Bicuspid Aortic Valve Patients Have an Increased Risk for Brain Aneurysm

Patients born with a bicuspid aortic valve (BAV), the most common type of congenital heart defect, are also more likely to develop an intracranial aneurysm, according to a new study.

Researchers at Cedars-Sinai Medical Center (Los Angeles, CA, USA) screened a group of 61 patients with BAV (mean 48 years) and 291 controls (mean age 56 years) for the presence of intracranial aneurysms. The researchers used magnetic resonance imaging (MRI) angiography or computerized tomography (CT) angiography of the brain.

The researchers found presence of intracranial aneurysms in 6 of 61 patients with BAV (9.8%), which was significantly higher than in the control population (1.1%). Risk factors for intracranial aneurysm, such as female sex and advanced age, were more common in the control group. No significant differences were detected in age, sex, smoking, arterial hypertension, alcohol use, aortic diameter, or frequency of aortic coarctation between BAV patients with and without intracranial aneurysms. The researchers also reported that BAV problems tend to cluster in families, noting that the mutations are probably genetically heterogeneous. The study was published in the May 4, 2010, issue of Neurology.

"The frequency of intracranial aneurysm among bicuspid aortic valve patients is similar to that found in patients with other systemic disorders that carry an increased risk, such as autosomal dominant polycystic kidney disease or coarctation of the aorta,” concluded lead author Walter Schievink, M.D., and colleagues of the department of neurosurgery.

A bicuspid aortic valve is a defect of the aortic valve that results in the formation of two leaflets or cusps instead of the normal three. It is the most common congenital heart defect, affecting 0.5 to 2% of the population. Most patients with BAV whose valve becomes dysfunctional will need careful follow-up and potentially valve replacement at some point in life. Another important fact is the aorta of patients with BAV is not normal, and has a reduced tensile strength, putting these patients at a higher risk for aortic dissection and aneurysm formation of the ascending aorta. This is one of the reasons a generalized connective tissue disorder that also involves the intracranial arteries has been suspected in this patient population.

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