Clinical and Computed Tomography Angiographic Predictors of Coronary Lesions That Later Progressed to Chronic Total Occlusion

Coronary chronic total occlusion on coronary CT angiography: what radiologists should know?

Coronary chronic total occlusion (CTO) often occurs in patients with obstructive coronary artery disease, which remains one of the greatest challenges for interventional cardiologists. Coronary computed tomography angiography (CCTA) with its emerging post-processing techniques can provide a detailed assessment of CTO lesions before percutaneous coronary intervention (PCI), playing an important role in the clinical management of CTO PCI, from early diagnosis, pre-procedural outcome prediction, the crossing algorithm planning, intraprocedural guidance, and finally post-procedural assessment and follow-up. In addition, the feasibility of CT perfusion (CTP) in patients with CTO has been validated. Combined CCTA and CTP have the great potential to be the one-stop-shop imaging modality for assessing both anatomy and function of CTO lesions. This review aims to make radiologists understand the role of CCTA in the diagnosis and assessment of CTO lesions, thus assisting interventionalists in optimizing CTO PCI crossing strategies with the expertise of radiologists.Critical relevance statement The anatomical features of CTO on CCTA can reveal the complexity of CTO lesions and are associated with CTO PCI outcome, thus helping interventionalists optimize CTO PCI crossing strategies.Key points • CTO is the common lesion in invasive coronary angiography, and CTO PCI is technically difficult and its success rate is relatively low.• Length, collaterals, and attenuation-related signs can help distinguish CTO from subtotal occlusion.• The anatomical features of CTO lesions can help grade the difficulty of CTO PCI and predict procedural outcomes and long-term outcomes of CTO PCI.• The real-time fusion of CCTA with fluoroscopic angiography can be applied in highly complicated CTO lesions.• After CTO PCI, CCTA can help guide a second CTO PCI re-entry or follow up stent patency.

Associations of lipid measures with total occlusion in patients with established coronary artery disease: a cross-sectional study

Background

Total occlusion is the most severe coronary lesion, indicating heavy ischemic burden and poor prognosis. The lipid profile is central to the development of atherosclerotic coronary lesions. Evidence on the optimal lipid measure to be monitored and managed in patients with established coronary artery disease (CAD) is inconclusive.

Methods

Total cholesterol (TC), total triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), nonhigh-density lipoprotein cholesterol (non-HDL-c), lipoprotein (a) [Lp(a)], apolipoprotein B (apoB), non-HDL-c/HDL-c, and apoB/apoA-1 were analyzed in quintiles and as continuous variables. The associations of lipid measures with total occlusion were tested using logistic regression models, visualized with restricted cubic splines, and compared by areas under the receiver operating characteristic curves (AUROC). Discordance analysis was performed when apoB/apoA-1 and non-HDL-c/HDL-c were not in concordance.

Results

The prospective cohort study included 10,003 patients (mean age: 58 years; women: 22.96%), with 1879 patients having total occlusion. The risks of total occlusion significantly increased with quintiles of Lp(a), non-HDL-c/HDL-c, and apoB/apoA-1 (all p for trend < 0.001). TG had no association with total occlusion. Restricted cubic splines indicate significant positive linear relations between the two ratios and total occlusion [odds ratio per 1-standard deviation increase (95% confidence interval): non-HDL-c/HDL-c: 1.135 (1.095–1.176), p < 0.001; apoB/apoA-1: 2.590 (2.049–3.274), p < 0.001]. The AUROCs of apoB/apoA-1 and non-HDL-c/HDL-c were significantly greater than those of single lipid measures. Elevation in the apoB/apoA-1 tertile significantly increased the risk of total occlusion at a given non-HDL-c/HDL-c tertile but not vice versa.

Conclusion

ApoB/apoA-1 confers better predictive power for total occlusion than non-HDL-c/HDL-c and single lipid measures in established CAD patients.

Accuracy of the Euro CTO(CASTLE) score obtained on coronary computed tomography angiography for Predicting 30-minute wire crossing in chronic total occlusions

Background

To investigate the feasibility and accuracy of the Euro CTO (CASTLE)_CTA score obtained on coronary computed tomography angiography (CCTA) for predicting the success of percutaneous coronary intervention (PCI) and the 30-min wire crossing in chronic total occlusions (CTO).

Method

One hundred and fifty patients (154 CTO cases; median age, 61 (interquartile range [IQR], 54–68) years; 75.3% male) received CCTA at the People's Hospital of Liaoning Provincce within 1 month before the procedure. The Euro CTO (CASTLE) score obtained on CCTA(CASTLE_CTA) was calculated and compared with the Euro CTO (CASTLE) score obtained based on coronary angiography (CASTLE_CAG) for the predictive value of 30-min wire crossing and CTO procedural success.

