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.

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 objective 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.

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.

P5750Manipulation strategy for crossing coronary chronic total occlusion: an update from the Japanese CTO-PCI expert registry

Background

The percutaneous coronary intervention (PCI) strategy for chronic total occlusion (CTO) based on the guidewire manipulation time remains infrequent.

Purpose

We aimed to assess CTO-PCI strategy on the basis of guidewire manipulation time.

Methods

A total of 5843 patients undergoing CTO PCI between January 2014 and December 2017 and enrolled in the Japanese CTO-PCI expert registry were assessed. Their CTO-PCI strategies, procedural outcomes, and guidewire manipulation time were analysed.

Results

The primary retrograde approach was performed on 1562 patients (26.7%). 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 (interquatile range [IQR]: 22 to 111) min and 176 (IQR: 130 to 229) min, respectively. The average Japanese CTO score of the primary antegrade approach with the antegrade alone, the primary antegrade approach with the retrograde approach, and the primary retrograde approach were 1.7±1.1, 2.1±1.2, and 2.3±1.1, respectively (p<0.001). Median successful guidewire crossing time of single wiring in the antegrade alone was 23 (IQR: 11 to 44) min, and that of the primary retrograde approach was significantly shorter than that of the primary antegrade approach with the retrograde approach (107 [IQR: 70 to 161] min vs. 126 [IQR: 87 to 174] min; p<0.001). Reattempt, CTO length ≥20 mm, and proximal cap ambiguity were the predictors of guidewire failure in the primary antegrade approach with antegrade alone, but were not those in the primary retrograde approach.

Conclusions

Although successful guidewire crossing time of the primary antegrade approach with the antegrade alone is short, that of the primary retrograde approach can be shorter than that of the primary antegrade approach with the retrograde approach. Choosing an appropriate CTO-PCI strategy leads to shortening of successful guidewire crossing time.

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 PlasmaWire^TM System to recanalize coronary chronic total occlusions (CTO) using controlled ablation inside the CTO.

BACKGROUND

The PlasmaWire^TM System is a new bipolar radiofrequency (RF) wire system utilizing plasma-mediated ablation to facilitate wire crossing in CTOs. Two independent PlasmaWire^TM 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 PlasmaWire^TM 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 PlasmaWire^TM wires and recanalization was achieved in all cases without any complication. The PlasmaWire^TM System may safely facilitate CTO recanalization with less vessel injury and improve initial results of CTO PCI while reducing procedure time.

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.

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.

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 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.

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.

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.

Colon tissue implanted into the glandular stomach in rats lack susceptibility to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) carcinogenesis

The present study was undertaken to determine the response of colon mucosa implanted into the fundus of stomach in 6-week old male F344 rats to oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Samples of colonic tissue about 8 mm in diameter were obtained from various colon sites and surgically implanted into the anterior wall of the fundus by isografting. MNNG was chronically administered at a concentration of 100 mg/l in the drinking water for 16 weeks starting 4 weeks after the operation and the grafted colon mucosa was examined at 12 months after the operation. Control rats received a sham-operation and the same amount of MNNG. In the MNNG administered groups, only one adenoma containing Paneth cells was noted in the implanted colon tissue whereas over 40% incidence of gastric tumors was observed in the pyloric mucosa. In the operated rats not given MNNG no gastric tumors were observed in either the grafted site or the pylorus.

Impact of frequency-domain optical coherence tomography guidance for optimal coronary stent implantation in comparison with intravascular ultrasound guidance

BACKGROUND

Frequency-domain optical coherence tomography (FD-OCT) is a novel, high resolution intravascular imaging modality. Intravascular ultrasound (IVUS) is a widely used conventional imaging modality for achieving optimal stent deployment. The aim of this study was to evaluate the impact of FD-OCT guidance for coronary stent implantation compared with IVUS guidance.

