Incidence, treatment, and in-hospital outcome of bifurcation lesions in patients undergoing percutaneous coronary interventions for chronic total occlusions

Impact of Bifurcation Involvement and Location in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the EuroCTO Registry

Bifurcation involvement close to or within the occluded segment poses increasing difficulties for chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). However, this variable is not considered in the angiography-based CTO scoring systems nor has been extensively investigated in large multicenter series. Accordingly, we analyzed a CTO-PCI registry involving 92 European centers to explore the incidence, angiographic and procedural characteristics, and outcomes specific to CTO-PCIs with bifurcation involvement. A total of 3,948 procedures performed between January and November 2023 were examined (33% with bifurcation involvement). Among bifurcation lesions, 38% and 37% were located within 5 mm of the proximal and distal cap, respectively, 16% within the CTO body, and in 9% of cases proximal and distal bifurcations coexisted. When compared with lesions without bifurcation involvement, CTO bifurcation lesions had higher complexity (J-CTO 2.33 ± 1.21 vs 2.11 ± 1.27, p <0.001) and were associated with higher use of additional devices (dual-lumen microcatheter in 27.6% vs 8.4%, p <0.001, and intravascular ultrasound in 32.2% vs 21.7%, p <0.001). Radiation dose (1,544 [836 to 2,819] vs 1,298.5 [699.1 to 2,386.6] mGy, p <0.001) and contrast volume (230 [160 to 300] vs 190 [130 to 250] ml, p <0.001) were also higher. Technical success was similar (91.5% with bifurcation involvement vs 90.4% without bifurcation involvement, p = 0.271). However, the bifurcation lesions within the CTO segment (intralesion) were associated with lower technical success than the other bifurcation-location subgroups (83.7% vs 93.3% proximal, 93.4% distal, and 89.0% proximal and distal, p <0.001). On multivariable analysis, the presence of an intralesion bifurcation was independently associated with technical failure (odds ratio 2.04, 95% confidence interval 1.24 to 3.35, p = 0.005). In conclusion, bifurcations are present in approximately one-third of CTOs who underwent PCI. PCI of CTOs with bifurcation can be achieved with high success rates except for bifurcations within the occluded segment, which were associated with higher technical failure.

Interventions in chronic total occlusions with bifurcation lesions: incidence, treatment, and in-hospital outcome

INTRODUCTION AND OBJECTIVES

Coronary chronic total occlusions (CTO) involving bifurcation lesions are a challenging lesion subset that is understudied in the literature. This study analyzed the incidence, procedural strategy, in-hospital outcomes and complications of percutaneous coronary interventions (PCI) for bifurcation-CTO (BIF-CTO).

METHODS

We assessed data from 607 consecutive CTO patients treated at the Institut Cardiovasculaire Paris Sud (ICPS), Massy, France between January 2015 and February 2020. Procedural strategy, in-hospital outcomes and complication rates were compared between 2 patient subgroups: BIF-CTO (n=245=and non-BIF-CTO (n=362).

RESULTS

The mean patient age was 63.2±10.6 years; 79.6% were men. Bifurcation lesions were involved in 40.4% of the procedures. Overall lesion complexity was high (mean J-CTO score 2.30±1.16, mean PROGRESS-CTO score 1.37±0.94). The preferred bifurcation treatment strategy was a provisional approach (93.5%). BIF-CTO patients presented with higher lesion complexity, as assessed by J-CTO score (2.42±1.02 vs 2.21±1.23 in the non-BIF-CTO patients, P=.025) and PROGRESS-CTO score (1.60±0.95 vs 1.22±0.90 in the non-BIF-CTO patients, P<.001). Procedural success was 78.9% and was not affected by the presence of bifurcation lesions (80.4% in the BIF-CTO group, 77.8% in the non-BIF-CTO-CTO group, P=.447) or the bifurcation site (proximal BIF-CTO 76.9%, mid-BIF-CTO 83.8%, distal BIF-CTO 85%, P=.204). Complication rates were similar in BIF-CTO and non-BIF-CTO.

CONCLUSIONS

The incidence of bifurcation lesions is high in contemporary CTO PCI. Patients with BIF-CTO present with higher lesion complexity, with no impact on procedural success or complication rates when the predominant strategy is provisional stenting.

