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.

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.

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.

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.

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.

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.

Successful bypass restenting across the struts of an occluded subintimal stent in chronic total occlusion using a retrograde approach.

Recently, subintimal angioplasty has been introduced as a bailout strategy to improve the success rate of PCI for vessels with CTO. However, the long-term outcome of subintimal angioplasty has not been determined, and a limitation of subintimal angioplasty is the uncertainty in making the re-entry point. We report two cases, where occlusive in-stent restenosis occurred in a stent implanted in the subintimal space of the RCA that had CTO. These two cases were successfully treated with bypass restenting across the struts of an occluded subintimal stent using a retrograde approach. A retrograde wire crossed the occluded segment through the lumen along the outside of the stent and reentered the inside of the stent across the stent struts. The reverse CART technique followed by multiple restenting across the stent struts restored antegrade flow. Follow-up angiography demonstrated the patency of the RCA.

Long-term serial angiographic outcomes after sirolimus-eluting stent implantation.

OBJECTIVE: We evaluated, using quantitative coronary angiography, the natural history of change that occurred in target lesions after successful sirolimus-eluting stent (SES) implantation. BACKGROUND: Percutaneous coronary intervention with drug-eluting stents (DES) has significantly reduced the rate of repeated target lesion revascularization. However, early studies have raised concerns regarding the "late catch-up" phenomenon of DES. METHODS: Between June 2004 and March 2007, consecutive 217 patients with 306 lesions without restenosis at early angiographic follow-up underwent late angiographic follow-up (early follow-up: 11.2 ± 2.1 months and late follow-up: 29.4 ± 5.2 months). Predictors of late catch-up were identified with univariate and multivariate regression analyses. RESULTS: Although reference vessel diameter did not significantly change during follow-up [3.15 mm (interquartile range (IQR): 2.81-3.49 mm), 3.12 mm (IQR: 2.79-3.47 mm), and 3.08 mm (IQR: 2.76-3.46 mm) at postprocedure, and early and late angiographic follow-up, respectively; P = 0.2653], late loss (LL) significantly increased during follow-up [0.05 mm (IQR: 0.00-0.13 mm) and 0.08 mm (IQR: 0.01-0.19 mm) at early and late follow-up, respectively; P < 0.0001]. Univariate analysis showed previous intervention, adjunctive use of cutting balloon, lesion length, and progression of MLD, LL, %DS at early follow-up as predictors of late catch-up. Multivariate regression analysis identified %DS at early follow-up as a predictor of late catch-up (OR 1.076, CI 1.039-1.114, P < 0.0001). CONCLUSION: Significant and continuous progression of neointima after SES implantation was observed in the present study. Larger LL may be a sign of late catch-up phenomenon.

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.

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.

Efficiency, safety, and long-term follow-up of retrograde approach for CTO recanalization: initial (Belgrade) experience with international proctorship.

BACKGROUND: Retrograde approach increases the success rate for percutaneous recanalization of complex chronic total occlusion (CTO) of coronary arteries. OBJECTIVES: The purpose of this study was to describe our initial experience of retrograde percutaneous coronary intervention for CTO program, focusing on its safety and feasibility, and long-term clinical follow-up. METHODS: The study was a single center retrospective registry which included a total of 40 patients, of 590 CTO treated patients (6.7%), between January 2008 and October 2011, who underwent retrograde approach for CTO recanalization. RESULTS: Mean occlusion duration was 37.8 ± 40.3 months. Overall success recanalization rate was 87.5% (35/40). Septal collaterals were used to access the occlusion in all cases (100%). Retrograde guidewire crossing of collateral channels was successful in 36/40 (90.0%) patients with success rate of CTO recanalization in these patients of 97.2%. Retrograde approach as the primary strategy was applied in 23/40 (57.5%) patients, retrograde approach immediately after antegrade failure attempt was performed in 8/40 (20.0%) patients, and retrograde approach as elective procedure, after previously failed antegrade attempt, was performed in 9/40 (22.5%) patients. The success rate of these strategies was: 87.0% (20/23 patients) for primary, 87.5% (7/8 patients) for retrograde immediately after antegrade failure, and 88.9% (8/9 patients) for retrograde after previous failed antegrade attempt, respectively. Total in-hospital major adverse cardiac events (MACE) rate was 5.0% (2 non-Q-wave myocardial infarctions). The MACE free survival at median follow-up of 20 months was 89% (95% CI: 78-100%). CONCLUSIONS: This study has demonstrated that adequate training and international proctorship for this complex and demanding technique is a necessity and prerequisite to achieve high overall success rates, with acceptable complication rates and excellent long-term survival rate.

