In-hospital outcomes of percutaneous coronary intervention in patients with chronic total occlusion: insights from the ERCTO (European Registry of Chronic Total Occlusion) registry

Novel proctorship effectively teaches interventionists coronary artery chronic total occlusion lesions

BACKGROUND

Interventionists' experience and skills are essential factors for successful chronic total occlusion-percutaneous coronary intervention (CTO-PCI). However, the construction of theoretical strategy independent from interventionists' procedure may also improve it. We sought to assess the feasibility of CTO-PCI using an educational system supported by a single expert proctor.

METHODS

A total of 160 patients underwent CTO-PCI between 2009 and 2016 at 92 Japanese centers in the Hands-on proctorship project. The CTO-PCI strategy was discussed with all participants and their specialists, before and during the procedure. We divided patients into 2 groups based on the CTO-PCI experience of their interventionist: (1) the less experienced group (CTO-PCI ≤50 cases, n=65) and (2) the more experienced group (CTO-PCI >50 cases, n=95). Baseline characteristics, procedural complications, and clinical outcomes were compared between groups.

RESULTS

No significant differences in patient age, sex, prevalence for coronary risk factors, and lesion complexity was observed between groups. The retrograde approach was used equivalently between groups (55.4% vs. 60.0%, p=0.56), and procedural success rates were similar (96.9% vs. 90.5%, p=0.12). The rate of proctor's bailout for recanalization were not frequent between groups (4.6% vs. 5.3%, p=0.85). No procedure-related mortality was noted in either group. In addition, no significant differences in procedural cardiac complications, including coronary dissection, perforation, or tamponade, were observed between groups (10.8% vs. 14.7%, p=0.47).

CONCLUSIONS

The expert-supported CTO-PCI maintained high success rates regardless of interventionists' experience. This highlights the importance of theoretical strategy for the management patients undergoing CTO-PCI.

The GuideLiner catheter: A supportive tool in percutaneous coronary intervention of chronic total occlusion

Background

Failure of delivering a stent or a balloon across the target lesion during percutaneous coronary intervention (PCI) of chronic total occlusion (CTO), especially in arteries with calcified tortuous anatomy, is often due to insufficient backup support from the guiding catheter. The purpose of this study was to assess the feasibility of the GuideLiner (GL) catheter use.

Methods

We examined 18 patients and used the GL catheter to overcome poor support and excessive friction in standardized antegrade and retrograde CTO procedures. The GL is a coaxial, monorail guiding catheter extension delivered through a standard guiding catheter and is available in different sizes.

Results

Almost all lesions were classified as severely calcified (94.4 ± 0.24%). The Japanese CTO score reflecting lesion complexity was 3.56 ± 0.78. All procedures were performed femorally; the retrograde approach was used in 27.8 ± 0.46% of cases. The overall success rate was 88.9 ± 0.32%; there were no relevant complications.

Conclusions

The GL catheter is an adjunctive interventional device which enhances and amplifies CTO-PCI. Its use is indicated in cases in which back-up force needs to be strengthened to pass a CTO despite advanced calcification. It can be recommended as an important additional tool in advanced interventional cardiology such as antegrade and retrograde CTO-PCI if other techniques like anchor balloon or anchor wire are not possible.

Contemporary Evidence, Treatment Strategies, and Indications for Chronic Total Occlusion-Percutaneous Coronary Intervention

Chronic total occlusions (CTOs) are detected incidentally in ˜20% of patients undergoing coronary angiography and are often associated with significant morbidity and mortality. CTOs can manifest with worsening symptoms, reduced left ventricular function, and increased incidence of ventricular arrhythmias. Despite this, according to USA, Italian, and Japanese national registry data, only ~5–22% of CTO lesions are treated by percutaneous coronary intervention (PCI). CTO-PCI is a particularly challenging technique for this subset of lesions and has traditionally been associated with increased risks and complications compared to conventional PCI. However, increased experience, the development of novel techniques, and dedicated equipment have revolutionised CTO-PCI. USA, Italian, and Japanese registry data have shown success rates of between 85% and 90%, with diminishing complication rates when performed by experienced operators. Moreover, observational studies have suggested that there are significant benefits of using CTO-PCI, including fewer symptoms, improved quality of life, reduced need for coronary artery bypass surgery, and reduction in ischaemic burden and mortality. In addition, when there is demonstrable ischaemia and viable myocardium in the CTO territory, there is further potential prognostic benefit from complete revascularisation. However, there has so far been a relative lack of randomised trial data to support the routine use of CTO-PCI. This paper reviews the current evidence surrounding this subject and discusses the arguments for and against CTO-PCI. It includes an exploration of the interventionalist’s ‘toolbox’ and the techniques used in CTO-PCI, including a section on ‘tips and tricks’ for the most challenging cases. Finally, there is a discussion on the future of CTO-PCI including promising ongoing clinical trials and novel equipment that may improve outcomes and help to establish a more widespread adoption of CTO-PCI.

