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Brain & Heart Modern imaging and management of bicuspid valves

2.4. Associated conditions may, in some cases, represent an incidental bystander

The most important associated condition with BAV is rather than the primary cause of disease. 27
aortopathies. Acute aortic syndromes, including acute 3. Diagnostic evaluation
aortic dissection, intramural hematoma, and penetrating
atherosclerotic ulcer, are the most feared complications The diagnosis of a BAV is typically made using transthoracic
of BAV. Aortic dilation, which typically precedes echocardiography (TTE). Key features include systolic
25
rupture and dissection, was found evident in ≥50% of doming, eccentric valve closure, leaflet redundancy or
young patients with normally functioning BAV who prolapse, the presence of a raphe, an elliptical valve orifice
underwent echocardiographic imaging. Previous studies during systole, a distinct opening pattern, and dilation
6
reported an acute aortic dissection incidence of 3.1 (95% of the aortic root or ascending aorta, and are classified
29
confidence interval: 0.5 – 9.5) cases/10,000 patient-years by the aforementioned Sievers’ criteria. Eccentric AR
among patients with BAV. Although low, this number is jets without an apparent cause may suggest the presence
significantly higher than the general population. The of a BAV. Accurate assessment during systole is critical,
26
exact cause of predisposition to aortic aneurysms in BAV as the raphe can resemble a tricuspid configuration
patients remains debated, with evidence supporting both during diastole. However, eccentric valve closure is not
hemodynamic and genetic factors. Genetically, unaffected a reliable standalone feature, given its limited sensitivity
first-degree relatives of patients with BAV have a higher and specificity – approximately 25% of BAV cases may
prevalence of aortic aneurysm compared to those with not display it, and it can occasionally be seen in tricuspid
tricuspid aortic valves (TAVs). On the other hand, studies valves. Moreover, it is important to recognize subtle
suggest that BAV hemodynamics are abnormal even or incomplete forms of BAV, such as valves with small
without significant valvular dysfunction on imaging, which raphes or partial commissural fusion, especially when
30,31
leads to increased stress on the aortic wall and subsequent evaluating patients with aortic root dilation. When
accelerated degeneration of the aortic media. 6,27 echocardiography evaluation is inclusive, transesophageal
echocardiography (on mid-esophageal aortic valve
The BAV has many other associations with short-axis view), cardiac computed tomography (CT)
congenital and genetic disorders. This includes left-sided (retrospective electrocardiogram [ECG]-gated cine
obstructive lesions such as coarctation of the aorta and imaging), or cardiac magnetic resonance imaging (MRI)
Shone complex, which refers to a rare congenital heart (aortic valve short-axis cine sequence) are all tools to assess
condition characterized by a combination of several aortic valve morphology and confirm or exclude BAV.
32
cardiac abnormalities. These typically include BAV, Table 1 summarizes the strengths and limitations of multi-
aortic coarctation, subaortic stenosis, and left ventricular modality cardiac imaging for evaluating BAV.
outflow tract obstruction. Shone complex can lead to Basic tests such as ECG, chest X-ray, and lab tests have
various complications such as heart failure or stroke, limited utility in BAV disease evaluation. ECG is typically
and it often requires surgical intervention to address the normal, although left atrial enlargement and left ventricular
structural abnormalities. It is considered a complex form hypertrophy can be seen in severe AS or insufficiency.
33
of congenital heart disease due to the multiple associated Plain chest radiographs have limited utility in diagnosing
conditions. 28
BAV. Detecting a solitary calcified raphe in the typical
Ventricular septal defects, syndromic conditions, location of a bicuspid valve, most clearly visualized on
such as Turner and Loeys-Dietz syndromes, familial lateral radiographic views, where the aortic valve overlaps
thoracic aortic aneurysm, and dissection diseases the spine in frontal projections, can raise suspicion for
linked to ACTA2 gene mutations. While familial BAV BAV. In addition, post-stenotic dilation of the ascending
inheritance often follows an autosomal dominant pattern aorta may serve as a supportive imaging feature. Lab
34
with incomplete penetrance and variable expression, its tests for brain natriuretic peptides may be elevated in the
genetic underpinnings remain poorly understood for most presence of severe BAV stenosis or regurgitation as a sign
patients. Rare mutations in genes such as NOTCH1, which of increased pressure and strain in the heart, as a precursor,
is linked to valvular calcifications, and GATA5, which is or in the presence of symptoms and heart failure.
associated with aortopathy, have been identified, but these
account for only a minority of cases. This intricate genetic 3.1. Echocardiography
and developmental profile raises the possibility that BAV TTE is typically sufficient for assessing aortic valve anatomy
may result from broader genetic changes impacting the and hemodynamics, and has a sensitivity of 78 – 92% and
aorta and other cardiac structures during development. a specificity of 96% for detecting BAV. 35,36 However, its
Hence, some researchers suggest that the valve anomaly accuracy is influenced by factors such as image quality,

Volume 3 Issue 3 (2025) 4 doi: 10.36922/BH025050008