Rotational atherectomy for fibro-calcific coronary artery disease in drug eluting stent era: procedural outcomes and angiographic follow-up results.

OBJECTIVES: The aim of this study was to examine the binary re-stenosis rates, procedural success, and in hospital outcomes following treatment of fibro-calcified coronary lesion with rotational atherectomy in drug eluting stent era. BACKGROUND: Binary restenosis rates have remained high with the use of bare metal stents following rotational atherectomy in calcified lesions. There is limited data available following rotational atherectomy in drug eluting stent era. METHODS: We evaluated the procedural and angiographic outcomes following a consecutive series of 516 procedures treated with rotational atherectomy followed by stenting. We compared the results between Rota + Drug eluting stent (DES) and Rota + bare metal stent (BMS) groups. RESULTS: Procedural success was achieved in 97.1% of the lesions with overall low in hospital adverse events (death in 1.1%, Q MI in 1.3%, Non Q MI in 5.3%, and urgent repeat PCI in 0.4%). There was significant reduction in the binary restenosis rates following Rota + DES use as compared to Rota + BMS use (11% vs. 28.1%, P < 0.001; OR = 3.17, 95% CI: 1.76-5.93) and similar reduction was seen in the target lesion revascularization (10.6% vs. 25%, P = 0.001; OR = 2.81, 95% CI: 1.53-5.14). We have identified ostial lesions, chronic total occlusion lesions, and use of bare metal stents as independent predictors of restenosis in this group of patients. CONCLUSIONS: Rotational atherectomy can be performed with high success rates and low complications, and rotational atherectomy followed by drug eluting stent implantation significantly reduces binary restenosis rates in fibrocalcific lesions as compared to rotational atherectomy and bare metal stents.

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.

Percutaneous coronary intervention for a right coronary artery stent occlusion using retrograde delivery of a sirolimus-eluting stent via a septal perforator.

In percutaneous coronary intervention for chronic total occlusion (CTO), the retrograde approach is an advanced technique. To improve the long-term patency rate, stent implantation is necessary for CTO, however, antegrade stent delivery to the lesion is contraindicated in cases where there is an anomalous origin or deviation of the coronary artery, or the edge of a previously implanted stent extends into the aorta. We report a successful case of retrograde stent implantation via a septal perforator in a patient with marked deviation of the RCA origin. In this case, antegrade stent implantation was difficult because antegrade catheter insertion carried a risk of crush deformation of an ostial stent.

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.

Impact of intramural thrombus in coronary arteries on the accuracy of tissue characterization by in vivo intravascular ultrasound radiofrequency data analysis.

Virtual Histology (VH) intravascular ultrasound (IVUS) allows differentiation between 4 different tissue phenotypes. However, the current classification tree for analysis cannot differentiate the presence of intramural thrombus. The aim of this study was to evaluate the impact of intramural thrombus for correlative accuracy between in vitro histopathology of coronary atherosclerotic plaque obtained by directional coronary atherectomy and corresponding in vivo tissue characterization obtained by VH IVUS. Coronary IVUS imaging of 30 coronary artery lesions was obtained using a 20-MHz phased-array IVUS catheter with a motorized pull-back system at set 0.5 mm/s. The debulking region of the in vivo histologic image was predicted from comparison between pre- and post-first debulking VH IVUS images. Cross-sectional histologic slices were cut every 0.5 mm starting from the most proximal part of the formalin-fixed debulking tissue. Histologic slices were divided into 2 groups by the presence or absence of pathologic thrombus. A total of 259 in vitro histologic slices were obtained, and pathologic thrombus was detected in 81 slices. Correlation was favorable, with high sensitivity for all plaque components, but specificities for fibrous (thrombus slices vs nonthrombus slices 36% vs 94%) and fibrofatty (9% vs 60%) tissue were lower in thrombus slices. Therefore, predictive accuracies for the 2 plaque components were lower in thrombus slices (fibrous tissue 78% vs 99%, fibrofatty tissue 68% vs 83%, respectively). In conclusion, intramural thrombus was colored as fibrous or fibrofatty by VH IVUS, reducing VH accuracy in these kinds of lesions.

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.