Intracoronary snaring of the retrograde guidewire: A novel method to solve compartment mismatch in complex retrograde CTO PCI.

The retrograde approach has allowed a remarkable improvement in the success rate of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). After collateral channel crossing, the most crucial aspect of retrograde CTO PCI is creating the connection between the antegrade and retrograde system. Currently, the most common technique to achieve this is reverse controlled antegrade and retrograde subintimal tracking. However, this maneuver sometimes fails due to compartment mismatch (intraplaque situation of one wire and extraplaque situation of the other). New approaches are therefore needed to overcome challenges in this important step of the procedure. Here we present an innovative solution to this problem, which involved capturing the retrograde guidewire (advanced into a side branch at the distal cap) with a microsnare that had been advanced antegradely: this severed the dissection flap separating the antegrade and retrograde system, thus allowing us to successfully recanalize the CTO.

Applicability of J-CTO channel score to predict microcatheter tracking during retrograde percutaneous coronary intervention of chronic total occlusions: Insights from the SURFING MICRO registry.

BACKGROUND: The J-chronic total occlusion (CTO) channel score can predict guidewire tracking of the collateral channels (CCs), but its efficacy in predicting microcatheter tracking has never been tested in the setting of retrograde CTO-percutaneous coronary intervention (PCI). AIMS: Predicting microcatheter collateral tracking during retrograde CTO-PCIs. METHODS: A total of 189 patients undergoing retrograde CTO-PCI from April 2017 to August 2021 were screened. The primary outcome of interest was a correlation between J-CTO channel score and microcatheter tracking failure (MTF) after successful CC tracking by the guidewire. The independent association between anatomical features of the J-CTO channel score and the primary outcome of interest was explored. RESULTS: After adjustment, only small size (adjusted OR: 12.70, 95% confidence interval [CI]: 1.79-89.82; p = 0.01) and continuous bends (adjusted OR: 14.15, 95% CI: 2.77-72.34; p < 0.001) remained significantly associated with an increased risk of MTF for septal collaterals. The small size was the only predictor of the MTF for epicardial collaterals (OR: 6.39, 95% CI: 1.13-35.96; p = 0.020) at univariate analysis. Patients in the MTF group had a lower incidence of procedural success compared with patients in the microcatheter tracking success (MTS) group (40.0% vs. 93.9%, p < 0.001) and had a higher incidence of collateral perforations (20.0% vs. 3.0%, p < 0.001). CONCLUSION: Small and tortuous septal collaterals, identified by a score ≥3, are associated with an increased risk of MTF, lower incidence of procedural success, and higher risk of procedural complications driven by collateral perforations.

International survey of chronic total occlusion percutaneous coronary intervention operators.

BACKGROUND: Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) practice has received limited study. AIM: To examine the contemporary CTO PCI practice. METHODS: We performed an online, anonymous, international survey of CTO PCI operators. RESULTS: Five hundred forty-five CTO PCI operators and 190 interventional cardiology fellows with an interest in CTO PCI participated in this survey. Almost half were from the United States (41%), most (93%) were men, and the median h/week spent in the hospital was 58. Median annual case numbers were 205 (150-328) for PCIs and 20 (5-50) for CTO PCIs. Almost one-fifth (17%) entered CTO cases into registries, such as PROGRESS-CTO (55%) and EuroCTO (20%). More than one-third worked at academic institutions (39%), 31% trained dedicated CTO fellows, and 22% proctored CTO PCI. One-third (34%) had dedicated CTO PCI days. Most (51%) never discharged CTO patients the same day, while 17% discharged CTO patients the same day >50% of the time. After successful guidewire crossing, 38% used intravascular imaging >90% of the time. Most used CTO scores including J-CTO (81%), PROGRESS-CTO (35%), and PROGRESS-CTO complications scores (30%). Coronary artery perforation was encountered within the last month by 19%. On a scale of 0-10, the median comfort levels in treating coronary artery perforation were: covered stents 8.8 (7.0-10), coil embolization 5.0 (2.1-8.5), and fat embolization 3.7 (0.6-7.3). Most (51%) participants had a complication cart/kit and 25% conducted regular complication drills with catheterization laboratory staff. CONCLUSION: Contemporary CTO PCI practices vary widely. Further research on barriers to following the guiding principles of CTO PCI may improve patient outcomes.

