Immediate results and one-year clinical outcome after percutaneous coronary interventions in chronic total occlusions: data from a multicenter, prospective, observational study (TOAST-GISE)

In-hospital and long-term outcomes after percutaneous coronary intervention for chronic total occlusion in elderly patients: A consecutive, prospective, single-centre study

BACKGROUND

Elderly patients are increasingly referred for complex percutaneous coronary interventions (PCI), including recanalization of chronic total occlusion (CTO).

AIMS

To assess the feasibility, safety and clinical benefits associated with CTO-PCI in elderly patients.

METHODS

Consecutive patients (n=356) who underwent CTO-PCI in our institution between January 2008 and December 2011 were prospectively included. The short-term outcomes of CTO-PCI were assessed by comparing the rates of successful recanalization and postoperative complications in patients aged ≥ 75 years and those < 75 years. The clinical effect of successful recanalization was evaluated in a 20-month follow-up analysis in patients ≥ 75 years.

RESULTS

Although patients ≥ 75 years (n = 93) had more complex coronary artery disease, the procedural success rate was similar to that in younger patients (78.2% vs. 74.3%, respectively; P = 0.41). Postoperative complications were more frequent in older patients (5.4% vs. 0.4%; P = 0.005). Major adverse cardiac event-free survival analysis at 20 months revealed that successful revascularization was indicative of a better prognosis in older patients (hazard ratio: 0.43, 95% confidence interval: 0.19-0.96; P = 0.039).

CONCLUSION

Elderly patients have more complex coronary disease and are at a higher risk of postoperative complications. Nevertheless, we observed a similar success rate for CTO-PCI in elderly patients as for younger patients. Successful CTO recanalization improved the event-free survival rate at 20 months. Thus, CTO-PCI constitutes an alternative strategy for treating selected elderly patients.

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

OBJECTIVES

The J-CTO score is based on invasive angiography, combines several parameters of chronic total coronary occlusions (CTO), and is well established to predict the likelihood of success of percutaneous recanalization. The purpose of this study was to evaluate and validate a J-CTOCT score derived from coronary computed tomography angiography (coronary CTA).

METHODS

Between April 2011 and December 2014, 159 consecutive patients were retrospectively included. All had at least one CTO in invasive angiography, had coronary CTA performed at an interval of no more than one week from invasive angiography, and had an attempt at percutaneous coronary intervention (PCI) following coronary CTA In parallel to the angiographic J-CTO score, the J-CTOCT score was determined by awarding one point each for a blunt vessel stump, bending > 45°, occlusion length ≥ 20 mm, presence of calcium covering > 50% of any vessel cross-section within the occlusion, or a previously failed attempt at PCI. a. Both scores were compared regarding their ability to predict successful recanalization.

RESULTS

A total of 171 CTO lesions were analyzed. Intraobserver (k = 0.814, p < 0.001) and interobserver agreement (k = 0.771, p < 0.001) for calculation of the J-CTOCT score were close. The mean occlusion length measured by coronary CTA was significantly shorter than in invasive angiography (27.6 ± 14.8 mm vs. 37.2 ± 18.8 mm, p < 0.001). The J-CTOCT score (mean: 1.9 ± 1.4) correlated closely to the angiographic J-CTO score (mean: 1.8 ± 1.3, r = 0.856, p < 0.001), and in 122/171 lesions (71%), the scores were identical. Both J-CTOCT score (area under curve: 0.882, p < 0.001) and angiographic J-CTO score (area under curve: 0.868, p < 0.001) yielded similarly high predictive value for successful guidewire crossing within 30 min (p = 0.496).

CONCLUSIONS

While the length of coronary occlusions in coronary CTA is significantly shorter than in invasive angiography, a J-CTOCT score determined by coronary CTA closely correlates to the angiographic J-CTO score. .

The evidence base for revascularisation of chronic total occlusions

When patients with ischaemic heart disease are considered for revascularisation the Heart Team's aim is to choose a therapy that will provide complete relief of angina for an acceptable procedural risk. Complete functional revascularisation of ischaemic myocardium is thus the goal and for this reason the presence of a chronic total occlusion (CTO) - which remain the most technically challenging lesions to revascularise percutaneously - is the most common reason for selecting coronary artery bypass surgery. From the behaviour of Heart Teams it is clear that physicians believe that CTOs are important. Yet when faced with patients with CTOs for whom surgery appears excessive (e.g. nonproximal LAD) or too high risk, there remains a reluctance to undertake CTO PCI, despite significant recent advances in procedural success and safety and a considerable body of evidence supporting a survival benefit following successful CTO PCI. This article reviews the relationship between CTOs, symptoms of angina, ischaemia and left ventricular dysfunction and further explores the evidence relating their treatment to improved quality of life and prognosis in patients with these features.

