The Role of Coronary Imaging in Chronic Total Occlusions: Applications and Future Possibilities

Chronic total occlusions (CTOs) represent a challenging scenario in coronary artery disease (CAD). The prevalence of CTOS in patients undergoing coronary angiography underscores the need for effective diagnostic and therapeutic strategies. Coronary angiography, while essential, offers limited insights into lesion morphology, vessel course, and myocardial viability. In contrast, coronary imaging techniques-including optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography (CCTA)-provide comprehensive insights for each stage of CTO percutaneous coronary intervention (PCI). OCT facilitates the assessment of plaque morphology and stent optimization, despite low evidence and several limitations in CTO-PCI. IVUS offers deeper penetration, allowing managing proximal cap scenarios and guiding subintimal navigation. CCTA provides a non-invasive, three-dimensional view of coronary anatomy, enabling the precise evaluation of myocardial mass at risk and detailed procedural planning. Despite their individual limitations, these imaging modalities have enhanced the success rates of CTO-PCI, thus reducing procedural and long-term complications and improving patient outcomes. The future of CTO management lies in further technological advancements, including hybrid imaging, artificial intelligence (AI) integration, and improved fusion imaging. These innovations promise to refine procedural precision and personalize interventions, ultimately improving the care of patients with complex coronary artery disease.

Long-term follow-up of patients with chronic total coronary artery occlusion previously randomized to treatment with optimal drug therapy or percutaneous revascularization of chronic total occlusion (COMET-CTO)

Background

The COMET-CTO trial was a randomized prospective study that assessed long-term follow-up in patients with chronic total occlusion (CTO) in coronary arteries treated with percutaneous coronary intervention (PCI) or with optimal medical therapy (OMT). During the 9-month follow-up, the incidence of major adverse cardiac events (MACE) did not differ between the two groups; no death or myocardial infarction (MI) was observed. There was a significant difference in quality of life (QoL), assessed by the Seattle Angina Questionnaire (SAQ), in favor of the PCI group. Here we report long-term follow-up results (56 ± 12 months).

Methods

Between October 2015 and May 2017, a total of 100 patients with CTO were randomized into two groups of 50 patients: PCI CTO or OMT group. The primary endpoint of the current study was the incidence of MACE defined as cardiac death, MI, and revascularization [PCI or coronary artery bypass graft (CABG)]. As the secondary exploratory outcome, we analyzed all the cause-mortality rate.

Results

Out of 100 randomized patients, 92 were available for long-term follow-up (44 in the PCI group and 48 in the OMT group). The incidence of MACE did not differ significantly between the two groups (p = 0.363). Individual components of MACE were distributed, respectively: cardiac death (OMT vs. PCI group, 6 vs. 3, p = 0.489), MI (OMT vs. PCI group, 1 vs. 0, p = 1), and revascularization (PCI: OMT vs. PCI group, 2 vs. 2, p = 1; CABG: OMT vs. PCI group, 1 vs. 1, p = 1). There was no significant difference between the two groups regarding the individual component of MACE. Six patients died from non-cardiac causes [five deaths were reported in the OMT group and one death in the PCI group (p = 0.206)]. Kaplan-Meier survival curves for MACE did not differ significantly between the study groups (log-rank 0.804, p = 0.370). Regarding the secondary exploratory outcome, a total of 15 patients died at 56 ± 12 months (11 in the OMT and 4 in the PCI group) (p = 0.093). The Kaplan-Meier survival curves for all-cause mortality rates did not differ significantly between the two groups (log rank 3.404, p = 0.065). There were no statistically significant differences between OMT and PCI groups in all five SAQ domains. There was a significant improvement in three SAQ domains in the PCI group: PL (p < 0.001), AF (p = 0.007), and QoL (p = 0.001).

Conclusion

After 56 ± 12 months of follow-up, the incidence of MACE, as well as QoL measured by SAQ, did not differ significantly between the PCI and OMT groups.

Cardiac and sudden death after chronic total occlusion percutaneous coronary intervention: Prognostic role of the target vessel

BACKGROUND

The role of the target vessel in percutaneous revascularization of chronic total occlusion (CTO) is unclear.

OBJECTIVE

We sought to assess the long-term results of percutaneous coronary intervention (PCI) for CTO lesions in each coronary artery and to investigate the impact of successful revascularization and previous myocardial infarction (MI) in the territory of the target vessel.

METHODS AND RESULTS

Cohort observational study on 1,124 patients who have undergone CTO PCI attempt: 371 on left anterior descending artery (LAD), 485 right coronary artery, and 268 left circumflex. Patients were further stratified by successfully revascularized and not-revascularized CTO (CTO-NR). Vessels affected by a previous MI were defined as infarct-related artery (IRA). The primary endpoint was cardiac death; the secondary endpoint was the combined rate of sudden cardiac-death and sustained ventricular-arrhythmias (SCD/SVAs). Propensity score-matching was performed to evaluate LAD versus NON-LAD CTO. Up to 12-year follow-up, the clinical benefit associated with successful PCI was consistent across the three groups. CTO-NR had the greatest association with cardiac death and SCD/SVAs in each coronary artery and in IRA-CTO patients.

CONCLUSIONS

Unsuccessful percutaneous CTO revascularization was associated with lower cardiac survival and freedom from SCD/SVAs, irrespective of the vessel treated. This result was mainly driven by patients with an IRA CTO.

Predictive value of the atherogenic index of plasma for chronic total occlusion before coronary angiography

BACKGROUND

The atherogenic index of plasma (AIP) is calculated by logarithmic transformation of the ratio of triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) concentrations. Although previous studies have demonstrated that the AIP is associated with coronary artery disease, its association with chronic total occlusion (CTO) requires elucidation.

