Coils embolization use for coronary procedures: Basics, indications, and techniques.

The use of coils is fundamental in interventional cardiology and can be lifesaving in selected settings. Coils are classified by their materials into bare metal, fiber coated, and hydrogel coated, or by the deliverability method into, pushable or detachable coils. Coils are delivered through microcatheters and the choice of coil size is important to ensure compatibility with the inner diameter of the delivery catheter, firstly to be able to deliver and secondly to prevent the coil from being stuck and damaged. Clinically, coils are used in either acute or in elective setting. The most important acute indication is typically the sealing coronary perforation. In the elective settings, coils can be used for the treatment of certain congenital cardiac abnormalities, aneurysms, fistulas or in the treatment of arterial side branch steal syndrome after CABG. Coils must always be delivered under fluoroscopy guidance. There are some associated complications with coils that can be acute or chronic, that nictitates regular followed-up. There is a need for education, training and regular workshops with hands-on to build the experience to use coils in situations that are infrequently encountered.

Definitions and Clinical Trial Design Principles for Coronary Artery Chronic Total Occlusion Therapies: CTO-ARC Consensus Recommendations.

Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence.

Extraplaque versus intraplaque tracking in chronic total occlusion percutaneous coronary intervention.

OBJECTIVE: To compare the clinical outcomes after extraplaque (EP) versus intraplaque (IP) tracking in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: The impact of modern dissection and reentry (DR) techniques on the long-term outcomes of CTO PCI remains controversial. METHODS: We performed a systematic review and meta-analysis of studies that compared EP versus IP tracking in CTO PCI. Odds ratios (ORs) with 95% confidence intervals (CIs) are calculated using the Der-Simonian and Laird random-effects method. RESULTS: Our meta-analysis included seven observational studies with 2982 patients. Patients who underwent EP tracking had significantly more complex CTOs with higher J-CTO score, longer lesion length, and more severe calcification and had significantly longer stented segments. During a median follow-up of 12 months (range 9-12 months), EP tracking was associated with a higher risk of major adverse cardiovascular events (MACE) (OR 1.50, 95% CI (1.10-2.06), p = 0.01) and target vessel revascularization (TVR) (OR 1.69, 95% CI (1.15-2.48), p = 0.01) compared with IP tracking. There was no difference in the incidence of all-cause death (OR 1.37, 95% CI (0.67-2.78), p = 0.39), myocardial infarction (MI) (OR 1.48, 95% CI (0.82-2.69), p = 0.20), stent thrombosis (OR 2.09, 95% CI (0.69-6.33), p = 0.19), or cardiac death (OR 1.10, 95% CI (0.39-3.15), p = 0.85) between IP and EP tracking. CONCLUSION: EP tracking is utilized in more complex CTOs and requires more stents. EP tracking is associated with a higher risk of MACE, driven by a higher risk of TVR at 1 year, but without an increased risk of death or MI compared with IP tracking. EP tracking is critically important for contemporary CTO PCI.

Outcomes with retrograde versus antegrade chronic total occlusion revascularization.

OBJECTIVES: The aim of the study was to evaluate the outcomes of retrograde versus antegrade approach in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: The retrograde approach has increased the success rate of CTO PCI but has been associated with a higher risk for complications. METHODS: We conducted a meta-analysis of studies published between 2000 and August 2019 comparing the in-hospital and long-term outcomes with retrograde versus antegrade CTO PCI. RESULTS: Twelve observational studies (10,240 patients) met our inclusion criteria (retrograde approach 2,789 patients, antegrade approach 7,451 patients). Lesions treated with the retrograde approach had higher J-CTO score (2.8 vs. 1.9, p < .001). Retrograde CTO PCI was associated with a lower success rate (80.9% vs. 87.4%, p < .001). Both approaches had similar in-hospital mortality, urgent revascularization, and cerebrovascular events. Retrograde CTO PCI was associated with higher risk of in-hospital myocardial infarction (MI; odds ratio [OR] 2.37, 95% confidence intervals [CI] 1.7, 3.32, p < .001), urgent pericardiocentesis (OR 2.53, 95% CI 1.41-4.51, p = .002), and contrast-induced nephropathy (OR 2.12, 95% CI 1.47-3.08; p < .001). During a mean follow-up of 48 ± 31 months retrograde crossing had similar mortality (OR 1.79, 95% CI 0.84-3.81, p = .13), but a higher incidence of MI (OR 2.07, 95% CI 1.1-3.88, p = .02), target vessel revascularization (OR 1.92, 95% CI 1.49-2.46, p < .001), and target lesion revascularization (OR 2.08, 95% CI 1.33-3.28, p = .001). CONCLUSIONS: Compared with antegrade CTO PCI, retrograde CTO PCI is performed in more complex lesions and is associated with a higher risk for acute and long-term adverse events.

