Blunt Stump Research Articles

A weighted angiographic scoring model (W-CTO score) to predict success of antegrade wire crossing in chronic total occlusion: analysis from a single centre.

The aim of this study was to derive a weighted score model predicting success/failure of antegrade wire crossing in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Four hundred and four consecutive CTO cases (408 lesions) undergoing CTO-PCI between January 2009 and March 2015 were included. Data were divided into two sets, namely "derivation" and "validation", in a 70:30 ratio. The score was derived using multivariate analysis to identify independent predictors of wire crossing failure from the derivation set (n=285 lesions) and validated on the remaining 123 lesions (validation set). The overall procedural success rate was 83.6%. Independent predictors of CTO-PCI failure and their contribution to the weighted score were a blunt stump (beta coefficient 2.12), length of occlusion >20 mm (beta coefficient 1.71), presence of calcification (beta coefficient 0.72), presence of tortuosity (beta coefficient 1.06) and collateral with Rentrop grade <2 (beta coefficient 1.06). The respective scores allotted were +2.0, +1.5, +1, +1, +1 (total 6.5), rounding the coefficient to the nearest 0.5. Score values of 0-2, >2-4 and >4 were classified as low, intermediate and high levels of difficulty for CTO-PCI success and were associated with 98%, 74.2%, and 42.5% (p<0.0001), respectively, of antegrade wire crossing success in the derivation set. This was also validated on the validation set with CTO success in the three derived difficulty levels being 100%, 82.4% and 48.4%, respectively. Our weighted angiographic CTO score is a strong predictor of final antegrade wire crossing success and could be used in day-to-day clinical practice of CTO interventions.

Impact of Hemodialysis on Procedural Outcomes of Percutaneous Coronary Intervention for Chronic Total Occlusion: Insights From the Japanese Multicenter Registry.

BackgroundAmong patients treated with percutaneous coronary intervention for chronic total occlusion (CTO‐PCI), patients on long‐term hemodialysis are at significantly high risk for cardiovascular mortality and morbidity. However, clinical or angiographic predictors that might aid in better patient selection remain unclear. We aimed to assess the acute impact of hemodialysis in patients who underwent CTO‐PCI.Methods and ResultsThe Retrograde Summit registry is a multicenter, prospective registry of patients undergoing CTO‐PCI at 65 Japanese centers. Patient characteristics and procedural outcomes of 4749 patients were analyzed, according to the presence (n=313) or absence (n=4436) of baseline hemodialysis. A prediction model for technical failure among hemodialysis patients was also developed. The technical success rate of CTO‐PCI was significantly lower in hemodialysis than in nonhemodialysis patients (78.0% versus 89.1%, P<0.001). The rates of in‐hospital major adverse cardiac and cerebrovascular events were similar between the 2 groups (1.6% versus 0.9%, P=0.24). Irrespective of clinical/angiographic characteristics or previously developed scoring systems, hemodialysis independently predicted technical failure for CTO‐PCI. Among hemodialysis patients, predictors of technical failure were blunt stump (odds ratio 2.45, 95% confidence interval, 1.15–5.21, P=0.021), severe lesion calcification (odds ratio 2.50, 95% confidence interval, 1.19–5.24, P=0.015), and absence of diabetes mellitus (odds ratio 3.15, 95% confidence interval, 1.49–6.64, P=0.003). In hemodialysis patients without these predictors, the technical success rate was 96.2%.ConclusionsHemodialysis is significantly associated with technical failure. Contemporary CTO‐PCI seems feasible and safe in selected hemodialysis patients.

Towards a contemporary, comprehensive scoring system for determining technical outcomes of hybrid percutaneous chronic total occlusion treatment: The RECHARGE score.

