Japanese Chronic Total Occlusion Research Articles

Characteristics of patients undergoing percutaneous coronary intervention for chronically total occluded arteries: a single-center observational study in India [RETRACTED

Background and purpose: Percutaneous coronary intervention (PCI) is the gold standard for managing chronic total occlusion (CTO), but data on characteristics of the patients undergoing PCI for CTO are scarce. The present study was designed to evaluate the clinical profile of the patients who underwent PCI to CTO. Methods: This single-center, prospective, and observational study included consecutive patients who successfully underwent PCI for angiographically confirmed CTO at author’s center from March 2017 to March 2019. Follow-up was conducted at 6 and 12 months. Results: The final analysis included a total of 108 patients. The mean age was 64.5 ± 8.2 years. Majority of the patients (72.2%) were men. The most common morbid risk factors were diabetes mellitus (56.5%), hypertension (53.7%), and dyslipidemia (52.8%). Mean left ventricular ejection fraction (LVEF) was 51% ± 0.0% and 73% had New York Heart Association (NYHA) class II. The most common site of CTO was the right coronary artery (34.3%). PCI was conducted using an antegrade approach, 75.9% of the cases. The majority of patients underwent wire escalation PCI technique (52.8%) followed by adverse drug reaction (34.3%), reverse-controlled antegrade and retrograde tracking (CART) (8.3%) and CART (4.6%). Stress test was negative in 63% and 64.8% of the patients at 6 and 12 months, respectively. The 6-month symptom-free survival rate was higher in patients without hypertension. Symptom-free survival rate was 96.9%, 95.9% and 88.9% in patients with Japanese Multicenter CTO Registry (J-CTO) score of 0, 1 and >3, respectively. The rate of abnormal electrocardiogram at 12 months was higher in patients with J-CTO score of 0 or 1 versus >3. Conclusion: PCI is a viable option for patients who are not willing to undergo coronary artery bypass grafting, particularly in those with low J-CTO score.

Validation of the J-Channel Score for retrograde channel crossing in the PROGRESS-CTO registry.

Successful collateral channel (CC) crossing is essential for the success of retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Based on the Japanese CTO PCI expert registry, the J-Channel score was developed to predict CC crossing. We examined the performance of the J-Channel score in patients who underwent retrograde CTO-PCI at 31 centers between 2013-2023 as part of the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO). We observed an association between successful CC crossing and the J-Channel score, its predictive efficacy was modest for both wire and microcatheter crossing.

Comparative Analysis of Polymer Versus Non-Polymer Jacketed Wires in Chronic Total Occlusion Percutaneous Coronary Intervention

There is significant variation in wire utilization patterns for chronic total occlusion (CTO) percutaneous coronary intervention. This study aimed to compare the outcomes of polymer-jacketed wires (PJWs) versus non-PJWs in anterograde procedures. We analyzed clinical and angiographic characteristics, and procedural outcomes of 7,575 anterograde CTO percutaneous coronary interventions that were performed at 47 centers between 2012 and 2023. Cases in which PJWs were exclusively used were classified in the PJW group, whereas cases where at least one non-PJW was employed were classified in the non-PJW group. Study end points were as follows: technical success, coronary perforation, major adverse cardiac event. PJWs were exclusively used in 3,481 cases (46.0%). These cases had lower prevalence of proximal cap ambiguity, blunt stump, and moderate/severe calcification. They also had lower Japanese CTO (J-CTO), Prospective Global Registry for the Study of Chronic Total Occlusion (PROGRESS-CTO), and PROGRESS-CTO complications scores, higher technical success (94.3% vs 85.7%, p <0.001), and lower perforation rates (2.2% vs 3.2%, p = 0.013). Major adverse cardiac event rates did not differ between groups (1.3% vs 1.5%, p = 0.53). Exclusive use of PJWs was independently associated with higher technical success in both the multivariable (odds ratio [OR] 2.66, 95% confidence interval [CI] 2.13 to 3.36, p <0.001) and inverse probability of treatment weight analysis (OR 2.43, 95% CI 2.04 to 2.89, p <0.001). Exclusive use of PJWs was associated with lower risk of perforation in the multivariable analysis (OR 0.69, 95% CI 0.49 to 0.95, p = 0.02), and showed a similar trend in the inverse probability of treatment weight analysis (OR 0.77, 95% CI 0.57 to 1.04, p = 0.09). Exclusive use of PJWs is associated with higher technical success and lower perforation risk in this non-randomized series of patients.

