Objective: Recent experimental and limited clinical studies have demonstrated the usefulness of delayed enhancement multislice computed tomography (MSCT) for assessing myocardial infarct size (IS) and transmurality. The aim of this study is to compare MSCT enhancement patterns immediately after coronary angiography (CAG) in an acute myocardial infarction (AMI) setting with cardiac magnetic resonance (CMR) enhancement during the second week follow-up.
Methods: 26 patients admitted for an AMI were evaluated by MSCT immediately after CAG without iodine re-injection. All but three were reperfused. The same patients had delayed enhancement CMR imaging at 10 (SD 4)-day follow-up. Myocardial enhancement was considered transmural (non-viable) when involving >75% of myocardial thickness, subendocardial (1 - < or =75%) or normal (viable for the two latter). Two or more >75% enhanced segments were required to define transmurality on patient-level or culprit artery-level analysis. A semi-quantitative scale score was defined for the 17 left ventricular segments. IS was computed from these scores.
Results: On segment analysis, sensitivity, specificity, accuracy, positive and negative predictive values of MSCT for transmurality assessment were 84%, 96%, 94%, 85% and 96%, respectively, compared to CMR. On patient analysis, these respective values were 90%, 80%, 88%, 95% and 67%. IS assessed by the two methods were highly correlated (r = 0.94, p<0.0001) and the regression line did not statistically differ from the identity line.
Conclusion: MSCT enhancement immediately following CAG without iodine re-injection for an AMI is a reliable method for evaluating transmurality and IS. This very early evaluation could be an interesting alternative to CMR.