Vessel density ratio: A novel approach to identify "culprit" coronary lesion by spiral computed tomography.
OBJECTIVE
We hypothesized that a "culprit" lesion in acute coronary syndrome (ACS) should have low overall vessel lumen and plaque density on multidetector computed tomography-assisted coronary angiography (MDCTA) because of lower calcification and the presence of occlusive thrombus. However, thrombi and calcification both can themselves blur the demarcation between vessel wall and lumen. If we calculated a "vessel density ratio" (VDR) obtained by measuring the mean density of contrast-enhancement within a region of interest (ROI), which includes the vessel wall, lumen, plaque, and thrombus, and comparing that with the aortic root mean density acting as a reference point, this ratio may be more convenient, standardized, and reproducible to test the feasibility of VDR in identifying "culprit" lesions in ACS.


METHODS
Sixty-four patients-21 exertional angina; 17 unstable angina/non-ST elevation myocardial infarction (NSTEMI); 26 ST elevation myocardial infarction (STEMI)-provided 188 diseased segments on conventional angiography. All underwent MDCTA within a week of angiography. ROI was mapped out from maximum intensity projections of diseased segments in planar view.


RESULTS
One hundred seventy-four segments were evaluated. Patients who presented with ACS (STEMI and unstable angina/non-ST elevation myocardial infarction) had lower mean VDR compared to patients with exertional angina (0.58 vs. 0.66 vs. 0.81; P < 0.001). Culprit lesions in ACS patients also had the lowest mean VDR when compared to nonculprit lesions and lesions in patients without ACS (0.51 vs. 0.68 vs. 0.81; P < 0.001).


CONCLUSIONS
VDR is a new, convenient, and standardized approach in identifying "culprit" lesions by MDCTA.
Chin
Bernard Sze-Piaw
BS
Department of Cardiology, Sarawak General Hospital, Kuching, Malaysia. chin.sze.piaw@health.gov.my
Ong
Tiong-Kiam
TK
Seyfarth
Tobias M
TM
Liew
Chee-Khoon
CK
Chan
Wei-Ling
WL
Rapaee
Annuar
A
Liew
Houng-Bang
HB
Ang
Choon-Kiat
CK
Sim
Kui-Hian
KH
D000208:Acute Disease; D000704:Analysis of Variance; D000787:Angina Pectoris / Q000000981:diagnostic imaging*; D000789:Angina, Unstable / Q000000981:diagnostic imaging; D002114:Calcinosis / Q000000981:diagnostic imaging; D003287:Contrast Media; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D013577:Syndrome; D036542:Tomography, Spiral Computed
D003287:Contrast Media; D007472:Iohexol