Novel proctorship effectively teaches interventionists coronary artery chronic total occlusion lesions

Institutional Volume and Initial Results for Endovascular Treatment for Chronic Occlusive Lower-Extremity Artery Disease: A Report From the Japanese Nationwide Registry

PURPOSE

Chronic total occlusion (CTO) remains as a major target for endovascular treatment (EVT) in improving symptomatic lower-extremity artery disease (LEAD). However, despite the technical demand and learning curve for the procedure, volume-outcome relationship of EVT targeted for CTO in symptomatic LEAD remains unclear.

MATERIALS AND METHODS

Data were obtained from a nationwide registry for EVT procedures limited to the Japanese Association of Cardiovascular Intervention and Therapeutics between January 2018 and December 2020 from 660 cardiovascular centers in Japan. In total, 96 099 patients underwent EVT for symptomatic LEAD, and 41 900 (43.6%) underwent CTO-targeted EVTs during the study period. Institutional volume was classified into quartiles. The association of institutional volumes with short-term outcomes was explored using the generalized linear mixed model using a logit link function, in which, interinstitution variability was used as a random effect.

RESULTS

The median institutional volume for all EVT cases per quartile was 29, 68, 125, and 299 cases/year for the first, second, third, and fourth quartiles, respectively. With each model analysis, the adjusted odds ratios (ORs) for technical success were significantly lower in patients who underwent EVT in institutions within the first quartile (<52 cases/year) than in the other quartiles (P < .01, respectively). On the contrary, the adjusted ORs for procedural complications were significantly higher in the first and second quartiles than in the third and fourth quartiles (P < .01, respectively).

CONCLUSION

In contemporary Japanese EVT practice, a higher institutional volume but not operator volume was associated with a higher technical success rate and a lower procedural complication rate in patients with symptomatic LEAD involving CTO lesions.

CLINICAL IMPACT

EVT for CTO lesions is still challenging for clinicians because of difficulties of wire/devise crossing or high procedural complications rate. Our study demonstrated that a higher institutional volume but not operator volume was associated with a higher technical success rate and a lower procedural complication rate in patients with symptomatic LEAD involving CTO lesions. In contemporary Japanese practice, a higher institutional experience has better impacts on short-term clinical outcomes. Future research should determine the relationship between institutional volume and long-term clinical outcomes.

Global Consensus Recommendations on Improving the Safety of Chronic Total Occlusion Interventions

Safety is of critical importance to chronic total occlusion (CTO) percutaneous coronary intervention (PCI). This global consensus statement provides guidance on how to optimise the safety of CTO) PCI, addressing the following 12 areas: 1. Set-up for safe CTO PCI; 2. Guide catheter--associated vessel injuries; 3. Hydraulic dissection, extraplaque haematoma expansion, and aortic dissections; 4. Haemodynamic collapse during CTO PCI; 5. Side branch occlusion; 6. Perforations; 7. Equipment entrapment; 8. Vascular access considerations; 9. Contrast-induced acute kidney injury; 10. Radiation injury; 11 When to stop; and, 12. Proctorship. This statement complements the global CTO crossing algorithm; by advising how to prevent and deal with complications, this statement aims to facilitate clinical practice, research, and education relating to CTO PCI.

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.

Operator experience and clinical outcomes of percutaneous coronary intervention for chronic total occlusion: insights from a pooled analysis of the Japanese CTO PCI Expert Registry and the Retrograde Summit General Registry

There have not been enough studies to examine the association between difference in operator experience and technical success rate in contemporary percutaneous coronary intervention for chronic total occlusion (CTO-PCI). The present study sought to provide insights into the impact of operator experience on clinical outcomes of CTO-PCI through a comparison of two largest Japanese CTO-PCI registries consisting of operators with different CTO-PCI experience. After combining clinical data from the Japanese CTO-PCI Expert Registry (ER) 2014-2016 (N = 4316) including CTO-PCI performed by highly experienced operators and the Retrograde Summit General Registry (RSGR) 2014-2016 (N = 2230) including CTO-PCI performed by less experienced operators, a pooled analysis was performed to compare clinical outcomes of CTO-PCI in 2 registries. The overall technical success rate and the incidence of in-hospital major adverse events were comparable between ER and RSGR (90.1% vs 88.9%, p = 0.133, 1.7% vs 1.5%, p = 0.606, respectively). Technical success rate in ER was significantly higher among the patients treated with primary antegrade approach (91.8% vs 89.5%, p = 0.009), whereas there was no significant difference among the patients treated with the primary retrograde approach (85.7% vs 85.3%, p = 0.857). Multivariate analysis suggested ER operator could not be an independent predictor for technical success. CTO-PCI performed by less experienced but appropriately trained operators could achieve similarly high technical success rate with comparable safety compared with those performed by highly experienced specialists in contemporary Japanese context.