Very late bioresorbable scaffold thrombosis and reoccurrence of dissection two years later chronic total occlusion recanalization of the left anterior descending artery

We describe the case of a patient presenting with ST-segment elevation myocardial infarction due to very late scaffold thrombosis. The patient was already admitted for an elective percutaneous recanalization of a chronically occluded left anterior descending artery (LAD). The procedure was performed according the sub-intimal tracking and re-entry (STAR) technique with 4 bioresorbable vascular scaffolds implantation. However, even though the coronary flow was preserved at the end of the procedure, the dissected segment was only partially sealed at the distal segment of the LAD. After 18 mo of regular assumption, dual antiplatelet therapy was discontinued for 10 mo before his presentation at the emergency room. This is the first reported case of a very late scaffold thrombosis after coronary chronic total occlusion (CTO) recanalization performed according to the STAR technique. This case raises concerns about the risk of very late scaffold thrombosis after complex CTO revascularization.

Risk Factors For Radiation-Induced Skin Ulceration in Percutaneous Coronary Interventions of Chronic Total Occluded Lesions: A 2-Year Observational Study

Relationship between radiation-induced skin ulceration (RSU) and variables in percutaneous coronary interventions (PCI) was rarely reported. RSU is a severe complication in PCIs, especially for chronic total occlusion (CTO) lesions. We investigated the RSUs and their risk factors in patients receiving CTO PCIs over a 2-year period. Data were analyzed using chi-square tests, t-tests and receiver operating characteristic (ROC) curve. Of 238 patients, 11 patients (4.6%) had RSUs all at right upper back. RSUs were significantly associated with use of left anterior oblique (LAO) views (100% vs. 47.1%, p < 0.001), retrograde techniques (36.3% vs. 7.9%, p = 0.012), or a procedure time (PT) defined as a time duration between the first and last angiograms of > 120, 180, or 240 minutes (p < 0.05). ROC analysis showed a long PT was an accurate predictor of RSUs (AUC = 0.88; p < 0.001) at a cut-off of 130 minutes (sensitivity = 0.91, specificity = 0.81). The results showed risk factors for RSUs containing use of large LAO views, retrograde techniques, and prolonged PTs. This study suggests that, to minimize RSU, interventionalists should limit PT to roughly 2 hours in fixed LAO views.

Incidence and impact on midterm outcome of intimal versus subintimal tracking with both antegrade and retrograde approaches in patients with successful recanalisation of chronic total occlusions: J-PROCTOR 2 study

AIMS

The aim of this study was to assess the incidence and impact on midterm outcomes of intimal versus subintimal tracking with both antegrade and retrograde approaches in patients undergoing successful percutaneous coronary intervention for chronic total occlusion (CTO).

METHODS AND RESULTS

In 2012, a total of 1,573 CTO cases from 30 hospitals were enrolled in the Japanese CTO registry. Successful guidewire crossing was performed in 1,411 cases (89.7%). Among them, the guidewire penetration position was clearly identified using intravascular ultrasound (IVUS) imaging in 352 cases, and clinical follow-up at 12 months was performed in 323 cases. These 323 cases were enrolled in this retrospective study: 242 cases were treated with the antegrade approach (antegrade group) and 81 cases were treated with the retrograde approach (retrograde group). The endpoint of this study was target vessel revascularisation (TVR) and major adverse cardiac events (MACE) at 12-month follow-up. Subintimal tracking occurred more frequently in the retrograde group (11.6% vs. 30.9%, p<0.01). TVR was more frequent in the subintimal tracking group in the retrograde group (7.1% vs. 16.0%, p=0.03) but not in the antegrade group (2.8% vs. 3.6%, p=0.99). Although the occlusion length was similar, the subintimal tracking group required a longer stent length compared to the intimal tracking group in the retrograde approach (59.7±24.4 mm vs. 74.0±24.4 mm, p<0.01).

CONCLUSIONS

Subintimal tracking was more frequent in the retrograde approach. Intimal tracking should be recommended in the retrograde approach to reduce stent length and to improve follow-up outcomes.

Survival after percutaneous coronary intervention for chronic total occlusion in elderly patients

AIMS

Few data are available on outcomes of percutaneous coronary intervention (PCI) for coronary chronic total occlusions (CTO) in very elderly patients in the drug-eluting stent (DES) era. We aimed to investigate long-term survival in a single-centre cohort of elderly patients following CTO PCI using DES.