METHODS AND RESULTS

A total of 70 patients with de novo coronary artery lesions and either unstable or stable angina pectoris were enrolled in this randomized study (optical coherence tomography [OCT] group: n=35, IVUS group: n=35). In the OCT group, stent implantation was performed under FD-OCT guidance alone and final stent expansion was evaluated by IVUS. In the IVUS group, conventional IVUS guidance was used and final stent apposition was evaluated by FD-OCT. There were no significant differences regarding the procedural, fluoroscopy time, and contrast volume. Although device and clinical success rates also were similar, the visibility of vessel border was significantly lower in the OCT group (P<0.05). Minimum and mean stent area and focal and diffuse stent expansion were smaller (6.1±2.2 mm versus 7.1±2.1 mm, 7.5±2.5 versus 8.7±2.4 mm, 64.7±13.7% versus 80.3±13.4%, 84.2±15.8% versus 98.8±16.5%, P<0.05, respectively), and the frequency of significant residual reference segment stenosis at the proximal edge was higher in the OCT group (P<0.05). Incomplete apposed struts in both groups were similar (P=0.34).

CONCLUSIONS

FD-OCT guidance for stent implantation was associated with smaller stent expansion and more frequent significant residual reference segment stenosis compared with conventional IVUS guidance.

Association of coronary plaque composition and arterial remodelling: a optical coherence tomography study

BACKGROUND

Conflicting data have been reported about the association between plaque composition and remodelling index (RI). The aim of this study is to evaluate the relationship between plaque morphology obtained by optical coherence tomography (OCT) and arterial remodelling.

METHODS AND RESULTS

OCT and intravascular ultrasound imaging pull back was performed at corresponding sites on 94 lesions in 47 patients. OCT plaque characteristics for lipid content, fibrous cap thickness, thin-cap fibroatheroma (TCFA), plaque rupture, thrombus, calcification and erosion were derived using validated criteria. Compared with intermediate/negative remodelling (RI<1.0), positive remodelling (RI>1.0) was associated with presence of higher lipid pool (2.86 ± 0.42 vs. 2.20 ± 0.78; p<0.001), thin fibrous cap (47.86 ± 25.43 μm vs. 74.41 ± 32.41 μm; p<0.001), TCFA>3mm (82.1% vs. 22.7%; p<0.0001), plaque rupture and thrombus (42.8% vs. 19.7%; p = 0.024), and higher plaque burden (73.70 vs. 70.70; p = 0.048). No difference was observed in the presence of calcification and plaque erosions.

CONCLUSIONS

Coronary lesions with positive remodelling show higher incidences of vulnerable plaque and plaque rupture across the lesion length. This potentially explains the correlation between unstable coronary syndromes and positive remodelling.

A novel modification of the retrograde approach for the recanalization of chronic total occlusion of the coronary arteries intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking

OBJECTIVES

The study evaluates the feasibility and efficacy of the novel modification of the retrograde recanalization of the chronic total occlusion (CTO) of the coronary arteries by using intravascular ultrasound (IVUS)-guided reverse controlled antegrade and retrograde tracking (CART).

BACKGROUND

Despite improvement in the techniques and materials, CTO recanalization is still suboptimal. The CART procedure has improved success rates, but there are certain inherent technical uncertainties and risk with this procedure.

METHODS

This first series involves 31 patients, with 22 patients having previous failed attempts at CTO recanalization. All patients were treated with bilateral approach and using IVUS-guided reverse CART concept.

RESULTS

Successful recanalization of the CTO was achieved in all cases (100%). The access route was septal collateral in 20 (70%) cases and epicardial collateral in 11 (30%) cases. IVUS guidance was used successfully in 30 cases, and the channel dilator (microcatheter) was used in 27 cases. Guidewire injury and grade 1 perforation was seen in 3 (9%) cases, which were managed conservatively. There was no death, coronary artery bypass surgery, or pericardiocentesis in this group of patients. Mean fluoroscopy time was 65.84 +/- 23.16 min, ranging from 31 to 106 min and total contrast volume used 321.32 +/- 137.77 ml (range 115 to 650 ml).

CONCLUSIONS

This first series describes a high success rate of CTO recanalization with IVUS-guided reverse CART in selected patients performed by an experienced operator.