Utility of the SYNTAX score in predicting outcomes after coronary intervention for chronic total occlusion

BACKGROUND

Chronic total occlusion (CTO) lesions are a challenging issue. When dealing with complex CTO lesions in patients undergoing percutaneous coronary intervention (PCI), it is important to evaluate not only the CTO lesion itself but also atherosclerotic lesions of the whole coronary artery tree. The utility of the SYNTAX (Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery Trial) score in patients with CTO undergoing PCI is unclear.

METHODS

This retrospective study included 304 consecutive patients with CTO lesions who underwent PCI. Primary endpoints were procedural failure and major adverse cardiac events (MACE) within 30 days. The SYNTAX and J-CTO (Multicenter CTO Registry in Japan) scores were assessed before the procedures, and patients were divided into two groups according to SYNTAX criteria: high (> 22; n = 158) and low (≤ 22; n = 146) SYNTAX scores.

RESULTS

Procedural success was achieved in 252 patients (82.9 %). Patients with a high SYNTAX score had significantly lower procedural success than those with a low SYNTAX score (74.7 % versus 91.8 %, p < 0.0001). There were 13 MACE (8.2 %) in patients with high SYNTAX scores and two MACE (1.4 %) in those with low scores. The SYNTAX and J-CTO scores had odds ratios of 3.33 (95 %CI, 1.44-7.74) and 3.64 (95 %CI, 1.24-10.66) for procedural failure. A higher SYNTAX score (> 22) was also an independent predictor of 30-day MACE after PCI (odds ratio = 4.80, 95 %Cl 1.03-22.42).

CONCLUSION

The SYNTAX score is predictive of procedural failure, as is the J-CTO score. Furthermore, a higher SYNTAX score is strongly associated with an increased risk of 30-day MACE. The SYNTAX score is useful for clinical decision making when treating patients with complex CTO lesions.

Current trends in patients with chronic total occlusions undergoing coronary CT angiography

OBJECTIVE

Data describing the prevalence, characteristics and management of coronary chronic total occlusions (CTOs) in patients undergoing coronary CT angiography (CCTA) have not been reported. The purpose of this study was to determine the prevalence, characteristics and treatment strategies of CTO identified by CCTA.

METHODS

We identified 23 745 patients who underwent CCTA for suspected coronary artery disease (CAD) from the prospective international CCTA registry. Baseline clinical data were collected, and allocation to early coronary revascularisation performed within 90 days of CCTA was determined. Multivariable hierarchical mixed-effects logistic regression reporting OR with 95% CI was performed.

RESULTS

The prevalence of CTO was 1.4% (342/23 745) in all patients and 6.2% in patients with obstructive CAD (≥50% stenosis). The presence of CTO was independently associated with male sex (OR 3.12, 95% CI 2.39 to 4.08, p<0.001), smoking (OR 2.02, 95% CI 1.55 to 2.64, p<0.001), diabetes (OR 1.60, 95% CI 1.22 to 2.11, p=0.001), typical angina (OR 1.51, 95% CI 1.12 to 2.06, p=0.008), hypertension (OR 1.47, 95% CI 1.14 to 1.88, p=0.003), family history of CAD (OR 1.30, 95% CI 1.01 to 1.67, p=0.04) and age (OR 1.06, 95% CI 1.05 to 1.07, p<0.001). Most patients with CTO (61%) were treated medically, while 39% underwent coronary revascularisation. In patients with severe CAD (≥70% stenosis), CTO independently predicted revascularisation by coronary artery bypass grafting (OR 3.41, 95% CI 2.06 to 5.66, p<0.001), but not by percutaneous coronary intervention (p=0.83).

CONCLUSIONS

CTOs are not uncommon in a contemporary CCTA population, and are associated with age, gender, angina status and CAD risk factors. Most individuals with CTO undergoing CCTA are managed medically with higher rates of surgical revascularisation in patients with versus without CTO.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT01443637.

