Predictors of aortic stenosis severity reclassification with imaging data fusion method in patients qualified for TAVI

B ackground: Imaging data fusion method (IDFM) with multislice computed tomography (MSCT) and two-dimensional transthoracic echocardiography (2D-TTE) in aortic stenosis (AS) may result in reclassification from severe to non-severe AS. Aim: The aim of the study was to establish potential predictors of AS reclassification with IDFM method. Methods: 54 high-risk patients (mean age 79±7.9 years; 40.7% male) with severe AS by 2D-TTE (indexed aortic valve area [AVAi] < 0.6 cm 2 /m 2 ), qualified for transcatheter aortic valve implantation (TAVI), were included in the analysis. AVAi was then recalculated with IDFM by replacing 2D-TTE left ventricular outflow tract (LVOT) measurements with MSCT LVOT parameters. Results: IDFM reclassified 20.4% patients as potentially non-severe AS. In a multivariable model including clinical variables, reclassification to non-severe AS by IDFM was independently associated with younger age and diabetes mellitus (DM), (Odds Ratio (OR): 0.864; 95% CI: 0.76-0.99; P < 0.035 and OR: 19.259; 95% CI: 2.28-162.41; P < 0.007, respectively). In a multivariable model including echocardiographic variables, reclassification was associated with: higher LVOT velocity time integral (VTI LVOT ) and lower aortic mean gradient (AMG) (OR: 1.402; 95% CI: 1.07-1.84; P < 0.014 and  OR: 0.858; 95%: CI: 0.760-0.968; P < 0.013, respectively). In addition 24.1% of patients were reallocated from low-flow (< 35 mL/m 2 ) to normal-flow AS. Conclusions: IDFM reclassified a substantial proportion of patients with severe AS into potentially moderate AS group and from low-flow to normal-flow AS group. Such regrouping calls for increased diagnostic prudence in AS patients, especially those with specific clinical and echocardiographic  predictors of reclassification, such as DM or low AMG.