This study sought to create a contemporary scoring tool to predict technical outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) from patients treated by hybrid operators with differing experience levels. Current scoring systems need regular updating to cope with the positive evolutions regarding materials, techniques, and outcomes, while at the same time being applicable for a broad range of operators. Clinical and angiographic characteristics from 880 CTO-PCIs included in the REgistry of CrossBoss and Hybrid procedures in FrAnce, the NetheRlands, BelGium and UnitEd Kingdom (RECHARGE) were analyzed by using a derivation and validation set (2:1 ratio). Variables significantly associated with technical failure in the multivariable analysis were incorporated in the score. Subsequently, the discriminatory capacity was assessed and the validation set was used to compare with the J-CTO score and PROGRESS scores. Technical success in the derivation and validation sets was 83% and 85%, respectively. Multivariate analysis identified six parameters associated with technical failure: blunt stump (beta coefficient (b)=1.014); calcification (b = 0.908); tortuosity ≥45° (b = 0.964); lesion length 20mm (b = 0.556); diseased distal landing zone (b = 0.794), and previous bypass graft on CTO vessel (b = 0.833). Score variables remained significant after bootstrapping. The RECHARGE score showed better discriminatory capacity in both sets (area-under-the-curve (AUC)=0.783 and 0.711), compared to the J-CTO (AUC = 0.676) and PROGRESS (AUC = 0.608) scores. The RECHARGE score is a novel, easy-to-use tool for assessing the risk for technical failure in hybrid CTO-PCI and has the potential to perform well for a broad community of operators. © 2017 Wiley Periodicals, Inc.

HOW TO SELECT CORONARY WIRE FOR ANTEGRADE RECANALIZATION OF CHRONIC TOTAL OCCLUSIONS

Aim. To define principles of coronary wire choice during coronary artery chronic total occlusion (CTO) recanalization by antegrade approach. Material and methods. From 2009 to 2013 the attempt of coronary artery CTO recanalization by antegrade approach was undertaken for 217 patients. Depending on success of CTO crossing by coronary wire patients were divided into 2 groups: group 1 (n=164) - successful wire crossing, group 2 (n=53) -unsuccessful attempt of CTO recanalization by coronary wire.Results. In the group 2 there were more frequent CTO localization in the right coronary artery (p&lt;0,05 as compared to group 1), presence of blunt stump, higher frequency of side branches in the zone of proximal CTO cup, and large CTO length (p&lt;0,001 as compared to group 1). CTO recanalization in 47% cases begun from soft wire with polymeric coating and tapered tip, successful recanalization by these wire type was achieved in 49,02% patients. Using non-tapered tip intermediate stiffness wire as the first choice wire was associated with the failure of recanalization (p=0,0440 in intergroup comparison). At impossibility of CTO recanalization by soft wire with polymeric coating and tapered tip used as a first choice, it replacement on non-tapered tip intermediate stiffness wire allowed to achieve successful recanalization in 36,67% patients. In the cases of this strategy uneffectiveness using stiff wire with polymeric coating and tapered tip as a third choice allowed additionally to attain successful recanalization in 60% cases. Replacement of the soft wire with polymeric coating and tapered tip on stiff wire with polymeric coating and tapered tip, executable at presence of meaningful rigidity in the proximal CTO cup zone associated with the achievement the successful recanalization in 60% cases.Conclusion. On the basis of the obtained data it was created the conception of step-up wire stiffness increase during the CTO recanalization by antegrade approach.

Predicting Successful Recanalization in Patients with Native Coronary Chronic Total Occlusion: The Busan CTO Score

Background: The optimal strategy to manage chronic total occlusion (CTO) remains unclear. The Japanese CTO multicenter registry (J-CTO) score is an established tool for predicting successful recanalization. However, it does not take into account nonangiographic predictors for final technique success. In the present study, we designed and tested a scoring model called the Busan single-center CTO registry (B-CTO) score combining clinical and angiographic characteristics to predict successful CTO recanalization in Korean patients. Methods: Prospectively enrolled CTO patients (n = 438) undergoing coronary intervention (1999-2015) were assessed. The B-CTO score comprises 6 independent predictors: age 60-74 years and lesion length ≥20 mm were assigned 1 point each, while age ≥75 years, female gender, lesion location in the right coronary artery, blunt stump, and bending >45° were assigned 2 points each. For each predictor, the points assigned were based on the associated odds ratio by multivariate analysis. The lesions were classified into 4 groups according to the summation of points scored to assess the probability of successful CTO recanalization: easy (score 0-1), intermediate (score 2-3), difficult (score 4-5), and very difficult (score ≥6). CTO opening was designated as the primary endpoint regardless of the interventional era or the skill of the operator. Results: The final success rate for B-CTO was 81.1%. The probability of successful recanalization for patient groups classified as easy (n = 64), intermediate (n = 148), difficult (n = 134), and very difficult (n = 92) was 95.3, 86.5, 79.1 and 65.2%, respectively (p for trend <0.001). When compared to the J-CTO, the B-CTO score demonstrated a significant improvement in discrimination as indicated by the area under the receiver-operator characteristic curve (AUC 0.083; 95% CI 0.025-0.141), with a positive integrated discrimination improvement of 0.042 and a net reclassification improvement of 56.0%. Conclusions: The B-CTO score has been designed and validated in Korean patients with native coronary CTO and is an improved tool for predicting successful recanalization. Wider application of the B-CTO score remains to be explored.