Independent predictors of retrograde failure in CTO-PCI after successful collateral channel crossing.

OBJECTIVES: To evaluate factors for predicting retrograde CTO-PCI failure after successful collateral channel crossing. BACKGROUND: Successful guidewire/catheter collateral channel crossing is important for the retrograde approach in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). METHODS: A total of 5984 CTO-PCI procedures performed in 45 centers in Japan from 2009 to 2012 were studied. The retrograde approach was used in 1656 CTO-PCIs (27.7%). We investigated these retrograde procedures to evaluate factors for predicting retrograde CTO-PCI failure even after successful collateral channel crossing. RESULTS: Successful guidewire/catheter collateral crossing was achieved in 77.1% (n = 1,276) of 1656 retrograde CTO-PCI procedures. Retrograde procedural success after successful collateral crossing was achieved in 89.4% (n = 1,141). Univariate analysis showed that the predictors for retrograde CTO-PCI failure were in-stent occlusion (OR = 1.9829, 95%CI = 1.1783 - 3.3370 P = 0.0088), calcified lesions (OR = 1.9233, 95%CI = 1.2463 - 2.9679, P = 0.0027), and lesion tortuosity (OR = 1.5244, 95%CI = 1.0618 - 2.1883, P = 0.0216). On multivariate analysis, lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing (OR = 1.3472, 95%CI = 1.0614 - 1.7169, P = 0.0141). CONCLUSIONS: The success rate of retrograde CTO-PCI following successful guidewire/catheter collateral channel crossing was high in this registry. Lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing. Devices and techniques to overcome complex CTO lesion morphology, such as lesion calcification, are required to further improve the retrograde CTO-PCI success rate. © 2016 Wiley Periodicals, Inc.

Appropriateness of percutaneous revascularization of coronary chronic total occlusions: an overview.

Coronary chronic total occlusions (CTOs) are commonly encountered in patients undergoing coronary angiography. Several 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 for patients remains debated. Over the past decade, the interest of the interventional community in CTO percutaneous coronary intervention (PCI) has exponentially grown due to important developments in dedicated equipment and techniques, resulting in high success and low complication rates. Both European and American guidelines have assigned a class IIa (level of evidence B) recommendation for CTO PCI. In the current review, we focus on the impact of CTO revascularization on clinical outcomes and QOL and on appropriate patient selection, and we provide a critical assessment of the current guidelines and recommendations on CTO PCI.

Complications during retrograde approach for chronic coronary total occlusion: Sub-analysis of Japanese multicenter registry.

OBJECTIVES: This study was performed to determine the complications occurring during retrograde percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) based on analysis of the multicenter, prospective, nonrandomized Retrograde Summit registry. BACKGROUND: Retrograde PCI for CTO has improved treatment success rates, but several complications related to the retrograde approach have been reported, including collateral channel injury and donor artery injury due to their use as retrograde roots. METHODS: This registry included data from 1,166 patients who underwent retrograde PCI for CTO in 28 Japanese centers between January 2009 and December 2011. RESULTS: Overall procedure success and retrograde procedure success were achieved in 985 (84.5%) and 838 (71.9%) of the 1,166 patients, respectively. In-hospital major adverse cardiac and cerebrovascular events (MACCE) occurred in 18 (1.5%) of the 1,166 patients. With regard to complications related to the retrograde approach, channel injury occurred in 111 (9.5%) of the 1,166 patients, but treatment was required in only 24 (2.1%) patients and subsequent cardiac tamponade occurred in only 4 (0.3%) patients. Donor artery problems occurred in only 10 (0.9%) of the 1,166 patients. In sub-analysis regarding the types of collateral channels, the septal channel was significantly safer than epicardial channel because of the lower frequency of non-Q-wave myocardial infarction (non-QMI) and channel injury requiring treatment. CONCLUSIONS: The MACCE rate during retrograde PCI for CTO determined from the Retrograde Summit registry was low and the frequency of complications related to the retrograde approach was acceptable. © 2015 Wiley Periodicals, Inc.

