2024 ESC guidelines recommend aortic replacement at ≥45 mm diameter when AVR is performed 1
• Replacement of the sinuses of Valsalva should be individualized based on coronary ostia displacement, as progressive sinus dilation after separate valve and graft repair is uncommon 1
• Separate valve and ascending aortic replacement is recommended in patients without significant aortic root dilatation 1

Isolated Aortic Dilatation Without Valve Dysfunction

Operate at 5.5 cm diameter for isolated ascending aortic aneurysms in BAV patients without additional risk factors. 1

Lower the threshold to 5.0 cm when risk factors are present:

• Family history of aortic dissection 1
• Rapid aortic growth ≥0.5 cm per year 1
• Aortic coarctation 1
• Resistant hypertension 1

The 2024 ESC guidelines further refine this, recommending surgery at ≥50 mm with additional risk factors including age <50 years, short stature, ascending aortic length ≥11 cm, or desire for pregnancy 1

Critical Caveats

• Do not use body surface area adjustment formulas for aortic diameter thresholds—the 2014 AHA/ACC guidelines explicitly moved away from this approach 1
• Recognize that the aortic sinuses are normally 0.5 cm larger in diameter than the tubular ascending aorta 1
• Surgery should be performed by experienced aortic surgical teams in centers with established expertise to ensure low morbidity and mortality 1
• BAV patients present with aortic dissection at younger ages than those with tricuspid valves, justifying earlier intervention 1

Surveillance Protocol

For BAV patients with ascending aorta >40 mm, perform annual transthoracic echocardiography initially, then every 2-3 years if stable. 1

• When diameter exceeds 45 mm or increases >3 mm per year on echocardiography, perform annual measurements 1
• Confirm measurements >50 mm or increases >3 mm per year with CT or MRI 1
• Use cardiac MRI or CT when the aortic root and ascending aorta cannot be accurately assessed by transthoracic echocardiography 1