Abstract 10394: Method to Measure the Valve Effective Orifice Area Following Transcatheter Aortic Valve Implantation
Background: Transcatheter aortic valve implantation (TAVI) has emerged as an alternative to aortic valve replacement. To calculate the effective orifice area (EOA) of TAVI valves by continuity equation, some investigators have used the LV outflow tract diameter (LVOTD) measured at insertion of prosthetic valve leaflets (Method #1), whereas others used the diameter measured immediately proximal to the prosthesis stent (Method #2) (Figure). The objective of this study was to compare the performance of these two methods for estimation of EOA in TAVI valves.
Methods and Results: 62 patients underwent TAVI with the use of SAPIEN-Edwards valve. Each patient underwent a complete echocardiography by two experienced echocardiographers. The average EOA obtained by method #2 (EOA2=1.60±0.41 cm2) was larger (p<0.01) than EOA obtained by method #1 (EOA1=1.29±0.36 cm2). Accordingly, incidence of severe prosthesis-patient mismatch was 2-fold lower with the use of EOA2 than EOA1 (11 vs. 22%; p<0.001). Mean transprosthetic gradient correlated better with indexed EOA2 (r=−0.71, p<0.0001) than with EOA1 (r=−0.50, p<0.0001). Inter-observer and intra-observer variability were lower with LVOTD2 compared to LVOTD1 (inter: 1.7±3.9% vs. 4.5±9.8%, p<0.001; intra: 0.4±4.0 vs. 1.6±12.2%, p=0.23) and for EOA2 compared to EOA1 (inter: 3.6±8.0 vs. 7.0±20%, p<0.001; intra: 0.5±7.9% vs. 3.9±18.7, p=0.06).
Conclusion: When estimating the EOA of TAVI valves by continuity equation method, it is recommended to use the LVOT diameter measured immediately proximal to the stent.
- © 2010 by American Heart Association, Inc.