CTO and Bifurcation Lesions: An Expert Consensus From the European Bifurcation Club and EuroCTO Club

Knowledge in the field of bifurcation lesions and chronic total occlusions (CTOs) has progressively improved over the past 20 years. Therefore, the European Bifurcation Club and the EuroCTO Club have decided to write a joint consensus statement to share general knowledge and practical approaches in this complex field. When percutaneously treating CTOs, bifurcation lesions with relevant side branches (SBs) are found in approximately one-third of cases (35% at the proximal cap, 38% at the distal cap, and 27% within the CTO body). Occlusion of a relevant SB is not rare and has been shown to be associated with procedural complications and adverse outcomes. Simple bifurcation rules are very useful to prevent SB occlusion, and provisional SB stenting is the recommended approach in the majority of cases: protect the SB as soon as possible by wiring it, respect the fractal anatomy of the bifurcation by using the 3-diameter rule, and avoid using dissection and re-entry techniques. A systematic 2-stent approach can be used if needed or sometimes to connect both branches of the bifurcation. The retrograde approach can be very useful to save a relevant SB, especially in the case of a bifurcation at the distal cap or within the CTO body. Intravascular ultrasound is also a very important tool to address the difficulties with bifurcations at the proximal or distal cap and sometimes also within the CTO segment. Double-lumen microcatheters and angulated microcatheters are crucial tools to resolve access difficulties to the SB or the main branch.

Percutaneous Coronary Intervention of Chronic Total Occlusions Involving a Bifurcation: Insights from the PROGRESS-CTO Registry

BACKGROUND

The impact of bifurcations at the proximal or distal cap on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

METHODS

We analyzed the clinical, angiographic, and procedural data of 4,584 cases performed in patients between 2012-2020 in a global CTO PCI registry. We compared 4 groups according to bifurcation location "proximal cap", "distal cap", "proximal and distal cap", and "no bifurcation".

RESULTS

The CTO involved a bifurcation in 67% cases, as follows: proximal cap (n=1451, 33%), distal cap (n=622, 14%), or both caps (n=954, 21%). "Proximal and distal cap" cases had higher J-CTO compared with "proximal cap", "distal cap" and "no bifurcation" cases, (2.9 ± 1.1 vs 2.5 ± 1.1 vs 2.4 ± 1.2 vs 2 ± 1.2, P<0.0001), and they were also associated with lower technical success rate (79% vs 85% vs 85% vs 90%, p<0.0001), higher pericardiocentesis rate (1% vs 1% vs 0.2% vs 0.3%, P=0.02) and higher emergency coronary artery bypass surgery rate (0.3 % vs 0% vs 0% vs 0%, P=0.01).

CONCLUSION

More than two thirds of CTO PCIs involve a bifurcation, which is associated with lower technical success and higher risk for complications.

Predictors and complications of side branch occlusion after recanalization of chronic total occlusions complicated with bifurcation lesions

Data on risk factors and periprocedural complications associated with side branch (SB) occlusion after chronic coronary total occlusion (CTO) recanalization are limited. The aims of this study were to identify independent predictors of side branch (SB) occlusion after chronic total occlusion (CTO) recanalization and assess the relationship between SB occlusion and perioperative complications. 245 patients with CTO bifurcation lesions (BFLs) who underwent successful CTO recanalization were included in the study. In the occlusion group, most of the SB occlusions were observed after the implantation of the stents and lack of SB protection was more common. However, there was no significant between-group difference in the angles between the main vessel (MV) and SB. SB occlusion was associated with a higher risk of periprocedural myocardial infarction and a higher composite periprocedural complication rate. Identified as predictors of SB occlusion were no SB protection, use of a dissection-reentry strategy, ostial SB stenosis, and proximal MV stenosis of 50% or more.

Revascularization of Coronary Artery Chronic Total Occlusion by Active Antegrade Reverse Wire Technique

Objectives

To assess the effectiveness and safety of ARW for vascular recanalization in CTO patients.