METHODS AND RESULTS

A total of 2,002 consecutive patients who underwent PCI of a CTO at our centre between January 2005 and December 2013 were followed for a median of 2.6 years (interquartile range 1.1-3.1 years). Four hundred and nine (409) patients were older than 75 years. The absolute reduction in all-cause mortality by successful CTO PCI was numerically greater in elderly patients as compared to younger patients (22.1% vs. 7.2% at three years). In multivariate models, successful CTO PCI was significantly associated with improved survival in both elderly (adjusted hazard ratio [HR] 0.58, 95% confidence interval [CI]: 0.39 to 0.87; p=0.009) and younger patients (adjusted HR 0.59, 95% CI: 0.40 to 0.86; p=0.006).

CONCLUSIONS

In the DES era, elderly patients (≥75 years) derive a similar survival benefit from successful CTO PCI to younger patients. These findings suggest that CTO PCI, when indicated, should not be withheld from the elderly.

Endovascular Crossing of Chronic Total Occlusions Using an Impulse: An Explorative Design Study

In this study we investigated whether exerting an impulse on a Chronic Total Occlusion (CTO) improves the success rate of CTO crossing as compared to the currently used method of statically pushing the guidewire against the CTO. A prototype (Ø2 mm) was developed that generates translational momentum using a spring-loaded indenter and converts it to an impulse during impact. Mechanical performance was evaluated by measuring the peak force and momentum for different spring compressions and strike distances in air and blood-mimicking fluid. Puncture performance, in terms of number of punctures, number of strikes to puncture, and energy transfer from the indenter to the CTO, was assessed for six tip shapes (stamp, wedge, spherical, pointed, hollow spherical, and ringed) on three CTO models with different weight percentages of gelatin and calcium. As a control, a Ø0.4 mm rigid rod was tested. A maximum indenter momentum of 1.3 mNs (velocity of 3.4 m/s), a peak force of 19.2 N (vs. 1.5 N reported in literature and 2.7 N for the control), and CTO displacement of 1.4 mm (vs. 2.7 mm for the control) were measured. The spherical and ringed tips were most effective, with on average 2.3 strikes to puncture the most calcified CTO model. The prototype generated sufficient peak forces to puncture highly calcified CTO models, which are considered most difficult to cross during PCI. Furthermore, CTO displacement was minimized, resulting in a more effective procedure. In future, a smaller, faster, and flexible clinical prototype will be developed.

Impact of diabetes mellitus on acute outcomes of percutaneous coronary intervention in chronic total occlusions: insights from a US multicentre registry

AIM

To examine the impact of diabetes mellitus on procedural outcomes of patients who underwent percutaneous coronary intervention for chronic total occlusion.

METHODS

We assessed the impact of diabetes mellitus on the outcomes of percutaneous coronary intervention for chronic total occlusion among 1308 people who underwent such procedures at 11 US centres between 2012 and 2015.

RESULTS

The participants' mean ± sd age was 66 ± 10 years, 84% of the participants were men and 44.6% had diabetes. As compared with participants without diabetes, participants with diabetes were more likely to have undergone coronary artery bypass graft surgery (38 vs 31%; P = 0.006), and to have had previous heart failure (35 vs 22%; P = 0.0001) and peripheral arterial disease (19 vs 13%; P = 0.002). They also had a higher BMI (31 ± 6 kg/m² vs 29 ± 6 kg/m² ; P = 0.001), similar Japanese chronic total occlusion scores (2.6 ± 1.2 vs 2.5 ± 1.2; P = 0.82) and similar final successful crossing technique: antegrade wire escalation (46 vs 47%; P = 0.66), retrograde (30 vs 28%; P = 0.66) and antegrade dissection re-entry (24 vs 25%; P = 0.66). Technical (91 vs 90%; P = 0.80) and procedural (89 vs 89%; P = 0.93) success was similar in the two groups, as was the incidence of major adverse cardiac events (2.2 vs 2.5%; P = 0.61).

CONCLUSIONS

In a contemporary cohort of people undergoing percutaneous coronary intervention for chronic total occlusion, nearly one in two (45%) had diabetes mellitus. Procedural success and complication rates were similar in people with and without diabetes.

Retrograde Approach is as Effective and Safe as Antegrade Approach in Contemporary Percutaneous Coronary Intervention for Chronic Total Occlusion: A Taiwan Single-Center Registry Study

BACKGROUND

In percutaneous coronary intervention (PCI) for chronic total occlusion (CTO), most experts regard the antegrade approach as the default initial strategy, reserving the retrograde approach for reattempts following antegrade failure. In this study, we aimed to compare the efficacy and safety between the antegrade and retrograde approaches in CTO PCI.

