Determinants of One-Year Outcome After Successful Percutaneous Coronary Intervention for Chronic Total Occlusion; Insight from Japanese CTO-PCI Expert Registry.

Although outcomes have improved with new-generation drug-eluting stents, few reports have analyzed the risk factors associated with chronic outcomes of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). This study aimed to investigate the independent risk factors for target lesion revascularization (TLR) and major adverse cardiac and cerebrovascular events (MACCEs) after CTO-PCI using Japanese multicenter data. A total of 3,666 patients, who underwent CTO-PCI and completed a 1-year follow-up, registered at the Japanese CTO-PCI Expert Registry from 2014 to 2019, were examined. The primary outcome was defined as TLR, and the secondary outcome was MACCEs at the 1-year follow-up. TLRs and MACCEs occurred in 175 (4.8%) and 524 (14.3%) patients, respectively. Multivariate logistic regression analysis demonstrated that in-stent occlusion (ISO) (odds ratio [OR] 2.604, 95% confidence interval [CI] 1.695 to 4.001), hemodialysis (OR 1.784, 95% CI 1.062 to 2.997), diabetes mellitus with insulin use (OR 1.741, 95% CI 1.060 to 2.861), moderate-to-severe calcification (OR 1.726, 95% CI 1.197 to 2.487), and the right coronary artery as the target vessel (OR 1.468, 95% CI 1.018 to 2.117) were significantly associated with TLR. Hemodialysis (OR 2.214, 95% CI 1.574 to 3.113), ISO (OR 1.499, 95% CI 1.127 to 1.993), arteriosclerosis obliterans (OR 1.414, 95% CI 1.074 to 1.863), and multivessel disease (OR 1.356, 95% CI 1.117 to 1.647) were significantly associated with MACCEs. One-year outcomes of new-generation drug-eluting stents for CTO-PCI were favorable, and ISO as a lesion factor and hemodialysis as a patient factor were strongly associated with TLR and MACCEs, respectively.

Retrograde Coronary Chronic Total Occlusion Intervention (JR-CTO) Score: From the Japanese CTO-PCI Expert Registry.

BACKGROUND: Despite the effectiveness of the retrograde approach for chronic total occlusion (CTO) lesions, there are no standardized tools to predict the success of retrograde percutaneous coronary intervention (PCI). OBJECTIVES: The aim of this study was to develop a prediction tool to identify CTO lesions that will achieve successful retrograde PCI. METHODS: This study evaluated data from 2,374 patients who underwent primary retrograde CTO-PCI and were enrolled in the Japanese CTO-PCI Expert Registry between January 2016 and December 2022 (NCT01889459). All observations were randomly assigned to the derivation and validation cohorts at a 2:1 ratio. The prediction score for guidewire failure in retrograde CTO-PCI was determined by assigning 1 point for each factor and summing all accrued points. RESULTS: The JR-CTO score (moderate-severe calcification, tortuosity, Werner collateral connection grade ≤1, and nonseptal collateral channel) demonstrated a C-statistic for guidewire failure of 0.72 (95% CI: 0.67-0.76) and 0.71 (95% CI: 0.64-0.77) in the derivation and validation cohorts, respectively. Patients with lower scores had higher guidewire and technical success rates and decreased guidewire crossing time and procedural time (P < 0.01). CONCLUSIONS: The JR-CTO (Japanese Retrograde Chronic Total Occlusion) score, a simple 4-item score that predicts successful guidewire crossing in patients undergoing retrograde CTO-PCI, has the potential to support clinical decision-making for the retrograde approach.

The Characteristics of Primary Retrograde Approach Selection for Native Coronary Chronic Occlusion With Short Occlusion Length from the Japanese CTO-PCI Expert Registry.

Although the coronary chronic total occlusion (CTO) crossing algorithm has been published, the characteristics associated with the first strategy selection for short-length lesions <20 mm is still debatable. This study aimed to determine the characteristics associated with primary retrograde approach (PRA) for native CTO with short occlusion length in percutaneous coronary intervention (PCI). Between January 2014 and December 2021, we examined data on 4,088 lesions in the Japanese CTO-PCI Expert Registry with occlusion lengths <20 mm. Then, the characteristics for short-length CTO, which was performed by way of the PRA, were assessed. PRA was performed in 785 patients (19.2%). The guidewire success rate was 93.6%, and the technical success rate was 91.3%. Previous coronary artery bypass grafting, chronic kidney disease, and 6 lesion/anatomic characteristics (i.e., blunt stump, distal runoff <1 mm, CTO lesion tortuosity, reattempt procedures, ostial location, and the presence of collateral channel grade 2) were associated with PRA (p <0.05). Moreover, hemodialysis was an independent factor of unsuccessful anterograde guidewire crossing, along with distal runoff <1 mm, the existence of calcification, and CTO lesion tortuosity (all p <0.05). In clinical settings, these independent factors for PRA in short-length CTO can help in selecting the CTO-PCI strategy.

