P949 Step by step guidance of MitraClip procedure with a new quantitative parameter

Abstract

Abstract Background/Introduction. In step by step guidance of percutaneous mitral valve (MV) repair with MitraClip System (Abbott Vascular, Santa Clara, CA, USA) evaluation of step by step MR reduction by color-Doppler echocardiography can be challenging requiring multiparametric approach and to freeze and process images while the procedure is going. Purpose: This prospective study aimed to assess the role of a new echocardiographic parameter obtained from 3D-Color-Full volume imaging of MR for evaluation of step-by-step MR reduction during MitraClip procedures by a comparison with step-by-step reduction of m-LAP. Methods: We prospectively performed the computation of a new parameter that is obtained by acquisition of MR by 3D-zoomed-color image in dual volume layout for seeing the ventricular aspect of the jet area corresponding to proximal isovelocity surface "zone"; then, measure of that area is traced, so that it represents the 2D area of the proximal isovelocity surface zone visualized from the ventricular view, without any imaging processing ("3D dual volume PISA area"). In double orifice, we added the two computations obtained by the two orifices. We compared the variation of this parameter with variations of m-LAP at the two steps of MitraClip procedures requiring implantation of 2 MitraClips. Results: The study includes dataset of 19 patients. The baseline value of 3D dual volume PISA area was 1,47 ± 0,49 cm2 and the mean change obtained after first clip was 0,25 ± 0,21 cm2 (- 65 % of reduction from baseline, p value: 0.001) and a further change from first to second clip was of 46% (p 0,1). Conversely, the m-LAP decreased more in the second step of procedure: basal m-LAP was 15 ± 13,3 mmHg and decreased by 32% by the end of procedure; in the first step m-LAP was reduced of 12% from baseline (from 15 ± 13,3 to 14,1 ± 9,8 mmHg) and in the second step of 18% (from 14,1 ± 9,8 to 11 ± 4 mmHg). We tested correlation between relative reduction of 3D-PISA and reduction of m-LAP at each of the procedural steps and we observed significant correlation only during the first procedural step (baseline-to-first clip) (R: 0,527, p 0.02), not in the second (1 st-to-2 nd clip) (R: 0,345, p 0.13). Considering the whole procedure, reduction of 3D-PISA was correlated to reduction of m-LAP at the end. Conclusions: Our study demonstrate that this new parameter is related to hemodynamic improvement during procedures, mostly in the first step, when the amount of reduction is marked; for further step invasive monitoring of LAP would be more pivotal. These data need to be confirmed by a larger study.