Difference of Culprit Lesion Morphologies Between ST-Segment Elevation Myocardial Infarction and Non-ST-Segment Elevation Acute Coronary Syndrome An Optical Coherence Tomography Study

Objectives The aim of this study was to investigate the difference of culprit lesion morphologies assessed by optical coherence tomography (OCT) between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndrome (NSTEACS). Background Autopsy studies have reported that rupture of a thin-cap fibroatheroma and subsequent thrombus formation is the most important mechanism leading to acute coronary syndrome (ACS). Optical coherence tomography is a high-resolution imaging modality that is capable of investigating detailed coronary plaque morphology in vivo. Methods We examined the culprit lesion morphologies by OCT in 89 consecutive patients with acute coronary syndrome (STEMI = 40; NSTEACS = 49). Results The incidence of plaque rupture, thin-cap fibroatheroma, and red thrombus was significantly higher in STEMI compared with NSTEACS (70% vs. 47%, p = 0.033, 78% vs. 49%, p = 0.008, and 78% vs. 27%, p < 0.001, respectively). Although the lumen area at the site of plaque rupture was similar in the both groups (2.44 +/- 1.34 mm(2) vs. 2.96 +/- 1.91 mm(2), p = 0.250), the area of ruptured cavity was significantly larger in STEMI compared with NSTEACS (2.52 +/- 1.36 mm(2) vs. 1.67 +/- 1.37 mm(2), p = 0.034). Furthermore, the ruptured plaque of which aperture was open-wide against the direction of coronary flow was more often seen in STEMI compared with NSTEACS (46% vs. 17%, p = 0.036). Conclusions The present OCT study demonstrated the differences of the culprit lesion morphologies between STEMI and NSTEACS. The morphological feature of plaque rupture and the intracoronary thrombus could relate to the clinical presentation in patients with acute coronary disease. (J Am Coll Cardiol Intv 2011;4:76-82) (C) 2011 by the American College of Cardiology Foundation