Comparison of percutaneous coronary intervention for chronic total occlusion outcome according to operator experience from the Japanese retrograde summit registry.

OBJECTIVES: This study was performed to evaluate the acute outcomes of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) based on operator experience. BACKGROUND: Despite developments in both technology and techniques, PCI procedures for CTO's remain challenging. METHODS: A total of 3,229 eligible subjects who underwent CTO-PCI were enrolled from 56 centers by a retrograde summit using a web registry system. To compare the acute outcomes of the CTO data, 18 centers were classified as higher volume centers (HC) and 38 centers as lower volume centers (LC) depending on the CTO-PCI experience of the operator. RESULTS: The mean procedural success rate of all centers was 88.4%. The overall procedural success rate was significantly higher in HC than LC (90.6% vs. 85.6%, respectively; P < 0.0001). In addition, overall antegrade success rate was also higher in HC than LC (91.0% vs. 83.9%, respectively; P < 0.0001). Although the overall retrograde approach success rate was significantly higher in HC than LC (85.0% vs. 77.6%, respectively; P < 0.0001), there was no significant difference in that of the retrograde alone (89.0% vs. 93.7%, respectively; P = 0.051). Major in-hospital adverse events were observed in 0.53% of cases, and the rates were similar between the two groups (0.45% vs. 0.62%, respectively; P = 0.25). CONCLUSIONS: Although CTO-PCI was safe in both groups, the procedural success rate was significantly higher in HC than LC, even in this new era of CTO-PCI. This difference was attributed to the difference in the antegrade procedural success rate. © 2015 Wiley Periodicals, Inc.

A randomized trial evaluating everolimus-eluting Absorb bioresorbable scaffolds vs. everolimus-eluting metallic stents in patients with coronary artery disease: ABSORB Japan.

AIMS: Theoretically, bioresorbable vascular scaffolds (BVSs) may provide superior long-term results compared with permanent metallic drug-eluting stents (DESs). However, whether BVSs are as safe and effective as metallic DESs prior to complete bioresorption is unknown. METHODS AND RESULTS: ABSORB Japan was a single-blind, multicentre, active-controlled, randomized trial designed to support regulatory approval of the Absorb BVS in Japan. Eligible patients with one or two de novo lesions in different epicardial vessels were randomized at 38 Japanese sites in a 2:1 ratio to Absorb BVS vs. cobalt-chromium everolimus-eluting stents (CoCr-EESs). The primary endpoint was target lesion failure [TLF: a composite of cardiac death, myocardial infarction attributable to target vessel, or ischaemia-driven target lesion revascularization (ID-TLR)] at 12 months, powered for non-inferiority. The major secondary endpoint was angiographic in-segment late lumen loss (LLL) at 13 months. A total of 400 patients were randomized to BVSs (266 patients and 275 lesions) or CoCr-EESs (134 patients and 137 lesions). TLF through 12 months was 4.2% with BVSs and 3.8% with CoCr-EESs [difference (upper one-sided 95% confidence limit) = 0.39% (3.95%); Pnon-inferiority < 0.0001]. Definite/probable stent/scaffold thrombosis at 12 months occurred in 1.5% of the patients with both devices (P = 1.0), and ID-TLR for restenosis was infrequent (1.1% with BVSs and 1.5% with CoCr-EESs, P = 1.0). With 96.0% angiographic follow-up, in-segment LLL at 13 months was 0.13 ± 0.30 mm with BVSs and 0.12 ± 0.32 mm with CoCr-EESs [difference (upper one-sided 95% confidence limit) = 0.01 (0.07); Pnon-inferiority < 0.0001). CONCLUSION: In the ABSORB Japan randomized trial, 12-month clinical and 13-month angiographic outcomes of BVSs were comparable to CoCr-EESs. CLINICAL REGISTRATION: ClinicalTrials.gov, number NCT01844284.

Update on chronic total occlusion percutaneous coronary intervention.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) continues to evolve. This review summarizes recent publications categorized by outcomes, techniques, complications, and ongoing studies in this rapidly growing area.

