Aortic Valve Replacement and Ascending Aorta Management in Bicuspid Aortic Valve

Valve Replacement Strategy

The American Heart Association and American College of Cardiology recommend replacing the ascending aorta when its diameter exceeds 4.5 cm in patients undergoing aortic valve replacement for severe aortic stenosis or regurgitation 1, 2, 3
Valve-sparing operations yield excellent results in patients without severely deformed or dysfunctional valves, according to the American Heart Association and American College of Cardiology 1, 2, 3

The American College of Cardiology recommends replacing the ascending aorta when its diameter exceeds 4.5 cm in patients undergoing aortic valve replacement for severe aortic stenosis or regurgitation 1, 2, 3, 4
The European Society of Cardiology guidelines recommend aortic replacement at ≥45 mm diameter when aortic valve replacement is performed 5
Operate at 5.5 cm diameter for isolated ascending aortic aneurysms in bicuspid aortic valve patients without additional risk factors, according to the American Heart Association and American College of Cardiology 1, 2, 3
Lower the threshold to 5.0 cm when risk factors are present, such as family history of aortic dissection, rapid aortic growth ≥0.5 cm per year, aortic coarctation, or resistant hypertension 1, 2, 3, 4, 6
The European Society of Cardiology 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 5

For bicuspid aortic valve patients with ascending aorta >40 mm, perform annual transthoracic echocardiography initially, then every 2-3 years if stable, according to the European Society of Cardiology 5
When diameter exceeds 45 mm or increases >3 mm per year on echocardiography, perform annual measurements, and confirm measurements >50 mm or increases >3 mm per year with CT or MRI 5
Use cardiac MRI or CT when the aortic root and ascending aorta cannot be accurately assessed by transthoracic echocardiography, as recommended by the European Society of Cardiology and the American Heart Association 5, 7

Bicuspid aortic valve (BAV) does not independently increase the risk of aortic dissection when aortic diameter is accounted for (hazard ratio ≈ 0.94, p = 0.95). This finding is based on high‑quality cohort data. 8
Rapid aortic expansion (≥ 0.5 cm per year) is a critical risk factor that lowers the surgical threshold from 5.5 cm to 5.0 cm, irrespective of the baseline diameter. (ACC/AHA guideline, Class IIa). 9
A positive family history of aortic dissection or sudden death reduces the surgical threshold to 5.0 cm and warrants intensified surveillance. (ACC/AHA guideline, Class IIa). 9

Standardized aortic measurement should be performed at four levels: annulus, sinuses of Valsalva, sinotubular junction, and mid‑ascending aorta. (European Heart Journal recommendation). 8
Aortic diameter should not be indexed to body‑surface area except in patients with extreme body‑size variations. (ACC/AHA guideline, Class III). 9
Measurements must be taken perpendicular to the direction of blood flow; oblique imaging is discouraged because it can overestimate size. (ACC/AHA guideline). 9

Diameter ≥ 5.5 cm: Surgical repair is recommended for all patients (Class I). 9
Diameter 5.0–5.4 cm with additional risk factors (e.g., family history, rapid growth, BAV with other features): Surgery is reasonable (Class IIa). 9
Diameter ≥ 4.5 cm when the patient is already undergoing aortic valve surgery: Concomitant aortic replacement is reasonable (Class IIa). 9
Diameter < 4.5 cm: Management should be medical with routine surveillance; no prophylactic surgery is indicated (Class III). 9