Technically Challenging Percutaneous Interventions of Chronic Total Occlusions Are Associated with Enhanced Platelet Activation.

Percutaneous coronary intervention (PCI) is a frequently performed treatment option for recanalization in patients with chronic total occlusion (CTO). As CTO-PCIs are often complicated and challenging for interventionalists, the stressful and damaging nature of the procedure can be remarkable, thus platelets can be easily activated. Our aim was to investigate the effect of CTO-PCI on platelet activation and the expression of selected circulating microRNAs (miR) of platelet and endothelium origin after CTO-PCI. In this study, 50 subjects after CTO-PCI were enrolled. Blood samples were obtained before PCI, at 2 days and 3-6 months after the procedure to measure the degree of platelet activation and the level of plasma miR-223, miR-181b, and miR-126. Patients were divided based on the characteristics of the intervention. Patients with higher Japanese CTO scores and longer duration of PCI showed significantly elevated platelet P-selectin positivity (p = 0.004 and p = 0.013, respectively) 2 days after the procedure compared to pre-PCI and increased concentration of soluble P-selectin 3-6 months after the intervention (higher Japanese CTO score: p = 0.028 and longer duration of PCI: p = 0.023) compared to baseline values. Shorter total stent length caused a significantly lower miR-181b expression at 3-6 months after the intervention (p = 0.031), while no difference was observed in miR-223 and miR-126. One stent thrombosis occurred during the follow-up period. Although these technically challenging CTO-PCIs may cause enhanced platelet activation right after the intervention and long-term endothelial cell dysfunction, these interventions are not associated with more adverse clinical events.

Contemporary In-Hospital Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions: Insights from the MENATA (Middle East, North Africa, Turkey, and Asia) Chapter of the PROGRESS-CTO Registry

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has been rapidly evolving in different parts of the world. We examined the clinical and angiographic characteristics and procedural outcomes of 1,079 consecutive CTO PCIs performed in 1,063 patients at 10 centers in the Middle East, North Africa, Turkey, and Asia regions between 2018 and 2022. The mean age was 61 ± 10years and 82% of the patients were men. The prevalence of diabetes (49%) and previous PCI (50%) was high. The most common target vessel was the right coronary artery (51%), followed by the left anterior descending artery (33%) and the circumflex artery (15%). The mean Japanese CTO score was 2.1 ± 1.2 and mean PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) score was 1.2 ± 1.0. The technical and procedural success rates were high (91% and 90%, respectively) with a low incidence (1.6%) of in-hospital major adverse cardiac events. The incidence of perforation was 4.6% (n=50): guidewire exit was the most common mechanism of perforation (48%) and 14 patients required pericardiocentesis (28%). Antegrade wire escalation was the most common crossing strategy used (91%), followed by retrograde approach (24%) and antegrade dissection and re-entry (12%). Median contrast volume, air kerma radiation dose, and fluoroscopy time were 300 (200 to 400) ml, 3.7 (2.0 to 6.3) Gy, and 40 (25 to 65) minutes, respectively. In conclusion, high success and acceptable complication rates are currently achieved at experienced centers in the Middle East, North Africa, Turkey, and Asia regions using a combination of crossing strategies.

Balloon-assisted subintimal entry (BASE) in chronic total occlusion percutaneous coronary interventions.

