Natural history of ascending aortic aneurysms in the setting of an unreplaced bicuspid aortic valve

Background. Patients with bicuspid aortic valve (BAV) are at risk for valvular disease and ascending aortic aneurysms and dissections. Although others have investigated the need for concomitant repair, the natural history of aortic disease has not been addressed. Methods. A review of our institutional clinical database identified 514 patients (326 male, 188 female) with unrepaired ascending aortic aneurysms followed from 1985 to 2005. Seventy patients (13.4%) diagnosed with BAV form group A; the remaining 445 patients form group B. Growth rates and risk factors for complications were assessed. Results. Patients in group A had a lower incidence of hypertension (p = 0.0185), carotid artery disease, and stroke (p = 0.0184), and presented at an earlier age (49.0 versus 64.2 years, p < 0.0001). Group A also had a higher rate of aortic growth (0.19 versus 0.13 cm/year, p = 0.0102). The incidence of rupture and dissection were similar. Overall survival was better among patients with BAV (p < 0.0001). Among patients with BAV, those with aortic stenosis had a higher risk of rupture, dissection, or death before operative repair than did those with normally functioning valves (odds ratio 10.475, 95% confidence interval: 1.153 to 95.155). Conclusions. Aortic stenosis presents a significant added risk for patients with aneurysmal disease in the face of BAV. Despite faster rates of growth, however, patients with BAV have similar rates of aortic rupture, dissection, and death and improved long-term survival. Contributing to this finding may be the lower incidence of comorbidities, the younger age at presentation, and the more attentive follow-up with earlier operative repair.