Abstract 15537: Morphological Characteristics of Culprit Ruptured Plaques Differ Between NSTEMI and STEMI
Purpose: Plaque rupture is a common trigger in the pathogenesis of non-ST-elevation myocardial infarction (NSTEMI) and ST-elevation myocardial infarction (STEMI). However, the association between the morphology of the ruptured plaque and the clinical presentation (i.e. STEMI or NSTEMI) has not been evaluated. We assessed by optical coherence tomography (OCT) the differences in the morphology of culprit ruptured plaques in patients with NSTEMI and patients with STEMI.
Methods: We included 36 patients with NSTEMI and 42 with STEMI. Coronary angiography and OCT study of the culprit lesion were performed within 24 hours from symptom onset in NSTEMI and immediately before primary angioplasty in STEMI patients. Only patients in whom plaque rupture was identified by OCT were included in the analysis.
Results: We identified plaque rupture in 25 out of 36 patients with NSTEMI (69.4%), and in 30 out of 42 patients with STEMI (71.4%, p=NS) and used those patients for analysis. NSTEMI was associated with lower length of plaque disruption compared to STEMI (1.57±0.72mm vs. 2.98±1.80 mm, p<0.01). The length of the missing fibrous cap was also lower in NSTEMI compared to STEMI (0.46±0.25 vs. 0.63±0.27mm, p<0.05). No significant differences were found in the distance of the rupture site from the site of minimal lumen area (1.95±1.93mm vs. 2.66±2.40 mm, p=0.24) and the number of plaques broken at cap shoulder (72.0% vs. 66.7%, p=0.77). Mean fibrous cap thickness was also similar (54±22 vs. 56±20um, p=0.79). There were less lipid quadrants in NSTEMI than STEMI (p=0.01) and a trend for less thrombus in NSTEMI (68% vs. 90%, p=0.09). Although minimal lumen area was greater in NSTEMI (2.76±1.78mm2 vs. 1.39±0.84mm2, p<0.01), no significant differences were found in the rupture site area (4.47±2.47mm2 vs. 3.62±2.19 mm2, p=0.18). In multivariate analysis only the rupture length (OR for 1mm increase 4.25; 95% CI 1.49-12.08), and minimal lumen area (OR for 1mm2 increase 0.39; 95% CI 0.18-0.82) were independently associated with STEMI.
Conclusion: Culprit ruptured plaques in STEMI have greater rupture length and lower minimal lumen area compared to culprit ruptured plaques in NSTEMI. Ruptured plaque morphology seems to be associated with the clinical presentation in myocardial infarction
- © 2011 by American Heart Association, Inc.