Difference of tissue characteristics between early and very late restenosis lesions after bare-metal stent implantation: an optical coherence tomography study

BACKGROUND

Although in-stent restenosis (ISR) after bare-metal stent (BMS) implantation peaks in the early phase, very late (VL) ISR occasionally is observed beyond a few years after BMS implantation. To date, this mechanism has not been fully clarified.

METHODS AND RESULTS

We compared the morphological characteristics of VL-ISR (>5 years, without restenosis within the first year) (n=43) to those of early (E) ISR (within the first year) (n=39) using optical coherence tomography (OCT). Qualitative restenotic tissue analysis included assessment of tissue structure (homogeneous or heterogeneous), presence of microvessels, disrupted intima with cavity, and intraluminal material and was performed at every 1-mm slice of the entire stent. The proportions of cross-sections with heterogeneous intima in the entire stent was significantly higher in the VL-ISR group compared to the E-ISR group (60.5±28.5% versus 5.8±11.5%, P<0.0001), with heterogeneous intima being more frequently observed at the minimum lumen area site in the VL-ISR group (90.7% versus 17.9%, P<0.0001). Disrupted intima with cavity and intraluminal material also were observed more frequently in the VL-ISR group for the entire stent (18.6% versus 0%, 20.9% versus 2.6%, P<0.03) as well as at the minimum lumen area site (13.9% versus 0%,16.2% versus 0%, P<0.03).

CONCLUSIONS

The morphological characteristics of restenotic tissue in VL-ISR were different from those in E-ISR and similar to atherosclerotic plaque. In BMS, progression of the atherosclerotic process within neointima after stent implantation may be associated with VL-ISR.

Comparison of in vivo assessment of vulnerable plaque by 64-slice multislice computed tomography versus optical coherence tomography

The aim of this study was to investigate the possibility of 64-slice multislice computed tomography (MSCT) to detect vulnerable plaque derived by optical coherence tomography. From September 2007 through December 2009, 122 lesions in 81 patients were evaluated by 64-slice MSCT and optical coherence tomography. Based on optical coherence tomographic findings, lesions were classified as thin-capped fibroatheroma (TCFA; n=37) and non-TCFA (n=85). Mean computed tomographic density value of the lesion was lower and remodeling index was larger in the TCFA group (44.9 ± 19.2 vs 78.7 ± 25.0 HU, p <0.0001; 1.14 ± 0.20 vs 0.95 ± 0.16, p<0.0001, respectively). Mean computed tomographic density value was correlated and remodeling index was inversely correlated with fibrous cap thickness (r=0.605, p<0.0001; r=-0.591, p<0.0001, respectively). Optimal threshold of mean computed tomographic value and remodeling index identified by receiver operating characteristic curve were 62.4 HU and 1.08 (area under the curve 0.859 and 0.781). Signet ringlike appearance was observed more frequently in the TCFA group (65% vs 16%, p<0.0001). In multivariate analysis, independent predictors of TCFA were mean computed tomographic density value ≤62.4 HU (odds ratio 8.20, 95% confidential interval 2.49 to 27.0, p=0.0005), remodeling index ≥1.08 (odds ratio 6.10, 95% confidential interval 2.04 to 18.2, p=0.0012), and signet ringlike appearance (odds ratio 6.33, 95% confidential interval 2.03 to 19.7, p=0.0014). In conclusion, based on comparisons with optical coherence tomographic findings, 64-slice MSCT may have the potential to detect vulnerable plaque.

Different patterns of vascular response between patients with or without diabetes mellitus after drug-eluting stent implantation: optical coherence tomographic analysis

OBJECTIVES

We performed this study to investigate with optical coherence tomography (OCT) the vascular response after sirolimus-eluting stent (SES) implantation between patients with and those without diabetes mellitus (DM).

BACKGROUND

The difference in vascular response after SES implantation between patients with and those without DM has not been fully evaluated with OCT.