Prediction of residual angina after percutaneous coronary intervention

Aims

Angina relief is a major goal of percutaneous coronary intervention (PCI); however, about one in five patients continue to have angina after PCI. Understanding patient factors associated with residual angina would enable providers to more accurately calibrate patients' expectations of angina relief after PCI, may support different follow-up strategies or approaches to coronary revascularization, and could potentially serve as a marker of PCI quality.

Methods and results

Among 2573 patients who had PCI at 10 US hospitals for stable angina, unstable angina, or non-ST-elevation myocardial infarction (NSTEMI), 24% reported angina 6 months after PCI, as assessed with the Seattle Angina Questionnaire angina frequency score (categorized as none vs. any angina; score = 100 vs. <100). Post-PCI angina was more common in those patients treated for unstable angina (30 vs. 20% stable angina and 21% NSTEMI, P < 0.001). Using a hierarchical logistic regression model, eight variables were independently associated with angina after PCI, including younger age, poor economic status, depression, and greater number of antianginal medications at the time of PCI (c-index = 0.75). The amount of angina at the time of PCI was more predictive of post-PCI angina in patients with stable or unstable angina when compared with NSTEMI (pinteraction = 0.01). The model demonstrated excellent calibration, both in the original sample (slope 1.04, intercept -0.01, r = 0.98) and in bootstrap validation.

Conclusion

Based on a large, multicentre cohort of PCI patients, we created a model of residual angina 6 months after PCI that can provide patients realistic expectations of angina relief, guide follow-up strategies, support the use of residual angina as a means of comparing PCI quality, and enable comparative effectiveness research.

Value of Hybrid Imaging with PET/CT to Guide Percutaneous Revascularization of Chronic Total Coronary Occlusion

Chronic total coronary occlusions (CTO) are documented in approximately one fifth of diagnostic invasive coronary angiographies (ICA). Percutaneous coronary interventions (PCI) of CTO are challenging and are accompanied by higher complication and lower success rates in comparison with non-CTO PCI. Scrutinous evaluation of ischemia and viability to justify percutaneous revascularization is therefore of importance to select eligible patients for such a procedure. Furthermore, knowledge of the anatomical features of the occlusion may predict the chances of success of PCI CTO and could even guide the procedural strategy to augment the likelihood of recanalization. Positron emission tomography (PET) is unequivocally accepted as the reference standard for ischemia and viability testing, whereas coronary computed tomography angiography (CCTA) currently allows for non-invasive detailed three-dimensional imaging of the coronary anatomy that adds morphological information over two-dimensional ICA. Hybrid PET/CT could therefore be useful for optimal patient selection as well as procedural planning. This review discusses the potential value of PET/CT to guide PCI in CTOs.

Ventricular tachycardic storm with a chronic total coronary artery occlusion treated with percutaneous coronary intervention

A 66-year-old man with a history of coronary artery disease was evaluated due to ventricular tachycardic (VT) storm. The patient continued to have frequent recurrences of VT despite treatment with amiodarone and lidocaine. Since the ventricular arrhythmia could be related to myocardial ischemia related to a chronic total occlusion (CTO) of the right coronary artery, the patient underwent successful percutaneous coronary intervention of the CTO, followed by implantable cardioverter defibrillator implantation. He had no further episodes of VT during his hospital stay. After 9 months of follow-up, he had no further chest pain or clinically apparent recurrent ischemia. Interrogation of his defibrillator has shown brief nonsustained episodes of ventricular tachycardia, but the patient has not required delivery of a shock. The temporal association between treatment of the CTO and resolution of the VT, as well as the lack of recurrence of sustained VT, suggest a causative link between underlying ischemia produced by a chronically occluded coronary artery and provocation of VT and lend supportive evidence to this treatment approach.

Drug-eluting stent thrombosis in the treatment of chronic total coronary occlusions: incidence, presentation and related factors. Data from the CIBELES trial

INTRODUCTION AND OBJECTIVES

The aim of this study was to analyze the incidence of drug-eluting stent thrombosis (sirolimus or everolimus) in patients with chronic total coronary occlusions (CTO) and to determine its clinical implications and related factors.

METHODS

Data from the 12-month follow-up of the 207 patients included in the CIBELES trial with CTO were analyzed.

