Darra Thomas Murphy MD, FRCPC, Presenter: Nothing to Disclose

Philipp Blanke MD, Abstract Co-Author: Nothing to Disclose

Shalan Alaamri, Abstract Co-Author: Nothing to Disclose

Bruce Precious MD, 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

Ronen Rubinshtein MD, Abstract Co-Author: Fellowship funded, Koninklijke Philips NV

Adam Berger, Abstract Co-Author: Nothing to Disclose

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

Jennifer Deryn Ellis MD, Abstract Co-Author: Nothing to Disclose

Gregor Pache MD, Abstract Co-Author: Nothing to Disclose

David Wood MD, FRCPC, Abstract Co-Author: Consultant, Edwards Lifesciences Corporation Consultant, St. Jude Medical, Inc

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

CT based sizing has been shown to reduce paravalvular leak following transcatheter aortic valve replacement (TAVR). However there is conflicting data on the extent of annular dynamism throughout the cardiac cycle. The objective of the current study is to assess the degree of variability of aortic annular measurements in systole and diastole using MDCT and to evaluate the impact on device sizing.

In this retrospective, multicenter analysis, ECG-gated retrospective CT data of 357 patients were analyzed. Aortic annulus dimensions were assessed on systolic and diastolic reconstructions by planimetry and using a smoothing algorithm not previously described, yielding values for both area and perimeter. Extent of annular calcification was graded using a semi-quantitative 4-point scale (0-3). Hypothetic device sizing was performed by area and perimeter.

There was an overall significant difference between systolic and diastolic reconstructions in both perimeter and area measurements (perimeter 3.52%, p<0.0001; area 7.98%, p > 0.0001), however these measurements lost statistical significance with increasing LVOT calcification (grade 2 and 3 LVOT calcium for both perimeter and area). Diastolic measurements would result in a smaller valve in 82 cases by area and 78 by perimeter with one perimeter case which diastole would recommend a larger valve using Vancouver guidelines for area and Kasel for perimeter.

Annular dimensions are subject to dynamic changes throughout the cardiac cycle, resulting in changes to the cross-sectional area, perimeter and subsequently derived diameters. This has implications for accurate valve sizing. The dynamic changes become less significant with increasing calcium burden in the LVOT.

Clinically significant changes in both annular area and perimeter are seen between systolic and diastolic phase cardiac CT imaging acquisitions. Utilisation of diastolic phase images for either perimeter or area derived measurements would result in a change of valve size in a substantial number of patients which could result in increased complications. The change in measured valve parameters appears less significant with increasing LVOT calcification.

Murphy, D, Blanke, P, Alaamri, S, Precious, B, Hague, C, Leipsic, J, Rubinshtein, R, Berger, A, Ganga Raju, S, Ellis, J, Pache, G, Wood, D, Webb, J, Effect of Annular Calcification on Area and Perimeter Measurements in Systole and Diastole: Implications for Device Sizing.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010680.html