METHODS

Optical coherence tomography was performed to examine 74 nonrestenotic SES implanted in 63 patients (32 with DM and 31 without DM) at 9 months after SES implantation. For struts showing neointimal coverage, the neointimal thickness on the luminal side of each strut section was measured, and neointimal characteristics were classified into high, low, and layered signal pattern.

RESULTS

Baseline patient characteristics and lesion and procedural characteristics data were similar between the 2 groups. In total, 11,422 struts were analyzed. High signal neointima was observed in 90.2 ± 13.9%, low signal neointima in 7.3 ± 10.0%, and layered neointima in 2.7 ± 5.8%/stents. There was higher incidence of low signal neointima (10.5 ± 10.3% vs. 4.5 ± 5.6%, p = 0.003), neointimal thickness was larger (median: 106.8 μm, interquartile range: 79.3 to 130.4 μm vs. median: 83.5 μm, interquartile range: 62.3 to 89.3 μm; p < 0.0001), and neointimal coverage of stent struts was higher (92.1 ± 6.2% vs. 87.2 ± 11.9%; p = 0.03) in DM patients.

CONCLUSIONS

High signal neointimal pattern was predominantly observed, and low or layered signal pattern was observed in some cases. In DM patients, low signal neointima was observed with high frequency. Neointimal coverage and neointimal thickness was also higher in DM patients as compared with non-DM patients.

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.

The dynamic nature of coronary artery lesion morphology assessed by serial virtual histology intravascular ultrasound tissue characterization

OBJECTIVES

We used virtual histology intravascular ultrasound (VH-IVUS) to investigate the natural history of coronary artery lesion morphology.

BACKGROUND

Plaque stability is related to its histological composition.

METHODS

We performed serial (baseline and 12-month follow-up) VH-IVUS studies and examined 216 nonculprit lesions (plaque burden >or=40%) in 99 patients. Lesions were classified into pathological intimal thickening (PIT), VH-IVUS-derived thin-capped fibroatheroma (VH-TCFA), thick-capped fibroatheroma (ThCFA), fibrotic plaque, and fibrocalcific plaque.

RESULTS

At baseline, 20 lesions were VH-TCFAs; during follow-up, 15 (75%) VH-TCFAs "healed," 13 became ThCFAs, 2 became fibrotic plaque, and 5 (25%) VH-TCFAs remained unchanged. Compared with VH-TCFAs that healed, VH-TCFAs that remained VH-TCFAs located more proximally (values are median [interquartile range]) (16 mm [15 to 18 mm] vs. 31 mm [22 to 47 mm], p = 0.013) and had larger lumen (9.1 mm(2) [8.2 to 10.7 mm(2)] vs. 6.9 mm(2) [6.0 to 8.2 mm(2)], p = 0.021), vessel (18.7 mm(2) [17.3 to 28.6 mm(2)] vs. 15.5 mm(2) [13.3 to 16.6 mm(2)]; p = 0.010), and plaque (9.7 mm(2) [9.6 to 15.7 mm(2)] vs. 8.4 mm(2) [7 to 9.7 mm(2)], p = 0.027) areas; however, baseline VH-IVUS plaque composition did not differ between VH-TCFAs that healed and VH-TCFAs that remained VH-TCFAs. Conversely, 12 new VH-TCFAs developed; 6 late-developing VH-TCFAs were PITs, and 6 were ThCFAs at baseline. In addition, plaque area at minimum lumen sites increased significantly in PITs (7.8 mm(2) [6.2 to 10.0 mm(2)] to 9.0 mm(2) [6.5 to 12.0 mm(2)], p < 0.001), VH-TCFAs (8.6 mm(2) [7.3 to 9.9 mm(2)] to 9.5 mm(2) [7.8 to 10.8 mm(2)], p = 0.024), and ThCFAs (8.6 mm(2) [6.8 to 10.2 mm(2)] to 8.8 mm(2) [7.1 to 11.4 mm(2)], p < 0.001) with a corresponding decrease lumen areas, but not in fibrous or fibrocalcific plaque.

CONCLUSIONS

Most VH-TCFAs healed during 12-month follow-up, whereas new VH-TCFAs also developed. PITs, VH-TCFAs, and ThCFAs showed significant plaque progression compared with fibrous and fibrocalcific plaque.