RESULTS

Stent thrombosis occurred in three patients, two definite and one probable (overall thrombosis rate: 1.4%). However, there were no cases of death or Q-wave myocardial infarction. In univariate analysis, patients with a higher incidence of stent thrombosis were those in whom the target vessel was the left anterior descending, who had single-vessel disease, were assigned to treatment with sirolimus-eluting stents, and those with smaller minimum luminal diameter immediately after the procedure. In multivariate analysis, the only independent predictor of stent thrombosis was minimal luminal diameter immediately after the procedure.

CONCLUSIONS

The rate of drug-eluting stent thrombosis in patients with CTO is relatively low (1.4%). The only independent predictor of stent thrombosis in this context was minimal luminal diameter after the procedure and the clinical presentation was in all cases relatively benign.

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

BACKGROUND

The hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly increased procedural success rates, yet some cases still fail. We sought to evaluate the causes of failure in a contemporary CTO PCI registry.

METHODS

We examined 380 consecutive patients who underwent CTO-PCI at 4 high volume CTO PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, complication, and efficiency outcomes were compared between successful and failed cases. Failed cases were individually reviewed by an independent reviewer to determine the cause of failure.

RESULTS

Procedural success was 91.3%. Compared with patients in whom CTO PCI was successful, those in whom CTO PCI failed had similar baseline clinical characteristics, but were more likely to have longer occlusion length, more tortuosity, more proximal cap ambiguity and blunt stump, and higher mean J-CTO scores (2.8 ± 1.1 vs. 3.5 ± 1.0, P < 0.001), and less likely to have collaterals suitable for the retrograde approach (66% vs. 45%, P = 0.021). Failure was due to a complication in 10 cases (30%). In the remaining 23 cases (70%) failure was due to inability to wire the lesion (n = 21, 4 of which were CTOs due to in-stent restenosis), or poor antegrade flow after PCI (n = 5).

CONCLUSIONS

Compared with successful cases, failed CTO-PCI cases are more likely to have higher J-CTO scores, longer occlusion length, ambiguous proximal cap and no appropriate collaterals for retrograde crossing. Development of novel CTO crossing techniques is needed to further increase CTO PCI success rates.

Percutaneous coronary intervention to treat chronic total occlusion: predictors of technical success and one-year clinical outcome

We investigated the overall success rate of percutaneous coronary intervention (PCI) as a treatment for coronary chronic total occlusion and sought to determine the predictive factors of technical success and of one-year major adverse cardiac events (MACE). These factors have not been conclusively defined. Using data from our single-center PCI registry, we enrolled 269 consecutive patients (mean age, 56.13 ± 10.72 yr; 66.2% men) who underwent first-time PCI for chronic total occlusion (duration, ≥3 mo) from March 2006 through September 2010. We divided them into 2 groups: procedural success and procedural failure. We compared occurrences of in-hospital sequelae and one-year MACE between the groups, using multivariate models to determine predictors of technical failure and one-year clinical outcome. Successful revascularization was achieved in 221 patients (82.2%). One-year MACE occurred in 13 patients (4.8%), with a predominance of target-vessel revascularization (3.7%). The prevalence of MACE was significantly lower in the procedural-success group (1.8% vs 18.8%; P <0.001). In the multivariate model, technical failure was the only predictor of one-year MACE. The predictors of failed procedures were lesion location, multivessel disease, the occurrence of dissection, a Thrombolysis In Myocardial Infarction flow grade of 0 before PCI, the absence of tapered-stump arterial structure, and an increase in serum creatinine level or lesion length. In our retrospective, observational study, PCI was successful in a high percentage of chronic total occlusion patients and had a low prevalence of complications. This suggests its safety and effectiveness as a therapeutic option.

Revascularization of lower extremity chronic total occlusions with a novel intraluminal recanalization device: results of the ReOpen study

PURPOSE

To report outcomes of a multicenter, nonrandomized study evaluating the safety and effectiveness of a guidewire-mounted mechanical recanalization device with a rotating distal tip (TruePath) in facilitating the crossing of infrainguinal chronic total occlusions (CTOs).

METHODS

Eligible patients had lower extremity ischemia and an angiographically confirmed occlusion, with no antegrade flow for at least 30 days, in an infrainguinal artery. Enrollment occurred when a previous or concurrent attempt to cross the CTO with a conventional guidewire had failed. A total of 85 patients with 85 lesions were enrolled; 61 (71.8%) target lesions were in the superficial femoral artery and 68 (80%) were considered moderately or heavily calcified. Clinical evaluations were assessed immediately post procedure and at 30-day follow-up.