RESULTS

Between 2012 and 2013, patients that underwent 321 consecutive attempts by high-volume operators (> 75 total CTO PCI cases during the period) in a tertiary university-affiliated hospital were enrolled. The antegrade approach was used in 152 patients, and retrograde in 169 patients. The duration of occlusion was significantly longer and the J-CTO score higher in the retrograde group. Technical success was achieved in 148 patients of the antegrade group (97.4%), and 163 patients in the retrograde group (96.4%) (p = 0.75). A major procedural complication occurred in 3 patients of the antegrade group (2.0%) and in 6 patients of the retrograde group (3.6%) (p = 0.51). In-hospital major adverse cardiac events (MACE) rates (antegrade 0.7%, n = 152; retrograde 0.6%, n = 169) were comparable. The procedure and fluoroscopy times were significantly longer, with more radiation exposure and contrast medium consumption, in the retrograde group. In the retrograde group, similar success, procedural complication and in-hospital MACE rates were achieved in the 3 collateral subgroups.

CONCLUSIONS

In selected cases and with highly experienced operators, retrograde approach in CTO PCI is as effective and safe as antegrade approach at the expense of longer procedure time, more radiation exposure and contrast medium consumption. For retrograde approach, either septal, epicardial or AV groove collaterals can be used with similarly success, complication and in-hospital MACE rates.

Approach to CTO Intervention: Overview of Techniques

OPINION STATEMENT

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.

Is Complete Revascularisation Mandated for all Patients with Multivessel Coronary Artery Disease?

In multivessel coronary artery disease (MVCAD), myocardial revascularisation can be achieved by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), with complete revascularisation on all diseased coronary segments or with incomplete revascularisation on selectively targeted lesions. Complete revascularisation confers a long-term prognostic benefit, but is associated with a higher rate of periprocedural events compared with incomplete revascularisation. In most patients with MVCAD, the main advantage of CABG over PCI is conferred by the achievement of more extensive revascularisation. According to current international guidelines, PCI is generally preferred in single-vessel disease, low-risk MVCAD or isolated left main disease; whereas CABG is usually recommended in patients with complex two-vessel disease, most patients with three-vessel disease and/or non-isolated left main disease. In patients with MVCAD, the choice on revascularisation modality should depend on a multifactorial evaluation, taking into account not only coronary anatomy, the ischaemic burden, myocardial function, age and the presence of comorbidities, but also the adequacy of myocardial revascularisation.

Long-Term Follow-Up of Patients With Previous Coronary Artery Bypass Grafting Undergoing Percutaneous Coronary Intervention for Chronic Total Occlusion

Successful revascularization of chronic total occlusions (CTOs) has been associated with clinical benefit. Data on outcomes in patients with previous coronary artery bypass grafting (CABG) undergoing percutaneous coronary intervention (PCI) for CTO, however, are scarce. A total of 2,002 consecutive patients undergoing PCI for CTO from January 2005 to December 2013 were divided into patients with and without previous CABG, and outcomes were retrospectively assessed. The primary outcome measure was all-cause mortality. Median follow-up was 2.6 years (interquartile range 1.1 to 3.1). A total of 292 patients (15%) had previous CABG; they were older and had a greater prevalence of comorbidities. Procedural success was achieved in 75% and 84% of patients in the previous CABG and the non-CABG groups (p <0.001), respectively. All-cause mortality was 16% and 11% in the previous CABG and the non-CABG groups (p = 0.002), and differences were mitigated after adjustment for baseline characteristics (adjusted hazard ratio [HR] 1.22, 95% confidence interval [CI] 0.86 to 1.74, p = 0.27). All-cause death was significantly reduced in patients with procedural success, both in the previous CABG (11% vs 32%, adjusted HR 0.43, 95% CI 0.24 to 0.77, p = 0.005) and the non-CABG groups (10% vs 20%, adjusted HR 0.63, 95% CI 0.45 to 0.86, p = 0.004), with similar mortality benefits associated with successful revascularization in both groups (interaction p = 0.24). In conclusion, the relative survival benefit of successful recanalization of CTO is independent of previous CABG. However, owing to a greater baseline risk, the absolute survival benefit of successful CTO procedures is more pronounced in patients with previous CABG than in non-CABG patients.

Successful revascularization improves long-term clinical outcome in patients with chronic coronary total occlusion

Background

Following the development of breakthrough techniques for percutaneous coronary intervention (PCI) in the treatment of chronic total occlusions (CTO), the initial success rate of PCI in CTO lesions (CTO-PCI) has improved; however, there are few reports regarding the effects of successful CTO revascularization on long-term mortality in Japan. The aim of this study was to compare the long-term clinical outcomes of patients with successful versus failed CTO recanalization and to identify related factors.

