Philipp Blanke MD, Presenter: Nothing to Disclose

Sasi Rekha Ganga Raju, Abstract Co-Author: Nothing to Disclose

Bruce Precious MD, Abstract Co-Author: Nothing to Disclose

Darra Thomas Murphy MD, FRCPC, Abstract Co-Author: Nothing to Disclose

Cameron John Hague MD, Abstract Co-Author: Nothing to Disclose

Jonathon Avrom Leipsic MD, Abstract Co-Author: Speakers Bureau, General Electric Company Speakers Bureau, Edwards Lifesciences Corporation Consultant, Heartflow, Inc Consultant, Circle Cardiovascular Imaging Inc

Robert Moss, Abstract Co-Author: Nothing to Disclose

Christopher Thompson, Abstract Co-Author: Nothing to Disclose

Kris Nowakowski, Abstract Co-Author: Nothing to Disclose

John Webb MD, FRCPC, Abstract Co-Author: Consultant, Edwards Lifesciences Corporation

To define the influence of left ventricular outflow tract (LVOT) geometry on calculation of the effective orifice area (eOA) and classification of patient-prosthesis mismatch (PPM) after transcatheter aortic valve replacement (TAVR). 

86 patients (52 male, mean age 82.1±7.6 years, mean BSA 1.9±0.22) status post TAVR underwent both transthoracic echocardiography and contrast enhanced cardiac computed tomography. LVOT dimensions were assessed by means of planimetry on systolic CT reconstructions with subsequent calculation of an area-derived LVOT diameter. EOA was calculated according to the continuity equation, based on transaortic measurements by continuous-wave Doppler and LVOT measurements obtained by pulsed-wave Doppler (EOATTE). In addition, a modified EOA was calculated using the area-based LVOT diameter by CT (EOACT). Moderate and severe PPM were defined as an indexed EOA (iEOA) 0.85 cm2/m2 and 0.65 cm2/m2, respectively. Postprocedural aortic valve area (AVA) was assessed by TEE planimetry.

Mean LVOT diameters were 2.4±0.3mm by TTE and 2.0±0.2mm by CT (p<0.001). Mean EOATTE was significantly lower (1.7±0.4cm2) than EOACT (2.4±0.7cm2, p<0.001). By iEOATTE, 20 patients (29%) were graded as moderate PPM and 4 (6%) as severe PPM. By iEOACT, PPM grade was reclassified in 21 patients, with 4 patients (6%) graded as moderate PPM and no patients (0%) graded as severe PPM. Postprocedural AVA was significantly higher than EOATTE (p<0.001) but similar to EOACT (p=n.s.). 

LVOT ellipticity and subsequent underestimation of true LVOT dimensions by TTE results in lower calculated eOA values and high frequencies of estimated PPM after TAVR. Cardiac computed tomography allows for individual correction of the calculated eOA and reclassification of the PPM grade.

Information provided by cardiac computed tomography can be used for individual correction of the calculated eOA and reclassification of the PPM grade

Blanke, P, Ganga Raju, S, Precious, B, Murphy, D, Hague, C, Leipsic, J, Moss, R, Thompson, C, Nowakowski, K, Webb, J, Underestimation of Effective Aortic Orifice Area after TAVR due to LVOT Ellipticity – Impact on Patient-prosthesis Mismatch Classification.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019331.html