HYPOTHESIS

We hypothesized that the AIP would have diagnostic value in cases of CTO and could be used to predict adverse events.

METHODS

This study involved 1131 inpatients who underwent coronary angiography. Data on demographic and clinical characteristics, coronary artery stenosis rated by the Gensini score, and clinical assessment by the Global Registry of Acute Coronary Events and thrombolysis in myocardial infarction (TIMI) scores were collected by cardiovascular doctors. Serum AIP values were evaluated by logarithmic transformation of the ratio of TG and HDL-C concentrations. The correlations of AIP values with clinical parameters were assessed, and receiver-operating characteristic curves were constructed for CTO diagnosis.

RESULTS

Overall, 1131 inpatients were assigned to the CTO (n = 398) and control (n = 733) groups. Compared with the control group, the CTO group showed a significantly higher AIP (p < .05). The AIP was positively correlated with body mass index, the TIMI score, the Gensini score, and stent length and was effective for the diagnosis and risk assessment of patients with CTO. Multivariate logistic regression analyses revealed that the AIP was an independent risk factor for CTO. The findings suggest that the AIP could predict the presence of CTO and disease severity.

Long-Term Outcomes of Percutaneous Coronary Intervention for Patients With In-Stent Chronic Total Occlusion Versus De Novo Chronic Total Occlusion

Limited data are available on long-term outcomes and health status in the treatment of in-stent coronary chronic total occlusion (IS-CTO) and de novo coronary chronic total occlusion (de novo CTO). This study compared the long-term clinical outcomes and health status of percutaneous coronary intervention (PCI) for patients with IS-CTO versus patients with de novo CTO in the drug-eluting stent era. We screened 483 consecutive patients with 1 CTO lesion, including 81 patients with IS-CTO and 402 patients with de novo CTO. Propensity score matching was used to balance baseline characteristics between the 2 groups. The clinical end point was major adverse cardiac events (MACE). The success rates of CTO lesion revascularization were similar in both groups. In the propensity score-matched patients, after a median follow-up of 36 months, MACE was observed in 32.8% of patients with IS-CTO versus 13.5% of the patients with de novo CTO (P < .001), mainly driven by target-vessel revascularization (21.9% vs 6.7%; P < .01). Moreover, patients with IS-CTO had significantly worse Seattle Angina Questionnaire anginal stability scores than the patients with de novo CTO. In conclusion, patients with IS-CTO after PCI had a worse clinical outcome, mainly MACE, and a poorer anginal stability in the long term than patients with de novo CTO.

Randomized Controlled Comparison of Optimal Medical Therapy with Percutaneous Recanalization of Chronic Total Occlusion (COMET-CTO)

The aim of this randomized prospective study was to evaluate the quality of life (QoL) using the "Seattle Angina Questionnaire" (SAQ) in patients with chronic total occlusion (CTO) in coronary arteries treated with either percutaneous coronary intervention (PCI) or optimal medical therapy (OMT), or only with OMT.The potential benefits of recanalization of CTO by PCI have been controversial because of the scarcity of randomized controlled trials.A total of 100 patients with CTO were randomized (1:1) prospectively into the PCI CTO or the OMT group (50 patients in each group). There were no baseline differences in the SAQ scores between the groups, except for physical limitation scores (P = 0.03). During the mean follow-up (FUP) of 275 ± 88 days, patients in the PCI group reported less physical activity limitations (72.7 ± 21.3 versus 60.5 ± 27, P = 0.014), less frequent angina episodes (89.8 ± 17.6 versus 76.8 ± 27.1, P = 0.006), better QoL (79.9 ± 22.7 versus 62.5 ± 25.5, P = 0.001), greater treatment satisfaction (91.2 ± 13.6 versus 81.4 ± 18.4, P = 0.003), and borderline differences in angina stability (61.2 ± 26.5 versus 51.0 ± 23.7, P = 0.046) compared to patients in the OMT group. There were no significant differences in SAQ scores in the OMT group at baseline and during the FUP. There was a statistically significant increase in all five domains in the PCI group.Symptoms and QoL measured by the SAQ were significantly improved after CTO PCI compared to OMT alone.

Percutaneous Coronary Intervention Offers Survival Benefit to Stable Patients With One Single Chronic Total Occlusion and Diabetes: A Propensity Score-Matched Analysis

Studies on chronic total occlusion (CTO) treatment strategy in stable patients have reported conflicting results. We focused on stable diabetic patients with a single CTO (other vessels have been successfully treated before). We attempted to identify which strategy (percutaneous coronary intervention [PCI] or medical therapy [MT]) is optimal; 545 patients were selected from a total of 39 952 patients. Based on the initial treatment strategy, we assigned patients to either the PCI or MT group. The primary end point was a major adverse cardiac event (MACE). After a median follow-up of 45 months (interquartile range: 25.7-79.2 months), we observed (1) no difference in MACE and myocardial infarction between groups, (2) multivariate analysis showed that PCI group was superior to MT group in cardiac death (hazard ratio: 4.758 (1.698-13.334); P = .003) and all-cause death (2.767 [1.157-6.618]; P = .022). The superiority was consistent in propensity score-matched analysis, and (3) a failed PCI group was not associated with higher risks in the clinical end points, except for target vessel revascularization, compared with MT. We concluded that for stable patients with diabetes and one single CTO, initial PCI strategy tended to offer patients survival benefits compared with MT.