Bicuspid aortic valve (BAV) is the most common congenital heart disease lesion with an estimated 280 000 to 560 000 people affected in the Canada. Dilatation of the ascending aorta is a common feature in patients with BAV and is a result of inherent vascular abnormalities with superimposed effects of age and acquired cardiovascular risk factors. Severe aortic dilatation (> 50mm) leads to aortic dissection and premature death.~Histopathological studies of the aortas in patients with BAVs report similar findings to that of patients with Marfan syndrome. Beta Blocker (BB) therapy and more recently, Angiotensin Receptor Blocker (ARB) therapy, have been shown to decrease to rate of aortic dilatation and be of benefit to patients with Marfan syndrome. There is no such data however in patients with BAV and aortopathy.~Within the context of a randomized clinical trial, the investigators proposed to test the hypothesis that BB or ARB will reduce the rate of progressive aortic dilatation in adults with BAVs and ascending aortopathy as compared to placebo.~Design: Multicentre, randomized, double-blind, placebo-controlled, trial of adult patients with bicuspid aortic valve aortopathy. Patients who are eligible to take either study medication will be randomly allocated to participate in either the BB (atenolol) vs. placebo arm, or the ARB (telmisartan) vs. placebo arm. Patients who are ineligible for the BB arm will be assigned to the ARB vs. placebo arm and patients who are ineligible for the ARB arm will be assigned to the BB vs. placebo arm. Within each arm, all participants will be randomized to take either placebo or active medication. The atenolol arm will be up-titrated to100mg/day and the telmisartan arm will be up-titrated to 80 mg/day, or to the maximum tolerated dose.
The purpose of this study is to determine whether long-term treatment with a beta-blocker (BB) such as atenolol and/or an angiotensin receptor blocker (ARB) such as telmisartan, given to adult patients with bicuspid aortic valve (BAV) disease (aortopathy) reduces the widening (dilatation) of the aorta from its baseline size.