Optimal Oversizing in Transcatheter Aortic Valve Replacement with the Self-Expanding Evolut Valve System

Objectives. Transcatheter valve oversizing has been associated with reduced paravalvular leaks (PVL) and valve migration risk. However, no optimal cut-off oversizing value has been defined for the Evolut system (Medtronic). The aim of this study was to assess the relationship between the degree of oversizing and moderate-to-severe PVL and determine the optimal oversizing cut-off value. Methods. We conducted a multicenter study that included 740 consecutive patients with multidetector computed tomography (CT) data. Valve size was selected according to manufacturer recommendations, with oversizing ranging from 10% to 30%. The primary endpoint was moderate-to-severe PVL. Results. The median age was 84 years (79-87 years), with 58.4% women, and a median EuroSCORE II of 4.1% (2.4-7.3%). Moderate-to-severe PVL was observed in 7.0% of the patients. An inverse relationship was found between oversizing and both PVL (11.4%, 8.6%, 5.4%, and 2.7% for quartiles Q1 to Q4; P = .007) and the need for post-dilation (P = .016). The multivariable analysis showed an association between oversizing and PVL (OR: 0.915 for each 1% increase [95% CI, 0.864-0.969; P = .002]). The optimal oversizing cut-off value to predict PVL was 20%, and PVL was significantly higher in patients with oversizing less than 20% (10.5% vs.4.2%, P < .001). There were no differences in major clinical events according to the degree of oversizing, and a higher oversizing did not translate into an increased risk of permanent pacemaker (18.4% vs.18.3%, P = .976). Conclusions. In TAVR with the Evolut valve, a higher oversizing was associated with lower rates of moderate-to-severe PVL and a lower need for post-dilation, with no negative impact on procedural and early clinical outcomes. A 20% oversizing threshold could be suggested to reduce PVLs. Further prospective studies are warranted to validate optimal oversizing for this valve system.