Background

Chronic total occlusion (CTO) of coronary artery accompanied with large branch distal to the occluded segment (<2 mm) is one of the challenges physicians are facing during the coronary intervention. In cases where the antegrade wire passed the occluded segment reaching the branch vessel, but could not access the main vessel through various adjustments, application of active antegrade reverse wire technique (ARW) could be considered. Patients and Methods. A total of 301 consecutive CTO patients who received the antegrade percutaneous coronary intervention (PCI) between December 2015 and December 2019 at our institution were included, of whom 11 were treated with ARW (10 successfully) for vascular recanalization. The applicability and safety of ARW were assessed.

Results

Among the 301 CTO patients who received antegrade vascular recanalization, 11 were treated with ARW. ARW was successful in 10 patients as follows: from the diagonal branch (D) to anterior descending branch (LAD) in 4 patients; from the septal branch (S) to LAD in 1 patient; from D to S and LAD in 1 patient; from the circumflex branch (LCX) to obtuse marginal branch (OM) in 1 patient; from OM to LCX in 1 patient; from a posterior descending artery (PDA) to the posterior lateral vein (PLV) in 2 patients. Yet, ARW in patient with RCAm CTO failed, while the consequent retrograde PCI succeeded. The mean J-CTO score of the 11 patients was 2.7 ± 0.65, among whom eight were accompanied with calcifications. Sion Black and Fielder XTR reverse wires were used in 9 and 2 patients, respectively. No loss of side branches or severe procedure-related complications occurred in 11 patients.

Conclusion

Therefore, ARW can improve procedural efficiency and should be popularized for further application.

Association of Acute Procedural Results With Long-Term Outcomes After CTO PCI

OBJECTIVES

The aim of this study was to determine the association of procedural outcomes with long-term mortality and myocardial infarction (MI) after chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

The association between acute procedural results and subsequent outcomes has received limited study.

METHODS

Between January 2010 and December 2013, a total of 2,659 CTO PCI patients were consecutively enrolled. Procedural results were categorized into 3 groups: 1) optimal recanalization, with reperfusion of the occluded vessel and side branches (if any) with TIMI (Thrombolysis In Myocardial Infarction) flow grade 3; 2) suboptimal recanalization, meeting any of the following criteria: persistence of significant side branch occlusion, final TIMI flow grade 1 or 2, or residual percentage diameter stenosis >30%; and 3) procedural failure (i.e., failure to cross a lesion with a balloon angioplasty catheter). The primary outcome was the 5-year composite endpoint of cardiac death and MI.

RESULTS

Overall, optimal recanalization was achieved in 1,562 patients (58.7%), suboptimal recanalization was achieved in 399 patients (15.0%), and recanalization failed in 698 patients (26.3%). The 5-year incidence of the primary outcome was significantly higher in the suboptimal recanalization group compared with the optimal recanalization and the failure groups (10.1% vs. 6.5% vs. 6.3%; p = 0.046), which was driven mainly by higher risk for MI. In subgroup analysis, significant side branch occlusion was associated with numerically higher risk for 5-year MI (hazard ratio: 1.55; 95% confidence interval: 0.99 to 2.43; p = 0.054).

CONCLUSIONS

In this large cohort of CTO PCI patients, suboptimal recanalization was associated with significantly higher long-term incidence of cardiac death and MI compared with optimal recanalization or procedural failure.

Endovascular recanalization for symptomatic non-acute middle cerebral artery occlusion: proposal of a new angiographic classification

BACKGROUND

Endovascular recanalization for medically refractory non-acute middle cerebral artery (MCA) occlusion remains a clinical dilemma, and limited data are available. We report the multicenter clinical results of endovascular recanalization for symptomatic non-acute MCA occlusion and propose a new angiographic classification to explore which subgroups of patients are most suitable for this treatment.

METHODS

From January 2015 to December 2019, 50 consecutive patients who underwent endovascular recanalization for recurrent symptomatic non-acute MCA occlusion were analyzed retrospectively. All patients were divided into three types according to the angiographic classification. The technical success rate, periprocedural complications, rate of stroke or death within 30 days, and follow-up results were evaluated.

RESULTS

The overall technical success rate was 84.0% (42/50). The perioperative complication rate was 14.0% (7/50), and the rate of stroke or death within 30 days was 12.0% (6/50). The revascularization success rate was higher in patients with type I occlusion than in those with type II or type III occlusion (95.5%, 83.3%, and 60%, respectively; p=0.014), and the opposite was true for the perioperative complication rate (4.5%, 11.1%, and 40.0%, respectively; p=0.013). The median clinical follow-up period was 13.4 months (IQR 12.5-15.6), and the rate of stroke or death beyond 30 days was 8.3%.