Predictors of Successful Chronic Total Occlusion Percutaneous Coronary Interventions: A Systematic Review and Meta-Analysis

Objective The aim of this study was to identify positive and negative predictors of technical and clinical success for percutaneous coronary intervention (PCI) of chronic total occlusions (CTO). Methods We conducted a systematic review and meta-analysis of studies published between 2000 and 2016 analysing rates of CTO PCI success with respect to demographic and angiographic characteristics. Crude ORs and 95% CIs for each predictor were calculated using a random effects model. Predictors of technical and clinical success were assessed among 28 demographic and 31 angiographic variables. Clinical success was defined as technical success without major adverse cardiac events. Results A total of 61 studies, totalling 69 886 patients were included in this analysis. The major demographic characteristics associated with a 20% or greater reduction in the odds of technical and clinical success were a history of myocardial infarction, PCI, coronary artery bypass grafting, stroke/transient ischaemic attack and peripheral vascular disease. Angiographic factors were generally stronger predictors of reduced technical and clinical success. Those associated with >20% odds reduction included non-left anterior descending CTOs, multivessel disease, presence of bridging collaterals, moderate-to-severe calcification, >45 degree vessel bending, tortuous vessel, blunt stump and ostial lesions. Of these, novel predictors included prior PCI, prior stroke, peripheral vascular disease, presence of multivessel disease and bridging collaterals. Conclusion The present study has identified strong negative predictors for clinical success for CTO PCI, which will aid in patient selection for this procedure.

Predictors of Excess Patient Radiation Exposure During Chronic Total Occlusion Coronary Intervention: Insights From a Contemporary Multicentre Registry

BackgroundHigh patient radiation dose during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) might lead to procedural failure and radiation skin injury. MethodsWe examined the association between several clinical and angiographic variables on patient air kerma (AK) radiation dose among 748 consecutive CTO PCIs performed at 9 experienced US centres between May 2012 and May 2015. ResultsThe mean age was 65 ± 10 years, 87% of patients were men, and 35% had previous coronary artery bypass graft surgery (CABG). Technical and procedural success was 92% and 90%, respectively. The median patient AK dose was 3.40 (interquartile range, 2.00-5.40) Gy and 34% of the patients received > 4.8 Gy (high radiation exposure). In univariable analysis male sex (P = 0.016), high body mass index (P < 0.001), history of hyperlipidemia (P = 0.023), previous CABG (P < 0.001), moderate or severe calcification (P < 0.001), tortuosity (P < 0.001), proximal cap ambiguity (P = 0.001), distal cap at a bifurcation (P = 0.006), longer CTO occlusion length (P < 0.001), blunt/no blunt stump (P < 0.001), and centre (P < 0.001) were associated with higher patient AK dose. In multivariable analysis high body mass index (P < 0.001), previous CABG (P = 0.005), moderate or severe calcification (P = 0.005), longer CTO occlusion length (P < 0.001), and centre (P < 0.001) were independently associated with higher patient AK dose. ConclusionsApproximately 1 in 3 patients who undergo CTO PCI receive high AK radiation dose (> 4.8 Gy). Several baseline clinical and angiographic characteristics can help predict the likelihood of high radiation dose and assist with intensifying efforts to reduce radiation exposure for the patient and the operator.

