Most common congenital cardiac abnormality in adults.
Affects 1.3% of the population.
Most common complication is valve dysfunction.
Associated with early degeneration of the aortic valve leading to aortic stenosis or regurgitation.
Initial valve function is relatively normal with little clinical consequence, but progressive valve fibrosis and calcification eventually results in severe aortic stenosis requiring aortic valve replacement in nearly all patients with bicuspid aortic valve in later life.
Survival among individuals with bicuspid aortic valve series is similar to that of the general patient population.
Presentation ranges from asymptomatic subjects to those with aortic stenosis or aortic insufficiency, endocarditis, aortic dilatation, and aortic dissection.
Can be clinically silent and discovered incidentally on a transthoracic echocardiogram.
Can progress to aortic stenosis, aortic insufficiency, and endocarditis and can be associated with aortic aneurysm and aortic dissection.
Has a wide phenotypic spectrum characterized by fusion of two of the normal three leaflets in 90 to 95% of cases or two equal hemispherical leaflets in 5 to 7% of patients.
Has marked phenotypic heterogeneity of the valves morphology, genetic heterogeneity and heterogeneity in its presentation.
Diagnosis of BAV depends on visualization of elliptical valve opening, rather than the normal circular opening of trileaflet aortic valves.
As the valves become progressively fibrotic, fused and calcified and results in reduced systolic opening an incomplete closure.
The most common reason for aortic valve replacement in bicuspid aortic valve is aortic stenosis.
during their lifetime most patients with BAV have relatively normal valve function until late adulthood.
Up to 30% of patients with BAV develop severe aortic regurgitation with left ventricular dilatation and dysfunction, requiring aortic valve replacement, typically at age 20 to 40 years.
BAV in most patients is associated with progressive calcific changes of the valve leaflets leading to severe aortic stenosis, requiring aortic valve replacement at age 50 to 70 years, rather than after age 70 typical with trileaflet aortic stenosis.
Associated with significant morbidity and mortality related to the development of aortic valve dysfunction, endocarditis, and dissection.
A study of cardiac outcomes of 642 consecutive adults with a mean age of 35 years with biscuspid aortic valves followed for a mean of 9 years: survival rates were not lower than for the general population (Tzemos).
In the above study 25% of patients experienced a primary cardiac event during a mean follow-up of 9 years and almost half of the population had dilation of either the aortic root or ascending aorta (Tzemos).
In older series patients with such valves had high rates of mortality and complications of endocarditis, cardiac surgery, heart failure and dissection,, while such problems were uncommon in present series.
Olmsted County study of asymptomatic patients with normally functioning aortic bicuspid valve had similar mortality as in the general population (Michelena).
In a cohort of 416 patients the incidence of aortic dissection over a mean of 16 years is low, but significantly higher than the general population:approximately 8 times higher (Michelena HI et al).
May be associated with more deaths than other congenital heart defects combined (Ward C).
Diagnosis is made primarily by echocardiography.
The most common echocardiography are 2-dimensional thoracic echocardiography followed by 2-dimensional transesophageal echocardiography.
3-dimensional echocardiography has demonstrated higher sensitivity and specificity.
Multidetecror computer tomography and magnetic resonance imaging can further evaluate aortic valve anatomy.
The process is not a simple fusion or non separation of two cusps but a more complex process involving cusps, sinuses, commissures, and position of the coronary orifices.
The fusion of 2cusps form a ridge, called the raphae, the presence and position in which contributes to the variability of the valve anatomy.
Bicuspid valve has the a spectrum of missing, underdeveloped, or developed commissures and adjacent cusps.
Patients who undergo TAVR for bicuspid aortic stenosis compared with tricuspid aortic stenosis have no significant difference in mortality, but increased risk of stroke at 30 days ( Makkar RR).