CONCLUSIONS

Endovascular recanalization for non-acute MCA occlusion is technically feasible in reasonably selected patients, especially type I patients, and has potential as an alternative option for patients with recurrent stroke or transient ischemic attack in the short term despite optimal medical therapy.

Percutaneous coronary intervention in aorto-ostial coronary chronic total occlusion: outcomes and technical considerations in a multicenter registry

INTRODUCTION AND OBJECTIVES

Percutaneous coronary intervention (PCI) for aorto-ostial chronic total coronary occlusion (CTO) can be a particularly challenging lesion subset. The aim of this study was to analyze the technical aspects and outcomes of aorto-ostial CTO PCI in a multicenter registry.

METHODS

Patients undergoing aorto-ostial CTO PCI at 4 centers between February 2013 and December 2018 were included. Success rates, as well as procedural aspects and outcomes, were analyzed.

RESULTS

A total of 103 patients were included. Mean age was 64±10 years and the mean J-CTO score was 3.1±1.1. Thirty-one lesions (30.4%) were flush ostial CTOs. Technical and procedural success were achieved in 79 (76.7%) and 78 (75.7%) of the patients, respectively. The retrograde approach was the most frequent successful crossing technique (n=49; 62.0%), especially in flush vs nonflush aorto-ostial CTOs (82.6% vs 53.5%; P=.02). The only variable independently associated with technical failure was the absence of interventional collaterals (OR, 12.38; 95%CI, 4.02-38.15; P <.001). Coronary perforation occurred in 4 patients (3.9%) requiring covered stent implantation (without subsequent cardiac tamponade) and 2 patients (1.9%) had a stroke (one of which was a transient ischemic attack). During a median follow-up of 31 months, 3 (2.9%) patients died from cardiovascular causes and 13 (12.6%) required repeat target vessel revascularization.

CONCLUSIONS

Aorto-ostial occlusions represent a challenging subset for PCI. However, an acceptable success rate with favorable outcomes during follow-up can be achieved by experienced operators. The presence of interventional collaterals allowing the use of the retrograde approach is key for achieving procedural success.

Current approaches for treatment of coronary chronic occlusions

Introduction: Coronary chronic total occlusions (CTO) represent a challenging subset in interventional cardiology.Areas covered: During the last decade, improvements in materials, techniques, and meticulous pre-procedural lesion assessment have increased the success rate in CTO lesions. Several scores have been developed to address overall lesion evaluation and help select the most appropriate treatment strategy. In addition, specific algorithms such as the hybrid algorithm have been introduced to provide a framework for CTO operators and a rapid management of the various challenging aspects of the procedure. The hybrid approach requires operator's ability to switch from one treatment strategy to another when the first one appears to be unsuccessful. Adequate training and operators' experience remain crucial to improve the likelihood of success.Expert opinion: The aim of this review is to provide insights and guidance for operators on current approaches for treatment of CTO and complication management.

Chronic Total Occlusion Interventions: Update on Current Tips and Tricks

PURPOSE OF REVIEW

To summarize novel techniques and developments in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

RECENT FINDINGS

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.

A randomized trial of bifurcation stenting technique in chronic total occlusions percutaneous coronary intervention

BACKGROUND

The optimal strategy to treat bifurcation lesions (BFLs) in a percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) remains unknown.

AIMS

We sought to assess whether T-provisional or mini-crush is appropriate for BFLs within CTO vessels.

PATIENTS AND METHODS

From January 2011 to December 2013, patients who underwent successful CTO guidewire crossing and with a BFL within the CTO target vessel were enrolled prospectively and assigned randomly to either T-provisional stenting or the mini-crush technique for BFL treatment. One-year clinical follow-up was performed. Major adverse cardiac and cerebrovascular events (MACCE) were defined as the composite of cardiovascular death, myocardial infarction, target vessel revascularization, and stroke.