First clinical experience of "flower petal stenting": a novel technique for the treatment of coronary bifurcation lesions

OBJECTIVES

We sought to report the results of both bench-testing and our first clinical experience with this novel technique.

BACKGROUND

The optimal stenting technique for bifurcation lesions has yet to be defined.

METHODS

This technique works by flaring the proximal side of the stent in side branch out like a flower petal. We tested it in vitro and the resultant stent structure and stent polymer damage was observed in both main branch and side branch with an optical microscopy, multislice computer tomography, intravascular ultrasound, endoscopy, and by electron microscopy. We also applied this technique in 33 patients and assessed patient outcomes up to 9 months prospectively. Drug-eluting stents were used for the bench tests and for all patients.

RESULTS

Bench-testing showed complete coverage of the bifurcation with minimal stent-layer overlapping. There was little polymer damage by electron microscopy. Procedural success was achieved in all cases and restenosis occurred in 2 cases. In both restenosis cases, "petal" stenting technique was done reluctantly after another stent had already been deployed in the main branch before any stenting of the side branch. There were no incidences of restenosis when this technique was used electively.

CONCLUSIONS

In terms of damage to the polymer and ostial strut coverage, this new "flower petal stenting" technique is effective for treatment of bifurcation lesion and it may well be superior to other available techniques.

The efficacy of a bilateral approach for treating lesions with chronic total occlusions the CART (controlled antegrade and retrograde subintimal tracking) registry

OBJECTIVES

The aim of this study was to evaluate the safety and feasibility of a new concept for chronic total occlusion (CTO) recanalization-using a bilateral approach that utilizes a Controlled Antegrade and Retrograde subintimal Tracking (CART) technique.

BACKGROUND

Successful percutaneous recanalization of coronary CTOs results in improved long-term outcomes. The recanalization of CTOs in native coronary arteries no doubt represents one of the most technically challenging of interventional procedures.

METHODS

A total of 224 consecutive patients (mean age 61 +/- 9 years; 86.2% men) were enrolled in this prospective multicenter registry. This technique combines the simultaneous use of antegrade and retrograde approaches. A subintimal dissection is created in both antegrade and retrograde fashion, thereby limiting the extension of the subintimal dissection within the CTO portion.

RESULTS

Of 224 CTO lesions (>3 months in duration) undergoing attempted recanalization using the CART technique, 145 cases (64.7%) had undergone previous CTO recanalization attempts. The success rates of crossing in a retrograde fashion with a wire and a balloon were 87.9% and 79.9%, respectively. The overall technical and procedural success rates achieved in this registry were 92.4% and 90.6%, respectively.

CONCLUSIONS

A bilateral approach for CTO lesions using the CART technique is feasible, safe, and has a higher success rate than previous approaches. These results indicate that a bilateral technique can solve a major dilemma that commonly affects CTO procedures.

Accuracy and reproducibility of stent-strut thickness determined by optical coherence tomography

BACKGROUND

Optical coherence tomography (OCT) has been increasingly used to evaluate stent apposition following implantation. Since stent struts are visualized as linear structures with strong surface reflection and typical dorsal shadowing, apposition of struts is evaluated by measuring the distance between the strut surface reflection and adjacent vessel surface in consideration of strut thickness. However, there are no data available to validate the measurements of strut thickness by OCT. The aim of this in vitro study is to validate the accuracy of OCT measurement of stent-strut thickness of different commercially available stents in evaluating stent apposition.

METHODS

We performed the in vitro study after implantation of 5 commonly used stents in a phantom model artery. Stent-strut thickness was measured by a commercially available OCT system and was compared to the manufacturers' nominal strut-thickness data for each stent. Intra- and interobserver variability were also assessed.

RESULTS

A total of 239 stent struts were evaluated. The differences in stent-strut measurements as compared to the manufacturers' nominal strut thickness data were low. The intra- and interobserver measurement differences were low (6 +/- 7 microm, and 6 +/- 7 microm, respectively), with high correlation coefficients (r = 0.957 and r = 0.957, respectively; p < 0.0001).