Methods and results

From all PCI procedures performed in our hospital between 2006 and 2013, CTO-PCIs were extracted and classified into two groups: PCI success (n = 656 patients) and PCI failure (n = 82 patients). Patients with successful procedures only on a second attempt, CTO-PCI in small branches, or CTOs in more than one vessel were excluded. Survival was determined from a telephone interview or the consultation history in the outpatient clinic. Initial angiographic success was achieved in 88.9% of the patients. A Kaplan–Meier plot with log-rank analysis showed that cumulative all-cause death was significantly lower in the success group than in the failure group (p = 0.0003; average follow-up duration in success group vs. failure group was 1531.3 ± 33.5 vs. 1565.3 ± 97.5 days, p = 0.7). Moreover, the rate of evident cardiac death was significantly lower in the success group than in the failure group (3.5% [23/656] vs. 15.9% [13/82], p < 0.0001).

Conclusions

This study suggests that successful revascularization in patients with CTO improves their long-term clinical outcomes.

A Novel Risk Score in Predicting Failure or Success for Antegrade Approach to Percutaneous Coronary Intervention of Chronic Total Occlusion: Antegrade CTO Score

Total occlusion of a coronary artery for more than 3 months is defined as chronic total occlusion (CTO). The goal of this study was to develop a risk score in predicting failure or success during attempted percutaneous coronary intervention (PCI) of CTO lesions using antegrade approach. This study was based on retrospective analyses of clinical and angiographic characteristics of CTO lesions that were assessed between February 2012 and February 2014. Success rate was defined as passing through occlusion with successful stent deployment using an antegrade approach. A total of 188 patients were studied. Mean ± SD age was 59 ± 9 years. Failure rate was 33%. In a stepwise multivariate regression analysis, bridging collaterals (OR = 6.7, CI = 1.97-23.17, score = 2), absence of stump (OR = 5.8, CI = 1.95-17.9, score = 2), presence of calcification (OR = 3.21, CI = 1.46-7.07, score = 1), presence of bending (OR = 2.8, CI = 1.28-6.10, score = 1), presence of near side branch (OR = 2.7, CI = 1.08-6.57, score = 1), and absence of retrograde filling (OR = 2.5, CI = 1.03-6.17, score = 1) were independent predictors of PCI failure. A score of 7 or more was associated with 100% failure rate whereas a score of 2 or less was associated with over 80% success rate. Most factors associated with failure of CTO-PCI are related to lesion characteristics. A new risk score (range 0-8) is developed to predict CTO-PCI success or failure rate during antegrade approach as a guide before attempting PCI of CTO lesions.

Recanalization of Chronic Total Occlusion Lesions: A Critical Appraisal of Current Devices and Techniques

Chronic Total Occlusion (CTO) has been considered as one of the "final frontier" in interventional cardiology. Until recently, the patients with CTO are often managed surgically or medically due to lack of published evidence of clinical benefits and lower success rate of percutaneous recanalization of CTO. However, the introduction of enhanced guidewires, microcatheters combined with novel specialized devices and techniques reduce the number of unapproachable CTO. In this review article, current techniques and devices of percutaneous recanalization of CTO have been systematically summarized, which may help budding interventional cardiologists to theoretically understand these complex procedures and to deliver safe and effective percutaneous management of CTO to the patients.

[Chronic coronary occlusions : When and how should revascularization be performed?]

Chronic occlusion of coronary arteries also known as chronic total occlusions (CTO) are found in approximately 20 % of patients undergoing percutaneous coronary interventions (PCI) and in approximately 50 % of patients after coronary artery bypass grafts (CABG). As a result of technical advancements in retrograde recanalization techniques specialized centers can now achieve success rates of over 85 %, regardless of the CTO anatomy. Given the complexity of retrograde CTO techniques, a consensus paper issued by the Euro CTO Club requires interventional cardiologists to have sufficient experience in antegrade approaches (>300 antegrade CTO cases and >50 per year) with an additional training program (25 retrograde cases each as first and second operating surgeon) before becoming a qualified independent retrograde surgeon. The increased investment in time and technical resources can only be justified if the patient has a clear clinical benefit. This technical advancement and the progressively clearer evidence that complete revascularization can be achieved in patients with multivessel coronary artery disease have attracted growing interest in recent years from interventional cardiologists in the recanalization of CTO.