Impact of Crossing Strategy on Intermediate-term Outcomes After Chronic Total Occlusion Percutaneous Coronary Intervention

BackgroundThere is ongoing controversy about the optimal crossing strategy selection for chronic total occlusion (CTO) percutaneous coronary intervention (PCI), especially regarding the relative merits of antegrade dissection/re-entry and the retrograde approach. MethodsWe retrospectively examined the clinical outcomes of 173 consecutive patients who underwent successful CTO PCI at our institution between January 2012 and March 2015. ResultsThe mean age was 65 ± 8 years, and 98% of the patients were men with a high prevalence of diabetes (60%), previous coronary artery bypass grafting (CABG) (31%), and previous PCI (54%). The successful CTO crossing strategy was antegrade wire escalation in 79 patients (45.5%), antegrade dissection/re-entry in 58 patients (33.5%), retrograde wire escalation in 11 patients (6.4%), and retrograde dissection and re-entry in 25 patients (14.5%). The retrograde approach was more commonly used in lesions with interventional collaterals (P < 0.0001), moderate/severe calcification (P = 0.02), blunt stump (P = 0.01), and a higher Japan Chronic Total Occlusion score (P = 0.0002). Use of dissection and re-entry (both antegrade and retrograde) was associated with bifurcation and the distal cap (P = 0.004), longer CTO occlusion length (P < 0.0001), and longer stent length (P < 0.0001). Median follow-up was 11 months. The 12-month incidence of death, myocardial infarction, and the composite of acute coronary syndrome/target lesion revascularization/target vessel revascularization was 2.5%, 4.9%, and 24.4%, respectively, and was similar with intimal and subintimal crossing strategies. ConclusionsAntegrade dissection/re-entry and retrograde approaches are frequently used during CTO PCI and were associated with similarly favorable intermediate-term outcomes as antegrade wire escalation.

Which parameters are important before attempting chronic total occlusions recanalization?

Which parameters are important before attempting chronic total occlusions recanalization?

Intravascular Ultrasound Guided Percutaneous Coronary Intervention for Chronic Total Occlusion.

Chronic total occlusion (CTO), a fascinating and dynamic niche in the realm of coronary artery disease, represents a major technical challenge for interventional cardiologists despite evolution of better guidewires, devices, experience and techniques. Effective wiring technique is the corner stone to success of percutaneous coronary intervention (PCI) in CTO. As a guide for guidewire crossing in CTO, coronary angiography is limited. On the other hand, intravascular ultrasound (IVUS) enhances the ability to identify coronary anatomy, the exact location of the guidewires within an artery, discriminating a true lumen from the false lumen before guidewire crossing. Some angiographic features have been suggested to be predictive of procedural failure, including blunt stump with a side branch at the site of occlusion. Novel use of IVUS can recognize the optimal entry point and evaluate if a guidewire properly penetrates the proximal cap of CTO.

GW26-e1597 Intravascular ultrasound-guided wiring technique for stumpless chronic total occlusion

To evaluate safety and efficacy of IVUS -guided wiring technique for stumpless chronic total occlusion (CTO) lesions. 40 Patients with blunt and vague stump (stumpless) CTO lesions while could not determine the wire progress orientation, were selected in this study. The IVUS catheter was introduced

Procedural success of CTO recanalization: Comparison of the J-CTO score determined by coronary CT angiography to invasive angiography

