Visualization of collateral channels with coronary computed tomography angiography for the retrograde approach in percutaneous coronary intervention for chronic total occlusion

[Background] There have been no reports about the diagnostic ability of coronary computed tomography angiography (CTA) in evaluating collateral channels used for retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). [Objective] We investigated the ability and diagnostic accuracy of coronary CTA compared with invasive coronary angiography to detect collaterals used in retrograde CTO PCI and to compared the success rates for wire crossing between collaterals that are detectable and not detectable in coronary CTA. [Methods] We retrospectively reviewed data from 43 patients (55 collaterals) who underwent coronary CTA and PCI for CTO with the retrograde approach. We compared the ability of coronary CTA to visualize collaterals to invasive coronary angiography and evaluated the rates of successful wire crossing between CTA-visible and invisible collaterals. [Results] The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of coronary CTA for detecting collaterals which were used for the retrograde approach was 100.0%, 50.0%, 65.9%, 100.0%, and 74.5%, respectively. Guidewire collateral crossing was more successful in CT-visible collaterals than those not detectable in CT (74.1% vs. 46.4%, p = 0.034). There were fewer collateral vessel injuries in CTA-visible collaterals (11.1% vs. 32.1%, p = 0.041). [Conclusion] Coronary CTA provides good visualization of collaterals used in retrograde CTO PCI. For retrograde guidewire crossing, a higher success rate with fewer complications was observed in CTA-visible collaterals than in those not detectable in coronary CTA