RESULTS

Freedom from clinical perforation at the time of the procedure was achieved in 98.8% of patients. The device facilitated CTO crossing into the distal true lumen (technical success) in 68 (80.0%) patients, with subsequent distal guidewire positioning in 65 (76.5%). The average ABI (n=58) improved from 0.65 (range 0.35-1.20) at baseline to 1.00 (range 0.50-2.00) through 30-day follow-up. Symptoms improved in 70 (82.4%) patients upon treatment, and improvement was maintained in 57/70 (81.4%) through 30 days.

CONCLUSION

The ReOpen Study demonstrated that the TruePath device is safe and effective for facilitating crossing of CTOs resistant to conventional guidewire maneuvers.

Quality of life benefits of percutaneous coronary intervention for chronic occlusions

OBJECTIVES

We aimed to compare quality of life benefits of percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) with non-CTO PCI.

BACKGROUND

Data quantifying the benefits of PCI of CTO are inconsistent.

METHODS

We leveraged a 10-center prospective PCI registry including Seattle Angina Questionnaire (SAQ) assessment at the time of PCI and in follow-up. We propensity matched attempted CTO PCIs with up to 10 non-CTO PCIs. The primary analysis compared changes between baseline and 6 months in SAQ Physical Limitation (PL), Quality of Life (QoL); Angina Frequency (AF) scores as well as the Rose Dyspnea scores (RDS) and the EQ5D Visual Analogue Scale (VAS). Noninferiority was assessed for quality of life changes between CTO and non-CTO PCI.

RESULTS

In 3,303 patients enrolled, 167 single-vessel CTOs were attempted; 147 (88%) were matched with 1,616 non-CTO PCI. Baseline PL (73.0 vs. 77.4, P = 0.039) and VAS (66.4 vs. 70.8, P = 0.005) scores were lower for CTO. There was no difference in AF, QoL, or RDS scores. At 6-month follow-up, all SAQ scores improved (P < 0.05 vs. baseline for all) and were equivalent for CTO and Non-CTO (P = NS for all). VAS scores remained lower for CTO, but improved in both groups (P < 0.05 vs. baseline for both). Formal noninferiority testing demonstrated that CTO PCI was not inferior to non-CTO PCI (P ≤ 0.02 for all).

CONCLUSIONS

Symptoms, function, QoL, and dyspnea improve to the same degree following CTO PCI as compared with non-CTO PCI. Symptom relief supports CTO PCI to improve patients' quality of life.

Dedicated devices and techniques - a cornerstone in recanalisation of chronic total occlusions of coronary arteries

Recanalisation of chronic total occlusion (CTO) is still a challenge in invasive cardiology, requiring operator experience, equipment, and techniques dedicated to CTO. Due to difficulties in crossing the lesion by wire and by balloon (both responsible for 98% of the procedure's failures), many helpful techniques have been described. We report the case of both Tornus system and anchor technique in successful recanalisation of a right coronary artery.

Percutaneous Treatment of Coronary Chronic Total Occlusions Part 1: Rationale and Outcomes

Coronary chronic total occlusions (CTOs) are commonly encountered in patients with coronary artery disease. Compared to patients without coronary CTOs, those with CTO have worse clinical outcomes and lower likelihood of complete coronary revascularisation. Successful CTO percutaneous coronary intervention (PCI) can significantly improve angina and improve left ventricular function. Although currently unproven, successful CTO PCI might also reduce the risk for arrhythmic events in patients with ischaemic cardiomyopathy, provide better tolerance of future acute coronary syndrome, and possibly improve survival. Evaluation by a heart team comprised of both interventional and non-interventional cardiologists and cardiac surgeons is important for determining the optimal revascularisation strategy in patients with coronary artery disease and CTOs. Ad hoc CTO PCI is generally not recommended, so as to allow sufficient time for (a) discussion with the patient about the indications, goals, risks, and alternatives to PCI; (b) careful procedural planning; and (c) contrast and radiation exposure minimisation. Use of drug-eluting stents is recommended for CTO PCI, given the lower rates of angiographic restenosis compared to bare metal stents.

