Use of computed tomographic coronary angiography after equivocal stress tests

Abstract

Background: Current international guidelines recognise Computed Tomographic Coronary Angiography (CTCA) as appropriate following equivocal stress tests, however this indication is not explicitly stated in the current Medicare Benefits Schedule in Australia. CTCA potentially avoids invasive cardiac catheterisation however could be redundant if invasive coronary angiography is still required. We sought to examine CTCA findings in patients with equivocal stress tests. Methods: Records were reviewed of 731 consecutive patients undergoing CTCA at a single institution between 30/09/2009 and 17/12/2014. Patients referred for CTCA following an equivocal cardiac stress test were identified based on radiology request forms. Results: 75 five patients were identified (mean age 59). 39 (52%) patients were of male gender. 44% (33/75) had normal coronary arteries; 36% (27/75) had clearly non-obstructive (<50% stenosis) disease, for which no further investigation was advised; 20% (15/75) had indeterminate or significant stenoses. These findings would have required further clarification or confirmation with invasive coronary angiography. Conclusions: CTCA successfully excluded obstructive coronary artery disease in 80% of patients with equivocal stress tests. Our finding suggest that CTCA can help further stratify patients following and equivocal stress test, and avoid invasive coronary angiography in a vast majority of these patients.