There is limited data on the use of the balloon-assisted subintimal entry (BASE) technique in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We analyzed the baseline clinical and angiographic characteristics and outcomes of 155 CTO PCIs that utilized the BASE technique at 31 US and non-US centers between 2016 and 2023. The BASE technique was used in 155 (7.9%) of 1968 antegrade dissection and re-entry (ADR) cases performed during the study period. The mean age was 66 ± 10 years, 88.9% of the patients were men, and the prevalence of diabetes (44.6%), hypertension (90.5%), and dyslipidemia (88.7%) was high. Compared with 1813 ADR cases that did not use BASE, the target vessel of the BASE cases was more commonly the RCA and less commonly the LAD. Lesions requiring BASE had longer occlusion length (42 ± 23 vs. 37 ± 23 mm, p = 0.011), higher Japanese CTO (J-CTO) (3.4 ± 1.0 vs. 3.0 ± 1.1, p < 0.001) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention chronic total occlusion) (1.8 ± 1.0 vs. 1.5 ± 1.0, p = 0.008) scores, and were more likely to have proximal cap ambiguity, side branch at the proximal cap, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Technical (71.6% vs. 75.5%, p = 0.334) and procedural success (71.6% vs. 72.8%, p = 0.821), as well as major adverse cardiac events (MACE) (1.3% vs. 4.1%, p = 0.124), were similar in ADR cases that used BASE and those that did not. The BASE technique is used in CTOs with longer occlusion length, higher J-CTO score, and more complex angiographic characteristics, and is associated with moderate success but also low MACE.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions in Patients With Previous Coronary Artery Bypass Graft Surgery

The outcomes of chronic total occlusion (CTO) percutaneous coronary interventions (PCIs) in patients with previous coronary artery bypass graft (CABG) surgery have received limited study. We examined the baseline characteristics and outcomes of CTO PCIs performed at 47 United States and non-United States centers between 2012 and 2023. Of the 12,164 patients who underwent CTO PCI during the study period, 3,475 (29%) had previous CABG. Previous CABG patients were older, more likely to be men, and had more comorbidities and lower left ventricular ejection fraction and estimated glomerular filtration rate. Their CTOs were more likely to have moderate/severe calcification and proximal tortuosity, proximal cap ambiguity, longer lesion length, and higher Japanese CTO scores. The first and final successful crossing strategy was more likely to be retrograde. Previous CABG patients had lower technical (82.1% vs 88.2%, p <0.001) and procedural (80.8% vs 86.8%, p <0.001) success, higher in-hospital mortality (0.8% vs 0.3%, p <0.001), acute myocardial infarction (0.9% vs 0.5%, p=0.007) and perforation (7.0% vs 4.2%, p <0.001) but lower incidence of pericardial tamponade and pericardiocentesis (0.1% vs 1.3%, p <0.001). At 2-year follow-up, the incidence of major adverse cardiac events, repeat PCI and acute coronary syndrome was significantly higher in previous CABG patients, whereas all-cause mortality was similar. In conclusion, patients with previous CABG who underwent CTO PCI had more complex clinical and angiographic characteristics and lower success rate, higher perioperative mortality, and myocardial infarction but lower tamponade, and higher incidence of major adverse cardiac events with similar all-cause mortality during follow-up.

Incidence, mechanisms, treatment, and outcomes of donor vessel injury during percutaneous coronary interventions for chronic total occlusion.

