Percutaneous Treatment of Coronary Chronic Total Occlusions Part 1: Rationale and Outcomes

Procedural Results and Long-term Outcome of Chronic Total Occlusion Percutaneous Coronary Intervention in a UK Non-surgical Centre

Background

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has evolved a great deal over recent years, with increased procedural success and lower complication rates being reported. This study aims to evaluate the feasibility, safety and success of a dedicated CTO programme in a large UK PCI centre without on-site cardiothoracic surgery facilities.

Methods

Clinical and procedural data were retrospectively collected for consecutive unselected patients undergoing CTO PCI between 2015 and 2019 from the local database and regional electronic patient records. In-hospital outcomes and long-term major adverse cardiovascular events (all-cause mortality, MI, stroke and target vessel revascularisation) were recorded.

Results

A total of 170 patients underwent 191 CTO procedures during the study period. The mean age was 63 ± 10 years and 80.6% of patients were male (n=137). The clinical indications were: stable chronic coronary syndromes in 88.5% (n=169) of patients; staged procedures in the context of acute coronary syndromes in 1.6% (n=3); and presentation with acute coronary syndrome in 9.9% (n=19). The procedural success rate was 50.0% (n=25) for general interventional cardiologists and 90.1% (n=127) for dedicated CTO operators. In-hospital major adverse cardiovascular events occurred once (0.5%) and interhospital transfer for emergency salvage cardiac surgery was not required. Long-term follow-up data at a median duration of 3.8 years revealed 4 (2.4%) cardiac deaths, 14 (8.3%) spontaneous MI events and 10 (5.9%) target vessel revascularisations.

Conclusion

These data suggest CTO PCI using contemporary techniques is both safe and effective when undertaken in a high-volume non-surgical centre by experienced operators.

Collateral grading systems in retrograde percutaneous coronary intervention of chronic total occlusions

BACKGROUND

The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade.

AIMS

To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success.

METHODS

A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%.

RESULTS

Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589).

CONCLUSIONS

The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success.

Chronic total occlusion percutaneous coronary intervention (CTO PCI) in an intractable heart failure patient: Is there any benefit?

One of the most difficult procedures in interventional cardiology is the percutaneous coronary intervention (PCI) on a chronic total occlusion (CTO) lesion case. To rate the difficulty of guidewire crossing, several angiographic scoring methods have been developed such as the Japan CTO (J-CTO) score. Here we demonstrate the advantages of revascularization using PCI procedure in a CTO case with intractable heart failure. A 53-year-old man presented to the emergency room of Dr. Zainoel Abidin Hospital, Banda Aceh, Indonesia with acute decompensated heart failure. The patient had a history of past PCI with two patent drug eluting stents (DES): one in the left main (LM)-left anterior descending (LAD) artery and one in the distal left circumflex (LCX) artery. The patient had three times rehospitalizations in the last three months. According to single-photon emission computed tomography (SPECT) imaging, the right coronary artery was remained functional; however, the lesion was categorized into very difficult level (J-CTO >3). The PCI was carried out on the right coronary artery and the blood vessel was successfully revascularized after applying multiple techniques. Following the procedure, the heart failure was treated and the 6-minute walking test (6MWT) that performed 12 days after the PCI increased from 220 to 260 meters. The success of this case depended on a comprehensive history taking, adequate imaging methods, and the selection of the proper tools and PCI strategy. In conclusion, despite the challenges, PCI is still an option for patients with persistent complete occlusion. The PCI requires comprehensive preparation and the use of angiographic scoring systems, such as the J-CTO score, to determine the approach and the likelihood of success.

Time Management in Chronic Total Occlusion Percutaneous Coronary Interventions: When Do We Need to Change the Crossing Strategy?

BACKGROUND

Most complex chronic total occlusions (CTOs) require the utilization of multiple recanalization strategies. However, data on wire manipulation time within CTO percutaneous coronary intervention (PCI) are limited.

OBJECTIVES

We sought to investigate the impact of crossover time between crossing strategies on CTO PCI technical success.

METHODS

A total of 1026 patients admitted to our center between 2013 and 2019 for CTO PCI were assessed, of whom 143 were included for analysis. In these patients, the primary antegrade approach was changed to retrograde within one procedure. The crossover time between strategies remained at the operator's decision.

RESULTS

In most cases the target vessel was the right coronary artery (72%), followed by the left anterior descending (18.2%) and left circumflex (9.1%) arteries. The mean J-CTO score was 2.1 ± 1.1. Logistic regression analysis was used to estimate the odds of technical success associated with various crossover times. The results showed that 33 minutes was the threshold of the initial timing at which to review crossover of antegrade to retrograde recanalization of CTO. The odds of technical success with earlier crossover were 3.4 times higher [95% confidence interval (CI): 1.3 to 8.6]. The chances of success reduced by 3% for every 1 minute longer than the threshold time (odds ratio: 0.97; 95% CI: 0.94 to 0.99, p = 0.05).

CONCLUSIONS

Crossover to the retrograde approach should be considered no later than 33 minutes after antegrade wire manipulation in order to maintain the maximum chances of final technical success.

The impact of percutaneous coronary intervention of chronic total occlusions on left ventricular function and clinical outcomes

A meta-analysis by Hoebers et al. reported that successful chronic total occlusion (CTO) recanalization resulted in an increase in left ventricular (LV) ejection fraction by 4.44% (P<0.01) and a reduction in LV end-diastolic volume by 6.14 mL/m(2) during follow-up as compared with baseline, suggesting beneficial LV remodeling. These findings are important as the myocardium supplied by a CTO frequently has sustained irreversible injury and further support the clinical benefits of CTO interventions.