Japanese multicenter registry evaluating the retrograde approach for chronic coronary total occlusion.

OBJECTIVES: This registry evaluated the current trends and outcomes associated with retrograde percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). BACKGROUND: Since its introduction, several techniques and technologies have been introduced for retrograde PCI for CTO. METHODS: Eight hundred and one patients who underwent retrograde PCI for CTO in 28 Japanese centers between January 2009 and December 2010 were enrolled in this registry. RESULTS: Overall procedural and clinical success rates were 84.8 and 83.8%, respectively, of which, retrograde procedures accounted for 71.2 and 70.3%, respectively. The use of channel dilators increased in 2010 compared to that in 2009 (36 vs. 95.3%, P < 0.0001), attributed improving collateral channel crossing using a wire and catheter (70.6% vs. 81.1%, P = 0.0005) and increased availability of epicardial channels (27.6% vs. 36.9%). The use of the reverse controlled antegrade and retrograde tracking technique also increased (41.9 vs. 66.5%). Although these changes decreased procedure time (203.3 min vs. 187.9 min, P = 0.024), they did not significantly improve overall procedural success rate (84.1% vs. 85.3%, P = 0.63). Multivariate analysis identified age 65 years or more and lesion calcification as unfavorable factors and the use of a channel dilator as a favorable factor for retrograde procedural success. CONCLUSIONS: Increased availability of channel dilators has altered strategies for retrograde PCI for CTO. However, retrograde PCI for CTO could be improved by overcoming its main obstacle of severe calcification.

Machine Learning for Prediction of Technical Results of Percutaneous Coronary Intervention for Chronic Total Occlusion.

(1) Background: The probability of technical success in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) represents essential information for specifying the priority of PCI for treatment selection in patients with CTO. However, the predictabilities of existing scores based on conventional regression analysis remain modest, leaving room for improvements in model discrimination. Recently, machine learning (ML) techniques have emerged as highly effective methods for prediction and decision-making in various disciplines. We therefore investigated the predictability of ML models for technical results of CTO-PCI and compared their performances to the results from existing scores, including J-CTO, CL, and CASTLE scores. (2) Methods: This analysis used data from the Japanese CTO-PCI expert registry, which enrolled 8760 consecutive patients undergoing CTO-PCI. The performance of prediction models was assessed using the area under the receiver operating curve (ROC-AUC). (3) Results: Technical success was achieved in 7990 procedures, accounting for an overall success rate of 91.2%. The best ML model, extreme gradient boosting (XGBoost), outperformed the conventional prediction scores with ROC-AUC (XGBoost 0.760 [95% confidence interval {CI}: 0.740-0.780] vs. J-CTO 0.697 [95%CI: 0.675-0.719], CL 0.662 [95%CI: 0.639-0.684], CASTLE 0.659 [95%CI: 0.636-0.681]; p < 0.005 for all). The XGBoost model demonstrated acceptable concordance between the observed and predicted probabilities of CTO-PCI failure. Calcification was the leading predictor. (4) Conclusions: ML techniques provide accurate, specific information regarding the likelihood of success in CTO-PCI, which would help select the best treatment for individual patients with CTO.

The safety and feasibility of live-stream proctoring for CTO procedures.

OBJECTIVE: To assess the technical feasibility of a new method of educational training, based on audio-video (AV) communication between an interventional cardiologist and the cath lab staff members in one location and a remote expert proctor. METHODS: Overall, 9 patients underwent a percutaneous coronary intervention (PCI) targeting a chronic total occlusion (CTO) between June 2021 and January 2022 at a single Belgian center using the virtual proctoring approach. For this assessment, the strategic planning of the CTO PCI and all the decisions throughout the intervention were the responsibility of the proctor. The operator was guided via an AV link, by the proctor throughout the procedure. RESULTS: The operator performed each procedural step, guided by the remote proctor, who had continuous access to all relevant interventional details. No major adverse cardiac events (MACE) occurred during the index hospitalization or within 6 months follow-up. CONCLUSIONS: A new method of virtual proctoring based on live AV communication is feasible, even in the case of highly complex CTO PCI procedures. This strategy also appears safe and may provide the patient the benefit of incremental expertise. This approach is facilitated by advances in AV communication and allows physicians to share expertise irrespective of location. It could increase global interaction between colleagues and facilitate sharing of knowledge, which are both key aspects in the development of CTO PCI. This preliminary experience could serve as a basis for future large studies to study the potential role and benefits of virtual proctoring for complex CTO PCI procedures.