Donor vessel injury is a potentially life-threatening complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Our goal was to examine the incidence, mechanisms, treatment, and outcomes of patients with donor vessel injury in a large multicenter CTO PCI registry. We analyzed the baseline clinical and angiographic characteristics, and procedural outcomes of 12,349 CTO PCIs performed between 2012 and 2022 at 44 centers. The incidence of donor vessel injury was 0.35% (n = 43). The baseline clinical characteristics of patients with and without donor vessel injury were similar. Cases complicated by donor vessel injury were more complex with higher Japanese CTO score (2.9 ± 1.1 vs. 2.4 ± 1.3; p = 0.004) and lower procedural success rate (69.8% vs. 85.2%; p = 0.004). The retrograde approach was used more commonly in donor vessel injury cases (68.9% vs. 30.9%; p < 0.001). Most (53.5%) donor vessel injuries were guide catheter-induced, whereas 20.9% were due to donor vessel thrombosis. Of the 43 patients with donor vessel injury, 36 (83.7%) were treated with stenting and seven (16.3%) received a left ventricular assist device. The incidence of major adverse cardiovascular events (MACEs) was significantly higher in cases with donor vessel injury (23.3% vs. 2.0%; p < 0.001). Of the 43 patients with donor vessel injury, five patients (11.6%) experienced acute myocardial infarction and four patients (9.3%) died. Donor vessel injury, occurred in 0.35% of CTO PCIs performed by experienced operators, was mainly due to guide catheter-induced dissection or thrombosis and was associated with lower procedural success and higher MACE.

Clinical outcomes after successful revascularization of long chronic total occlusions using amphilimus-eluting polymer-free stent: a single center experience.

Chronic total occlusions (CTOs) are complex lesions that usually require stenting of long segments, and, therefore more prone to restenosis and/or thrombosis. Polymer-free stents to avoid chronic inflammatory response in the vessel wall are a potential solution to reduce target lesion revascularization. We, therefore, investigated the clinical outcomes following successful amphilimus-eluting polymer-free stent implantation in long CTOs. A total of 77 consecutive patients who underwent successful revascularization for long CTOs (lesion length ≥30 mm) using Cre8 stents were included. Baseline demographics, periprocedural characteristics, in-hospital events, and post-discharge long-term cardiovascular events were retrospectively screened for all patients. The Japanese CTO score was 1.58 ± 0.96, and the lesion length was 54.0 ± 9.89 mm. All cases were technically successful (n = 77, 100%), while procedural success was obtained in 74 patients (96.1%). Periprocedural complications were contrast-induced nephropathy (n = 4, 5.2%), coronary perforation (n = 3, 3.8%), residual dissection (n = 1, 1.3%), and femoral artery pseudoaneurysm (n = 1, 1.3%). Three patients (3.9%) presented periprocedural myocardial infarction requiring repeat percutaneous coronary intervention. At 25.0 ± 15.8 months follow-up, major adverse cardiac and cerebrovascular events were observed in 14 patients (18.1%). The Cre8 polymer-free drug- eluting stents seems safe and effective for percutaneous revascularization of long CTO lesions with a high success and low adverse event rate.

Distal Target Vessel Quality and Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention

BackgroundDistal vessel quality is a key parameter in the global chronic total occlusion (CTO) crossing algorithm. ObjectivesThe study sought to evaluate the association of distal vessel quality with the outcomes of CTO percutaneous coronary intervention. MethodsWe examined the clinical and angiographic characteristics and procedural outcomes of 10,028 CTO percutaneous coronary interventions performed at 39 U.S. and non-U.S. centers between 2012 and 2022. A poor-quality distal vessel was defined as <2 mm diameter or with significant diffuse atherosclerotic disease. In-hospital major adverse cardiac events (MACE) included death, myocardial infarction, urgent repeat target vessel revascularization, tamponade requiring pericardiocentesis or surgery, and stroke. ResultsA total of 33% of all CTO lesions had poor-quality distal vessel. When compared with good-quality distal vessels, CTO lesions with a poor-quality distal vessel had higher J-CTO (Japanese chronic total occlusion) scores (2.7 ± 1.1 vs 2.2 ± 1.3; P < 0.01), lower technical (79.9% vs 86.9%; P < 0.01) and procedural (78.0% vs 86.8%; P < 0.01) success, and higher incidence of MACE (2.5% vs 1.7%; P < 0.01) and perforation (6.4% vs 3.7%; P < 0.01). A poor-quality distal vessel was independently associated with technical failure and MACE. Poor-quality distal vessels were associated with higher use of the retrograde approach (25.2% vs 14.9%; P < 0.01) and higher air kerma radiation dose (2.4 [IQR: 1.3-4.0] Gy vs 2.0 [IQR: 1.1-3.5] Gy; P < 0.01). ConclusionsA poor-quality distal vessel in CTO lesions is associated with higher lesion complexity, higher need for retrograde crossing, lower technical and procedural success, higher incidence of MACE and coronary perforation, and higher radiation dose.