Machine Learning for Prediction of Technical Results of Percutaneous Coronary Intervention for Chronic Total Occlusion.

(1) Background: The probability of technical success in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) represents essential information for specifying the priority of PCI for treatment selection in patients with CTO. However, the predictabilities of existing scores based on conventional regression analysis remain modest, leaving room for improvements in model discrimination. Recently, machine learning (ML) techniques have emerged as highly effective methods for prediction and decision-making in various disciplines. We therefore investigated the predictability of ML models for technical results of CTO-PCI and compared their performances to the results from existing scores, including J-CTO, CL, and CASTLE scores. (2) Methods: This analysis used data from the Japanese CTO-PCI expert registry, which enrolled 8760 consecutive patients undergoing CTO-PCI. The performance of prediction models was assessed using the area under the receiver operating curve (ROC-AUC). (3) Results: Technical success was achieved in 7990 procedures, accounting for an overall success rate of 91.2%. The best ML model, extreme gradient boosting (XGBoost), outperformed the conventional prediction scores with ROC-AUC (XGBoost 0.760 [95% confidence interval {CI}: 0.740-0.780] vs. J-CTO 0.697 [95%CI: 0.675-0.719], CL 0.662 [95%CI: 0.639-0.684], CASTLE 0.659 [95%CI: 0.636-0.681]; p < 0.005 for all). The XGBoost model demonstrated acceptable concordance between the observed and predicted probabilities of CTO-PCI failure. Calcification was the leading predictor. (4) Conclusions: ML techniques provide accurate, specific information regarding the likelihood of success in CTO-PCI, which would help select the best treatment for individual patients with CTO.

Procedural results and in-hospital outcomes of percutaneous coronary intervention for chronic total occlusion in patients with reduced left ventricular ejection fraction: Sub-analysis of the Japanese CTO-PCI Expert Registry.

OBJECTIVES: To evaluate the procedural results and in-hospital outcomes of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) in patients with reduced left ventricular ejection fraction (LVEF). BACKGROUND: While the technical success of general CTO-PCI has improved, CTO-PCI patients with reduced LVEF remain at high-risk for adverse events. METHODS: The data of 820 patients with LVEF ≤ 35% (Group 1), 1816 patients with LVEF = 35%-50% (Group 2), and 5503 patients with LVEF ≥ 50% (Group 3), registered in the Japanese CTO-PCI Expert Registry from January 2014 to December 2019, were retrospectively analyzed. The primary endpoint was in-hospital major adverse cardiac or cerebrovascular events (MACCEs), including death, myocardial infarction, stent thrombosis, stroke, and emergent revascularization. Secondary endpoints included procedural details, guidewire success, and technical success. RESULTS: There were no differences in guidewire and technical success rates between the groups. In-hospital MACCEs was significantly higher in Group 1 (Group 1 vs. Group 2 vs. Group 3: 3.4% vs. 1.7% vs. 1.5%, p = 0.001) and was especially driven by death (1.3% vs. 0.3% vs. 0.1%, p < 0.001) and stroke (0.7% vs. 0.2% vs. 0.2%, p = 0.007). Multivariate analysis showed that LVEF ≤ 35% (odds ratio [OR]; 1.58, 95% confidence interval [CI]; 1.04-2.41, p = 0.03) and New York Heart Association (NYHA) class ≥ 3 (OR; 2.01, 95% CI; 1.03-3.93, p = 0.04) were predictors of in-hospital MACCEs. CONCLUSIONS: In-hospital MACCEs were significantly higher in patients with LVEF ≤ 35%. LVEF ≤;35% and NYHA class ≥ 3 were predictors of in-hospital MACCEs after CTO-PCI.

Successful guidewire crossing via collateral channel at retrograde percutaneous coronary intervention for chronic total occlusion: the J-Channel score.

