P4366Application of 3D-dual volume layout imaging for rapid intraprocedural guidance in Mitraclip procedure

Abstract

Abstract Introduction Intraprocedural guidance and monitoring with transesophageal echocardiography (TEE) and invasive hemodynamic assessment are currently the best available options for evaluating procedural success of percutaneous mitral valve (MV) repair with Mitraclip System (Abbott Vascular, Santa Clara, CA, USA). However, despite its crucial importance, echocardiography has some limitations in immediate evaluation of residual jets after clip implantation, so that, in absence of validated method for double orifice effective regurgitant orifice (ERO) assessment, the most reliable parameter that is currently used is the mean trans-valvular gradient. 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 outcomes of mitraclip procedures, comparing it with invasive LAP measurements. Material and methods We prospectively performed the computation of a new parameter in patients with symptomatic moderate-severe to severe primary or secondary mitral regurgitation (MR) underwent MitraClip procedure. This parameter is easy and fast to be obtained out of 3D dataset and represents the 2D area of the proximal isovelocity surface zone visualized from the ventricular view, without any imaging processing (“3D dual volume PISA area”) (figure). It was obtained as following: i) acquisition of 3D-zoomed-color image of MR jet with adequate frame rates; ii)displaying of the volume sampling in “dual volume layout” so one can see the “ventricular aspect” of the jet area corresponding to proximal isovelocity surface “zone”; iii) awareness of correct alignment to the direction of the flow in proximal zone; iiii) freezing and direct measurement of this area (summarize if more than 1 orifice) (1 attached). We compared the variation of this parameter from the beginning to end of procedure with the variation of LAP measurements, that is currently the most important parameter for assessing outcome of procedures. Results The study includes dataset of 11 patients. The baseline value of 3D dual volume PISA area was 1,191±0,40 cm2 and the mean change we obtained was 0,65±0,30 cm2 (mean of 77% of reduction until the end of procedure). Mean values of LAP were slightly decreased in all cases: basal m-LAP was 12±3,3 mmHg and decreased by 15%. Despite the small number of patients, we observed a significant correlation between the changes of LAP and the change of 3D dual volume PISA area (R: 0.6, p: 0,048). Conclusions This is the first demonstration of the usefulness of echocardiographic parameter obtained by 3Ddual volume layout imaging for rapid intraprocedural guidance in Mitraclip procedure. This parameter is related to hemodynamic variations that it currently considerable surrogate of outcomes. These data need to be confirmed by a larger study.