Update on Chronic Total Occlusion Percutaneous Coronary Intervention.

BACKGROUND: Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) lesions can be challenging to perform. In the present review we summarize recent publications in this rapidly evolving area grouped according to indications, outcomes, technique, and complications.

Sirolimus eluting coronary stent implantation in patients on maintenance hemodialysis: the OUCH study (outcome of cypher stent inhemodialysis patients).

BACKGROUND: Pivotal studies on drug-eluting stents have excluded hemodialysis (HD) patients. No quantitative coronary angiography (QCA) analysis has been reported. METHODS AND RESULTS: The OUtcome of Cypher stent in Hemodialysis patients (OUCH) Study is a prospective non-randomized single-arm registry designed to assess the results of sirolimus-eluting stents in HD patients, with follow-up QCA in an independent core laboratory. The primary endpoint was the occurrence of target-vessel failure (TVF) defined as cardiac death, myocardial infarction (MI), and target-vessel revascularization (TVR) at 1 year. A total of 117 patients were enrolled. The TVF rate was 24.9% (2.6% cardiac death, 1.4% MI, 23.9% TVR), and stent thrombosis was documented in 1 patient (0.9%). Coronary calcification was a predictor of TVF. Late lumen loss (LLL) averaged 0.69±0.93mm. The histogram of LLL showed that a total of 76% of lesions were distributed the same normally as that in normal renal function (average LLL 0.20±0.29mm), but 24% of lesions were outliers (average LLL 2.07±0.62mm). CONCLUSIONS: This report describes different clinical and QCA results in HD patients as higher TVF rate, different predictive factors, and different histogram of LLL compared with normal renal function. The different histogram of LLL was the existence of many outliers with the same average and the same deviation, suggesting the loss of sirolimus had an effect on a significant number of HD patients.

Acute myocardial infarction presenting with pharyngeal pain alone.

BACKGROUND: Pharyngeal pain alone due to acute myocardial infarction is rare. CASE REPORT: A 37-year-old man felt sudden pharyngeal pain. He was transferred to a medical facility under a misdiagnosis of pharyngitis. However, he was thereafter found to have acute myocardial infarction and thus was transferred to another hospital. An emergency coronary angiogram revealed complete occlusion of the right coronary artery and he underwent coronary angioplasty. The patient was later discharged ambulatory. CONCLUSION: A misdiagnosis of acute myocardial infarction can lead to unfavorable outcomes; therefore, physicians or emergency medical technicians should be aware of this disease even when a patient complains of sudden pharyngeal pain alone.

Operator experience and clinical outcomes of percutaneous coronary intervention for chronic total occlusion: insights from a pooled analysis of the Japanese CTO PCI Expert Registry and the Retrograde Summit General Registry.

There have not been enough studies to examine the association between difference in operator experience and technical success rate in contemporary percutaneous coronary intervention for chronic total occlusion (CTO-PCI). The present study sought to provide insights into the impact of operator experience on clinical outcomes of CTO-PCI through a comparison of two largest Japanese CTO-PCI registries consisting of operators with different CTO-PCI experience. After combining clinical data from the Japanese CTO-PCI Expert Registry (ER) 2014-2016 (N = 4316) including CTO-PCI performed by highly experienced operators and the Retrograde Summit General Registry (RSGR) 2014-2016 (N = 2230) including CTO-PCI performed by less experienced operators, a pooled analysis was performed to compare clinical outcomes of CTO-PCI in 2 registries. The overall technical success rate and the incidence of in-hospital major adverse events were comparable between ER and RSGR (90.1% vs 88.9%, p = 0.133, 1.7% vs 1.5%, p = 0.606, respectively). Technical success rate in ER was significantly higher among the patients treated with primary antegrade approach (91.8% vs 89.5%, p = 0.009), whereas there was no significant difference among the patients treated with the primary retrograde approach (85.7% vs 85.3%, p = 0.857). Multivariate analysis suggested ER operator could not be an independent predictor for technical success. CTO-PCI performed by less experienced but appropriately trained operators could achieve similarly high technical success rate with comparable safety compared with those performed by highly experienced specialists in contemporary Japanese context.

