Abstract 2627: Comparison of Delayed Enhancement on 64 Slice Computed Tomography Following Coronary Angiography and Low Dose Dobutamine Echocardiography for Viability Assessment After Acute Myocardial Infarction
Early evaluation of myocardial viability in acute myocardial infarction is essential to guide therapy. We assessed 64 slice CT immediately following coronary angiography in this setting.
Methods: Thirty patients admitted for a first acute myocardial infarction had a coronary angiogram at admission. Reperfusion of the culprit coronary artery was reached by thrombolysis, primary angioplasty or spontaneously. Immediately following coronary angiography all the patients had 64 slice CT without iodine reinjection. The 16 segments of the left ventricle depicted by the ASE were graded : no, subendocardial or transmural enhancement on MSCT. Two to four weeks later, the same segments contractility were evaluated at rest. Low dose dobutamine echocardiography was performed in case of akinetic segments at rest. Viability was defined as a normal or hypokinetic segment at rest or an akinetic segment improving with low dose dobutamine infusion.
Results: Myocardial infarction was anterior (12), inferior (11), posterior (3) and lateral (4). Mean delay between coronary angiography and MSCT was 25±11 min (range 7 to 51 min). Mean iodine volume used for coronary angiography was 173±71 ml. We compared 480 segments evaluated by each method. Agreement were noted for 467: 384 segments with normal and 44 with subendocardial hyperenhancement were considered normal or viable and 39 segments with transmural hyperenhancement were non viable at dobutamine echocardiography. Disagreement was noted for 13 segments (2 with normal enhancement were considered non viable and 11 with transmural hyperenhancement were viable at dobutamine echocardiography).Thus 64 slice CT following coronary angiography for an acute myocardial infarction had a sensitivity of 95%, specificity 97,5% and an accuracy of 97,3% for detecting non viable myocardial segments at a very early stage of an acute myocardial infarction. On a per-patient analysis, sensitivity, specificity and accuracy were respectively: 100%, 91% and 93%.
Conclusion: 64 slice CT following coronary angiography for an acute myocardial infarction is a promising method for evaluating the extent of irreversible myocardial damage compared to an already validated method (low dose dobutamine echocardiography).