Author + information
- Viktoria Stanovaa,b,
- Anne-Sophie Zensesa,b,
- Régis Rieua,b,
- Lionel Thollona,b,
- Lyes Kadema,b,
- Morgane A. Evina,b and
- Philippe Pibarota,b
Background: Transcatheter valve replacement has emerged as a viable alternative in high and intermediate risk patients with severe aortic stenosis. However, the durability of transcatheter valves remains currently largely unknown. Moderate valve oversizing (OS)(5–20% in area) is recommended to prevent paravalvular regurgitation and valve embolization. There are few reports concerning the impact of OS on valve leaflet mechanical stress. This in vitro study aims at evaluating, on a pulse duplicator, leaflet bending stress (LBS) in the CoreValve (CV) for different valve size and OS.
Methods: Three CV (23; 26 and 29mm) were tested on a pulse duplicator under the following configurations: 1) CV 23mm implanted in aortic annuli (AA) ranging from 17 to 20mm (%OS of 15–35); 2) CV 26mm implanted in AA ranging from 20 to23mm (%OS of 13–30); 3) CV 29mm implanted in AA ranging from 23 to26mm (%OS of 11.5–26). For each configuration, geometric orifice area (GOA) and LBS were measured using high-speed camera imaging during both systole and diastole. Tested heart rate was set to 70bpm, mean aortic pressure to 100 mmHg and stroke volume to 70 ml.
Results: For each CV, the GOA increased significantly with OS (range:1.33cm2-2.94cm2, p=0.02) whereas LBS decreased with OS (p=0.008), increasing prosthesis size and AA size. The smallest value of peak LBS (0.99 MPa) was obtained for the CV 29mm in AA of 26mm (%OS=35) and the largest value (3.60 MPa) for the CV 23mm in AA of 17mm (%OS=11.5). Interestingly, for each configuration, the peak LBS was obtained during valve opening or closing and not when the valve is fully open. Larger %OS was associated with higher maximum LBS (r=0.84, p<0.001).
Conclusions: Moderate valve OS, such as generally used for transcatheter aortic valve implantation, is associated with increased LBS during valve opening and closing, which might, in turn, negatively impact long-term durability of the valve.
Poster Hall, Hall C
Friday, March 17, 2017, 10:00 a.m.-10:45 a.m.
Session Title: Interventional Cardiology: TAVR 1
Abstract Category: 17. Interventional Cardiology: Aortic Valve Disease
Presentation Number: 1114-164
- 2017 American College of Cardiology Foundation