Procedural Time and Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusion (CTO) percutaneous coronary interventions (PCIs) can be lengthy procedures. We sought to investigate the effect of procedural time on CTO PCI outcomes. We examined the procedural time required for the various steps of CTO PCI in 6,442 CTO PCIs at 40 US and non-US centers between 2012 and 2022. The mean and median procedure times were 129 ± 76 and 112minutes, respectively, with no significant change over time. The median times from access to wire insertion, guidewire manipulation time, and post crossing were 20, 32, and 53minutes, respectively. Lesions crossed in <30minutes were less complex, as reflected by lower Japanese CTO score (1.89 ± 1.19, p <0.001) than lesions that were not successfully crossed (2.88 ± 1.22) and lesions that were crossed in ≥30minutes (2.85 ± 1.13). The likelihood of successful crossing if crossing was not achieved after 30, 90, and 180minutes were a 76.7%, 60.7%, and 42.7%, respectively. The parameters independently associated with ≥30minutes guidewire manipulation time in patients with a primary antegrade approach included left anterior descending target vessel, proximal cap ambiguity, blunt/no stump, occlusion length, previous failed attempt, medium/severe calcification, and medium/severe tortuosity. The mean duration of CTO PCI is approximately 2hours (∼20% of time for access to wire insertion, ∼30% wire manipulation time, and ∼50% postwiring time). Guidewire crossing time was shorter in less complex lesions and in cases without complications.

B-19 | Follow-Up Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention: Insights from the PROGRESS-CTO Registry

There is limited information on follow-up major adverse cardiac events (MACE) after chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We examined the clinical and angiographic characteristics, as well as procedural and follow-up outcomes of patients who underwent CTO PCI at 38 US and non-US centers between 2012 and 2022 and had follow-up. Of the 3,488 patients with follow-up, 246 (7.1%) experienced MACE, including 73 deaths, 102 acute myocardial infarctions, and 122 target vessel revascularizations (with PCI or coronary artery bypass graft surgery [CABG]). The mean and median follow-up periods were 268±335 and 98 days, respectively. The incidence of MACE at 1, 2, and 3 years was 12%, 23%, and 27%, respectively. Patients with follow-up MACE were more likely to have comorbidities and had more complex lesions as indicated by higher Japanese CTO (J-CTO) scores (2.52 vs 2.33; p=0.026), and longer procedure (135 vs 110 min; p<0.001) and fluoroscopy (48.9 vs 40.0 min; p=0.006) times, higher contrast volume (250 vs 200 mL; p<0.001) and air kerma radiation dose (2.86 vs 2.20; p<0.001). The antegrade crossing strategy was less commonly the successful crossing strategy in patients with follow-up MACE (40.4%) compared with patients without follow-up MACE (58.3%; p<0.001). Cox regression analysis identified parameters associated with follow-up death, acute coronary syndrome, repeat target vessel PCI and target vessel coronary artery bypass graft surgery. Several parameters are associated with follow-up MACE after CTO PCI.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention After a Previous Failed Attempt