RESULTS

The prevalence of BFLs was 54.3%. A total of 146 patients with BFLs within CTO vessel were enrolled prospectively and assigned randomly to either T-provisional stenting (N=73) or the mini-crush technique (N=73). Angiographic and clinical success rates were similar in the two groups: 91.8 versus 97.2% (P=0.27) and 91.8 versus 94.5% (P=0.67), respectively.Although T-provisional stenting was associated with a nonsignificantly lower incidence of MACCE in case of BFLs located far from the CTO (9.3 vs. 22.2%; P=0.426), the mini-crush technique resulted in higher MACCE-free survival at 1 year in the presence of BFLs within the CTO body or close to the proximal or the distal cap (89.1 vs. 64.9%; P=0.007).

CONCLUSION

The mini-crush technique appeared to be associated with improved 1-year clinical and angiographic outcomes, particularly when used to treat BFLs located within the CTO body or close to the proximal or the distal cap.

The "double stingray technique" for recanalizing chronic total occlusions with bifurcation at the distal cap

Antegrade dissection re-entry is often discouraged for chronic total occlusions (CTOs) with a bifurcation at the distal cap due to risk of side branch occlusion that can lead to periprocedural myocardial infarction and incomplete revascularization. Antegrade dissection re-entry, however, is often needed, especially in complex cases. We present the novel "double Stingray technique" for CTOs involving bifurcations, in which the Stingray system is used twice for re-entry into both vessel branches, followed by two-stent bifurcation stenting to maintain the patency of both branches.

Dual lumen microcatheters for complex percutaneous coronary interventions

In some bifurcation anatomies side branch wiring can be difficult particularly when side branch is highly angulated. Furthermore a combination of bifurcations and chronic total occlusion can be a real challenge for interventional cardiologists. New devices have been produced to facilitate complex PCI and recently introduced dual lumen microcatheters can be really helpful in these scenarios. All these devices have both a rapid-exchange and an over-the-wire lumen. The rationale for dual lumen microcatheters is to preserve the highest number of side-branches. Nevertheless PCI should always aim to the most complete revascularization and to the lowest rate of side-branch loss. The purpose of this review is to describe current available dual lumen microcatheters, interventional scenarios in which their use may be helpful and basics of their proper use.

One Versus 2-stent Strategy for the Treatment of Bifurcation Lesions in the Context of a Coronary Chronic Total Occlusion. A Multicenter Registry

INTRODUCTION AND OBJECTIVES

There is little evidence on the optimal strategy for bifurcation lesions in the context of a coronary chronic total occlusion (CTO). This study compared the procedural and mid-term outcomes of patients with bifurcation lesions in CTO treated with provisional stenting vs 2-stent techniques in a multicenter registry.

METHODS

Between January 2012 and June 2016, 922 CTO were recanalized at the 4 participating centers. Of these, 238 (25.8%) with a bifurcation lesion (side branch ≥ 2mm located proximally, distally, or within the occluded segment) were treated by a simple approach (n=201) or complex strategy (n=37). Propensity score matching was performed to account for selection bias between the 2 groups. Major adverse cardiac events (MACE) consisted of a composite of cardiac death, myocardial infarction, and clinically-driven target lesion revascularization.

RESULTS

Angiographic and procedural success were similar in the simple and complex groups (94.5% vs 97.3%; P=.48 and 85.6% vs 81.1%; P=.49). However, contrast volume, radiation dose, and fluoroscopy time were lower with the simple approach. At follow-up (25 months), the MACE rate was 8% in the simple and 10.8% in the complex group (P=.58). There was a trend toward a lower MACE-free survival in the complex group (80.1% vs 69.8%; P=.08). After propensity analysis, there were no differences between the groups regarding immediate and follow-up results.

CONCLUSIONS

Bifurcation lesions in CTO can be approached similarly to regular bifurcation lesions, for which provisional stenting is considered the technique of choice. After propensity score matching, there were no differences in procedural or mid-term clinical outcomes between the simple and complex strategies.

Angiographic predictors of success in antegrade approach of Chronic Total Occlusion interventions in a South Indian population in the contemporary era

Chronic Total Occlusion (CTO) intervention is a challenging area in interventional cardiology. Presently about 70% of CTO interventions are successful.

MATERIALS AND METHODS

This was a single center prospective study of a cohort of all patients undergoing percutaneous coronary intervention (PCI) as elective or adhoc procedure for CTO from August 2014 to June 2015. Only antegrade CTO interventions were included. In all patients the following data were recorded.