CONCLUSIONS

This in vitro study demonstrates that OCT analysis measuring stent-strut thickness provides accurate data with high reproducibility, suggesting that assessment of stent-strut apposition using OCT is feasible.

Impact of multislice computed tomography to estimate difficulty in wire crossing in percutaneous coronary intervention for chronic total occlusion

BACKGROUND

Percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) remains a challenge. Multislice computed tomographic coronary angiography (CTCA) allows noninvasive evaluation of the coronary artery by visualizing vessel trajectory and morphological features at the occluded site. The aim of this study was to assess the value of CTCA to predict the success of guidewire crossing in PCI to treat CTOs.

METHODS

We performed CTCA in patients with CTOs (of > 3 months' duration); 110 lesions were scanned. Wiring success was defined as complete crossing of the guidewire past the occluded site. Correlation of the following morphological parameters with wiring success was analyzed: target vessel bending (defined as > 45 degrees), shrinkage, severe calcification, presence of side branches, stump morphology, in-stent occlusion and occlusion length.

RESULTS

Wiring success was obtained in 93 lesions (85%). In the unsuccessful group, bending, shrinkage and severe calcification were significantly higher compared to the successful group (76% vs. 18%, p < 0.0001; 29% vs. 4%, p = 0.0005; 41% vs. 18%, p = 0.0356, respectively). The wiring success rate was significantly lower in cases with bending, shrinkage and severe calcification (57% vs. 95%, p < 0.0001; 44% vs. 88%, p = 0.0005; 71% vs. 88%, p = 0.0356, respectively). Stump morphology, in-stent occlusion or occlusion length did not significantly affect the outcome. Multivariate analysis showed that bending, shrinkage and severe calcification remained significant independent predictors of wiring failure.

CONCLUSION

Bending, shrinkage and severe calcification are significant predictors for wiring success. CTCA provides a practical determinant of the outcomes in PCI to treat CTOs.

Predictors of angiographic restenosis after drug eluting stents in the coronary arteries: contemporary practice in real world patients

AIMS

Drug eluting stents (DES) have been used routinely in a wide variety of clinical situations. The impact of DES on reducing restenosis has not been uniform across complex subsets and limited data is available examining predictors of restenosis in unselected population.

METHODS AND RESULTS

We investigated predictors of angiographic restenosis in an unselected population. The study population consisted of 4,143 lesions and angiographic follow-up was available for 3,020 (73%) lesions in 1,885 patients. The intravascular ultrasound (IVUS) was used in 95% of the patients during the procedure. Angiographic restenosis was seen in 339 (11.2%) lesions and target lesion revascularisation was performed in 290 (9.6%) lesions. The patient population included large numbers of renal failure patients on haemodialysis, ISR, and Type C lesions with routine use of intravascular ultrasound. We identified diabetes mellitus, renal failure, Type C lesions, calcified lesion, tortuous lesion, ISR, long lesion, small baseline diameter and final vessel diameter as predictors of restenosis. On multivariate analysis diabetes (OR 1.45, 95% CI 1.07-1.97, p= 0.01), renal failure on haemodialysis (OR 2.02, 95% CI 1.37-3.27, p=0.001), ISR (OR 3.56, 95% CI 2.16-5.89, P<0.001), lesion length (OR 1.02, CI 1.01-1.03.P<0.001), reference vessel diameter (OR 0.50, 95% CI 0.31-0.80, p=0.005) and post-intervention IVUS lumen area (p<0.001) were independent predictors of angiographic restenosis. Female gender (OR 0.61, 95% CI 0.410.91, p=0.015) was found to have a negative correlation for ISR. We did not find any significant difference in restenosis between the usage of sirolimus and paclitaxel eluting stents.

CONCLUSIONS

DES usage was associated with overall low in-stent restenosis and we have identified several clinical, angiographic, and IVUS predictors of angiographic restenosis in unselected patients with complex anatomy.