To evaluate feasibility, safety and advantage of underexpansion of Edwards SAPIEN XT prosthesis during transcatheter aortic valve implantation (TAVI).

We retrospectively analyzed 157 transfemoral TAVI procedures performed between October 2012 and December 2013 in the University Hospital of Rouen. Thirty-six (22.9%) patients had intentional underexpansion of the EDWARDS SAPIEN XT prosthesis since more than 20% area oversizing was anticipated with Computed tomography (CT) assessment of aortic annulus. Underexpansion of Edwards SAPIEN XT prosthesis was performed by reducing the volume of fluid within the valve deployment balloon. The Primary endpoint was aortic regurgitation (AR) at the end of the procedure.

Mean age was 83.4±5.8 years and the mean logistic EuroSCORE of 15.4±9.6%. The initial fluid volume used for valve deployment was 90.1±3.1% of the theorical total volume (TTV) without significant difference among the 3 sizes of prostheses (90.2±4.1%, 89.5±2.6%, and 84.8±3.2% for 23, 26, and 29-mm valves, respectively). AR immediately after the first inflation was grade ≤I in 20 (55.6%) pts, grade II in 9 (25%) pts, and grade III in 7 (19.4%) pts. Stent diameter measured immediately after first inflation represented 94.2±4.1% of the prosthesis theorical diameter. Post-dilatation was deemed necessary in 14 cases (39.4%). At the end of the procedure, AR was < grade I in 34 (94.4%) patients and grade II in the 2 remaining patients. After post-dilatation, one patient presenting with fatal aortic annulus rupture. Other procedures were safe without stroke, myocardial infarction, or prosthesis migration.

Our study suggest that underexpansion of Edwards SAPIEN-XT prosthesis is feasible during transfemoral TAVI procedures when more than 20% area oversizing is anticipated by CT. However, post-dilatation is mandatory in about 40% of cases to reduce significant residual aortic regurgitation but can be complicated by aortic annulus rupture