RESULTS

A total of 210 (8.9% of total PCI (2353) during the study period) CTO patients were followed up. The mean age was 56.54±8.9. In the study sixty nine patients (32.9%) presented with chronic stable angina and rest of the patients had history of acute coronary syndrome of which 22.9% (n=48) had unstable angina (UA) or non ST elevation myocardial infarction (NSTEMI) and 44.2% (n=93) had ST Elevation Myocardial Infarction (STEMI). In those with history of ACS, 64.78% (n=92) had ACS during the previous year and remaining 35.22% (n=49) had ACS prior to that. Single vessel CTO was seen in 89.5% (n=188) and two vessel CTO in 10.5% (n=22). LAD was involved in 36.7% (n=77), RCA in 48.1% (n=101), and LCX in 15.2% (n=32). Procedural success in the first attempt was 68.1% (n=143), which increased to 71.42% (n=150) after the second attempt. CTO interventions were more frequently successful when the calcium was absent or minimal (p-0.05), CTO length was <10mm (p<0.01) and good distal reformation (p<0.01).

Percutaneous coronary interventions of chronic total -occlusions; a review of clinical indications, treatment strategy and current practice

Chronic total occlusions (CTOs) are commonly encountered in patients undergoing coronary angiography, but percutaneous coronary intervention (PCI) for CTO is currently infrequently performed owing to the perception of limited clinical benefit, high complexity and cost of intervention, and perceived risk of complications. Numerous observational studies have demonstrated that successful CTO revascularization is associated with better cardiovascular outcomes and enhanced quality of life (QOL). However, in the absence of randomized trials, its prognostic benefit remains debated. Nevertheless, over the past decade the interest in CTO-PCI has exponentially grown due to important developments in dedicated equipment and techniques, resulting in high success and low complication rates. A number of factors must be taken into consideration in selecting patients for CTO-PCI, including presence of symptoms attributable to the CTO, extent of ischaemia distal to the occlusion, and degree of myocardial viability. In this review, we focus on the impact of CTO revascularization on clinical outcomes and QOL and on appropriate patient selection. Data regarding efficacy and safety of recent advances in PCI-CTO techniques will be discussed. Steps involved in setting up a dedicated CTO program will be outlined and the current CTO landscape in Belgium will be briefly highlighted. The overall aim of this review is to promote a more balanced approach to management of patients with a CTO.

Influence about the flow of distal branch after intervention of the right coronary artery chronic total occlusion

OBJECTIVE

Limited data are available for the clinical outcomes after the recanalization of right coronary artery (RCA) chronic total occlusion (CTO). The study aims to assess the clinical outcomes in the antegrade flow of the distal branch after successful RCA CTO percutaneous coronary intervention (PCI).

METHODS

Between January 2002 and December 2012, 538 patients who underwent RCA CTO PCI were enrolled. The clinical outcomes as myocardial infarction (MI), target vessel revascularization, cardiac death, major adverse cardiac events, and all-cause mortality, were compared to the antegrade flow of distal branch after successful RCA CTO PCI.

RESULTS

The CTOs were located in proximal segments (57.6%), mid segments (27.5%) and distal segments (14.9%). The average Syntax score was 18.4±9.6 and 47.8% patients had a Syntax score greater than 27.5. A total of 62.8% patients had final thrombolysis of myocardial infarction (TIMI)-3 flow of distal branch, 16.9% patients had final TIMI-3 flow of only one major branch, 11.3% patients had TIMI-1-2 flow, and 8.9% patients had no antegrade flow. The incidence of periprocedural MI was lower in both side branches were preserved (13.9% vs. 23.0% and 18.8%, p=0.01). The clinical outcomes were similar between the groups with and without good antegrade flow of distal side branch. End stage renal disease (ESRD) and left ventricular ejection fraction (LVEF) <40% predicted three-year cardiac death.

CONCLUSIONS

There is no significant difference of clinical outcomes when distal side branches of RCA are recanalized successfully. ESRD and LVEF <40% were the predictors for three-year cardiac death.

