Does the choice of MSCT aortic annulus measurement method affect Corevalve size selection and eligibility in patients referred for percutaneous valve replacement?
Eligibility and size selection for percutaneous aortic valve replacement vary substantially depending on the MSCT sizing criterion used, highlighting the need for guidelines to account for the oval shape of the aortic annulus.
AIMS: To evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection. METHODS AND RESULTS: Multislice computer tomography annulus diameters minimum: D(min); maximum: D(max); mean: D(mean) = (D(min) + D(max))/2; mean from circumference: D(circ); mean from surface area: D(CSA) were measured in 75 patients referred for percutaneous valve replacement. Fifty patients subsequently received a CRS (26 mm: n = 22; 29 mm: n = 28). D(min) and D(max) differed substantially mean difference (95% CI) = 6.5 mm (5.7-7.2), P < 0.001. If D(min) were used for sizing 26% of 75 patients would be ineligible (annulus too small in 23%, too large in 3%), 48% would receive a 26 mm and 12% a 29 mm CRS. If D(max) were used, 39% would be ineligible (all annuli too large), 4% would receive a 26 mm, and 52% a 29 mm CRS. Using D(mean), D(circ), or D(CSA) most patients would receive a 29 mm CRS and 11, 16, and 9% would be ineligible. In 50 patients who received a CRS operator choice corresponded best with sizing based on D(CSA) and D(mean) (76%, 74%), but undersizing occurred in 20 and 22% of which half were ineligible (annulus too large). CONCLUSION: Eligibility varied substantially depending on the sizing criterion. In clinical practice both under- and oversizing were common. Industry guidelines should recognize the oval shape of the aortic annulus.
Schultz et al. (2009) studied this question.