New Advances in Chronic Total Occlusions

Coronary chronic total occlusions (CTOs) still represent the greatest technical challenge that interventional cardiologists face. CTOs remain seriously undertreated with percutaneous techniques, far below their prevalence. One reason for the low uptake was the suboptimal CTO percutaneous coronary intervention (PCI) success rates over a long period of time. During the last years, dedicated groups of experts in Japan, Europe and United States fostered the development and standardisation of modern CTO recanalisation techniques, along with providing focused training and proctorship worldwide. As a result, dedicated operators achieved success rates far beyond 90 %, while coping with lesions of increasing complexity. A series of studies, mainly retrospective and observational in nature, explored the prognostic impact of CTO PCI, revealing that successful lesion recanalisation is related to improved patient outcome and anginal status; further evidence from randomised trials is on the way. The following review reports on the most recent advances in the field of CTO recanalisation, in an attempt to promote a more balanced approach in patients with chronically occluded coronary arteries and encourage more operators to cope with these inherently complex lesions.

Application of the "hybrid approach" to chronic total occlusions in patients with previous coronary artery bypass graft surgery (from a Contemporary Multicenter US registry)

Percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) has been traditionally associated with lower success rates in patients with previous coronary artery bypass graft surgery (CABG). We sought to examine the success and complication rates of CTO PCI using the "hybrid" crossing algorithm among patients with a history of previous CABG. The procedural outcomes of 496 consecutive CTO PCIs performed at 5 high-volume PCI centers in the United States from January 2012 to August 2013 were assessed. The outcomes of patients with previous CABG were compared with those of patients without previous CABG. Compared with patients without previous CABG (n = 320), patients with previous CABG (n = 176, 35%) were older, had more coronary artery disease risk factors, and had less favorable baseline angiographic CTO characteristics. Technical and procedural success was slightly lower among patients with previous CABG (88.1% vs 93.4%, p = 0.044 and 87.5 vs 92.5%, p = 0.07, respectively). Patients with previous CABG more commonly underwent CTO PCI using the retrograde approach (39% vs 24%, respectively, p <0.001) and received higher air kerma radiation exposure (4.8 [interquartile range 3.0 to 6.4] vs 3.1 [1.9 to 5.3] Gray, p <0.001) and fluoroscopy time (59 [38 to 77] vs 34 [21 to 55] minutes, p <0.001). Major procedural complications were similar in the 2 groups: 2 of 176 (1.1%) patients with previous CABG versus 7 of 320 (2.1%) patients without previous CABG (p = 0.40). In conclusion, with application of the "hybrid" approach to CTO PCI, success was slightly lower, and complication rates were similar between patients with and without previous CABG.

Contemporary overview and clinical perspectives of chronic total occlusions

Chronic total occlusions (CTOs) are often detected on diagnostic coronary angiograms, but percutaneous coronary intervention (PCI) for CTO is currently infrequently performed owing to high technical difficulty, perceived risk of complications, and a lack of randomized data. However, successful CTO-PCI can significantly increase a patient's quality of life, improve left ventricular function, reduce the need for subsequent CABG surgery, and possibly improve long-term survival. A number of factors must be taken into account for the selection of patients for CTO-PCI, including the extent of ischaemia surrounding the occlusion, the level of myocardial viability, coronary location of the CTO, and probability of procedural success. Moreover, in patients with ST-segment elevation myocardial infarction, a CTO in a noninfarct-related artery might lead to an increase in infarct area, increased end-diastolic left ventricular pressure, and decreased left ventricular function, which are all associated with poor clinical outcomes. In this Review, we provide an overview of the anatomy and histopathology of CTOs, perceived benefits of CTO-PCI, considerations for patient selection for this procedure, and a summary of emerging techniques for CTO-PCI.

Advances in the management of coronary chronic total occlusions

Chronic total occlusions (CTOs) have been called "the last frontier" of percutaneous coronary intervention (PCI) due to traditionally low success rates and high risk for restenosis and re-occlusion. Recent advances in equipment and crossing techniques have significantly increased CTO PCI success rates while maintaining low risk of complications. Specifically, the retrograde approach and controlled antegrade dissection and re-entry in conjunction with advanced guidewires and microcatheters have significantly improved procedural success rates. Moreover, the introduction of the "hybrid" approach has created a unified framework for operators to approach CTOs in a systematic and efficient fashion. Finally, drug-eluting stents, especially second generation, have improved long-term patency after CTO PCI.