Bifurcation lesions involved in the recanalization process of coronary chronic total occlusions: Incidence, treatment and clinical implications

BACKGROUND

The presence of a bifurcation (BL) in the context of a coronary chronic total occlusion (CTO) represents an additional difficulty. This study analyzes the incidence of BLs in CTO recanalization, the treatment, predictors of bifurcation technical success and their clinical impact.

METHODS AND RESULTS

BLs with a side branch (SB) ≥2.0mm located proximally, distally or within the occluded segment were observed in 130 (33%) of 391 CTO. Provisional stenting was the strategy more frequently used (94%). Bifurcation success (stenosis <30% in main vessel and TIMI flow III in both branches) was achieved in 105 patients (81%). In the remaining 25 (19%), the TIMI flow at the SB was <III. Predictors of bifurcation success were baseline SB wiring (OR 0.01, 95% CI: 0.001-0.09; p<0.01), the absence of dissection across the bifurcation (OR 0.10, 95% CI: 0.02-0.49; p<0.01) and non-true BLs (OR 0.16, 95% CI: 0.04-0.68; p<0.05). Regarding in-hospital results, patients with final TIMI flow <III at the SB had a higher incidence of periprocedural MI (32% vs 4.8%; p<0.01). Subsequently, the rate of MI was higher in patients with CTO-BLs than in those without BLs. At follow-up, there were no differences in the event rate between CTO-BLs and non CTO-BLs (7.7% vs 9.5%, p=ns) CONCLUSIONS: BLs in CTO is a frequent finding and could be approached as regular bifurcations. The primary success was low and this was associated with a higher incidence of periprocedural MI. Baseline SB wiring was a powerful predictor of technical success.

CT Angiography for Revascularization of CTO: Crossing the Borders of Diagnosis and Treatment

Coronary computed tomography angiography (CTA) is increasingly used to diagnose and rule out coronary artery disease. Beyond stenosis detection, the ability of CTA to visualize and characterize coronary atherosclerotic plaque, as well as to obtain 3-dimensional coronary vessel trajectories, has generated considerable interest in the context of pre-procedural planning for revascularization of chronic total occlusions (CTOs). Coronary CTA can characterize features that influence the success rate of percutaneous coronary intervention (PCI) for CTOs such as the extent of calcification, vessel tortuosity, stump morphology, presence of multiple occlusions, and lesion length. Single features and combined scoring systems based on CTA may be used to grade the level of difficulty of the CTOs before PCI and have been shown to predict procedural success rates in several trials. In addition, the procedure itself may be facilitated by real-time integration of 3-dimensional CTA data and fluoroscopic images in the catheterization laboratory. Finally, the ability of coronary CTA to assess anatomy, perfusion, and viability in 1 single examination makes it a potential "one stop shop" that predicts not only the likelihood of successful PCI but also the clinical benefit of CTO revascularization. Further research is clearly needed, but many experienced sites have already integrated coronary CTA into the routine planning and guiding of CTO procedures.

Fatal derecruitment of occluded left anterior descending collaterals after left circumflex revascularization

Coronary arteries are not definitely functionally terminal arteries, as previously thought; indeed, they are linked and interconnected by a rich network of collaterals. Chronic total occlusions (CTOs) represent a subset of frequent lesions encountered in everyday catheterization laboratory practice, generally associated with a developed system of collateral connections. These latter have the capacity to prevent myocardial necrosis and may even uphold metabolic supply to the ischemic territory to maintain its contractile capacity. Authors have reported a rapid and progressive reduction of collateral function and their decline after antegrade flow restoration, resulting in higher myocardial susceptibility to ischemia in the CTO territory. Here, we report the case of a fatal derecruitment of collaterals for a left anterior descending CTO not reopened, after left circumflex subocclusion revascularization.

The impact of percutaneous coronary intervention of chronic total occlusions on left ventricular function and clinical outcomes

A meta-analysis by Hoebers et al. reported that successful chronic total occlusion (CTO) recanalization resulted in an increase in left ventricular (LV) ejection fraction by 4.44% (P<0.01) and a reduction in LV end-diastolic volume by 6.14 mL/m(2) during follow-up as compared with baseline, suggesting beneficial LV remodeling. These findings are important as the myocardium supplied by a CTO frequently has sustained irreversible injury and further support the clinical benefits of CTO interventions.