A contemporary review of clinical significances of percutaneous coronary intervention for chronic total occlusions, with some Japanese insights

The clinical "significance" of percutaneous coronary intervention for coronary chronic total occlusion (CTO-PCI) has been evaluated. In the beginning, the effects on clinical endpoints were investigated by comparisons between cases of success and failure of CTO-PCI, which mostly demonstrated better long-term outcomes in the successful cases. Similarly, improvement of cardiac function or wall motion was proven by serial observational studies. Accordingly, several prospective randomized trials (RCTs), which should confirm such accumulated potential benefits, were recently conducted by comparison with studies of patients that had received optical medical therapy (OMT) alone. While they mostly demonstrated significant improvement of angina symptoms and quality of life (QOL) in the CTO-PCI group, they failed to prove a reduction of clinical events or improvement of left ventricle wall motion, compared with OMT. Concurrent guidelines or consensus documents emphasize that the principal indication for CTO-PCI is to improve symptoms. To determine strategy, the following must be discussed in each individual case: the probability of procedural success, the expectation of long-term patency, and an assessment of the balance between procedure-related complications and overall benefits. In essence, we believe the following facts to be the current sincere appraisal of CTO-PCI: (1) improvements of symptoms and QOL are established, but the others remain inconclusive, and; (2) their margins for improvement are narrowing and numbers of candidates are shrinking. Precision medicine or individualization may be the right directions to take, to enhance the potential of this treatment. This course of action demands discrimination of those candidates who will truly receive benefits from invasive treatment, and that still requires further clinical studies or actions.

Safety of Percutaneous Coronary Intervention for Chronic Total Occlusion in Patients With Multi-Vesel Disease: Sub-Analysis of the Japanese Retrograde Summit Registry

BACKGROUND

The success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has gradually increased thanks to the continuous development of devices and techniques. However, the impact of multi-vessel disease (MVD) on its success rate and safety is not well known.

METHODS

The clinical records of 5009 patients enrolled in the Japanese Retrograde Summit Registry and who had undergone PCI for CTO at 65 centers between 2012 and 2015 were reviewed. We compared the outcome for patients with and without MVD.

RESULTS

Two thousand nine hundred and seventy-eight patients (59%) had MVD. Although there was no significant difference in the J-CTO score between the two groups [MVD group 1.51 ± 1.07 vs. SVD group 1.48 ± 1.07, p = 0.48], the procedural success rate of CTO-PCI in the MVD group was significantly lower than that in the SVD group (87.2% vs. 90.2%, p = 0.001). However, occurrence of procedure-related adverse events (4% vs. 5%, p = 0.11), total fluoroscopy (70 ± 45 min vs. 69 ± 50 min, p = 0.75) and procedural time (154 ± 86 min vs. 151 ± 89 min, p = 0.36), and total amount of contrast media (219 ± 102 mL vs. 222 ± 105 mL, p = 0.33) did not differ between the two groups.

CONCLUSIONS

Although MVD had an impact on the success rate of CTO-PCI, it did not affect procedure-related adverse events.

Prognostic impact of recanalizing chronic total occlusion in non-infarct related arteries on long-term clinical outcomes in acute myocardial infarction patients undergoing primary percutaneous coronary intervention

Although chronic total occlusion (CTO) in non-infarct-related arteries (non-IRAs) negatively affects long-term mortality in patients with acute myocardial infarction (AMI) who are undergoing primary percutaneous coronary intervention (PCI), the prognostic impact of successful CTO-PCI has not been completely addressed. Among 1855 consecutive patients with AMI who underwent primary PCI, those who were treated for CTO with either PCI or medical therapy were included. We evaluated the association between recanalization of CTO and long-term cardiac mortality. Of the 172 included patients, 88 underwent CTO-PCI, and the procedures were successful in 65 patients. Thus, the successfully recanalized CTO (SR-CTO) group included 65 patients; and the no recanalized CTO (NR-CTO) group, 107 patients. During the follow-up, 72 patients died, and of whom 56 (77.8%) died because of cardiac causes. The cumulative 10-year, 30-day, and 30-day to 10-year incidences of cardiac mortality were lower in the SR-CTO group than in the NR-CTO group (19.0% vs. 51.9% p = 0.004; 4.6% vs. 14.0%, p = 0.05; 15.0% vs. 44.1%, p = 0.003, respectively). After adjusting for confounding factors, the benefits of SR-CTO for the 10-year cardiac mortality remained significant compared with those of NR-CTO (hazard ratio 0.37; 95% confidence interval 0.17-0.75; p = 0.004). In conclusion, patients with SR-CTO in non-IRAs after AMI was associated with reduced long-term cardiac mortality compared with those with NR-CTO.