Percutaneous intervention for chronic total occlusion: integrating strategies to address an unmet need

Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With Prior Coronary Artery Bypass Graft: Current Evidence and Future Perspectives

Coronary chronic total occlusion (CTO), which occurs in 18. 4-52% of all patients referred for coronary angiography, represents one of the last barriers in coronary intervention. Approximately half of all patients with prior coronary artery bypass graft (CABG), who undergo coronary angiography, are diagnosed with coronary CTO. In fact, these patients often develop recurrent symptoms and events, necessitating revascularization. Currently, there is neither a consensus nor developed guidelines for the treatment of CTO patients with prior CABG, and the prognosis of these patients remains unknown. In this review, we discuss current evidence and future perspectives on CTO revascularization in patients with prior CABG, with special emphasis on clinical and lesion characteristics, procedural success rates, periprocedural complications, and long-term outcomes.

Invasive Versus Medical Management in Patients With Prior Coronary Artery Bypass Surgery With a Non-ST Segment Elevation Acute Coronary Syndrome

Supplemental Digital Content is available in the text.

The benefits of routine invasive management in patients with prior coronary artery bypass grafts presenting with non-ST elevation acute coronary syndromes are uncertain because these patients were excluded from pivotal trials.

Non-invasive versus invasive management in patients with prior coronary artery bypass surgery with a non-ST segment elevation acute coronary syndrome: study design of the pilot randomised controlled trial and registry (CABG-ACS)

Introduction

There is an evidence gap about how to best treat patients with prior coronary artery bypass grafts (CABGs) presenting with non-ST segment elevation acute coronary syndromes (NSTE-ACS) because historically, these patients were excluded from pivotal randomised trials. We aim to undertake a pilot trial of routine non-invasive management versus routine invasive management in patients with NSTE-ACS with prior CABG and optimal medical therapy during routine clinical care. Our trial is a proof-of-concept study for feasibility, safety, potential efficacy and health economic modelling. We hypothesise that a routine invasive approach in patients with NSTE-ACS with prior CABG is not superior to a non-invasive approach with optimal medical therapy.

Methods and analysis

60 patients will be enrolled in a randomised clinical trial in 4 hospitals. A screening log will be prospectively completed. Patients not randomised due to lack of eligibility criteria and/or patient or physician preference and who give consent will be included in a registry. We will gather information about screening, enrolment, eligibility, randomisation, patient characteristics and adverse events (including post-discharge). The primary efficacy outcome is the composite of all-cause mortality, rehospitalisation for refractory ischaemia/angina, myocardial infarction and hospitalisation for heart failure. The primary safety outcome is the composite of bleeding, stroke, procedure-related myocardial infarction and worsening renal function. Health status will be assessed using EuroQol 5 Dimensions (EQ-5D) assessed at baseline and 6 monthly intervals, for at least 18 months.

Trial registration number

NCT01895751 (ClinicalTrials.gov).

The collateral circulation of coronary chronic total occlusions

AIMS

Despite advances in understanding the physiological role of collaterals in coronary chronic total occlusions (CTOs), collateral anatomy remains poorly defined. Our aim was to define the anatomy and interventional utility of collaterals within a large population of patients with CTOs.

METHODS AND RESULTS

We studied the coronary angiograms of 481 patients with 519 CTOs at six centres in the U.K. over four years. Detailed angiographic analysis was performed by interventional cardiologists specialising in CTO percutaneous coronary intervention (PCI). All visible collaterals with a collateral connection (CC) grade ≥1 were recorded. A subgroup of CTOs (n=277) was assessed for interventional capability, defined as whether the collateral supply was able to facilitate retrograde access. We described 45 different collateral patterns: 20 in right coronary artery (RCA), 13 in left anterior descending (LAD), and 12 in circumflex artery CTOs. Septal collaterals from the LAD to the right posterior descending artery (RPDA), and from the posterior descending artery to the LAD were most common, and most often considered as having "interventional capability".

CONCLUSIONS

This is the largest analysis of collateral circulation anatomy in a population of patients with CTOs. We anticipate that these data will be of significant benefit in angiographic analysis and procedure planning for CTO PCI.

Impact of proctoring on success rates for percutaneous revascularisation of coronary chronic total occlusions

OBJECTIVE

To assess the impact of proctoring for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in six UK centres.

METHODS

We retrospectively analysed 587 CTO procedures from six UK centres and compared success rates of operators who had received proctorship with success rates of the same operators before proctorship (pre-proctored) and operators in the same institutions who had not been proctored (non-proctored). There were 232 patients in the pre-proctored/non-proctored group and 355 patients in the post-proctored group. Complexity was assessed by calculating the Japanese CTO (JCTO) score for each case.

RESULTS

CTO PCI success was greater in the post-proctored compared with the pre-proctored/non-proctored group (77.5% vs 62.1%, p<0.0001). In more complex cases where JCTO≥2, the difference in success was greater (70.7% vs 49.5%, p=0.0003). After proctoring, there was an increase in CTO PCI activity in centres from 2.5% to 3.5%, p<0.0001 (as a proportion of total PCI), and the proportion of very difficult cases with JCTO score ≥3 increased from 15.3% (35/229) to 29.7% (105/354), p<0.0001.

CONCLUSIONS

Proctoring resulted in an increase in procedural success for CTO PCI, an increase in complex CTO PCI and an increase in total CTO PCI activity. Proctoring may be a valuable way to improve access to CTO PCI and the likelihood of procedural success.

Retrograde Wiring of Collateral Channels of the Heart in Chronic Total Occlusions

Aim:

To conduct a systematic review and meta-analysis on retrograde wiring in chronic total occlusions (CTOs) with focus on its safety and feasibility.

Methods and Results:

We searched publications from 1990 to December 2013 in PubMed, Ovid, EMBASE, and the Cochrane database inserting a number of terms relating to the collateral circulation of the heart in CTOs. A total of 18 case series (n range17-462) with a total of 2280 CTO revascularization attempts fulfilled criteria for a study of retrograde wiring of collateral channels in CTOs. There were no randomized studies comparing a primary antegrade with a primary retrograde approach. Procedural CTO revascularization rates ranged from 67% to 90.6% with a large proportion having previously failed an “antegrade” approach. The septal perforator collaterals and epicardial channels were used in 73.2% (n = 1670) and 21.7% (n = 495) of cases. Although collateral/coronary perforation was not infrequent (n = 90, 5%), serious acute complications were uncommon; in the combined population 18 cases of cardiac tamponade (0.8%) and 3 deaths (0.1%). Septal perforating wiring (79.3%) was significantly more likely to be successful compared to epicardial coronary artery wiring (72.5%) when chosen by the operator as a route of retrograde access to the CTO body (relative risk 1.11 [95% confidence interval: 1.02-1.20; P = .013]).

Conclusion:

Successful retrograde wiring of collateral channels in selected patients undertaken by “CTO dedicated” operators can significantly enhance the chances of revascularization of complex CTOs with a low risk of acute serious complications. Septal perforator channels are significantly more likely to be successfully retrogradely wired compared to epicardial vessels when either is selected, by reference to their anatomical suitability by the operator, as a route of access.