title: Coronary CT angiographic characteristics of culprit lesions in acute coronary syndromes not related to plaque rupture as defined by optical coherence tomography and angioscopy.
abstract: OBJECTIVE
  Pathological and clinical optical coherence tomography (OCT) studies have indicated that acute coronary syndrome (ACS) lesions have either ruptured fibrous caps (RFC-ACS) or intact fibrous caps (IFC-ACS). Although computed tomographic (CT) angiographic characteristics of RFC-ACS include low-attenuation plaques and positive plaque remodelling, features associated with IFC-ACS have not been previously described. The aim of this study was to assess the CT characteristics of IFC-ACS lesions.
  
  
  RESULTS
  Seventy-four patients with ACS/stable angina consented to multimodality imaging, of which 66 underwent CT angiography. Of these, 57 culprit lesions in 57 patients were evaluated with sufficient image quality from all four of OCT, angioscopy, intravascular ultrasound, and CT angiography. Intraluminal thrombus was assessed by OCT/angioscopy, and culprit lesions further classified by OCT-based demonstration of fibrous cap integrity. Of 35 culprit lesions with ACS, OCT revealed IFC with thrombus in 10 (29%) and RFC in the remaining 25 (71%); all 22 lesions with stable angina had intact fibrous caps. Fibrous caps were significantly thinner in RFC-ACS than IFC-ACS and stable angina (45 ± 12, 131 ± 57, and 321 ± 146 μm, respectively; P = 0.001). CT angiography revealed that low-attenuation plaques were more frequently observed in RFC-ACS than IFC-ACS and stable angina (88, 40, and 18%; P = 0.001) lesions. Similarly, positive remodelling was more predominantly seen in RFC-ACS than IFC-ACS and stable angina (96, 20, and 14%; P = 0.001). However, none of the specific CT angiography features clearly distinguished IFC-ACS from stable lesions.
  
  
  CONCLUSIONS
  In contrast to the situation with RFC-ACS, distinct culprit lesion characteristics associated with non-rupture-related mechanisms are not identified by CT angiography. It will therefore not be possible to differentiate plaques likely to develop IFC-ACS from stable plaques.
authors: Department of Cardiology, Fujita Heath University Hospital, 1-98 Dengaku, Kutsukake, Toyoake 470-1192, Japan. ozakiyuk@fujita-hu.ac.jp
authors: Yukio
authors: Y
authors: Ozaki
authors: Masanori
authors: M
authors: Okumura
authors: Tevfik F
authors: TF
authors: Ismail
authors: Sadako
authors: S
authors: Motoyama
authors: Hiroyuki
authors: H
authors: Naruse
authors: Kousuke
authors: K
authors: Hattori
authors: Hideki
authors: H
authors: Kawai
authors: Masayoshi
authors: M
authors: Sarai
authors: Yasushi
authors: Y
authors: Takagi
authors: Junichi
authors: J
authors: Ishii
authors: Hirofumi
authors: H
authors: Anno
authors: Renu
authors: R
authors: Virmani
authors: Patrick W
authors: PW
authors: Serruys
authors: Jagat
authors: J
authors: Narula
mesh_terms: D054058:Acute Coronary Syndrome / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D060050:Angina, Stable / Q000473:pathology*; D017546:Angioscopy / Q000379:methods; D017023:Coronary Angiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D011446:Prospective Studies; D012422:Rupture, Spontaneous / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods