Proximal Cap Research Articles

Chronic Total Occlusion Interventions: Update on Current Tips and Tricks.

To summarize novel techniques and developments in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Using an algorithmic, step-by-step approach can help overcome several complex CTO lesions subsets, such as proximal cap ambiguity, ostial location, in-stent occlusion, bifurcations, balloon uncrossable and undilatable lesions. Similarly, an algorithmic approach can help prevent and optimally treat CTO PCI-related complication, such as perforation, radiation, and contrast-induced nephropathy. Continual update and reassessment of each operator's algorithm for performing CTO PCI can lead to improved outcomes.

Intravascular Imaging for Chronic Total Occlusion Intervention

We sought to summarize the current evidence on use of intravascular imaging (with intravascular ultrasound [IVUS] or optical coherence tomography [OCT]) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Utilization of intravascular imaging in CTO PCI is increasing over time, both to facilitate CTO crossing and for optimization of the final result. OCT is used less often than IVUS due to its lower depth of penetration and need for contrast injection. Intravascular imaging has multiple uses in CTO PCI: (a) it can facilitate CTO crossing by resolving proximal cap ambiguity and facilitating and confirming true lumen wire re-entry in case of initial subintimal wire crossing in both the antegrade and retrograde direction (for example by selecting the appropriate balloon size during the reverse controlled antegrade and retrograde tracking (reverse CART) technique; (b) it can be used to optimize the PCI result by ensuring good stent expansion and stent strut apposition, which may in turn result in lower rates of subsequent in-stent restenosis and stent thrombosis; (c) can facilitate evaluation and treatment of complications.

Retrograde algorithm for chronic total occlusion from the Asia Pacific Chronic Total Occlusion club.

Retrograde CTO PCI is an effective method to improve the success rate of CTO PCI. Despite several comprehensive and detailed descriptive papers on the retrograde techniques, retrograde CTO PCI remains difficult for many interventionists. We, the Asia Pacific CTO club, propose a new retrograde CTO PCI algorithm, which focuses on three specific problems in the retrograde approach. First, how to overcome the tough proximal cap. Then, how to cross the collateral channels safely and efficiently. Finally, how to cross the CTO and, in particular, the problems of reverse CART. We explain our new philosophy of contemporary reverse CART. We hope that this algorithm will provide the tools for operators to overcome the difficulties of retrograde CTO PCI and that it will become a platform for discussion, training, and proctoring for the retrograde approach.

Procedural, Functional and Prognostic Outcomes Following Recanalization of Coronary Chronic Total Occlusions. Results of the Iberian Registry

Introduction and objectivesThere is current controversy regarding the benefits of percutaneous recanalization (PCI) of chronic total coronary occlusions (CTO). Our aim was to determine acute and follow-up outcomes in our setting. MethodsTwo-year prospective registry of consecutive patients undergoing PCI of CTO in 24 centers. ResultsA total of 1000 PCIs of CTO were performed in 952 patients. Most were symptomatic (81.5%), with chronic ischemic heart disease (59.2%). Previous recanalization attempts had been made in 15%. The mean SYNTAX score was 19.5 ± 10.6 and J-score was > 2 in 17.3%. A retrograde procedure was performed in 92 patients (9.2%). The success rate was 74.9% and was higher in patients without previous attempts (82.2% vs 75.2%; P = .001), those with a J-score ≤ 2 (80.5% vs 69.5%; P = .002), and in intravascular ultrasound-guided PCI (89.9% vs 76.2%, P = .001), which was an independent predictor of success. In contrast, severe calcification, length > 20mm, and blunt proximal cap were independent predictors of failed recanalization. The rate of procedural complications was 7.1%, including perforation (3%), myocardial infarction (1.3%), and death (0.5%). At 1-year of follow-up, 88.2% of successfully revascularized patients showed clinical improvement (vs 34.8%, P < .001), which was associated with lower mortality. At 1-year of follow-up, the mortality rate was 1.5%. ConclusionsCompared with other national registries, patients in the Iberian registry undergoing PCI of a CTO showed similar complexity, success rate, and complications. Successful recanalization was strongly associated with functional improvement, which was related to lower mortality.

Resultados inmediatos e impacto funcional y pronóstico tras la recanalización de oclusiones coronarias crónicas. Resultados del Registro Ibérico

Introduction and objectivesThere is current controversy regarding the benefits of percutaneous recanalization (PCI) of chronic total coronary occlusions (CTO). Our aim was to determine acute and follow-up outcomes in our setting. MethodsTwo-year prospective registry of consecutive patients undergoing PCI of CTO in 24 centers. ResultsA total of 1000 PCIs of CTO were performed in 952 patients. Most were symptomatic (81.5%), with chronic ischemic heart disease (59.2%). Previous recanalization attempts had been made in 15%. The mean SYNTAX score was 19.5 ± 10.6 and J-score was > 2 in 17.3%. A retrograde procedure was performed in 92 patients (9.2%). The success rate was 74.9% and was higher in patients without previous attempts (82.2% vs 75.2%; P = .001), those with a J-score ≤ 2 (80.5% vs 69.5%; P = .002), and in intravascular ultrasound-guided PCI (89.9% vs 76.2%, P = .001), which was an independent predictor of success. In contrast, severe calcification, length > 20mm, and blunt proximal cap were independent predictors of failed recanalization. The rate of procedural complications was 7.1%, including perforation (3%), myocardial infarction (1.3%), and death (0.5%). At 1-year of follow-up, 88.2% of successfully revascularized patients showed clinical improvement (vs 34.8%, P < .001), which was associated with lower mortality. At 1-year of follow-up, the mortality rate was 1.5%. ConclusionsCompared with other national registries, patients in the Iberian registry undergoing PCI of a CTO showed similar complexity, success rate, and complications. Successful recanalization was strongly associated with functional improvement, which was related to lower mortality.Full English text available from: www.revespcardiol.org/en

PP-441 - Unseen Part of the Iceberg Before Obesity Surgery: Multivessel Coronary Artery Disease

Case report: 47 years old man evaluated for class II exertional dsypnea before obesity surgery as an outpatient. He had a history of hyperlipidemia and smoking with 30 packs a year. Physical examination revealed obesity (body mass index 36.2 kg/m2, 120 kg, 1.82 cm). Electrocardiography demonstrated sinus rhythm, and left anterior hemiblock. Echocardiography demonstrated normal systolic function, and mild mitral regurgitation. Due to the exertional dyspnea, he underwent myocardial perfusion scintigraphy which is showed myocardial ischemia of inferior and anterior myocardial wall. The coronary angiography showed severe stenosis of proximal left anterior descending and circumflex coronary artery. The retrograd collaterals from left coronary system to right coronary artery and total occlusion and antegrad bridge collaterals at proximal right coronary artery were also demonstrated in left and right coronary angiography. Coronary bypass surgery recommended for the complete revascularization but the patient didn't accept the surgery. First, the opening of the chronic total occlusion of right coronary artery, and then left coronary system were planned. 7F JR4 guiding, and 6F JL4 diagnostic catheters used for dual injection. The conus branch was use to anchor with 1,5 × 15 mm semi-compliant balloon. Gaia-3 guidewire was used to advance proximal cap under back-up with Corsair microcatheter and using drilling technique. By using Gaia 3 guidewire we weren't able to enter from distal cap to true lumen. Therefore, microcatheter changed to Twinpass microcatheter and the Fielder FC was used to enter acute margine branch or distal right coronary artery. Fielder FC was penetrated into the acute margine branch, and distal cap was punctured with the Conquest Pro through the side hole of the Twinpass microcatheter by advancing wire into the distal right coronary artery. By using TRAP technique, Twinpass microcatheter was removed and Corsair microcatheter was advanced into distal right coronary artery to protect coronary perforation by Conquest Pro manipulation. Grand Slam guidewire was advanced through Corsair microcatheter. After removing Corsair microcatheter by TRAP technique, multiple balloon dilatations were performed. 3.0 × 48 mm Xience Pro and 3.0 × 38 mm Cre8 DES were implanted mid-distal right coronary artery while 3.5 × 23 mm Xience Pro was implanted proximally. Multiple post-dilatations were performed with 3.5 × 18 mm non-compliant balloon and TIMI III flow was achieved. The revascularization of left coronary system was planned for two weeks later. Firstful, 4.0 × 26 mm Resolute stent was succesfully implanted to circumflex coronary artery. At the same procedure, 4.0 × 38 mm Resolute stent was succesfully implanted to the left anterior descending coronary artery. Control coronary angiography of the right coronary artery also showed that TIMI III flow with no evidence of thrombosis or stenosis. He discharged with the advice of the lifestyle changes, quit smoking, and weight lost. The obesity surgery was postponed until the 6 months from the procedure for reducing stent thrombosis risk.

Chronic Total Occlusion Crossing Approach Based on Plaque Cap Morphology: The CTOP Classification

Purpose: To present the chronic total occlusion (CTO) crossing approach based on plaque cap morphology (CTOP) classification system and assess its ability to predict successful lesion crossing. Methods: A retrospective analysis was conducted of imaging and procedure data from 114 consecutive symptomatic patients (mean age 69±11 years; 84 men) with claudication (Rutherford category 3) or critical limb ischemia (Rutherford category 4–6) who underwent endovascular interventions for 142 CTOs. CTO cap morphology was determined from a review of angiography and duplex ultrasonography and classified into 4 types (I, II, III, or IV) based on the concave or convex shape of the proximal and distal caps. Results: Statistically significant differences among groups were found in patients with rest pain, lesion length, and severe calcification. CTOP type II CTOs were most common and type III lesions the least common. Type I CTOs were most likely to be crossed antegrade and had a lower incidence of severe calcification. Type IV lesions were more likely to be crossed retrograde from a tibiopedal approach. CTOP type IV was least likely to be crossed in an antegrade fashion. Access conversion, or need for an alternate access, was commonly seen in types II, III, and IV lesions. Distinctive predictors of access conversion were CTO types II and III, lesion length, and severe calcification. Conclusion: CTOP type I lesions were easiest to cross in antegrade fashion and type IV the most difficult. Lesion length >10 cm, severe calcification, and CTO types II, III, and IV benefited from the addition of retrograde tibiopedal access.

RESIDUAL MICROBIOLOGICAL CONTAMINATION OF DIGESTIVE ENDOSCOPES IN GASTROENTEROLOGICAL UNITS AT THE UNIVERSITY HOSPITAL CENTERS OF TLEMCEN, MAGHNIA AND GHAZAOUAT, ALGERIA

Abstract Background: Digestive endoscopy remains a medical examination which can be at the origin of nosocomial infections. During a gastro-intestinal endoscopy, the device crosses natural cavities always with commensal bacterial flora and sometimes pathogenic flora. In all cases, the device is contaminated after the examination. The lack of effective disinfection exposes the risk of transmission of germs. Aim: The objective of this study is to test the effectiveness of the disinfection procedure for endoscopes. This will be done by evaluation of residual microbiological contamination after disinfection and after storage of endoscopes in gastroenterological units of the UHCs of Tlemcen, Maghnia and Ghazaouat Methods: The samples concerned all endoscope services. It was undertaken in two phases: the injection of a stall in the channels of the endoscope, and a swab of the distal and proximal end caps. Results: We have isolated and identified more than 60 microorganisms with nosocomial risk and their ability to form biofilm was proved. Conclusion: Respecting basic principles of hospital hygiene and application of rigorous cleaning and disinfecting processes are major elements in preventing and fighting infections related to endoscopy.

TCT-681 Retrograde popliteal access interventions for chronic total superficial femoral artery occlusions

Vascular intervention of superficial femoral artery (SFA) chronic total occlusions (CTO) is sometimes unsuccessful when the CTO cannot be crossed antegradely via contralateral or ipsilateral femoral approach because the proximal CTO cap is fibrocalcific or a CTO “nubbin” is absent. We performed

Accuracy of J-CTO Score Derived From Computed Tomography Versus Angiography to Predict Successful Percutaneous Coronary Intervention

ObjectivesThe aim of this study was to compare the ability of conventional versus computed tomography angiography (CTA) to predict procedural success and 30-min wire crossing rates in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions. BackgroundCoronary CTA can be used to assess the morphology of CTO lesions. MethodsWe examined 205 consecutive patients (218 CTO lesions) who underwent coronary CTA pre-PCI. The J-CTO (Multicenter CTO Registry of Japan) score (the sum of the following 5 binary parameters: blunt proximal cap, calcification, bending >45°, and length of occluded segment >20 mm plus previously failed PCI attempt) was calculated using both CTA and conventional coronary angiography and compared. ResultsThe median patient age was 69 years (interquartile range: 62 to 75 years), 82.4% were male, and a retrograde approach was attempted in 72 (33.0%) cases. The procedural success rate of the CTO-PCI procedures was 82.6%, and 29.4% of cases achieved 30-min wire crossing. The areas under the curve of the CTA-derived J-CTO score for predicting procedural success and 30-min wire crossing were significantly greater than those derived from conventional angiography (0.855 vs. 0.698; p < 0.001 for procedural success and 0.812 vs. 0.692; p < 0.001, for 30-min wire crossing). In addition, the areas under the curve of CTA-derived evaluations of calcification, bending, and occlusion length were significantly higher than those of derived from angiography for predicting procedural success. ConclusionsThe CTA-derived J-CTO score was a more useful predictor of both procedural success and 30-min wire crossing than the J-CTO score derived from conventional angiography.

Predictors of Successful Hybrid-Approach Chronic Total Coronary Artery Occlusion Stenting: An Improved Model With Novel Correlates

ObjectivesThe aim of this study was to develop a hybrid approach–specific model to predict chronic total coronary artery occlusion (CTO) percutaneous coronary intervention success, useful for experienced but not ultra-high-volume operators. BackgroundCTO percutaneous coronary intervention success rates vary widely and have improved with the “hybrid approach,” but current predictive models for success have major limitations. MethodsData were obtained from consecutively attempted patients from 7 clinical sites (9 operators, mean annual CTO volume 61 ± 17 cases). Angiographic analysis of 21 lesion variables was performed centrally. Statistical modeling was performed on a randomly designated training group and tested in a separate validation cohort. The primary outcome of interest was technical success. ResultsA total of 436 patients (456 lesions) met entry criteria. Twenty-five percent of lesions had prior failed percutaneous coronary interventions at the site. The right coronary artery was the most common location (56.4%), and mean occlusion length was 24 ± 20 mm. The initial approach was most often antegrade wire escalation (70%), followed by retrograde (22%). Success was achieved in 79.4%. Failure was most closely correlated with presence of an ambiguous proximal cap, and in the presence of an ambiguous proximal cap, specifically defined collateral score (combination of Werner and tortuosity scores) and retrograde tortuosity. Without an ambiguous proximal cap, poor distal target, occlusion length >10 mm, ostial location, and 1 operator variable contributed. Prior failure, and Werner and tortuosity scores alone, were only weakly correlated with outcomes. The basic 7-item model predicted success, with C statistics of 0.753 in the training cohort and 0.738 in the validation cohort, the later superior (p < 0.05) to that of the J-CTO (Multicenter CTO Registry of Japan) (0.55) and PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) (0.61) scores. ConclusionsSuccess can be reasonably well predicted, but that prediction requires modification and combination of angiographic variables. Differences in operator skill sets may make it challenging to create a powerful, generalizable, predictive tool.

Impact of Calcium on Chronic Total Occlusion Percutaneous Coronary Interventions

We sought to examine the impact of calcific deposits on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The outcomes of 1,476 consecutive CTO PCIs performed in 1,453 patients (65.5 ± 10years, 85% male) between 2012 and 2016 at 11 US centers were evaluated. Moderate or severe quantity of calcium was present in 58% of target lesions. Calcified lesions were more tortuous and more likely to have proximal cap ambiguity and interventional collaterals. PCI of moderately/severely calcified CTOs more often required use of the retrograde approach (54% vs 30%, p <0.001) and was associated with longer procedure and fluoroscopy time and higher air kerma radiation dose and contrast volume. Moderate/severe quantity of calcium was associated with lower technical (86.6% vs 93.8%, p <0.001) and procedural (84.4% vs 92.7%, p <0.001) success rates and higher incidence of major adverse cardiac events (3.7% vs 1.8%, p=0.033). On multivariate analysis, the presence of moderate/severe quantity of calcium was not independently associated with technical success. Balloon angioplasty was the most common lesion preparation technique for calcified lesions, followed by rotational atherectomy and laser. To conclude, in a contemporary, multicenter registry, moderate/severe calcific deposits were present in 58% of attempted CTO lesions and were associated with higher use of the retrograde approach, lower success, and higher complication rates. However, on multivariable analysis, the amount of calcium was not independently associated with technical success.

Predictors of procedural success and improvement of left ventricular ejection fraction after successful recanalization of coronary chronic total occlusion (CTO)

ObjectivesThis study sought to examine the pre-interventional parameters for procedural success of CTO angioplasty and to assess improvement of Left ventricular ejection fraction after successful angioplasty of CTO. BackgroundChronic total occlusions (CTOs) are the most technically challenging lesion subset that interventional cardiologists might face, and that recanalization of these lesions will have the most impact on future percutaneous coronary interventions (PCI) success. Considering the recent development of catheter based technologies specific for CTO recanalization and the potential of drug-eluting stents, these lesions are now recognized as the last barrier to percutaneous revascularization success. Methods30 patients with CTO lesion(s) and evidence of viable myocardium underwent PCI in Kobry Elkobba hospital. We studied the effect of demographic data, angiographic data as lesion length, stump and proximal cap, calcification, angulation, bridging collaterals and distal cap and finally echocardiography pre and 3months post procedural. ResultsProcedural success was obtained in 25 patients (83.3%), 19 of them was antegrade and 6 was retrograde. There was no significant effect of different demographic data on the outcome, but angiographic criteria favoring success was tapered proximal cap, short lesions <15mm, lesion angle <45 degree and no origin of side branch at the CTO segment. Stiff wires had the greatest chance to cross the CTO lesions, with the help of microcatheter. Rotablator was used to overcome heavily calcified plaques; IVUS was used to study the effect of plaque composition on the success of the procedure. There was significant reduction in LVIDd & LVIDs and highly significant increase in LVEF after successful recanalization of CTO. ConclusionPCI for CTO lesions has achieved a better chance for success especially with modern facilities, but we should revise criteria of success and failure as this success has a considerable effect on LV function and patient outcome.

The first clinical experience with a novel "locking" microcatheter in chronic coronary total occlusions.

A novel "locking" microcatheter has been developed to address residual failure modes in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The aim of this study was to report the first clinical experience of this device. The microcatheter was assessed prospectively in 92 unselected CTO cases across six European sites. Overall technical success was 85.9% (79/92) and 97.5% for patients with a J-CTO score of <3 (39/40). Within-CTO tortuosity was the only lesion characteristic to predict reduced technical success (OR 0.10 [0.01-0.97], p=0.047). Calcification (OR 0.45 [0.04-5.31], p=0.53), lesion length >20 mm (OR 0.58 [0.05-6.81], p=0.66) and a blunt proximal cap (OR 0.47 [0.08-2.90], p=0.42) were not associated with technical failure in this case series. Locking facilitated guidewire crossing (after initial failure) of the proximal cap in 23 cases, distal cap in 11 cases and CTO body in 10 cases, and delivery of the microcatheter through to the distal vessel in 22 cases. The overall procedural complication rate was 1.1% (1/92) with no major events. Guidewire locking with this novel microcatheter assists penetration and crossing of fibrocalcific anatomy with a high degree of safety. Using this device in CTO PCI may lead to improved primary wiring and overall procedural success rates.

Wire escalation in emergent revascularization procedures of internal carotid artery occlusions: the use of high tip stiffness microguidewires

ObjectiveWe examined the usefulness and safety of high tip stiffness cardiac microguidewires in the endovascular revascularization of selected cases of internal carotid artery (ICA) occlusion.MethodsFiles of patients with acute ischemic...

Approach to CTO Intervention: Overview of Techniques.

Successful percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has been associated with significant clinical benefits, but remains technically demanding. Failure to cross the CTO with a guidewire is the most common cause of CTO PCI failure. CTO crossing can be achieved in the antegrade or retrograde direction and can be accomplished by maintaining true lumen position throughout or via subintimal dissection/reentry techniques. A procedural plan should be created prior to the procedure through careful angiographic review of four key parameters: (a) morphology of the proximal occlusion cap; (b) length of the occlusion; (c) quality of the distal vessel and presence of bifurcation at the distal cap; and (d) suitability of collateral circulation for retrograde crossing. Dual coronary injection is recommended in all cases with contralateral collaterals for detailed characterization of the lesion. If one approach fails to progress, a quick transition to the next approach is encouraged to maximize efficacy and efficiency. Procedural complications, including vessel perforation, may occur more frequently in CTO as compared with non-CTO PCI; hence, availability of necessary equipment and expertise in treating such complications are essential.

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.

Coronary artery spatial distribution of chronic total occlusions: Insights from a large US registry.