The impact of a previous failure on procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We examined the clinical and angiographic characteristics and procedural outcomes of 9,393 patients who underwent 9,560 CTO PCIs at 42 United States and non-United States centers between 2012 and 2022. A total of 1,904 CTO lesions (20%) had a previous failed PCI attempt. Patients who underwent reattempt CTO PCI were more likely to have a family history of coronary artery disease (37% vs 31%, p <0.001) and dyslipidemia (87.9% vs 84.3%, p <0.001) but were less likely to have heart failure (25.1% vs 29.5%; p <0.001) and cerebrovascular disease (8.7% vs 10.4%, p=0.04). Patients with previous failure had a higher Japanese CTO (3.33 ± 1.16 vs 2.12 ± 1.19, p <0.001) score and required longer procedure (120 vs 111minutes, p <0.001) and fluoroscopy (46.9 vs 40.4minutes, p <0.001) times and higher air kerma radiation dose (2.3 vs 2.1 gray, p=0.013). Technical success rates (84.3% vs 86.5%, p=0.011) were lower in patients with a previous failure compared with patients who underwent first-attempt CTO PCI with no significant difference in in-hospital major adverse cardiac events. After adjusting for potential confounders, a previous failure was not associated with technical failure. Operators performing >30 CTO PCIs annually were more likely to achieve technical success in patients with previous failure. In conclusion, a previous failed CTO PCI attempt was associated with higher lesion complexity, longer procedure time, and lower technical success; however, the association with lower technical success did not remain significant in multivariable analysis.

Impact of target vessel on the procedural techniques and outcomes of chronic total occlusion percutaneous coronary intervention.

There is limited information on the impact of the target vessel on the procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 11,580 CTO PCIs performed between 2012 and 2022 at 44 centers. The most common CTO target vessel was the right coronary artery (RCA) (53.1%) followed by the left anterior descending artery (LAD) (26.0%) and the left circumflex artery (LCX) (19.8%). RCA CTOs were longer and more complex, with a higher Japanese CTO score compared with LAD or LCX CTOs. Technical success was higher among LAD (88.8%) lesions when compared with RCA (85.7%) or LCX (85.8%) lesions (P less than .001). The incidence of major adverse cardiovascular events (MACE) was overall 1.9% (n = 220) and was similar among target vessels (P=.916). There was a tendency toward more frequent utilization of the retrograde approach for more proximal occlusions in all 3 target vessels. When compared with all other RCA lesions combined, distal RCA lesions had higher technical success (87.7% vs 85.3%; P=.048). Technical success was similar between various locations of LAD CTOs (P=.704). First/second/third obtuse marginal branch had lower technical success when compared with all other LCX lesion locations (82.7% vs 86.8%; P=.014). There was no association between MACE and CTO location in all 3 target vessels. LAD CTO PCIs had higher technical and procedural success rates among target vessels. The incidence of MACE was similar among target vessels and among various locations within the target vessel.

Postdischarge prognostic significance of periprocedural myocardial injury after percutaneous intervention of chronic total occlusion

BackgroundThe postdischarge prognostic implication of periprocedural myocardial injury in patients undergoing percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) remains scarcely studied.AimsThe aim of this study is to...

Performance of the J-CTO score versus other risk scores for predicting procedural difficulty in coronary chronic total occlusion interventions

