Management of Sievers Type 1 Bicuspid Aortic Valve with Mild Aortic Regurgitation

Initial Diagnostic Evaluation

The European Society of Cardiology recommends serial echocardiographic surveillance every 3-5 years for patients with Sievers type 1 bicuspid aortic valve and mild aortic regurgitation, with mandatory assessment of the ascending aorta by CT or MRI at initial diagnosis to evaluate for associated aortopathy 1, 2
Comprehensive transthoracic echocardiography (TTE) should be performed to assess valve morphology, quantify aortic regurgitation severity, measure left ventricular dimensions and function, and evaluate aortic root and ascending aorta diameters at multiple levels 3
CT angiography or cardiac MRI of the entire thoracic aorta should be obtained at initial diagnosis, as approximately 50% of bicuspid aortic valve patients have associated aortopathy 2, 4
First-degree relatives should be screened with TTE for bicuspid aortic valve and aortopathy, particularly when the patient has root phenotype aortopathy or isolated aortic regurgitation 2, 3, 4

For patients with mild aortic regurgitation and normal aortic dimensions, TTE should be performed every 3-5 years to monitor progression of aortic regurgitation, left ventricular size and function, and aortic dimensions 1, 5
For patients with mild aortic regurgitation and aortic dilation (≥40 mm), TTE should be performed annually to assess for progression 1, 5
Surveillance frequency should be increased to every 6 months if rapid aortic growth (>0.5 cm/year) is documented 5

Blood pressure should be controlled aggressively if hypertension is present, using any effective antihypertensive agent 6
Beta-blockers or angiotensin receptor blockers (ARBs) may be considered for patients with aortic dilation, though evidence for slowing progression in bicuspid aortic valve-associated aortopathy is limited 5, 6
Beta-blockers should be avoided if aortic regurgitation becomes moderate or severe, as they may increase regurgitant volume by prolonging diastole 5

Surgery is recommended when ascending aorta diameter reaches ≥55 mm in most patients with bicuspid aortic valve 2, 6
Surgery is recommended at ≥50 mm specifically for bicuspid aortic valve patients with root phenotype aortopathy (dilation primarily at sinuses of Valsalva) 2, 4, 6
Consider surgery at lower thresholds (45-50 mm) if there is a family history of aortic dissection or rapid progression (>0.5 cm/year) 5, 6

Sievers type 1 bicuspid aortic valves carry specific risks, including higher rates of paravalvular regurgitation with transcatheter aortic valve replacement due to the calcified raphe preventing adequate stent apposition 8
Post-implantation aortic regurgitation is more common in type 1 bicuspid valves (34.2%) compared to type 0 (13.3%) when transcatheter procedures are performed 8

Color Doppler jet assessment alone should not be relied upon for aortic regurgitation severity in bicuspid valves, as eccentric jets may underestimate severity; use vena contracta width, holodiastolic flow reversal in descending aorta, and left ventricular dimensions instead 1, 9
Aortic imaging from TTE alone is often inadequate, and CT or MRI should be used to assess the ascending aorta beyond the proximal 2-3 cm 3, 6
Aortic imaging should not be delayed until symptoms develop, as aortic complications can occur independently of valve dysfunction severity 2, 4