To assess the spatial distribution of chronic total occlusions (CTOs) within the coronary arteries and describe procedural strategies and outcomes during CTO percutaneous coronary intervention (PCI). Acute occlusions due to plaque rupture tend to cluster within the proximal third of the coronary artery. We examined the clinical and procedural characteristics of 1,348 patients according to lesion location within the coronary tree. A total of 1,369 lesions in 1,348 patients (mean age 66 ± 10 years, 85% male) were included. CTO PCI of proximal segments (n = 633, 46%) was more common than of mid (n = 557, 41%) and distal segments (n = 179, 13%). Patients undergoing CTO PCI of proximal segments were more likely to be smokers (P < 0.01), have prior coronary artery bypass graft surgery (P = 0.03) and lower ejection fraction (P = 0.04). CTOs occurring in proximal segments had longer length (P <0.01), proximal cap ambiguity (P < 0.01), and moderate/severe calcification (P < 0.01) compared to mid or distally located CTOs. Interventional collaterals were more often present in CTO PCI of proximal segments (64%, 53%, 56%, P < 0.01) consistent with the higher use of retrograde approach (47%, 33%, 37%, P < 0.01) relative to antegrade wire escalation (67%, 82%, 82%, P < 0.01). Procedural complexity was higher in CTO PCI of proximal segments (vs. mid and distal): contrast volume= 275 ml (200-375), 260 ml (200-350), 250 ml (175-350), P = 0.01; fluoroscopy time 53 minutes (32-83), 39 minutes (24-65), 40 minutes (22-72), P < 0.01. However, procedural success (87%, 90%, 85%, P = 0.1), technical success (89%, 91%, 88%, P = 0.24), and complications rates (2.8%, 2.5%, 2.2%, P = 0.88) were not different. The most common target vessel location for CTO PCI is the proximal coronary segment. PCI of proximal occlusions is associated with adverse clinical and angiographic characteristics and often requires use of the retrograde approach, but can be accomplished with high procedural and technical success and low complication rates. © 2016 Wiley Periodicals, Inc.

Utility of Intravascular Ultrasound inPercutaneous Revascularization ofChronicTotal Occlusions: An Overview.

Intravascular ultrasound has been used for >20 years to guide percutaneous coronary intervention in different subsets of coronary lesions. During the last decade, the interest in percutaneous coronary intervention for chronic total occlusion (CTO) has increased dramatically, leading to high success rates. Failure of guidewire crossing is the most common reason for failed CTO attempts. Certain angiographic features, such as blunt proximal CTO cap, tortuosity, heavy calcification, and lack of visibility of path in the distal vessel, increase procedural difficulty. A better understanding of the behavior of the guidewire within the CTO segment may represent a key issue to achieve successful outcome. In this respect, intravascular ultrasound imaging might have potential roles in the recanalization of CTOs. In this paper, we focused on the usefulness andthe applications of intravascular ultrasound imaging in percutaneous CTO recanalization, underlying its impact on clinical outcome.

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry

BackgroundIntravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention.Methods and ResultsWe examined the frequency of use and outcomes of intravascular imaging among 619 CTO percutaneous coronary interventions performed between 2012 and 2015 at 7 US centers. Mean age was 65.4±10 years and 85% of the patients were men. Intravascular imaging was used in 38%: intravascular ultrasound in 36%, optical coherence tomography in 3%, and both in 1.45%. Intravascular imaging was used for stent sizing (26.3%), stent optimization (38.0%), and CTO crossing (35.7%, antegrade in 27.9%, and retrograde in 7.8%). Intravascular imaging to facilitate crossing was used more frequently in lesions with proximal cap ambiguity (49% versus 26%, P<0.0001) and with retrograde as compared with antegrade‐only cases (67% versus 31%, P<0.0001). Despite higher complexity (Japanese CTO score: 2.86±1.19 versus 2.43±1.19, P=0.001), cases in which imaging was used for crossing had similar technical and procedural success (92.8% versus 89.6%, P=0.302 and 90.1% versus 88.3%, P=0.588, respectively) and similar incidence of major cardiac adverse events (2.7% versus 3.2%, P=0.772). Use of intravascular imaging was associated with longer procedure (192 minutes [interquartile range 130, 255] versus 131 minutes [90, 192], P<0.0001) and fluoroscopy (71 minutes [44, 93] versus 39 minutes [25, 69], P<0.0001) time.ConclusionsIntravascular imaging is frequently performed during CTO percutaneous coronary intervention both for crossing and for stent selection/optimization. Despite its use in more complex lesion subsets, intravascular imaging was associated with similar rates of technical and procedural success for CTO percutaneous coronary intervention.Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.