Impact of Valve Over-Sizing After Transcatheter Aortic Valve Implantation With a Self-Expanding Valve: A Multislice Computed Tomography Study.

Background: In transcatheter aortic valve implantation (TAVI), prosthesis over-sizing prevents paravalvular leak (PVL). Strategies of over-sizing for self-expanding bioprostheses are not well established at present.

Methods: Patients with aortic valve stenosis scheduled for TAVI underwent preprocedural multislice computed tomography. Based on the degree of over-sizing, a ROC curve was drawn to define the optimal value of valve sizing for reducing PVL after TAVI.

Results: A total of 152 consecutive patients were included in the study (mean age, 79.95 ± 7.71 years; log EuroScore: 23.87 ± 8.93%). Based on the ROC curve, sizing of 14% was the optimal that would lead to less moderate/severe PVL (P<.01). Group 1 was defined as sizing <14% (n = 49 patients) and group 2 was defined as sizing ≥14% (n = 103 patients). During a follow-up period of 36 ± 14 months, a total of 9 patients died from group 1 vs 4 patients from group 2 (P<.01). Two of the patients who died had moderate/severe PVL and 11 had no/mild PVL (P=.27). From the population, a total of 49 patients (32%) were found to be in the "borderline" zone. Patients who received the smaller valve had lower mean left ventricular outflow tract diameter (P=.048), higher rate of calcium load (mild: 10 [32%] vs 13 [72%]; moderate: 16 [52%] vs 3 [17%]; severe: 5 [16%] vs 2 [11%]; P=.02) and lower mean of sinus of Valsalva diameter (P=.046) compared with patients who received the bigger valve.

Conclusions: In patients undergoing TAVI, over-sizing the prosthesis at least 14% reduces PVL. In borderline cases, taking into consideration additional anatomical parameters may result in low rates of PVL.