Results

In our study, the CTO-PCI success rate was 89.0%, with guidewires of 65 cases (42.2%) crossing within 30 min. There were no significant differences in the median CASTLE_CTA and CASTLE_CAG scores in the procedure success group (3 [IQR, 2–4] vs 3 (IQR, 2–3]; p = 0.126). However, the median CASTLE_CTA score was significantly higher than the median CASTLE_CAG score in the procedure failure group (4 [IQR, 3–5.5] vs 4 [IQR, 2.5–5.5]; p = 0.021). There was no significant difference between the median CASTLE_CTA score and the median CASTLE_CAG score in the 30-min wire crossing failure group (3 [IQR, 3–4] vs 3 [IQR, 2–4]; p = 0.254). However, the median CASTLE_CTA score was significantly higher than the median CASTLE_CAG score in the 30-min wire crossing group (3 [IQR, 2–3] vs 2 [IQR, 2–3]; p < 0.001). The CASTLE_CTA score described higher levels of calcification than the CASTLE_CAG score (48.1% vs 33.8%; p = 0.015). There was no significant difference between the CASTLE_CTA score (area under the curve [AUC], 0.643; 95% confidence interval [CI], 0.561–0.718) and the CASTLE_CAG score (AUC, 0.685; 95% CI, 0.606–0.758) for predicting procedural success (p = 0.488). The CASTLE_CTA score (AUC, 0.744; 95% CI, 0.667–0.811) was significantly better than the CASTLE_CAG score (AUC, 0.681; 95% CI, 0.601–0.754; p = 0.046) for predicting 30-min wire crossing with the best cut-off value being CASTLE_CTA ≤ 3. The sensitivity, specificity, positive predictive value, and negative predictive value were 90.8%, 55.2%, 54.6%, and 87.0%, respectively.

Conclusion

The CASTLE_CTA scores obtained from noninvasive CCTA perform better for the prediction of the 30-min wire crossing than the CASTLE_CAG score.

Comparative differences in the atherosclerotic disease burden between the epicardial coronary arteries: quantitative plaque analysis on coronary computed tomography angiography

AIMS

Anatomic series commonly report the extent and severity of coronary artery disease (CAD), regardless of location. The aim of this study was to evaluate differences in atherosclerotic plaque burden and composition across the major epicardial coronary arteries.

METHODS AND RESULTS

A total of 1271 patients (age 60 ± 9 years; 57% men) with suspected CAD prospectively underwent coronary computed tomography angiography (CCTA). Atherosclerotic plaque volume was quantified with categorization by composition (necrotic core, fibrofatty, fibrous, and calcified) based on Hounsfield Unit density. Per-vessel measures were compared using generalized estimating equation models. On CCTA, total plaque volume was lowest in the LCx (10.0 ± 29.4 mm3), followed by the RCA (32.8 ± 82.7 mm3; P < 0.001), and LAD (58.6 ± 83.3 mm3; P < 0.001), even when correcting for vessel length or volume. The prevalence of ≥2 high-risk plaque features, such as positive remodelling or spotty calcification, occurred less in the LCx (3.8%) when compared with the LAD (21.4%) or RCA (10.9%, P < 0.001). In the LCx, the most stenotic lesion was categorized as largely calcified more often than in the RCA and LAD (55.3% vs. 39.4% vs. 32.7%; P < 0.001). Median diameter stenosis was also lowest in the LCx (16.2%) and highest in the LAD (21.3%; P < 0.001) and located more distal along the LCx when compared with the RCA and LAD (P < 0.001).

CONCLUSION

Atherosclerotic plaque, irrespective of vessel volume, varied across the epicardial coronary arteries; with a significantly lower burden and different compositions in the LCx when compared with the LAD and RCA. These volumetric and compositional findings support a diverse milieu for atherosclerotic plaque development and may contribute to a varied acute coronary risk between the major epicardial coronary arteries.

A computed tomography algorithm for crossing coronary chronic total occlusions: riding on the wave of the proximal cap and distal vessel segment

With wider adoption of coronary computed tomography angiography (coronary CTA), chronic total occlusions (CTOs) are being increasingly identified and characterised by non-invasive angiography. In particular, the ability of coronary CTA to clearly delineate atherosclerotic plaque, as well as to display three-dimensional vessel trajectories, has garnered particular attention in the context of preprocedural planning and periprocedural guidance of CTO percutaneous coronary intervention (PCI). Single CTO features and combined scoring systems derived from CTA (mostly exceeding the diagnostic performance of the angiographic J‑CTO score) have been used to predict time-efficient guidewire crossing, and thus grade the CTO difficulty level prior to PCI. In addition, the introduction of three-dimensional CTA/fluoroscopy co-registration for periprocedural navigation during CTO PCI offers the unprecedented opportunity to resolve proximal cap ambiguity and clearly visualise the distal CTO segment, thereby potentially influencing CTO PCI strategies and techniques. In this review, the potential advantages of non-invasive evaluation of CTO by coronary CTA are described, and a CTA-based hybrid algorithm is introduced for further enhancing the efficiency of CTO PCI. Further studies are clearly needed to verify the proposed approach. However, several luminary operators have already implemented coronary CTA for planning and periprocedural guidance of CTO interventions using the hybrid algorithm.