ObjectivesThe J-CTO score is based on invasive angiography, combines several parameters of chronic total coronary occlusions (CTO), and is well established to predict the likelihood of success of percutaneous recanalization. The purpose of this study was to evaluate and validate a J-CTOCT score derived from coronary computed tomography angiography (coronary CTA). MethodsBetween April 2011 and December 2014, 159 consecutive patients were retrospectively included. All had at least one CTO in invasive angiography, had coronary CTA performed at an interval of no more than one week from invasive angiography, and had an attempt at percutaneous coronary intervention (PCI) following coronary CTA In parallel to the angiographic J-CTO score, the J-CTOCT score was determined by awarding one point each for a blunt vessel stump, bending > 45°, occlusion length ≥ 20 mm, presence of calcium covering > 50% of any vessel cross-section within the occlusion, or a previously failed attempt at PCI. a. Both scores were compared regarding their ability to predict successful recanalization. ResultsA total of 171 CTO lesions were analyzed. Intraobserver (k = 0.814, p < 0.001) and interobserver agreement (k = 0.771, p < 0.001) for calculation of the J-CTOCT score were close. The mean occlusion length measured by coronary CTA was significantly shorter than in invasive angiography (27.6 ± 14.8 mm vs. 37.2 ± 18.8 mm, p < 0.001). The J-CTOCT score (mean: 1.9 ± 1.4) correlated closely to the angiographic J-CTO score (mean: 1.8 ± 1.3, r = 0.856, p < 0.001), and in 122/171 lesions (71%), the scores were identical. Both J-CTOCT score (area under curve: 0.882, p < 0.001) and angiographic J-CTO score (area under curve: 0.868, p < 0.001) yielded similarly high predictive value for successful guidewire crossing within 30 min (p = 0.496). ConclusionsWhile the length of coronary occlusions in coronary CTA is significantly shorter than in invasive angiography, a J-CTOCT score determined by coronary CTA closely correlates to the angiographic J-CTO score. .

Procedural failure of chronic total occlusion percutaneous coronary intervention: Insights from a multicenter US registry.

The hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly increased procedural success rates, yet some cases still fail. We sought to evaluate the causes of failure in a contemporary CTO PCI registry. We examined 380 consecutive patients who underwent CTO-PCI at 4 high volume CTO PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, complication, and efficiency outcomes were compared between successful and failed cases. Failed cases were individually reviewed by an independent reviewer to determine the cause of failure. Procedural success was 91.3%. Compared with patients in whom CTO PCI was successful, those in whom CTO PCI failed had similar baseline clinical characteristics, but were more likely to have longer occlusion length, more tortuosity, more proximal cap ambiguity and blunt stump, and higher mean J-CTO scores (2.8 ± 1.1 vs. 3.5 ± 1.0, P < 0.001), and less likely to have collaterals suitable for the retrograde approach (66% vs. 45%, P = 0.021). Failure was due to a complication in 10 cases (30%). In the remaining 23 cases (70%) failure was due to inability to wire the lesion (n = 21, 4 of which were CTOs due to in-stent restenosis), or poor antegrade flow after PCI (n = 5). Compared with successful cases, failed CTO-PCI cases are more likely to have higher J-CTO scores, longer occlusion length, ambiguous proximal cap and no appropriate collaterals for retrograde crossing. Development of novel CTO crossing techniques is needed to further increase CTO PCI success rates.

Coronary computed tomographic prediction rule for time-efficient guidewire crossing through chronic total occlusion: insights from the CT-RECTOR multicenter registry (Computed Tomography Registry of Chronic Total Occlusion Revascularization).

This study sought to establish a coronary computed tomography angiography prediction rule for grading chronic total occlusion (CTO) difficulty for percutaneous coronary intervention (PCI). The uncertainty of procedural outcome remains the strongest barrier to PCI in CTO. Data from 4 centers involving 240 consecutive CTO lesions with pre-procedural coronary computed tomography angiography were analyzed. Successful guidewire (GW) crossing ≤30 min was set as an endpoint to eliminate operator bias. The CT-RECTOR (Computed Tomography Registry of Chronic Total Occlusion Revascularization) score was developed by assigning 1 point for each independent predictor, and then summing all points accrued. Continuous distribution of scores was used to stratify CTO into 4 difficulty groups: easy (score 0); intermediate (score 1); difficult (score 2); and very difficult (score ≥3). Discriminatory performance was tested by 10-fold cross-validation and compared with the angiographic J-CTO (Multicenter CTO Registry of Japan) score. Study endpoint was achieved in 55% of cases. Multivariable analysis yielded multiple occlusions, blunt stump, severe calcification, bending, duration of CTO ≥12 months, and previously failed PCI as independent predictors for GW crossing. The probability of successful GW crossing ≤30 min for each group (from easy to very difficult) was 95%, 88%, 57%, and 22%, respectively. Areas under receiver-operator characteristic curves for the CT-RECTOR and J-CTO scores were 0.83 and 0.71, respectively (p < 0.001). Both the original model fit and 10-fold cross-validation correctly classified 77.3% of lesions. The CT-RECTOR score represents a simple and accurate noninvasive tool for predicting time-efficient GW crossing that may aid in grading CTO difficulty before PCI. (Computed Tomography Angiography Prediction Score for Percutaneous Revascularization for Chronic Total Occlusions [CT-RECTOR]; NCT02022878).

