O1010: Bicuspid Aortic Valve in Infants Without Severe Congenital Heart Defects: Epidemiology, Clinical Features and Outcomes

Background: Bicuspid aortic valve (BAV) is the most common congenital heart defect (CHD). However, no guidelines exist for frequency of imaging surveillance among children, particularly infants, without severe congenital lesions.

Methods: The Mayo Clinic echocardiography database was retrospectively searched for infants (age < 1 year) diagnosed with BAV from 2001–2019. A total of 307 patients were identified and divided into two cohorts for longitudinal follow-up. Cohort 1 (n=189, 61%) includes patients with BAV and significant CHD. Cohort 2 (n=118, 39%) includes patients with isolated BAV and concomitant simple CHD (atrial septal defects, muscular ventricular septal defects and/or patent ductus arteriosus). This study reviewed Cohort 2 for echocardiographic characteristics, clinical features and cardiac outcomes related to BAV.

Results: Among 118 infants, 59% (n=70) had an associated simple CHD and 41% (n=48) had isolated BAV. Overall, there was male predominance (67%), associated genetic syndromes were present in 36% of patients, and 21% of patients were premature. Infants underwent first echocardiogram at a median age of 8 days (IQR 2-76 days, range 0-349 days), most commonly for murmur (71%, n=84), followed by concern for genetic syndrome (8%, n=10) or other examination findings (4%, n=5). At first echocardiogram, aortic regurgitation (AR) was present in 38 patients (32%); only 1 patient with more than moderate AR. Aortic stenosis (AS) was present in 74 patients (63%); of these, 27 (23%) had a mean gradient >20 mm Hg and 16 (13%) had a mean gradient >40 mmHg. Altogether, 106 patients (90%) had a follow-up echocardiogram at a median age of 8.8 years (IQR 3.9-14.4 years) with total clinical follow-up of 966 patient years. Aortic valve interventions were performed in 27 patients (25%), primarily during the first year of life, for severe AS including balloon aortic valvuloplasty (56%, n=15) or surgical aortic valvulotomy (19%, n=5). For patients initially with no AS (aortic valve mean gradient < 10 mm Hg) and trivial or less AR (n=64), none required aortic or valvular intervention at a median follow-up age of 5.2 years (IQR 0.6-10.1 years). For patients with mild-moderate or less AS and/or mild-moderate or less AR (n=15), only 1 (7%) required aortic valve intervention with median follow-up age of 12.7 years (IQR 4.9-18.4). For patients with moderate or more AS and/or moderate or more AR (n=27), 19 (68%) required aortic or valvular surgery with median follow-up age of 12.9 years (IQR 6.4-16.5 years). Overall, 7 patients died with only one death related to cardiac disease.

Conclusion: Infants with BAV without severe CHD who had relatively normal aortic valve function at first echocardiogram did not have significant progression over the first few years of life and required no interventions on aortic valve or aorta. Therefore, initial echocardiographic valvulopathy assessment can guide follow-up surveillance imaging.