Abstract 18719: Relationship Between Proximal Aorta Morphology and Progression Rate of Aortic Stenosis
Background: Morphological changes of the proximal aorta, such as effacement of the sinotubular junction (STJ), may result in increased mechanical stress on the aortic valve leaflets and contribute to calcification and progression of aortic stenosis (AS). The aim of this study was to examine the association between abnormal morphology of proximal aorta and AS progression rate. Methods: Between 2010 and 2012, 426 patients with mild to moderate AS (peak aortic jet velocity >2.5 and <4 m/s) and LVEF≥50% with at least two years of follow up were included in this study. Aortic dimensions were measured at 3 different levels: sinus of Valsalva (SVal), STJ and ascending aorta (Aa). The ratios of SVal by STJ (SVal/STJ) and Aa by STJ (Aa/STJ) were used to determine degree of aortic deformity with smaller ratios consistent with greater perturbation of normal geometry. SVal/STJ<1.13 and Aa/STJ<1.09 were defined as significant low ratios per normal range reported in Guidelines. AS progression rate was assessed by annualized increase in mean gradient (MG; follow-up time = 3.2±0.8 yrs). Results: Mean age was 71±13 yrs and 64% were male. 16% had bicuspid aortic valve and MG was 21±8 mmHg. SVal, STJ and Aa dimensions were respectively 33±4 mm, 27±4 mm and 36±5 mm. Mean SVal/STJ ratio was 1.21±0.15 and Aa/STJ ratio was 1.29±0.19. Patients with significant low ratios had faster AS progression (p≤0.05; figure). After adjustment for age, gender, hypertension, diabetes, renal disease, bicuspid aortic valve, baseline MG, LVEF, aortic regurgitation and indexed STJ, SVal/STJ (p=0.025) or Aa/STJ (p=0.027) were independently associated with faster AS progression. Conclusion: Abnormal aortic root geometry such as effacement of the sinotubular junction is a strong and independent predictor of faster AS progression, regardless of arterial hemodynamics, aortic valve phenotype and baseline AS severity. This finding suggests an interrelation between proximal aorta morphology and stenosis progression.