Morphological assessment of chronic total occlusions by combined coronary computed tomographic angiography and intravascular ultrasound imaging.
OBJECTIVE
The relationship between CTO morphology and vessel remodelling is unclear. We described chronic total occlusion (CTO) morphology using coronary computed tomographic angiography (CCTA) combined with intravascular ultrasound (IVUS).


RESULTS
Pre-intervention CCTA and IVUS of 130 CTO lesions (128 patients) were evaluated. Based on CCTA, positive CTO lesion remodelling [PR, maximum CTO segment vessel diameter > proximal reference vessel diameter (RVD)] was seen in 44 (33.8%) lesions. In the other 86 lesions without PR, 74 (56.9%) had a minimum CTO segment vessel diameter >50% of the proximal RVD and were classified as non-PR; 12 (9.2%) lesions had a minimum CTO segment vessel diameter ≤50% of the proximal RVD and were classified as collapse. Comparing the three groups, CTO with PR had the greatest maximum atheroma cross-sectional area (CSA) while the collapse group had the least atheroma CSA (16.0 mm2 [12.0, 19.4] vs. 9.1 mm2 [6.0, 15.9], P < 0.001). The maximum arc of attenuated plaque was greatest in the PR group (51° [0, 167]); and the maximum arc of calcium was greatest in the non-PR group (91° [51, 174]). In the collapse group distal to the occluded segment, there was a normal-appearing vessel by IVUS that corresponded to the collapsed segment by CCTA; its minimum plaque burden was 33.2% [19.9, 38.1] with a smooth concave-shaped lumen surface, implying that the CCTA collapse segment was not occluded.


CONCLUSIONS
Not all CTOs are the same with regard to lesion remodelling and underlying morphology. The combination of IVUS and CCTA can help to categorize CTO morphology.
Cardiovascular Research Foundation, 111 East 59th Street, New York, NY, USA.|Showa University Northern Yokohama Hospital, Yokohama, Japan.
Myong Hwa
MH
Yamamoto
Cardiovascular Research Foundation, 111 East 59th Street, New York, NY, USA.|Columbia University Medical Center, New York, NY, USA.
Akiko
A
Maehara
Stony Brook University Medical Center, Stony Brook, NY, USA.
Michael
M
Poon
Chinese PLA General Hospital, Beijing, China.
Jun
J
Guo
Showa University Northern Yokohama Hospital, Yokohama, Japan.
Kennosuke
K
Yamashita
Showa University Northern Yokohama Hospital, Yokohama, Japan.
Tadayuki
T
Yakushiji
Showa University Northern Yokohama Hospital, Yokohama, Japan.
Shigeo
S
Saito
Cardiovascular Research Foundation, 111 East 59th Street, New York, NY, USA.
Kohei
K
Koyama
Cardiovascular Research Foundation, 111 East 59th Street, New York, NY, USA.
Gary S
GS
Mintz
Showa University Northern Yokohama Hospital, Yokohama, Japan.
Masahiko
M
Ochiai
D000368:Aged; D002908:Chronic Disease; D015331:Cohort Studies; D000072226:Computed Tomography Angiography / Q000379:methods*; D016001:Confidence Intervals; D017023:Coronary Angiography / Q000379:methods*; D054059:Coronary Occlusion / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D057510:Endovascular Procedures / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D061214:Patient Safety; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional / Q000379:methods*
Chronic total occlusion; Coronary computed tomographic angiography; Intravascular ultrasound