AIMS: Guidewire (GW) tracking in a collateral channel (CC) is an important step during retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The aim of this study was to create a prediction score model for CC GW crossing success. METHODS AND RESULTS: We analysed data on 886 CCs included in the Japanese CTO PCI Expert Registry during 2016. CCs were categorised as septal (n=610) and non-septal (n=276). CCs were randomly assigned to derivation and validation sets in a 2:1 ratio. The score was developed by multivariate analysis with angiographic findings. Small vessel, reverse bend, and continuous bends were independent predictors in the septal CC subset. Small vessel, reverse bend, and corkscrew were independent predictors in the non-septal CC subset. The extent of intervention was easy, intermediate, and difficult in 92.9%, 57.4%, and 16.7% in the septal CC subset and 91.7%, 54.3%, and 19.0% in the non-septal CC subset, respectively, in the validation set. The area under the receiver operating characteristic curve was >0.7 in the derivation and validation sets of both CC subsets. CONCLUSIONS: The prediction score model can suggest grading of the difficulty of CC GW crossing based on angiographic findings for each type of CC.

A Novel Algorithm for Treating Chronic Total Coronary Artery Occlusion.

BACKGROUND: Guidewire manipulation time is rarely used in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) strategies. OBJECTIVES: This study sought to develop an algorithm based on angiographic characteristics and guidewire manipulation time. METHODS: This study assessed 5,843 patients undergoing CTO PCI between January 2014 and December 2017 and enrolled in the Japanese CTO-PCI expert registry and analyzed their CTO-PCI strategies, procedural outcomes, and guidewire manipulation time. RESULTS: Primary retrograde approach was performed on 1,562 patients. The average Japanese CTO score of primary antegrade approach and primary retrograde approach were 1.7 ± 1.1 and 2.3 ± 1.1, respectively (p < 0.001). The overall guidewire and technical success rates were 92.8% and 90.6%, respectively. Median guidewire manipulation time of guidewire success and failure were 56 min (interquartile range [IQR]: 22 to 111 min) and 176 min (IQR: 130 to 229 min), respectively. Median successful guidewire crossing time of single wiring and parallel wiring in the antegrade alone were 23 min (IQR: 11 to 44 min) and 60 min (IQR: 36 to 97 min), and rescue retrograde approach and primary retrograde approach were 126 min (IQR: 87 to 174 min) and 107 min (IQR: 70 to 161 min), respectively (p < 0.001). Significant predictors for antegrade guidewire failure in primary antegrade approach, which were reattempt, CTO length of ≥20 mm, and no stump, did not predict guidewire failure after collateral channel crossing in primary retrograde approach. CONCLUSIONS: Results from a large registry with information on guidewire manipulation time as well as CTO characteristics suggest a redefinition of the current strategy algorithms.

Initial results of a first-in-human study on the PlasmaWire™ System, a new radiofrequency wire for recanalization of chronic total occlusions.

OBJECTIVES: To examine the safety, efficacy, and efficiency of the PlasmaWireTM System to recanalize coronary chronic total occlusions (CTO) using controlled ablation inside the CTO. BACKGROUND: The PlasmaWireTM System is a new bipolar radiofrequency (RF) wire system utilizing plasma-mediated ablation to facilitate wire crossing in CTOs. Two independent PlasmaWireTM wires are used in tandem for channel creation by applying RF energy between the tips so as to localize the ablation. METHODS: Prospective, nonrandomized, single-arm, multicenter study in seven patients with CTOs indicated for percutaneous coronary intervention (PCI). RESULTS: In this study, both wires were antegradely delivered to the distal end of CTO for antegrade re-entry in two cases and bidirectionally (antegrade and retrograde) delivered to the CTO for retrograde re-entry in five cases. In all cases, channel creation was achieved within a few seconds and was confirmed on angiogram or intravascular ultrasound (IVUS) and CTO recanalization was successfully achieved without any major adverse cardiac and cerebrovascular events (MACCE) or other minor complications. The clinical follow-up showed no clinical event at 1 month. CONCLUSIONS: The PlasmaWireTM System was shown to be safe and effective in obtaining CTO recanalization through a re-entry channel utilizing plasma-mediated ablation while reducing procedure time. The PlasmaWire™ System is a new bi-polar RF wire system utilizing plasma-mediated ablation for channel creation to facilitate CTO recanalization. This first-in-human study in which seven patients were enrolled was conducted to demonstrate the safety, efficacy, and efficiency of this system for CTO recanalization. Channels through the CTOs were successfully created within a few seconds by applying RF energy between the tips of two independent PlasmaWireTM wires and recanalization was achieved in all cases without any complication. The PlasmaWireTM System may safely facilitate CTO recanalization with less vessel injury and improve initial results of CTO PCI while reducing procedure time.

Outcomes of Percutaneous Coronary Interventions for Chronic Total Occlusion Performed by Highly Experienced Japanese Specialists: The First Report From the Japanese CTO-PCI Expert Registry.