Safety of Live Case Demonstrations in Patients Undergoing Percutaneous Coronary Intervention for Chronic Total Occlusion

The data regarding the risk and benefits associated with live demonstrations at interventional cardiology congresses are scarce and controversial. We aimed to assess the clinical safety of chronic total occlusion percutaneous coronary intervention (CTO-PCI) procedures during live demonstrations. From January 2008 to December 2013, 739 consecutive patients underwent CTO-PCI at our center, and 199 patients were scheduled to undergo live CTO-PCI demonstrations at cardiology congresses that were globally transmitted to international meetings. The baseline characteristics, procedural complications, and clinical outcomes were compared between the live demonstration group and nonlive demonstration group. The procedural success rates were similar in the live demonstration group than in the nonlive demonstration group (91.5% vs 86.7%, p = 0.076), although the CTO lesions were longer and more tortuous in the live demonstration group (p = 0.029, p = 0.022, respectively). No cases of 30-day mortality were noted in the live demonstration group (0% vs 0.7%, p = 0.28), and no significant differences in procedural complications, such as coronary dissection, coronary perforation, and cardiac tamponade, were observed between the groups (p = 0.53, p = 0.12, and p = 0.40, respectively). The survival rates were similar in the 2 groups at a median follow-up duration of 51.2 ± 28.9 months (log-rank test: p = 0.45). Compared with cases of unsuccessful CTO-PCI, the cases of successful CTO-PCI exhibited improved all-cause survival in both the live and nonlive demonstration groups (log-rank test: p = 0.045, p = 0.0056, respectively). In conclusion, we found that procedural and clinical outcomes of live demonstration CTO-PCI were not significantly different compared with cases undergoing routine CTO-PCI procedures.

Complications encountered in coronary chronic total occlusion intervention: Prevention and bailout

Despite the continuing developments of improved medical devices and increasing operator expertize, coronary chronic total occlusion (CTO) remains as one of the most challenging lesion subsets in interventional cardiology. Percutaneous coronary intervention (PCI) of CTO is a complex procedure carrying the risk of complications that are responsible for significant morbidity and mortality. The complications can be classified as coronary (such as coronary occlusion, perforation, device embolization, or entrapment); cardiac non-coronary (such as periprocedural myocardial infarction); extra cardiac (such as vascular access complications, systemic embolization, contrast-induced nephropathy, and radiation-induced injury). Further, certain complications (such as donor vessel dissection or thrombosis) are unique to CTO-PCI. There are also complications related to specialized techniques, such as dissection/reentry and retrograde crossing techniques. A thorough understanding of the potential complications is critical to mitigate risk during these complex procedures.

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

BACKGROUND

Intravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention.

METHODS AND RESULTS

We 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.

CONCLUSIONS

Intravascular 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.

Recanalization of Chronic Total Occlusions in Patients With Previous Coronary Bypass Surgery and Consideration of Retrograde Access via Saphenous Vein Grafts

Background—

The prevalence of native coronary chronic total occlusions (CTOs) after coronary artery bypass grafts (CABGs) is higher than in non-CABG population. We examined outcomes of CTO percutaneous coronary intervention (PCI) post-CABG versus without CABG. Then, we looked at feasibility and outcomes of retrograde CTO PCI via patent or occluded saphenous vein graft.

Methods and Results—

We compared patient and procedural characteristics of 470 CTO cases treated from January 2010 to December 2015 depending on history of CABG. We assessed major adverse cardiac events, including cardiac death, myocardial infarction, ischemia-driven target-vessel revascularization, or reocclusion 1 year after successful CTO PCI in patients treated before February 2015. Post-CABG patients (175 cases) had a higher J-CTO score (2.5 versus 2.1; P =0.002). In-hospital complications were similar, although the incidence of contrast-induced nephropathy was higher in post-CABG patients (4.6% versus 1%; P =0.01). With multivariable analysis, post-CABG status was associated with higher incidence of 1-year major adverse cardiac event (hazards ratio=2.2; P =0.02). As a second level analysis, we looked at the feasibility and safety of CTO PCI via saphenous vein grafts (19% of post-CABG cases) versus collateral channels (36%) versus with an antegrade-only approach (45%), and assessed short-term outcomes and complications. High success was achieved in the saphenous vein graft group. In-hospital events were similar in the 3 groups.

Conclusions—

Post-CABG CTO PCI is associated with similar high success and low complications compared with CTO PCI in patients who never had CABG. However, it is associated with higher recurrent events at 1 year. To achieve high success rate, use of saphenous vein grafts as retrograde conduits seems to be safe and effective.

Crossing Total Occlusions: Navigating Towards Recanalization

Chronic total occlusions (CTOs) represent the "last frontier" of percutaneous interventions. The main technical challenges lies in crossing the guidewire into the distal true lumen, which is primarily due to three problems: device buckling during initial puncture, inadequate visualization, and the inability to actively navigate through the CTO. To improve the success rate and to identify future research pathways, this study systematically reviews the state-of-the-art of all existing and invented devices for crossing occlusions. The literature search was executed in the databases of Scopus and Espacenet using medical and instrument-related keyword combinations. The search yielded over 840 patents and 69 articles. After scanning for relevancy, 45 patents and 16 articles were included. The identified crossing devices were subdivided based on the determinant for the crossing path through the occlusion, which is either the device (straight and angled crossing), the environment (least resistance, tissue selective, centerline, and subintimal crossing) or the user (directly steered and sensor enhanced crossing). It was found that each crossing path is characterized by specific advantages and disadvantages. For a future crossing device, a combination of crossing paths is suggested were the interventionist is able to exert high forces on the CTO (as seen in the device approach) and actively steer through the CTO (user: directly steered crossing) aided by intravascular imaging (user: sensor enhanced crossing) or an intrinsically safe device following the centerline or path of least resistance (environment: centerline crossing or least resistance crossing) to reach the distal true lumen.

