Serial evaluation of the thoracic aorta in patients with a bicuspid aortic valve: a magnetic resonance angiography study

Bicuspid aortic valve (BAV) is associated with an arteriopathy leading to a progressive dilatation of the aortic root. Recent studies have shown that the whole thoracic aorta is affected by this arteriopathy. Longitudinal data regarding the progression of this arteriopathy in the whole thoracic aorta has not been reported before. In this retrospective study 40 patients (mean age 28.5 +/- 9.1 years) had 2 MR-angiographies (mean interval 37.1 +/- 15.2 months). In 23 patients the aortic valve was regurgitant, in 1 stenotic, in 4 combined aortic stenosis / regurgitation was found, while in 12 the valve function was normal. Aortic diameters were measured at 6 different, standardized anatomical points. The influence of demographic and clinical parameters was assessed. A significant increase of the diameter was observed at the aortic root (35.4 +/- 5.6 mm --> 39.1 +/- 6.5 mm, p < 0.001), the ascending aorta (37.3 +/- 8.0 mm --> 39.5 +/- 8.5 mm, p = 0.001), proximal to the innominate artery (29.4 +/- 6.1 mm --> 31.6 +/- 6.8 mm, p = 0.008), and the descending aorta (20.2 +/- 2.4 mm --> 21.6 +/- 4.2 mm, p = 0.03). There was no significant increase proximal (24.0 +/- 5.7 mm --> 24.6 +/- 5.3 mm, p = 0.44) and distal to the left subclavian artery (21.4 +/- 4.6 mm --> 21.9 +/- 4.5 mm, p = 0.19). These observations were independent of the presence of arterial hypertension, a previous operation, gender, and functional status of the aortic valve. The progressive dilatation of the aortic root and ascending aorta that can be observed in patients with BAV was not found in the more distal parts of the thoracic aorta with the exception of the descending aorta in this study. If the dilatation of the descending aorta bears any clinical significance can't be answered with the current data. A prospective study should be performed to confirm these results.