Reduced aortic elasticity and dilatation are associated with aortic regurgitation and left ventricular hypertrophy in nonstenotic bicuspid aortic valve patients.

OBJECTIVES

This study sought to assess elasticity and dimensions of the aorta and their impact on aortic valve competence and left ventricular (LV) function in patients with a nonstenotic bicuspid aortic valve (BAV).

BACKGROUND

Intrinsic pathology of the aortic wall is a possible explanation for reduced aortic elasticity and aortic dilatation in patients with BAVs, even in the absence of a stenotic aortic valve. The relationship between aortic wall elasticity, aortic dimensions, aortic valve competence, and LV function in patients with BAVs has not previously been studied with magnetic resonance imaging.

METHODS

Magnetic resonance imaging was performed in 20 patients with nonstenotic BAVs (mean +/- SD, age 27 +/- 11 years) and 20 matched control patients.

RESULTS

The BAV patients showed reduced aortic elasticity as indicated by increased pulse wave velocity in the aortic arch and descending aorta (5.6 +/- 1.3 m/s vs. 4.5 +/- 1.1 m/s, p = 0.01; and 5.2 +/- 1.8 m/s vs. 4.3 +/- 0.9 m/s, p = 0.03, respectively), and reduced aortic root distensibility (3.1 +/- 1.2 x 10(-3) mm Hg(-1) vs. 5.6 +/- 3.2 x 10(-3) mm Hg(-1), p < 0.01). In addition, BAV patients showed aortic root dilatation as compared with control patients (mean difference 3.6 to 4.2 mm, p < or = 0.04 at all 4 predefined levels). Minor degrees of aortic regurgitation (AR) were present in 11 patients (AR fraction 6 +/- 8% vs. 1 +/- 1%, p < 0.01). The LV ejection fraction was normal (55 +/- 8% vs. 56 +/- 6%, p = 0.61), whereas LV mass was significantly increased in patients (54 +/- 12 g/m2 vs. 46 +/- 12 g/m2, p = 0.04). Dilatation at the level of the aortic annulus (r = 0.45, p = 0.044) and reduced aortic root distensibility (r = 0.37, p = 0.041) correlated with AR fraction. Increased pulse wave velocity in the aortic arch correlated with increased LV mass (r = 0.42, p = 0.041).

CONCLUSIONS

Reduced aortic elasticity and aortic root dilatation were frequently present in patients with nonstenotic BAVs. In addition, reduced aortic wall elasticity was associated with severity of AR and LV hypertrophy.