Is my aortic valve bicuspid?

Is Your Aortic Valve Bicuspid?

I cannot determine if your specific aortic valve is bicuspid without diagnostic imaging—transthoracic echocardiography is the primary modality to diagnose bicuspid aortic valve (BAV) and should be performed to answer this question definitively. 1

Understanding Bicuspid Aortic Valve

BAV is the most common congenital cardiac malformation, affecting 1-2% of the population, where the valve has only two functional leaflets instead of the normal three. 2, 3, 4

Key Epidemiologic Features:

• Occurs in 0.5-2% of live births with strong male predominance 2, 5
• 9% of BAV patients have first-degree relatives with the condition, indicating significant familial clustering 2, 6
• Can be inherited in an autosomal dominant pattern in some families, though no single gene explains most cases 2, 5

How to Diagnose BAV

Transthoracic echocardiography (TTE) is the primary diagnostic tool for identifying BAV, providing detailed assessment of leaflet morphology, valve function, and associated aortic abnormalities. 1

Diagnostic Approach:

• TTE should evaluate leaflet number and configuration, distinguishing between normal tricuspid anatomy versus bicuspid morphology 1
• Note that 20% of cases may be reclassified after additional imaging with cardiac MRI, CT, or transesophageal echocardiography (TEE), as surface echocardiography can misidentify leaflet morphology 1
• TEE is useful when TTE results are suboptimal or clinically discordant 1

Why This Diagnosis Matters

BAV is not just a valve abnormality—it's a syndrome affecting both the valve and aortic wall, with significant lifetime morbidity reaching 86%. 2, 4

Critical Associated Risks:

• 40% of BAV patients develop ascending aortic aneurysms in clinical series 2
• 15% of acute aortic dissections occur in BAV patients, with dissection rates 8-10 fold higher than the general population 2
• 50% of BAV patients develop premature calcific valve disease, leading to aortic stenosis or regurgitation requiring intervention 3, 5
• Aortic dissection can occur even with aortic diameter <5 cm in 12.5% of BAV patients 2

Age-Related Complications:

• Younger patients typically present with aortic regurgitation, while older patients more commonly develop aortic stenosis 2
• 40% of women and one-third of men over age 70 undergoing aortic valve replacement have BAV as the underlying pathology 2

What Happens After BAV Diagnosis

All patients with confirmed BAV require comprehensive evaluation of both the aortic valve and the entire thoracic aorta. 1, 7

Mandatory Assessments:

• Both the aortic root and ascending thoracic aorta must be evaluated for dilatation at the time of BAV diagnosis 7
• Serial imaging surveillance is required throughout life to monitor for progressive valve dysfunction and aortic enlargement 4

Family Screening Requirements:

First-degree relatives of BAV patients should undergo echocardiographic screening for both abnormal valve morphology and asymptomatic thoracic aortic disease, given the 9% familial clustering rate. 7, 2, 6

Clinical Coding Considerations

If BAV is confirmed, the appropriate ICD-10 code is:

• Q23.1 for congenital insufficiency of the aortic valve (encompasses BAV as a congenital malformation) 6
• Z82.49 for family history when documenting familial clustering 6
• I35.1 for nonrheumatic aortic insufficiency when regurgitation is present 6
• I77.811 for associated aortic dilatation when present 6

Special Considerations for Interventions

BAV anatomy creates unique challenges for transcatheter aortic valve replacement (TAVR):

• The asymmetric valvular anatomy predisposes to noncircular device expansion, increasing risk of paravalvular regurgitation 1
• BAV is considered a relative contraindication to TAVR due to limited clinical experience and higher complication rates 1
• Moderate paravalvular leaks occurred in 2 of 11 BAV patients in Canadian experience, with one case of late device migration 1