Impact of Ultrasound Attenuation and Plaque Rupture as Detected by Intravascular Ultrasound on the Incidence of No-Reflow Phenomenon After Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction

Objectives The aim of this study was to assess whether ultrasound attenuation and plaque rupture as detected by intravascular ultrasound (IVUS) are associated with the incidence of no-reflow phenomenon after percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). Background No-reflow phenomenon is associated with worse long-term outcomes after STEMI. Therefore, reliable and feasible intravascular imaging techniques are needed to identify patient subgroups that would be at high risk for no-reflow phenomenon. Methods One hundred seventy consecutive patients with STEMI who underwent PCI within 12 h after symptom onset were enrolled. The IVUS interrogation was performed before PCI. Results No-reflow phenomenon occurred in 30 patients (18%), who had a higher incidence of no ST-segment resolution (50% vs. 9%; p < 0.001), a higher peak creatine kinase level (4,090 IU/l vs. 2,823 IU/l; p < 0.001), and a lower left ventricular ejection fraction in the chronic phase (51% vs. 59%; p < 0.01). Multivariate logistic regression analysis revealed that ultrasound attenuation with a longitudinal length of >= 5 mm, plaque rupture, and reperfusion time correlated with no-reflow phenomenon (all p < 0.05). In patients with both ultrasound attenuation >= 5 mm and plaque rupture, the incidence of no-reflow phenomenon was 88%, and the risk of decreased coronary reflow was higher than that predicted by either factor alone (p = 0.004 for interaction). Conclusions In patients with STEMI, a longer ultrasound attenuation and plaque rupture on IVUS are associated with an increased incidence of no-reflow phenomenon, suggesting that this subset of patients might be at high risk for distal embolism. (J Am Coll Cardiol Intv 2010;3:540-9) (C) 2010 by the American College of Cardiology Foundation