Abstract 12553: Value of Multi-Slice Computed Tomography for Valve Sizing and Prevention of Aortic Regurgitation in Patients Referred for Transcatheter Aortic Valve Implantation
Moderate to massive aortic regurgitation (AR) is occurring in 30% of cases after TAVI. Pre-procedural assessment of aortic annulus diameter is key for appropriate sizing of the prosthesis and prevention of AR. Transoesophageal echocardiography (TEE) is currently the method of choice in this setting. The value of multi-slice computed tomography (MSCT) is unknown.
Methods: In 70 consecutive patients, implantation of the SAPIEN XT prosthesis was performed using TEE as recommended: 1) When annulus was > 24.5mm the procedure was not performed; 2) The cut-off point of 21.5m was used to choose between a 23mm or a 26mm prosthesis. Annulus diameter by MSCT was measured in all patients pre-procedural. For each modality; TEE and MSCT; the “sizing index” was defined as the ratio “prosthesis diameter/annulus diameter”. Aortic regurgitation was evaluated by echocardiography performed at discharge and graded as: 0=none/trace, 1=mild, 2=moderate, 3=severe and 4=massive.
Results: Moderate to massive AR was observed in 20/70 (28%) patients, including 6 (8.5%) with a severe/massive AR. Annulus diameter was significantly larger by MSCT than by TEE (25.3±2.7vs 22.4±1.9, p=0.001). A significant but weak correlation was found between these 2 measurements (r=0.42; p=0.001). No significant correlation was found between annulus diameter by TEE and the degree of AR or between the “sizing index” by TEE and AR. A significant and inverse correlation was found between annulus diameter by MSCT and the degree of AR (R=0.51; p=0.001). The inverse correlation between the “sizing index” by MSCT and AR was higher (R=0.62; p=0.0001). In the 17 patients with a “sizing index” by MSCT ≤1; 6 had a moderate AR (35%) and 6 had a severe/massive AR (35%). In the 53 patients with a “sizing index” by MSCT >1; 8 had a moderate AR (15%) and none had severe/massive AR (0%). The difference was highly significant (p=0.0001).
Conclusion: Once patients with a very large annulus by TEE (>24.5mm) have been excluded, TEE is of no use to predict AR after TAVI. By contrast MSCT has a good ability to predict such complication. In addition our analysis suggests that a simple approach of choosing a prosthesis diameter > annulus diameter by MSCT should eliminate the risk of severe/massive AR and drastically reduce the risk of moderate AR.
- Valvular heart disease
- Aortic stenosis
- Transcatheter Aortic Valve Implantation
- Aortic regurgitation
- Cardiac imaging
- © 2011 by American Heart Association, Inc.