Background Although the Japanese chronic total occlusion (J-CTO) score is widely used to assess the complexity of revascularization for CTO lesions, ambiguous and conflicting results are reported in validation studies. Therefore, we aimed to quantitatively evaluate the effectiveness of the J-CTO score and explore the heterogeneity of its comparison with other CTO scores. Methods PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov databases were systematically searched from January 1st, 2011 to December 23rd, 2021. Studies that examined the accuracy of the J-CTO score were eligible. Where feasible, estimates of discrimination and calibration were pooled with a random-effects model. The Prediction model Risk Of Bias ASsessment Tool (PROBAST) was used for risk-of-bias assessment. This study was reported according to PRISMA guidelines and prospectively registered with PROSPERO (CRD42019126161). Results Of 28 included studies (N = 34,944 lesions), 24 were eligible for meta-analysis. The J-CTO score demonstrated significant discrimination for 30-min wire crossing (summary C-statistic 0.76; 95% CI 0.68–0.84) and technical success (0.68; 95% CI 0.61–0.74) despite significant heterogeneity. Only 19 (33%) of the 58 pairwise comparisons with 14 competing scores that were based on discrimination reported a statistical result. The J-CTO score performed worse (relative difference of C-statistics >5%) in eight out of 33 independent comparisons but better in another 13. Methodological shortcomings resulted from only one study evaluating model calibration appropriately. Conclusion The discrimination power of the J-CTO score was useful for time-efficient wire crossing and moderate for angiographic success. Head-to-head comparisons of CTO scores would benefit from standardized reporting and appropriate statistical methods. Key messages The J-CTO score has useful discrimination in predicting 30-min wire crossing while performing moderately for technical success. After excluding optimism bias, there is insufficient independent evidence supporting the superiority of newly introduced models over the J-CTO score. Standardized methodology and assessment are needed to achieve a better understanding of CTO scores, especially for their calibration.

Incidence, Mechanisms, Treatment, and Outcomes of Coronary Artery Perforation During Chronic Total Occlusion Percutaneous Coronary Intervention

Coronary artery perforation is a feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Our objective was to describe the incidence, mechanisms, treatment, and outcomes of coronary artery perforation during CTO PCI. We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 10,454 CTO PCIs performed in 10,219 patients between 2012 and 2022. The incidence of coronary perforation was 4.9% (n=503). Patients who experienced coronary perforation were older and were more likely to have had previous coronary artery bypass graft surgery. Procedures that resulted in perforation were more complex, with higher Japanese CTO and Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) scores. Technical (66% vs 87%, p &lt;0.001) and procedural (55% vs 87%, p &lt;0.001) success rates were lower in perforation cases. The CTO target vessel was the most common perforation site (66%). The retrograde approach was responsible for the perforation in 47% of cases, and guidewire exit was the most common perforation mechanism. The proportion of Ellis class 1, 2, 3, and 3 -"cavity spilling" coronary perforations was 20%, 41%, 28%, and 11%, respectively. In 52% of perforations, 1 or more interventions were required: prolonged balloon inflation (23%), covered stent deployment (21%), coil embolization (6%), and/or autologous fat embolization (4%). Tamponade requiring pericardiocentesis occurred in 69 patients (14%). The incidence of major adverse cardiovascular events was higher in perforation cases (18% vs 1.3%, p &lt;0.001). In conclusion, coronary artery perforation occurred in 4.9% of CTO PCIs performed by experienced operators and was associated with lower technical success and higher in-hospital major adverse cardiovascular events.

On-line estimated peak skin dose during percutaneous coronary intervention for chronic total occlusion using new patient dose mapping technology

X-ray exposure during complex percutaneous coronary intervention is a very important issue. To reduce patient peak skin dose during percutaneous coronary intervention procedures for chronic total occlusion using on-line estimated peak skin dose software (Dose Map). Throughout the procedure, Dose Map provided a map of local cumulative peak skin dose. This map was displayed in-room from 1Gy cumulative air kerma, and was updated every 0.5Gy. The operator's actions to minimize deterministic risks following map notification were collected. Skin reaction was evaluated 3 months after the procedure. A comparison with our historical X-ray exposure data (207 patients from January 2013 to July 2014) was performed. From November 2015 to October 2016, 97 patients (Japanese chronic total occlusion score 2.1±1.1; 100 percutaneous coronary intervention procedures for chronic total occlusion) were prospectively enrolled. Fluoroscopy time was 40.8 (21.6-60.3) minutes, cumulative air kerma 1884 (1144-3231) mGy, estimated peak skin dose 962 (604-1474) mGy and kerma area product 115.8 (71.5-206.7) Gy.cm2. Cumulative air kerma was>3Gy in 28% of cases, and>5Gy in 11% of cases. In 68% of cases, at least one action was taken by the operator after map notification to optimize skin dose distribution. Main changes included: gantry angulation (52%); field of view (25%); and collimation (13%). No skin injuries were observed at follow-up. In comparison with our chronic total occlusion historical radiation data, median cumulative air kerma and kerma area product were reduced by 31% and 33%, respectively (P<0.005. Online skin dose mapping software allows the distribution of patient skin dose during complex percutaneous coronary intervention procedures, and may minimize X-ray exposure.

