CT Coronary Angiography vs. Coronary Artery Calcium Scoring for the Occupational Assessment of Military Aircrew

INTRODUCTION: To ensure flight safety military aircrew undergo regular clinical and occupational assessment. Coronary artery calcium scoring (CACS) has been established as an imaging modality to noninvasively assess coronary artery disease (CAD). CT coronary angiography (CTCA) potentially offers a more accurate assessment of CAD, but has not been formally assessed in military aircrew. This retrospective cohort study is designed to compare the theoretical differences in downstream investigations and occupational outcomes in aircrew with suspected CAD comparing CTCA with existing CACS pathways. METHOD: A 2-yr retrospective cohort study of consecutive UK military patients who underwent a CTCA and CACS was undertaken. Patient demographics, CTCA and CACS results, and initial and final occupational restrictions were analyzed comparing current UK, Canadian, and U.S. pathways. RESULTS: There were 44 patients who underwent CACS and CTCA.The commonest indication for a CTCA was a positive exercise ECG. Increasing CACS, stenosis severity, and stenosis burden were associated with significantly greater likelihood of occupational restriction (P = < 0.01). Following CTCA, 26/44 (59%) patients were found to have evidence of CAD, with 13/44 (30%) having at least a single vessel stenosis >= 50%. All of these patients had subsequent occupational restrictions. Two patients with a calcium score <= 10 had at least 1 single vessel stenosis >= 50%. DISCUSSION: A CTCA pathway is potentially a better discriminator of CAD burden in aircrew when compared with CACS and may reduce downstream testing, allowing a more efficacious approach to CAD assessment in military aircrew.