No-reflow phenomenon and lesion morphology in patients with acute myocardial infarction.

BACKGROUND The no-reflow phenomenon is associated with poor functional and clinical outcomes for patients with acute myocardial infarction (AMI). In the era of primary intervention, accurately identifying lesions at high risk of no reflow is of crucial importance. At present, no study into the relationship between lesion morphology and no reflow has been performed. The aim of this study was to investigate the relationship between preintervention intravascular ultrasound (IVUS) lesion morphology and the no-reflow phenomenon. METHODS AND RESULTS This study comprised 100 consecutive patients with AMI who underwent preintervention IVUS and were successfully recanalized with primary balloon angioplasty or stenting. IVUS was again performed to identify and exclude any mechanical vessel obstruction in cases of thrombolysis in myocardial infarction flow grade 0, 1, or 2 after intervention in the absence of angiographic stenosis. Angiographic no reflow was seen in 13 patients (13%). Univariate analysis indicated that hypercholesterolemia, fissure and dissection, lipid pool-like image, lesion, and reference external elastic membrane cross-sectional area correlate with the no-reflow phenomenon. Multivariate logistic regression analysis showed that lipid pool-like image (P<0.05; odds ratio 118; 95% CI, 1.28 to 11 008) and lesion elastic membrane cross-sectional area (P<0.05; odds ratio 1.55; 95% CI 1.01 to 2.38) are independent predictive factors of no-reflow phenomenon after reperfusion for AMI. CONCLUSIONS Large vessels with lipid pool-like image are at high risk for no reflow after primary intervention for AMI. Also, plaque content may play a role in damage to the microcirculation after primary intervention for AMI.