OBJECTIVES: This report describes the registry and presents an initial analysis of outcomes for the different PCI approaches taken by the specialists. BACKGROUND: Strategies for percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) are complex. The Japanese Board of CTO Interventional Specialists has developed a prospective, nonrandomized registry of patients undergoing CTO-PCIs performed by 41 highly experienced Japanese specialists. METHODS: Over the study period of January 2014 to December 2015, the registry included 2,846 consecutive CTO-PCI cases undertaken in Japan. The authors compared clinical outcomes between the different PCI approaches, following the intention-to-treat principle. RESULTS: The overall technical success rate of the procedures was 89.9%. The specialists frequently chose a retrograde approach as the primary CTO-PCI strategy (in 27.8% of cases). The technical success rate of the primary antegrade approach was significantly better than that of the primary retrograde approach (91.0% vs. 87.3%; p < 0.0001). The technical success rate decreased to 78.0% with the rescue retrograde approach. Parallel guidewire crossing and intravascular ultrasound-guided wire crossing were performed after guidewire escalation during antegrade CTO-PCI with a high technical success rate (75.0% to 88.9%). Severe lesion calcification was a strong predictor of failed CTO-PCI. CONCLUSIONS: CTO-PCI performed by highly experienced specialists achieved a high technical success rate.

Appropriateness of percutaneous revascularization of coronary chronic total occlusions: an overview.

Coronary chronic total occlusions (CTOs) are commonly encountered in patients undergoing coronary angiography. Several observational studies have demonstrated that successful CTO revascularization is associated with better cardiovascular outcomes and enhanced quality of life (QOL). However, in the absence of randomized trials, its prognostic benefit for patients remains debated. Over the past decade, the interest of the interventional community in CTO percutaneous coronary intervention (PCI) has exponentially grown due to important developments in dedicated equipment and techniques, resulting in high success and low complication rates. Both European and American guidelines have assigned a class IIa (level of evidence B) recommendation for CTO PCI. In the current review, we focus on the impact of CTO revascularization on clinical outcomes and QOL and on appropriate patient selection, and we provide a critical assessment of the current guidelines and recommendations on CTO PCI.

First reported revascularization of complex occlusion of the right coronary artery using the IVUS-guided reverse CART technique via a gastroepiploic artery graft.

When patients who have previously undergone coronary artery bypass graft surgery develop ischemia symptoms that cannot be controlled by optimal medical therapy, repeat revascularization is indicated. The revascularization strategy should be based on individual clinical and anatomical characteristics. We report here a challenging patient who presented with recurrent stable angina due to worsening of a proximal right coronary artery (RCA) stenosis to chronic total occlusion (CTO) after anastomosis of the right gastroepiploic artery (GEA) to the posterior descending artery. A soft guidewire was advanced through the right GEA collateral channel to the distal end of the CTO, but the dedicated CTO guidewires could not be advanced across the severely calcified CTO using the retrograde wire crossing or kissing wire techniques. The RCA was eventually revascularized by implantation of drug-eluting stents using the intravascular ultrasound-guided reverse controlled antegrade and retrograde subintimal tracking technique.

Current Retrograde Approach Is Unfavorable to Long-Term Clinical Outcomes after Percutaneous Coronary Intervention for Chronic Total Occlusion.

Surgeons currently use two different wire-based approaches to recanalize coronary chronic total occlusion (CTO): antegrade and retrograde. It has been demonstrated that the retrograde approach has improved the procedural success rate, but it remains unclear whether the retrograde approach is better than the antegrade approach for the long term. In this study, we enrolled a total of 187 patients with a diagnosis of CTOs. We evaluated the baseline characteristics of these patients and performed percutaneous coronary intervention to treat their problems by using either antegrade or retrograde approaches and different techniques in both groups. In the antegrade approach, we used three techniques: single wire, parallel wire, and side branch. The techniques in retrograde included kissing wire, controlled antegrade and retrograde subintimal tracking (CART), and reverse CART. We found that the antegrade and retrograde groups had similar baseline characteristics, with a few minor differences. Most importantly, we found that within 1 yr of the recanalizing procedure, the restenosis rate and major adverse cardiac event rate of the retrograde group were significantly higher compared to the antegrade group. We conclude that the retrograde approach may not be as beneficial as the antegrade approach for long-term clinical outcomes.

Percutaneous intervention in a patient with a single coronary artery arising from the right coronary sinus of valsalva.

