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Published on: August 28, 2018
Noninvasive Discrimination of Coronary Chronic Total Occlusion and Subtotal Occlusion by Coronary Computed Tomography
Jin-Ho Choi1, Eun-Kyoung Kim2, Sung Mok Kim3
1Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Department of Emergency Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Insights
Coronary computed tomography angiography (CTA) can noninvasively differentiate chronic total occlusions (CTO) from subtotal occlusions (STO). CTA findings also predict the success of percutaneous coronary intervention (PCI) for these coronary artery blockages.
Area of Science:
- Cardiology
- Radiology
- Medical Imaging
Background:
- Chronic total occlusion (CTO) and subtotal occlusion (STO) represent distinct coronary artery pathologies.
- These differences in pathophysiology may necessitate varied clinical treatment strategies.
Purpose of the Study:
- To evaluate the feasibility of noninvasively distinguishing CTO from STO using coronary computed tomography angiography (CTA).
- To assess the predictive value of CTA findings for percutaneous coronary intervention (PCI) success.
Main Methods:
- A study involving 486 patients with 553 completely occluded coronary arteries assessed by coronary CTA.
- Analysis of anatomical findings (occlusion length, side branches, stump shape, collaterals) and physiological surrogates (transluminal attenuation gradient).
- Follow-up with invasive coronary angiography to validate CTA findings.
Main Results:
- CTO arteries exhibited longer occlusion length, higher transluminal attenuation gradient, more side branches, blunted stumps, and collateral vessels compared to STO.
- CTA accurately distinguished CTO from STO (c-statistic=0.88), with high sensitivity (83%) and specificity (77%).
- CTA findings predicted PCI success (c-statistic=0.70), identifying arteries where intervention was likely to fail.
Conclusions:
- Coronary CTA is a viable noninvasive tool for differentiating CTO from STO.
- CTA can effectively predict the likelihood of successful PCI in patients with coronary occlusions.
Objectives:
The aim of this study was to investigate whether noninvasive discrimination of chronic total occlusion (CTO), a complete interruption of coronary artery flow, and subtotal occlusion (STO), a functional total occlusion, is feasible using coronary computed tomography angiography (CTA).
Background:
CTO and STO may be different in pathophysiology and clinical treatment strategy.
Methods:
We included 486 consecutive patients (median age 63 years, 82% male) who showed a total of 553 completely occluded coronary arteries in coronary CTA. The length of occlusion, side branches, shape of proximal stump, and collateral vessels were measured as anatomical findings. Transluminal attenuation gradient, which reflects intraluminal contrast kinetics and functional extent of collateral flow, was measured as a physiological surrogate. All patients were followed by invasive coronary angiography.
Results:
Coronary arteries with CTO showed longer occlusion length (cutoff ≥ 15 mm), higher distal transluminal attenuation gradient (cutoff ≥-0.9 Hounsfield units [HU]/10 mm), more frequent side branches, blunted stump, cross-sectional calcification ≥ 50%, and collateral vessels compared with arteries with STO (p < 0.001, all). The combination of these findings could distinguish CTO from STO (c-statistics = 0.88 [95% confidence interval: 0.94 to 0.90], sensitivity 83%, specificity 77%, positive predictive value 55%, negative predictive value 93%; p < 0.001). Percutaneous coronary intervention (PCI) was attempted in 342 arteries and was successful in 279 arteries (82%). The computed tomography findings could predict the unsuccessful PCI (c-statistics = 0.70 [95% confidence interval: 0.65 to 0.75], sensitivity 63%, specificity 73%, positive predictive value 91%, negative predictive value 31%; p < 0.001).
Conclusions:
Noninvasive coronary CTA could discern CTO from STO, and also could predict the success of attempted PCI.
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