Quantification of paravalvular regurgitation after transcatheter aortic valve implantation by 3D transthoracic echocardiography in comparison with cardiac magnetic resonance imaging

Abstract

Purpose: Paravalvular aortic regurgitation is common after transcatheter aortic valve implantation (TAVI). Assessment of regurgitation severity is limited by conventional 2-dimensional (2D) transthoracic echocardiography (TTE). 3-dimensional (3D) TTE has shown to accurately allow quantification of regurgitation in native valves. This study sought to evaluate 3D TTE for quantification of paravalvular aortic regurgitation after TAVI and compare it with cardiac magnetic resonance imaging (CMR). Methods: In 71 patients (age 81±6 years) with severe aortic stenosis 2D TTE, 3D TTE and CMR were performed to assess paravalvular regurgitation severity after TAVI. Aortic regurgitation after TAVI was graded mild, moderate or severe by 2D TTE analysis as recommended by the valve academic research consortium. 3D color Doppler TTE was used for direct planimetry of the vena contracta area of paravalvular regurgitation jet. Regurgitant volume (RV) by 3D TTE was calculated by multiplying the vena contracta area with the velocity time integral of paravalvular regurgitation assessed by continuous-wave Doppler echocardiography. CMR was used for quantitative flow measurement of the ascending aorta. RV by CMR was assessed by quantification of diastolic aortic backward flow. Results: In 53 patients (74%) paravalvular regurgitation after TAVI was mild, in 14 patients (20%) moderate and in 4 patients (5%) severe as assessed by 2D TTE. In patients with mild paravalvular regurgitation RV quantified by 3D TTE was lower compared to quantification by CMR (3.5±5.8 ml/beat vs. 6.5±5.4 ml/beat; p=0.0080). There was no significant difference of RV assessed by 3D TTE and by CMR in patients with moderate (10.1±8.8 ml/beat vs. 11.7±7.0 ml/beat; p=0.5986) and severe paravalvular regurgitation (38.4±8.3 ml/beat vs. 37.2±14.8 ml/beat; p=0.8905). In all patients paravalvular RV assessed by 3D TTE (6.8±10.5ml/beat) correlated well with RV assessed by CMR (9.2±9.6ml/beat; r=0.895). Bland Altman plot showed good agreement between measurements of RV by CMR and by 3D TTE (mean bias=2.4 ml/beat, 95% CI -6.7 to 11.6 ml/beat). Conclusions: 3D TTE allows accurate quantification of paravalvular aortic regurgitation after TAVI in comparison with analysis by CMR.