Bicuspid Aortic Valve Diagnosis and Management

Valve Morphology and Diagnosis

In a bicuspid aortic valve, the A2 cusp is typically larger and asymmetric compared to the other cusp, often resulting from fusion of the right and left coronary cusps (80% of cases) or right and non-coronary cusps (20% of cases) 1
The most common pattern (80%) is fusion of right and left coronary cusps, resulting in a larger anterior (A2) and smaller posterior cusp, with both coronary arteries arising from the anterior cusp 1
The less common pattern (20%) is fusion of right and non-coronary cusps, resulting in a larger right cusp than left cusp, with one coronary artery arising from each cusp 1
Diagnosis of bicuspid aortic valve is most reliable when two cusps are seen in systole, only two commissures are visible, and an elliptical systolic orifice is present 1

Bicuspid aortic valve is strongly associated with aortic dilatation (bicuspid valvulo-aortopathy) 1
Calcification in bicuspid valves is often more asymmetric compared to tricuspid valves, and in younger patients, bicuspid valves may be stenotic without extensive calcification 1
In most adults, stenosis of bicuspid valves typically results from superimposed calcific changes 1

When a bicuspid aortic valve is first diagnosed, complete imaging of the thoracic aorta is necessary 2
Annual monitoring of the aortic root/ascending aorta with transthoracic echocardiography is recommended, with additional imaging with CMR/CCT every 3-5 years 2

Prophylactic aortic surgery should be considered when aortic diameter reaches ≥45 mm, or lower with additional risk factors, or when concomitant aortic valve surgery is being performed and aortic diameter is ≥45 mm 2, 3

Mistaking a raphe for a commissure in diastole, overlooking bicuspid morphology in heavily calcified valves, failing to assess in systole when the bicuspid nature is most apparent, and not considering associated aortopathy when bicuspid valve is identified 1