Assessment of the presence and extent of coronary collateralization by coronary computed tomographic angiography in patients with total occlusions

Abstract

Coronary computed tomography angiography (CTA) may be helpful to manage patients with chronic coronary occlusions. The aim of this study was to determine the sensitivity and specificity of CTA to detect the presence and extent of coronary collaterals as compared to invasive coronary angiography (ICA). We retrospectively evaluated 26 patients who underwent both coronary CTA and ICA within 3 weeks and demonstrated a total coronary occlusion (TIMI grade 0) in one of the major coronary arteries. CTA was performed using a 64-slice multidetector CT. The presence, and extent of collateralization was assessed by two blinded observers using the Rentrop classification for ICA. CTA accurately identified the presence and location of all 26 total occlusions. The presence of any collaterals was accurately detected in 21/23 patients [sensitivity 91% (CI: 71-98%)] and the absence in three patients [specificity 100% (CI: 29%-100%)]. The sensitivity of coronary CTA to identify patients with collateralization increased from 91 to 94% (CI: 71-99%) and 100% (CI: 59-100%) for collaterals Rentrop grade 2 and 3 in ICA, respectively. Coronary CTA accurately detects the presence of any coronary collateralization in patients with total occlusions. Although CT technology is currently limited in the assessment of individual collaterals and smaller vessels, it may be helpful in the management of patients with total occlusions.

Impact of calcification length ratio on the intervention for chronic total occlusions

“…However, MSCT cannot show collateral circulation as clearly as traditional FCA [22]. The characteristics of microcollaterals could be clearly demonstrated by contralateral injection.…”

Salient features of the coronary collateral circulation and its clinical relevance

“…Noninvasive coronary angiography is feasible with coronary CT angiography (CCTA) and coronary MR angiography. Compared with invasive coronary angiography, the spatial and temporal resolution achievable by these techniques remain considerably lower [75], essentially rendering them unsuitable for structural evaluation of coronary collaterals [76][77][78].…”

What is the role of invasive versus non‐invasive coronary angiography in the investigation of patients suspected to have coronary heart disease?

“…The visualization of a small residual channel that is present in high grade obstruction but not in total occlusion is below the resolution of CTA. However, CTA can fairly reliably detect collaterals, 11 which may make a total occlusion more likely. While the angiographic detail required to judge the potential for percutaneous revascularization of a total occlusion is not available from CTA, recent data suggest that the absence of calcification in an occluded segment does make successful percutaneous intervention more likely 12 .…”