Three-Dimensional Fibrous Cap Structure of Coronary Lipid Plaque　― ST-Elevation Myocardial Infarction vs. Stable Angina ―

Abstract

overcome this bias. 5 So far, there have been no reports comparing the distribution and total sum area of non-culprit TCFA between acute coronary syndrome (ACS) and stable angina (SA) patients. The aim of the present study was therefore to compare non-culprit TCFA patterns using the novel volumetric analysis algorithm between patients presenting with ST-elevation myocardial infarction (STEMI) and SA. Methods Subjects were selected from the Massachusetts General Hospital (MGH) OCT Registry. The MGH OCT Registry is an international multi-center registry of patients who have undergone OCT of the coronary arteries, and involves 20 sites across 6 countries (http://www.clinicaltrials.gov: NCT01110538). For the purpose of this study, we identified non-culprit plaques in the culprit vessel of patients L ipid plaque with thin fibrous cap (FC) in the coronary arteries is thought to be responsible for the majority of major adverse cardiac events (MACE). 1 In the Providing Regional Observations to Study Predictors of Events in the Coronary Tree (PROSPECT) study, thin cap fibroatheroma (TCFA) in non-culprit areas was one of the predictors of future MACE. 2 Moreover, an optical coherence tomography (OCT) study by Uemura et al showed that TCFA was one of the predictors of rapid plaque progression. 3 A recent OCT study, however, has shown that TCFA predicted MACE in only 2.4% of patients at 4-year follow-up. 4 One of the reasons for these contradictory findings could be the definition of TCFA. Currently, TCFA is measured at an arbitrary point determined by visual assessment on a qualitative level: in other words, even though 2 lesions may have TCFA with the same FC thickness (FCT), the distribution and total sum area of thin FC may be different. Moreover, this type of measurement is subject to greater intra-and inter-observer variability. Wang et al proposed a computer-aided method that allows 3-D volumetric analysis of FC, which may Editorial p 1197

Low Endothelial Sheer Stress ― A Silent Killer ―

“…In this issue of the Journal, they showed that the lipid burden was greater and fibrous cap was thinner in the STEMI group than in the SA group. 3 This may be appropriate, as demonstrated by the many prior clinical studies showing similar results. 4,5 Interestingly, in the Bryniarski et al study, the baseline statin usage was significantly higher in the SA group, compared with the STEMI group, which may have affected the results.…”

“…The current study by Bryniarski et al provides information on the 3-D evaluation of fibrous cap extent and TCFA distribution as a landmark of plaque vulnerability. 3 Future studies showing that this information leads to prediction of outcome and to prevention of cardiovascular events are expected.…”

“…4,5 Interestingly, in the Bryniarski et al study, the baseline statin usage was significantly higher in the SA group, compared with the STEMI group, which may have affected the results. 3 This bias, however, may not be an important issue. Although a thinning of fibrous cap is deeply associated with plaque rupture, OCT-based TCFA is not always a predictor of this.…”

“…4,6 As Bryniarski et al described, even though 2 lesions have TCFA with the same fibrous cap thickness, the distribution and total sum area of thin fibrous cap may be different. 3 Moreover, this type of measurement is subject to greater intra-and inter-observer variability. Therefore, they furthermore assessed the 3-D structure of the TCFA, using computer-aided volumetric analysis.…”

“…Therefore, they furthermore assessed the 3-D structure of the TCFA, using computer-aided volumetric analysis. 3 The fibrous cap thickness was mapped with respect to each distribution and the TCFA area was calculated. As a result, the largest single TCFA area and the total sum of TCFA area were significantly greater in the STEMI group than in the SA group.…”