Abstract 16117: Clinical and Angiographic Scoring System to Predict the Probability of Successful First Attempt PCI in Patients With Coronary Chronic Total Occlusion

Background: Coronary chronic total occlusion (CTO) remains the lesion subtype in which angioplasty has the lowest success rate. Although many independent predictors of final procedural success have been identified, no studies have yet analyzed their combined impact on final procedural outcome. In order to obtain a scoring model to predict final CTO-PCI success, we analyzed a population of patients who underwent a percutaneous coronary intervention for a chronic total occlusion (CTO-PCI) at our institution. Methods: We included 1,657 consecutive patients who underwent a first-attempt CTO-PCI at ICPS from January 2004 to December 2013. Clinical, angiographic procedural and technical characteristics were prospectively collected. A backword stepwise logistic regression including clinical and angiographic variables was used to create a multivariable model of independent predictors of CTO-PCI success. Independent variables were then scored. Results: Overall procedural success rate was 72.5%. The backward logistic regression model showed that two clinical variables: previous CABG (OR2.28, 95%CI1.53-3.4), previous MI (1.56, 95%CI 1.19-2.0) and four angiographic variables: severe lesion calcification (OR 2.95, 95%CI 2.08-4.2), longer CTOs (≥20 mm: OR 2.04, 95%CI 1.62-2.58), non LAD location (OR 1.58, 95%CI 1.21-2-06) and blunt stump morphology (OR 1.57, 95%CI 1.24-1.99) were independent predictors of CTO-PCI failure. The OR values of these variables were used to create the Clinical and Angiographic Scoring System (CL-SCORE). CL-Score values of 0, 1-3, &gt;3 and ≤5 and &gt;5 indentified subgroups at high (class 0), intermediate (class 1), low (class 2), very low (class 3) probability of CTO-PCI success (80.3%, 64.2%, 49.4 and 29% respectively; p&lt;0,0001) Figure 1. The probability of CTO-PCI failure increased significantly from class 0 to class 1 (19.7% to 35.8%, p&lt;0.0001), from class 1 to class 2 (35.8 to 50.6 p&lt;0.0001) and from class 2 to class 3 (50.6% to 81% p=0.001), respectively. Conclusion: This clinical and angiographic score strongly predicted the final CTO-PCI procedural outcome of our study population. Further studies are required to validate this model.

Intravascular ultrasound-guided chronic total occlusion wiring technique using 6 Fr catheters via bilateral transradial approach

A blunt stump-type entry of chronic total occlusion (CTO) is one of the most difficult morphologic features to overcome in percutaneous coronary intervention (PCI), which often requires the guidance of intravascular ultrasound (IVUS) to identify the entry point. However, real-time, IVUS-guided PCI usually requires an 8 Fr guiding catheter. In this report, we describe a successful PCI for blunt stump CTO using bi-radial, IVUS-guided CTO wiring technique. Two 6 Fr guiding catheters (one as an operating guidewire; second for IVUS imaging) were simultaneously inserted into the left coronary artery via bilateral radial arteries. This technique may be useful for CTO intervention.