A single coronary artery (SCA) arising from the sinus of Valsalva and supplying the entire heart is a rare congenital anomaly. According to the modified Lipton's classification, R-1 is by far the most rare subtype of SCA, with an incidence of 0.0008% in patients undergoing coronary angiography. We present a case with an unreported anomaly, classified as Lipton R-I subtype, which initially followed the normal course of the right coronary artery. The posterior descending artery then proceeded as the distal and middle sections of the left anterior descending artery, while the posterolateral branch proceeded as the left circumflex artery and finally terminated as the proximal left anterior descending artery. The patient underwent percutaneous intervention in the posterolateral branch for an acute coronary syndrome.

Percutaneous intervention in a patient with a rare single coronary artery from the left coronary sinus of valsava.

A single coronary artery (SCA) arising from the sinus of Valsalva and supplying the entire heart is a rare congenital anomaly. According to modified Lipton's classification, L-1 subtype is a most rare type of SCA. We presented a case classified as L-I subtype, in which initially left main divided into the left anterior descending and circumflex arteries normally; then, the second septal artery proceeded as the proximal right coronary artery, the distal circumflex artery proceeded as the middle and distal right coronary artery. The patient finally underwent percutaneous intervention in the left anterior descending artery owing to a stable angina.

Antegrade approach to stumpless chronic total occlusion of ostial left anterior descending artery: first using a side branch cutting technique.

The approach to a chronic total occlusion (CTO) still remains one of the most technical challenges in percutaneous coronary intervention (PCI). CTO lesions with a blunt entry point, calcification, and failure of a previous approach, are the independent predictors of CTO-PCI failure. Here we report a successful antegrade approach for reattempted CTO-PCI of a left anterior descending artery (LAD) with unknown, calcified ostium. We used a novel side branch cutting technique, combined with intravascular ultrasound-guided wiring and parallel wire techniques. Considering the ramus artery as a side branch and dilating it with a cutting balloon was a crucial part of the strategy for achieving overall procedural success using this approach. This is the first report describing a side branch cutting technique in CTO-PCI. The combined application of multiple antegrade techniques, using the latest devices, might provide an effective and safe approach for complex CTO-PCI.

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

BACKGROUND: Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. OBJECTIVES: Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. METHODS: From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. RESULTS: The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. CONCLUSIONS: IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success.

Impact on clinical outcomes of predilatation using the kissing-balloon technique for crossover stenting in true coronary bifurcation lesions.

BACKGROUND: Provisional crossover stenting has the potential risk of side-branch (SB) compromise, which may result in periprocedural myocardial infarction. Predilatation is a useful technique to prevent SB compromise. OBJECTIVES: The aim of this study was to assess the safety and efficacy of predilatation using the kissing-balloon technique (preKBT) during provisional crossover stenting compared with sequential predilatation on clinical outcomes in true coronary bifurcation lesions. METHODS: We retrospectively evaluated 204 consecutive non-left main true bifurcation lesions (182 patients) in whom provisional crossover stenting was performed with preKBT (preKBT group, n = 144) or sequential predilatation (sequential group, n = 60) from March 2006 to February 2012. RESULTS: There were 30 lesions (20.8%) in the preKBT group that developed SB ostial dissection compared with 8 lesions (13.3%) in the sequential group (P=.241). There was no SB flow impairment or SB access failure due to SB ostial dissection. SB compromise (Thrombolysis in Myocardial Infarction <3) immediately after crossover stenting occurred in 5 lesions (3.5%) in the preKBT group versus 7 lesions (11.7%) in the sequential group (P=.043). Major adverse cardiac events at 6-8 months of follow-up were observed in 5 lesions (3.5%) in the preKBT group versus 8 lesions (13.3%) in the sequential group (P=.022). CONCLUSIONS: Regardless of more complex bifurcation lesions in the preKBT group, preKBT successfully prevented SB compromise due to crossover stenting without unfavorable complications and improved the mid-term clinical outcome compared with sequential PTCA in patients with non-left main, true coronary bifurcation lesions.

Successful IVUS-guided reentry from iatrogenic coronary arteriovenous fistula related to wire perforation following wiring of a totally occluded vessel.

We experienced a rare case in which a guidewire was advanced into a coronary vein through an arteriovenous fistula caused by wire perforation. The patient, who had chronic total occlusion (CTO) of the left circumflex coronary artery, was treated successfully with a procedure guided by intravascular ultrasound (IVUS). The IVUS-guided parallel-wire technique allowed recrossing of the guidewire into the distal true lumen of the CTO by identifying the anatomy of the occluded segment and the appropriate re-entry point. Angiography demonstrated that the fistula was completely sealed after stent deployment, and there was no extravasation.