Deirdre C. Sheahan MD, Presenter: Nothing to Disclose

Shreyas Shreenivas Vasanawala MD, PhD, Abstract Co-Author: Research support, General Electric Company Consultant, Zimmer Holdings, Inc Consultant, ArthroCare Corporation

Beverley Newman MD, Abstract Co-Author: Nothing to Disclose

Frank Hanley MD, Abstract Co-Author: Nothing to Disclose

Richard Mainwaring MD, Abstract Co-Author: Nothing to Disclose

Interarterial aberrant coronary artery (IACA) is associated with sudden death. The presence of intramural course of the IACA permits surgical unroofing to relieve the obstruction, while its absence requires coronary translocation or bypass. We test whether CT and MRI coronary angiography can reliably determine intramural coronary artery.

From 2004 to present, patients who had IACA imaged by cardiac CT or MRI and had surgical correction were identified with retrospective IRB approval. Surgical findings served as the standard of reference. Studies were randomized and presented independently to three cardiac radiologists. They interpreted the type of IACA and its anatomic characteristics. The certainty of intramural course was scored on a five-point scale. Interobserver variability was evaluated with the kappa coefficient. The accuracy of intramural interpretation was assessed by ROC area. Statistical significance of anatomic characteristics was tested with the Fisher’s exact test.

22 cases (19 CT and 3 MRI) from 21 patients were identified. Patient’s age ranged from 1 month to 46 years old, average 12 years old. There were 15 cases of RCA from the left coronary cusp, 2 cases of RCA from the LMCA, 1 case of LMCA from the right coronary cusp, 1 case of LMCA from the RCA, and 2 cases of coronary origin above the sinotubular junction. 16 cases were found to have intramural coronary in surgery. The ROC areas for detecting intramural coronary were 0.70, 0.54, and 0.49 for the three readers. Large interobserver variability was seen (k=0.06). The best sensitivity and specificity were 0.81 and 0.67. In one reader, there was a significant correlation between intramural course and tapered coronary narrowing (p=0.013). There was no correlation with the location and take off angle of the IACA or its closeness to the aortic root relative to the pulmonary trunk.

No anatomic detail reliably predicts intramural course of an IACA, with the exception of tapered narrowing at its origin. The large interobserver variability points to the need for standardization of imaging findings and interpretation.

Pre-operative determination of intramural aberrant coronary artery helps surgeons select the proper surgical procedure for coronary reconstruction.

Sheahan, D, Vasanawala, S, Newman, B, Hanley, F, Mainwaring, R, Diagnostic Accuracy of Coronary CTA Determining Intramural Course of Malignant Aberrant Coronary Artery.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014116.html