Differences in the Clinical and Angiographic Characteristics of Chronic Total Occlusion Lesions in the Three Major Coronary Arteries

The purpose of this study was to evaluate the differences in the clinical and angiographic characteristics of chronic total occlusion (CTO) lesions among the 3 major coronary arteries (LAD, LCx, and RCA). The success rate of percutaneous coronary intervention (PCI) of CTO lesions is not uniform among the 3 major coronary arteries and this may be influenced by the differences in angiographic and clinical characteristics that may exists between them. We retrospectively evaluated clinical and angiographic characteristics of patients who underwent PCI of CTO lesions at our 2 centers between 2003 and 2010. We analyzed 708 CTO-PCI procedures between 2003 and 2010. The CTO lesions were located in LAD: 222 (31.4%), LCx: 167 (23.6%), and RCA: 319 (45.0%). Patients with CTO in LAD had lower incidence of previous history of PCI and CABG compared to those with CTO lesions in LCx or RCA. In regard to angiographic findings, LAD lesions tended to have more side branches and blunt occlusion stump. The LCx lesions presented more frequently as a part of multivessel disease. RCA lesions were significantly longer, more severely angulated, and calcified. Good collateral circulations were more often encountered in the RCA. In regard to success rates, RCA showed lower procedural success rates (71.8%) followed by LAD (74.8%) and LCx (79.0%). There were several differences in the clinical and angiographic characteristics of CTO lesions among the 3 major coronary arteries. These differences can explain the discrepancy in procedure success rates.

Impact of negative lesion characteristics of chronic total occlusions on procedural outcome and strategy

Objective In the past, certain lesion characteristics of chronic total occlusions (CTOs) have been shown to have an infl uence on guidewire crossing and thus percutaneous coronary interventional outcome. However, a clear description of the individual impact of these characteristics on procedural outcome, procedural characteristics and treatment strategy is lacking. The purpose of this study was to give a “weight” to these individual characteristics and evaluate their infl uence on interventional strategy.Methods Between November 2011 and May 2013, a non-randomized, prospective study was conducted in the hospitals of Genk and Aalst, leading to the inclusion of 132 consecutive patients. Lesions were classifi ed according to the J-CTO (Multicenter CTO Registry of Japan) score (Morino et al., 2011). Both antegrade and retrograde procedures were performed. For antegrade procedures, a step-up strategy was applied. Univariate and multivariate analyses were performed and compared with the results of Morino et al. The study end point was general procedural success, defi ned as successful stenting with thrombosis in myocardial infarction 3 fl ow.Results Overall procedural success was achieved in 74% and according to J-CTO criteria, in 92% (easy), 82% (intermediate), 77% (difficult) and 40% (very difficult), respectively. Independent predictors included bending, blunt stump, multivessel PCI and a retrograde approach with corresponding odds ratios for failure of 5.3, 2.7, 2.8 and 4.0, respectively.Conclusion Lesion characteristics of CTOs remain important in the prediction of success. In this study, bending and a blunt stump at the entry site came forth as the most important independent predictors of failure.

A thirty-four-year-old chronic total occlusion successfully treated by percutaneous coronary intervention