Meta-analysis of the effect of percutaneous coronary intervention on chronic total coronary occlusions

Background and purpose

Coronary chronic total occlusion (CTO) is the last stage of coronary artery atherosclerosis. Percutaneous coronary intervention (PCI) is a therapeutic procedure used to recanalize vessels with total occlusion. However, successful recanalization of CTO is still not optimal, and the key influence factors are still uncertainty. Therefore, a scientific evaluation on the effective of PCI for CTO treatment is necessary.

Methods

Relevant studies of PCI treatment for CTO were examined. Data were extracted and assessed by two independent clinical experts. Embase, PubMed and Medline et al. were used as database. The main research key words include “CTO”, “PCI”, “Stent”, “Reopen”, “long-term”, “follow-up” and “outcome”. Quality assessment was carried out according to the Cochrane Handbook. The selected data were pooled and analyzed using fixed-effect model and random-effect model. Heterogeneity was assessed using the I² test, Q test, L’abbe and Galbraith. Comprehensive Meta -Analysis 2.0 and Metanalysis 1.0 were used for statistics analysis in this research.

Results

A total of 16 articles involving 6695 cases in successful CTO recanalization (CTO success group) and 2370 cases in failed CTO recanalization(CTO failure group) were included in this research. Low CTO success was associated with elder age, previous coronary artery bypass graft surgery (CABG) history, multi-vessel diseases and right coronary artery disease lesion. Six follow-up variables including major adverse cardiac events (MACE), recurrent myocardial infarction (MI), all-cause death, incidence of angina, subsequent CABG and cumulative survival rate were found significantly reduced associated with CTO success.

Conclusions

Clinical baseline characteristics such as age, previous CABG history and lesion baseline characteristics such as lesion length, multi-vessel diseases might be important factors influencing the successful rate of CTO recanalization. Compared to CTO failure patients, all six follow-up variables showed advantage for CTO success patients.

Collateral vessel opacification with CT in patients with coronary total occlusion and its relationship with downstream myocardial infarction

PURPOSE

To assess the correlation between the filling pattern of distal coronary vessels in patients with chronic total occlusion (CTO) observed at coronary computed tomographic (CT) angiography and the extent of downstream myocardial infarction (MI).

MATERIALS AND METHODS

All patients gave written informed consent, and the institutional review board approved the study protocol. A total of 97 patients (mean age, 68.5 years ± 11.5 [standard deviation]; age range, 38-87 years; 77 men, 20 women) with 106 CTOs were prospectively enrolled. Distal filling of the epicardial segment was semiquantitatively classified by using a four-point scale according to patterns at coronary CT angiography (0 = absence of distal filling; 1 = partial distal filling, with a length less than one-third of the segment; 2 = partial distal filling, with a length between one-third and two-thirds of the segment; 3 = complete or partial distal filling, with a length longer than two-thirds of the segment). A coronary CT angiography score of 3 was considered indicative of well-developed collaterals. Downstream MI transmurality and wall motion abnormality were verified semiquantitatively with cardiac magnetic resonance imaging. Mann-Whitney U test and t test were used for comparison.

RESULTS

Coronary CT angiography revealed three lesions with a score of 0, 21 with a score of 1, 35 with a score of 2, and 47 with a score of 3. The non-MI subgroup was associated with higher collateral grading at CT angiography, whereas the transmural MI subgroup was associated with lower collateral grading (P = .005). When compared with the poorly developed (score 0-2) collaterals group, the well-developed (score 3) collateral group correlated to a lower summed transmurality score (P < .001) and a lower summed regional wall motion abnormality score (P = .029).

CONCLUSION

The presence of well-developed distal collaterals as revealed by coronary CT angiography in patients with CTO lesions correlates with the lower frequency and extent of downstream MI.

