‘No-reflow’ after acute myocardial infarction: direct visualisation of microvascular obstruction by gadolinium-enhanced CMR

Survival and prognosis of patients with an acute myocardial infarction (AMI) have improved substantially using therapies aiming at early restoration of myocardial blood flow.1 Despite successful recanalisation of the infarct-related artery by percutaneous coronary intervention (PCI), perfusion of the ischaemic myocardium is not or incompletely restored in up to 30% of patients due to microvascular obstruction (MVO), angiographically referred to as the no-reflow phenomenon.2 The presence of angiographically assessed no-reflow in these patients has been found to be a predictor of adverse events, with higher incidence of left ventricular remodelling, congestive heart failure and death. The diagnosis of no-reflow is clinically most often made using angiographic (TIMI flow grade, myocardial blush grade)3,4 or electrocardiographic (STsegment resolution)5 criteria of reperfusion. However, these criteria are indirect reflections of MVO and do not allow visualisation of the actual size and extent of the injury. …