Primary Stenting of Totally Occluded Native Coronary Arteries III (PRISON III): a randomised comparison of sirolimus-eluting stent implantation with zotarolimus-eluting stent implantation for the treatment of total coronary occlusions

AIMS

We investigated whether sirolimus-eluting stents (SES) are superior to next-generation zotarolimus-eluting stents (ZES) in treating patients with total coronary occlusions (TCO).

METHODS AND RESULTS

In a prospective, randomised trial we compared the SES with the zotarolimus-eluting stent (ZES; Endeavor or Resolute) after successful recanalisation of TCO. During the first phase of the trial, 51 patients were assigned to receive the SES and 46 patients to receive the Endeavor ZES. In the second phase we randomised 103 patients to the SES group and 104 patients to the Resolute ZES group. The primary endpoint was in-segment late lumen loss at eight-month follow-up. At eight months, patients in the SES group had less in-segment and in-stent late loss as compared to the Endeavor group: -0.13±0.3 mm vs. 0.27±0.6 mm (p=0.0002) and -0.13±0.5 mm vs. 0.54±0.5 mm (p<0.0001), respectively. In contrast, the SES and the Resolute ZES showed comparable amounts of in-segment (-0.03±0.7 mm vs. -0.10±0.7 mm, p=0.6) and in-stent (0.03±0.8 mm vs. 0.05±0.8 mm, p=0.9) late loss.

CONCLUSIONS

In the treatment of TCOs, the SES was associated with superior angiographic outcomes compared to the Endeavor ZES. On the other hand, the SES and the Resolute ZES showed comparable angiographic outcomes.

Percutaneous Coronary Revascularization for Chronic Total Occlusions: A Novel Predictive Score of Technical Failure Using Advanced Technologies

OBJECTIVES

The aims of this study were to describe the 10-year experience of a single operator dedicated to chronic total occlusion (CTO) and to establish a model for predicting technical failure.

BACKGROUND

During the last decade, the interest in percutaneous coronary interventions (PCIs) of chronic total occlusions (CTOs) has increased, allowing the improvement of success rate.

METHODS

One thousand nineteen patients with CTO underwent 1,073 CTO procedures performed by a single CTO-dedicated operator. The study population was subdivided into 2 groups by time period: period 1 (January 2005 to December 2009, n = 378) and period 2 (January 2010 to December 2014, n = 641). Observations were randomly assigned to a derivation set and a validation set (in a 2:1 ratio). A prediction score was established by assigning points for each independent predictor of technical failure in the derivation set according to the beta coefficient and summing all points accrued.

RESULTS

Lesions attempted in period 2 were more complex in comparison with those in period 1. Compared with period 1, both technical and clinical success rates significantly improved (from 87.8% to 94.4% [p = 0.001] and from 77.6% to 89.9% [p < 0.001], respectively). A prediction score for technical failure including age ≥75 years (1 point), ostial location (1 point), and collateral filling Rentrop grade <2 (2 points) was established, stratifying procedures into 4 difficulty groups: easy (0), intermediate (1), difficult (2), and very difficult (3 or 4), with decreasing technical success rates. In derivation and validation sets, areas under the curve were comparable (0.728 and 0.772, respectively).

CONCLUSIONS

With growing expertise, the success rate has increased despite increasing complexity of attempted lesions. The established model predicted the probability of technical failure and thus might be applied to grading the difficulty of CTO procedures.

Assessment of Inducible Myocardial Ischemia, Quality of Life, and Functional Status After Successful Percutaneous Revascularization in Patients With Chronic Total Coronary Occlusion

The benefits of chronic total coronary occlusion (CTO) revascularization are not well established. In this prospective cohort study, 47 consecutive patients with successful percutaneous recanalization of CTO underwent adenosine stress cardiac magnetic resonance (CMR), 6-minute walk test (6MWT), and the Short Form-36 Health Survey before and 6 months after the procedure. Successful recanalization of a CTO was followed by significant improvement of (1) global physical and mental health status; (2) the distance walked in the 6MWT; (3) the incidence of chest pain at the end of the 6MWT; and (4) the score of a novel CMR ischemic burden index on the basis of the characteristics of adenosine stress perfusion defects (extension, persistence, transmurality, and induced contractile regional dysfunction). Patients with greater CMR ischemic index before percutaneous revascularization showed better improvement in the 6MWT. In conclusion, successful recanalization of a CTO leads to a concurrent improvement in ischemic burden, exercise tolerance, angina frequency, and quality of life scores. Patients with a high ischemic CMR score before CTO recanalization showed the better improvement in exercise tolerance.

