What screening is needed for a bicuspid aortic valve?

Screening Recommendations for Bicuspid Aortic Valve

Patients with bicuspid aortic valve (BAV) require regular imaging surveillance of the aorta and screening of first-degree relatives to prevent morbidity and mortality from aortic complications. 1

Initial Evaluation for Newly Diagnosed BAV

When a bicuspid aortic valve is first diagnosed:

• Transthoracic echocardiography (TTE) to assess:

  • Aortic valve morphology and function
  • Aortic measurements at multiple levels (annulus, sinuses, sinotubular junction, mid-ascending aorta)
  • Presence of aortic regurgitation or stenosis
  • Left ventricular function and dimensions 1

• Cardiac MRI or CT angiography of the entire thoracic aorta is recommended at first diagnosis to:

  • Evaluate areas not well visualized by echocardiography
  • Establish baseline measurements of the entire aorta
  • Assess for associated abnormalities 1

• Screening for coarctation of the aorta by:

  • Clinical examination (blood pressure in both arms and one lower extremity)
  • Doppler interrogation of the proximal descending aorta 1

Ongoing Surveillance for BAV Patients

The frequency of follow-up imaging depends on aortic diameter:

1. For aortic diameter ≤40 mm with no indication for surgery:

   • TTE every 2-3 years if stability is observed 1

2. For aortic diameter >40 mm:

   • TTE surveillance after 1 year, then every 2-3 years if stability is observed 1

3. For aortic diameter >45 mm:

   • Annual TTE surveillance 1
   • CMR or CCT of the entire thoracic aorta is recommended when:
     • Important discrepancies in measurements are found between subsequent TTE controls
     • When the diameter of the aorta exceeds 45 mm 1

4. For aortic diameter >50 mm:

   • More frequent monitoring may be warranted, especially with rapid growth (>3 mm/year) 1

Family Screening

• Screening by TTE is recommended in first-degree relatives (parents, siblings, children) of patients with BAV, particularly those with:

  • Root phenotype aortopathy
  • Isolated aortic regurgitation
  • Family history of thoracic aortic disease 1

• Screening should begin at the time of diagnosis of BAV in the index case 1, 2

Special Considerations

• Pregnancy planning: Women with BAV and aortic diameters >45 mm should undergo prophylactic aortic root surgery before pregnancy 1

• Athletes with BAV: Require individualized assessment based on aortic dimensions and rate of growth 1

• Post-surgical patients: Those who have undergone isolated aortic valve surgery still require ongoing surveillance of the aorta 1

Surgical Intervention Thresholds

While not directly related to screening, it's important to note when intervention is indicated:

• Surgery for bicuspid aortopathy is recommended when:
  • Maximum aortic diameter is ≥55 mm
  • Maximum aortic diameter is ≥50 mm for root phenotype
  • Maximum aortic diameter is ≥50 mm with risk factors (coarctation, hypertension, family history of dissection, or increase in aortic diameter >3 mm/year) 1

Pitfalls to Avoid

1. Inadequate imaging: Ensure complete visualization of the entire thoracic aorta, as TTE alone may miss segments of the ascending aorta

2. Inconsistent measurement technique: Measurements should be perpendicular to the long axis of the aorta and at the same cardiac phase (end-diastole for echo)

3. Overlooking associated conditions: BAV patients should be evaluated for coarctation of the aorta and other congenital abnormalities

4. Neglecting family screening: The 6.6% prevalence of BAV in first-degree relatives supports the importance of family screening 3

5. Underestimating growth rate: An increase of >3 mm/year is significant and warrants more frequent monitoring and possible intervention

By following these screening recommendations, clinicians can effectively monitor BAV patients and their families to prevent the potentially fatal complications of aortic dissection and rupture.