Percutaneous coronary intervention for multiple chronic total occlusions

No data exist about successful percutaneous coronary intervention (PCI) and clinical outcome in patients with multiple coronary chronic total occlusions (CTOs). The aim of this study was to determine the impact on cardiac mortality of PCI of multiple CTOs. The Florence CTO PCI registry includes patients treated with drug-eluting stent for at least 1 CTO. From this registry, we examined consecutive patients with ≥2 CTOs. Patients were stratified into successful PCI of all attempted CTOs and partially successful PCI (1 CTO PCI successful) or failed PCI (no CTO PCI success) groups. The primary end point of the study was cardiac mortality. Of 1,035 patients with CTO, 120 (11.6%) underwent PCI for ≥2 CTOs for a total of 249 CTOs. CTO PCI was successful in 195 CTOs (78.3%), and in 76 patients (63.3%), PCI was successful in all attempted lesions, whereas in 34 patients, CTO PCI was partially successful and in 10, completely unsuccessful. Cardiac mortality at 12 months was lower in the CTO PCI success group than CTO PCI failure or partial success group (1.3% vs 11.3%; p = 0.025). The 2-year survival rate was lower in patients with a complete coronary revascularization compared with those with incomplete revascularization (96 ± 3% vs 78 ± 7%; p = 0.002); completeness of revascularization was inversely related to the risk of death (hazard ratio 0.10; p = 0.029). In patients with multiple CTOs, a successful PCI of all CTOs was associated with increased survival and completeness of revascularization was a strong predictor of survival.

Use of ranolazine in patients with incomplete revascularization after percutaneous coronary intervention: design and rationale of the Ranolazine for Incomplete Vessel Revascularization Post-Percutaneous Coronary Intervention (RIVER-PCI) trial

BACKGROUND

Incomplete revascularization (ICR) after percutaneous coronary intervention (PCI) is common and is associated with increased rates of rehospitalization, revascularization, and mortality. Adjunctive pharmacotherapy with ranolazine, an inhibitor of the late sodium current with anti-ischemic properties, may be effective in reducing recurrent events after PCI in patients with ICR.

TRIAL DESIGN

RIVER-PCI is a phase 3, randomized, double-blind, placebo-controlled, international event-driven clinical trial evaluating the efficacy of ranolazine in patients with a history of chronic angina and ICR after PCI. Approximately 2,600 participants with ICR post-PCI will be randomized in a 1:1 ratio to ranolazine or matched placebo within 14 days of an index PCI. The primary end point of the trial is time to the first occurrence of ischemia-driven revascularization or ischemia-driven hospitalization without revascularization. Participants will be followed up for a minimum of 1 year and until at least 720 confirmed primary end point events have occurred. Secondary end points include sudden cardiac death, cardiovascular death, myocardial infarction, and measures of quality of life and cost-effectiveness. The evaluation of long-term safety will include all-cause mortality, stroke, transient ischemic attack, and hospitalization for heart failure. Enrollment commenced in November 2011 and was completed in summer 2013.

CONCLUSIONS

RIVER-PCI is a novel, large-scale, international, randomized, double-blind, placebo-controlled clinical trial evaluating the role of ranolazine in the long-term medical management of patients with ICR post-PCI.

Comparison of pathology of chronic total occlusion with and without coronary artery bypass graft

AIMS

The aim of our study was to investigate chronic total occlusion (CTO) in human coronary arteries to clarify the difference between CTO with prior coronary artery bypass graft (CABG) and those without prior CABG.

METHODS AND RESULTS

A total of 95 CTO lesions from 82 patients (61.6 ± 14.0 years, male 87.8%) were divided into the following three groups: CTO with CABG (n = 34) (CTO+CABG), CTO without CABG--of long-duration (n = 49) (LD-CTO) and short-duration (n = 12) (SD-CTO). A histopathological comparison of the plaque characteristics of CTO, proximal and distal lumen morphology, and negative remodelling between groups was performed. A total of 1127 sections were evaluated. Differences in plaque characteristics were observed between groups as follows: necrotic core area was highest in SD-CTO (18.6%) (LD-CTO: 7.8%; CTO+CABG: 4.5%; P = 0.02); calcified area was greatest in CTO+CABG (29.2%) (LD-CTO: 16.8%; SD-CTO: 12.1%; P = 0.009); and negative remodelling was least in SD-CTO [remodelling index (RI) 0.86] [CTO+CABG (RI): 0.72 and LD-CTO (RI): 0.68; P < 0.001]. Approximately 50% of proximal lumens showed characteristics of abrupt closure, whereas the majority of distal lumen patterns were tapered (79%) (P < 0.0001).

CONCLUSION

These pathological differences in calcification, negative remodelling, and presence of necrotic core along with proximal and distal tapering, which has been associated with greater success, help explain the differences in success rates of percutaneous coronary intervention in CTO patients with and without CABG.