Acute myocardial infarction: early CT aspects of myocardial microcirculation obstruction after percutaneous coronary intervention

To evaluate the capabilities of delayed enhanced multidetector CT (DE-MDCT), performed immediately after percutaneous coronary intervention (PCI), in predicting myocardial microvascular obstruction (MVO) formation assessed by delayed enhanced MRI (DE-MRI). Thirty-two patients presenting with a primary acute myocardial infarction, successfully recanalised by PCI, underwent a DE-MDCT immediately after PCI and a DE-MRI within 1 week. The left ventricle was split into 64 subsegments, rated as "healthy", "infarcted" or "MVO" on DE-MRI. Their mean density was measured on DE-MDCT and calculated relative to the patient's mean healthy myocardium density. Hypoenhanced DE-MDCT subsegments, termed "CT early MVO", were also recorded. Sensitivity and specificity of DE-MDCT for MRI-assessed "MVO" subsegments detection was calculated for mean CT relative density (threshold determined from a ROC analysis), "CT early MVO" and both. Mean CT relative density was higher in MRI-assessed "MVO" than in "infarcted" and "healthy" subsegments (1.82 +/- 0.46, 1.43 +/- 0.36 and 1.0 +/- 0.13 respectively; P < 0.001) leading to a sensitivity and specificity of 94.3 % and 89.2 % for a cutoff of 1.36. Sensitivity and specificity were respectively 16.9 % and 99.8 % for "CT early MVO" and 95.3 % and 89.3 % when considering the two patterns. DE-MDCT, performed immediately after PCI, allows for an accurate prediction of MVO formation. Myocardial microvascular obstruction (MVO) is an important prognostic sequel following myocardial infarction. MVO can be accurately predicted by multidector CT (MDCT). Both hypo- and hyperenhanced myocardial areas can be analysed by MDCT. MDCT may become a useful prognostic tool for acute MI outcome.