Appropriateness of Percutaneous Coronary Intervention Performed by Japanese Expert Operators in Patients With Chronic Total Occlusion.

The appropriateness of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions has rarely been investigated.Methods and Results: The Japanese CTO-PCI Expert Registry enrolled consecutive patients undergoing CTO-PCI carried out by highly experienced Japanese CTO specialists who performed more than 50 CTO-PCIs per year and 300 CTO-PCIs in total. This study included patients undergoing CTO-PCI between January 2014 and December 2019. The appropriateness, trends, and differences among the procedures performed by the operators using the 2017 appropriate use criteria were analyzed. Furthermore, we performed a logistic regression analysis to assess whether the appropriateness was associated with in-hospital major adverse cardiovascular and cerebrovascular events (MACCE). Of the 5,062 patients who underwent CTO-PCI, 4,309 (85.1%) patients who did not undergo the non-invasive stress test were classified as having no myocardial ischemia. Of the total cases, 3,150 (62.2%) were rated as "may be appropriate," and 642 (12.7%) as "rarely appropriate" CTO-PCI cases. The sensitivity analyses showed that the number (%) of "may be appropriate" ranged from 4,125 (57.8%) to 4,744 (66.4%) and the number of "rarely appropriate" ranged from 843 (11.8%) to 970 (13.6%) among best and worst scenarios. In a large Japanese CTO-PCI registry, approximately 13% of CTO-PCI procedures were classified as "rarely appropriate". Substantial efforts would be required to decrease the number of "rarely appropriate" CTO-PCI procedures.

Collagenase to facilitate guidewire crossing in chronic total occlusion PCI—The Total Occlusion Study in Coronary Arteries‐5 (TOSCA‐5) trial

Chronic total occlusions (CTO) are common and are associated with lower percutaneous coronary intervention (PCI) success rates, often due to failure of antegrade guidewire crossing. Local, intralesional delivery of collagenase (MZ-004) may facilitate guidewire crossing in CTO. To evaluate the effect of MZ-004 in facilitating antegrade wire crossing in CTO angioplasty. A total of 76 patients undergoing CTO PCI were enrolled at 13 international sites: 38 in the randomized training stage (collagenase [MZ-004] 900 or 1200 μg) and 38 in the placebo-controlled stage (MZ-004 900 or 1200 μg or placebo). Patients received the MZ-004 or identical volume saline (placebo group) in a double-blind design, injected via microcatheter directly into the proximal cap of the CTO. The following day patients underwent CTO PCI using antegrade wire techniques only. Patients were generally similar except for a trend for higher Japanese chronic total occlusion (J-CTO) score in the MZ-004 group (MZ-004 J-CTO score 1.9 vs. 1.4, p = 0.07). There was a numerical increase in the rates of guidewire crossing in the MZ-004 groups compared to placebo (74% vs. 63%, p = 0.52). Guidewire crossing with a soft-tip guidewire (≤1.5 g tip load) was significantly higher in the MZ-004 groups (0% in placebo, 17% in 900 μg, and 29% in 1200 μg MZ-004 group, p = 0.03). Rates of the major adverse cardiovascular event were similar between groups. Local delivery of MZ-004 into coronary CTOs appears safe and may facilitate CTO crossing, particularly with softer tipped guidewires. These data support the development of a pivotal trial to further evaluate this agent.