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) represents a major challenge for interventional cardiology. CTOs are identified in up to 30% of patients with significant coronary disease on angiography and represent only 10–15% of cases treated by PCI, with the majority of patients being treated medically or referred for surgery [ [1] Stone G.W. Kandzary D.E. Mehran R. et al. Percutaneous recanalization of chronically occluded coronary artery: a consensus document: part I. Circulation. 2005; 112: 2364-2372 Crossref PubMed Scopus (456) Google Scholar ]. This may be explained considering the lower procedural success achieved in these lesions in comparison with non-occluded lesions [ [2] Stone G.W. Rutherford B.D. Mc-Conahay D.R. et al. Procedure outcome of angioplasty for total coronary occlusion: an analysis of 971 lesions in 905 patients. J Am Coll Cardiol. 1990; 15: 849-856 Abstract Full Text PDF PubMed Scopus (212) Google Scholar ]. The major reason for procedural failure is represented by the inability to cross the occlusion, with a guidewire or a balloon [ 2 Stone G.W. Rutherford B.D. Mc-Conahay D.R. et al. Procedure outcome of angioplasty for total coronary occlusion: an analysis of 971 lesions in 905 patients. J Am Coll Cardiol. 1990; 15: 849-856 Abstract Full Text PDF PubMed Scopus (212) Google Scholar , 3 Stone G.W. Colombo A. Teirstein P.S. et al. Percutaneous recanalization of chronically occluded coronary arteries: procedural techniques, devices, and results. Catheter Cardiovasc Interv. 2005; 66: 217-236 Crossref PubMed Scopus (127) Google Scholar ]. A number of predictors of procedural success have been reported in the literature. It is accepted that a blunt occlusion stump, heavy calcification, proximity to a side branch, presence of bridging collaterals and longer occlusions, all impact unfavorably on the likelihood of procedural success [ [4] Kinoshita I. Katoh O. Nariyama J. et al. Coronary angioplasty of chronic total occlusions with bridging collateral vessels: immediate and follow-up outcome from a large single-center experience. J Am Coll Cardiol. 1995; 26: 409-415 Abstract Full Text PDF PubMed Scopus (154) Google Scholar ]. In addiction previous studies have reported that long occlusion duration may also be associated with procedural failure [ 5 Kereiakes D.J. Selmon M.R. McAuley D.B. et al. Angioplasty in total coronary artery occlusion: experience in 76 consecutive patients. J Am Coll Cardiol. 1985; 6: 526-533 Abstract Full Text PDF PubMed Scopus (140) Google Scholar , 6 Melchoir J.P. Meire B. Urban P. et al. Percutaneous transluminal coronary angioplasty for chronic total occlusion. Am J Cardiol. 1987; 59: 535-538 Abstract Full Text PDF PubMed Scopus (149) Google Scholar ]. It was supposed that this issue was related to the increase lesion organization with deposition of fibrous tissue and severe calcifications, which occur in the course of time. Furthermore aging of occlusion may determine a change in plaque composition with an increase of frequency and severity of plaque calcification [ [7] Suzuki T. Hosokawa H. Yokoya K. et al. Time-dependent morphologic characteristics in angiographic chronic total coronary occlusions. Am J Cardiol. 2001; 88: 167-169 Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar ]. A study of Barlis et al. underlined how indetermination of occlusion duration (IOD) could play a role in prediction of procedural failure and cardiac adverse events [ [8] Barlis P. Kaplan S. Dimopoulos K. et al. An indeterminate occlusion duration predicts procedural failure in the recanalization of coronary chronic total occlusions. Catheter Cardiovasc Interv. 2008; 71: 621-628 Crossref PubMed Scopus (23) Google Scholar ]. However Tomasello et al. have recently showed that IOD and long duration of CTO do not affect procedural and clinical outcome of patients who underwent CTO PCI [ [9] Tomasello S.D. Costanzo L. Campisano M.B. et al. J Interv Cardiol. 2011; 24: 223-231 Crossref PubMed Scopus (14) Google Scholar ].

Percutaneous Coronary Intervention for Intra-stent Chronic Total Occlusion Assisted by Stent Visualization Enhancement Technology

A 50-year-old female patient with a history of prior acute inferior myocardial infarction successfully treated 2 years earlier by primary percutaneous coronary intervention (PCI) with thrombus aspiration and implantation of a 3x30 mm bare-metal stent in the proximal right coronary artery (RCA) was submitted to coronary angiography after reappearance of effort angina. An initial coronary angiogram showed a chronic total occlusion (CTO) intra-stent with Rentrop III collateral filling of the RCA originating from distal left anterior descending (LAD). A mid LAD 60% stenosis and a 60% mid circumflex stenosis were considered non-significant since fractional flow reserve (FFR) was measured at 0.84 and 0.90 respectively. After demonstrating inferior wall viability by cardiac magnetic resonance imaging (MRI), a PCI was programmed two months after the initial coronary angiogram. The intra-stent CTO was ≥ 30 mm long, with no blunt stump and at least 2 small branches originating at its proximal cap level. Mid and distal RCA antegrade filling existed due to bridging collaterals. The crossing technique by guidewire exchange and use of a microcatheter is described. After balloon predilatation the RCA was recanalized. The use of a stent visualization enhancement technology (StentViz) helped understand the most probable procedure-related restenosis mechanisms (stent undersizing and underexpansion) and guided the subsequent successful implantation of two drug-eluting stents. The use of this technology is described step by step for this intervention.