Contemporary Issues in Chronic Total Occlusion Percutaneous Coronary Intervention.

Remarkable progress has been achieved in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent years, with refinement of the indications and technical aspects of the procedure, imaging, and complication management. Randomized controlled trials and rigorous prospective registries have provided high-quality data on the benefits and risks of CTO PCI. Global collaboration has led to an agreement on nomenclature, indications, endpoint definition, and principles of clinical trial design that have been distilled in global consensus documents such as the CTO Academic Research Consortium. Increased use of preprocedural coronary computed tomography angiography and intraprocedural intravascular imaging, as well as development of novel techniques and structured CTO crossing and complication management algorithms, allow a systematic, stepwise approach to this difficult lesion subset. This state-of-the-art review provides a comprehensive discussion about the most recent developments in the indications, preprocedural planning, technical aspects, complication management, and future directions of CTO PCI.

Outcomes of successful vs. failed contemporary chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There are limited contemporary data on the impact of success vs. failure on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We conducted a systematic review and a meta-analysis of contemporary studies that compared the outcomes in patients who underwent successful vs. failed contemporary (2010 onwards) CTO PCI. We performed a sensitivity analysis limited to studies that started enrollment after the publication of the hybrid algorithm in 2012. RESULTS: We included five studies with a total of 6,084 patients (successful CTO PCI n = 4,861, failed CTO PCI n = 1,223). During a median follow-up time of 12 months (range 6-60 months), successful CTO PCI was associated with a lower risk of major adverse cardiovascular events [OR: 0.61, 95% CI (0.41, 0.92), p = 0.02, I2 = 63%] and all-cause death [OR: 0.57, 95% CI (0.33, 0.99), p = 0.05, I2 = 60%]. Both groups had similar risk of myocardial infarction (MI) [OR 0.69, 95% CI (0.43, 1.10), p = 0.38, I2 = 80%], target vessel revascularization (TVR) [OR: 0.56, 95% CI (0.25, 1.27), p = 0.17, I2 = 80%], and stroke [OR: 0.52, 95% CI (0.14, 1.91), p = 0.33, I2 = 0%]. CONCLUSION: In contemporary practice, successful CTO PCI was associated with a lower incidence of MACE driven by lower all-cause mortality compared with failed CTO PCI at a median follow-up of 1 year.

A Systematic Review and Meta-Analysis of Clinical Outcomes of Patients Undergoing Chronic Total Occlusion Percutaneous Coronary Intervention.

OBJECTIVES: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) can improve patient symptoms, but it remains controversial whether it impacts subsequent clinical outcomes. METHODS: In this systematic review and meta-analysis, we queried PubMed, ScienceDirect, Cochrane Library, Web of Science, and Embase databases (last search: September 15, 2021). We investigated the impact of CTO-PCI on clinical events including all-cause mortality, cardiovascular death, myocardial infarction (MI), major adverse cardiovascular event (MACE), stroke, subsequent coronary artery bypass surgery, target-vessel revascularization, and heart failure hospitalizations. Pooled analysis was performed using a random-effects model. RESULTS: A total of 58 publications with 54,540 patients were included in this analysis, of which 33 were observational studies of successful vs failed CTO-PCI, 19 were observational studies of CTO-PCI vs no CTO-PCI, and 6 were randomized controlled trials (RCTs). In observational studies, but not RCTs, CTO-PCI was associated with better clinical outcomes. Odds ratios (ORs) and 95% confidence intervals (CIs) for all-cause mortality, MACE, and MI were 0.52 (95% CI, 0.42-0.64), 0.46 (95% CI, 0.37-0.58), 0.66 (95% CI, 0.50-0.86), respectively for successful vs failed CTO-PCI studies; 0.38 (95% CI, 0.31-0.45), 0.57 (95% CI, 0.42-0.78), 0.65 (95% CI, 0.42-0.99), respectively, for observational studies of CTO-PCI vs no CTO-PCI; 0.72 (95% CI, 0.39-1.32), 0.69 (95% CI, 0.38-1.25), and 1.04 (95% CI, 0.46-2.37), respectively for RCTs. CONCLUSIONS: CTO-PCI is associated with better subsequent clinical outcomes in observational studies but not in RCTs. Appropriately powered RCTs are needed to conclusively determine the impact of CTO-PCI on clinical outcomes.