Predictors of successful percutaneous coronary intervention in chronic total coronary occlusions

Introduction

Percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) is one of the most challenging procedures of interventional cardiology and is associated with increased risk of significant complications. However, debate continues in regard to which factors adversely influence the success rate of PCI and whether the benefits of revascularization of CTO outweigh the risks and challenges.

Aim

To analyze the relationship between lesion characteristics and overall success rates as well as in-hospital outcomes after PCI for CTO.

Material and methods

We retrospectively examined the procedural outcomes of 173 consecutive native coronary artery CTO PCIs performed from February 2012 to March 2013 (78% men; mean age: 60.3 ±12.1 years).

Results

The CTO target vessel was the right coronary artery (53.8%), circumflex (10.4%) and left anterior descending artery (35.8%), respectively. The retrograde approach was used in 13.9% of all procedures. Successful revascularization was achieved in 83.2% of patients. Major complications occurred in 13.3% of patients. In multivariate analysis, bridge collaterals, severe calcification and tortuosity as well as tandem occlusions were independent predictors of procedural failure, whereas existence of micro-channels was the only predictor of procedural success.

Conclusions

Revascularization of coronary CTOs may be performed with high success and low major complication rates. Bridge collaterals, severe calcification and tortuosity, tandem/multiple occlusions and micro-channels were independent predictors of successful CTO revascularization.

Theory and practical based approach to chronic total occlusions

Coronary chronic total occlusions (CTOs) represent the most technically challenging lesion subset that interventional cardiologists face. CTOs are identified in up to one third of patients referred for coronary angiography and remain seriously undertreated with percutaneous techniques. The complexity of these procedures and the suboptimal success rates over a long period of time, along with the perception that CTOs are lesions with limited scope for recanalization, account for the underutilization of CTO Percutaneous Coronary Intervention (PCI). During the last years, dedicated groups of experts in Japan, Europe and United States fostered the development and standardization of modern CTO recanalization techniques, achieving success rates far beyond 90%, while coping with lesions of increasing complexity. Numerous studies support the rationale of CTO revascularization following documentation of viability and ischemia in the territory distal to the CTO. Successful CTO PCI provide better tolerance in case of future acute coronary syndromes and can significantly improve angina and left ventricular function. Randomized trials are on the way to further explore the prognostic benefit of CTO revascularization. The following review reports on the theory and the most recent advances in the field of CTO recanalization, in an attempt to promote a more balanced approach in patients with chronically occluded coronary arteries.

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)

OBJECTIVES

This study sought to establish a coronary computed tomography angiography prediction rule for grading chronic total occlusion (CTO) difficulty for percutaneous coronary intervention (PCI).

BACKGROUND

The uncertainty of procedural outcome remains the strongest barrier to PCI in CTO.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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).

Procedural outcomes of chronic total occlusion percutaneous coronary intervention: a report from the NCDR (National Cardiovascular Data Registry)

OBJECTIVES

The aim of this study was to describe contemporary frequency, predictors, and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in the United States.

BACKGROUND

CTO PCI can provide significant clinical benefits, yet there is limited information on its success and safety in unselected patient populations.

METHODS

We analyzed the frequency and outcomes of CTO PCI compared with non-CTO PCI in elective patients, and of successful versus failed CTO PCI between July 1, 2009, and March 31, 2013, in the National Cardiovascular Data Registry CathPCI Registry. Generalized estimating equations logistic regression modeling was used to generate independent variables associated with procedural success and procedural complications.

RESULTS

During the study period, CTO PCI represented 3.8% of the total PCI volume for stable coronary artery disease (22,365 of 594,510). Overall, patients undergoing CTO PCI required greater contrast volume and longer fluoroscopy time and had lower procedural success (59% vs. 96%, p < 0.001) and higher major adverse cardiac event (1.6% vs. 0.8%, p < 0.001) rates than non-CTO PCI patients. On multivariable analysis, several parameters (including older age, current smoking, previous myocardial infarction, previous coronary artery bypass graft, previous peripheral arterial disease, previous cardiac arrest, right coronary artery CTO target vessel, and less operator experience) were associated with a lower likelihood of CTO PCI procedural success, whereas operators' annual CTO PCI volume was associated with improved success without a significant increase in major complications.

CONCLUSIONS

CTO PCI is currently performed infrequently in the United States for stable coronary artery disease and is associated with lower procedural success and higher complication rates compared with non-CTO PCI. Procedural success was associated with several patient factors and operator experience.