Validation of the BCIS CHIP Score in chronic total occlusion percutaneous coronary intervention.

BACKGROUND: The complex high-risk indicated percutaneous coronary intervention (CHIP) score is a tool developed using the British Cardiovascular Intervention Society (BCIS) database to define CHIP cases and predict in-hospital major adverse cardiac or cerebrovascular events (MACCE). AIM: To assess the validity of the CHIP score in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We evaluated the performance of the CHIP score on 8341 CTO PCIs from the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) performed at 44 centers between 2012 and 2023. RESULTS: In our cohort, 7.8% (n = 647) of patients had a CHIP score of 0, 50.2% (n = 4192) had a CHIP score of 1-2, 26.2% (n = 2187) had a CHIP score of 3-4, 11.7% (n = 972) had a CHIP score of 5-6, 3.3% (n = 276) had a CHIP score of 7-8, and 0.8% (n = 67) had a CHIP score of 9+. The incidence of MACCE for a CHIP score of 0 was 0.6%, reaching as high as 8.7% for a CHIP score of 9+, confirming that a higher CHIP score is associated with a higher risk of MACCE. The estimated increase in the risk of MACCE per one score unit increase was 100% (95% confidence interval [CI]: 65%-141%). The AUC of the CHIP score model for predicting MACCE in our cohort was 0.63 (95% CI: 0.58-0.67). There was a positive correlation between the CHIP score and the PROGRESS-CTO MACE score (Spearman's correlation: 0.37; 95% CI: 0.35-0.39; p < 0.001). CONCLUSIONS: The CHIP score has modest predictive capacity for MACCE in CTO PCI.

Retrograde chronic total occlusion percutaneous coronary intervention via ipsilateral collaterals.

BACKGROUND: There is limited data on retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) via ipsilateral epicardial collaterals (IEC). AIMS: To compare the clinical and angiographic characteristics, and outcomes of retrograde CTO PCI via IEC versus other collaterals in a large multicenter registry. METHODS: Observational cohort study from the Prospective Global registry for the study of Chronic Total Occlusion Intervention (PROGRESS-CTO). RESULTS: Of 4466 retrograde cases performed between 2012 and 2023, crossing through IEC was attempted in 191 (4.3%) cases with 50% wiring success. The most common target vessel in the IEC group was the left circumflex (50%), in comparison to other retrograde cases, where the right coronary artery was most common (70%). The Japanese CTO score was similar between the two groups (3.13 ± 1.23 vs. 3.06 ± 1.06, p = 0.456); however, the IEC group had a higher Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) score (1.95 ± 1.02 vs. 1.27 ± 0.92, p < 0.0001). The most used IEC guidewire was the SUOH 03 (39%), and the most frequently used microcatheter was the Caravel (43%). Dual injection was less common in IEC cases (66% vs. 89%, p < 0.0001). Technical (76% vs. 79%, p = 0.317) and procedural success rates (74% vs. 79%, p = 0.281) were not different between the two groups. However, IEC cases had a higher procedural complications rate (25.8% vs. 16.4%, p = 0.0008), including perforations (17.3% vs. 9.0%, p = 0.0001), pericardiocentesis (3.1% vs. 1.2%, p = 0.018), and dissection/thrombus of the donor vessel (3.7% vs. 1.2%, p = 0.002). CONCLUSION: The use of IEC for retrograde CTO PCI was associated with similar technical and procedural success rates when compared with other retrograde cases, but higher incidence of periprocedural complications.

Mechanical Circulatory Support for High-Risk Percutaneous Coronary Intervention.

PURPOSE OF REVIEW: This review will focus on the indications of mechanical circulatory support (MCS) for high-risk percutaneous coronary intervention (PCI) and then analyze in detail all MCS devices available to the operator, evaluating their mechanisms of action, pros and cons, contraindications, and clinical data supporting their use. RECENT FINDINGS: Over the last decade, the interventional cardiology arena has witnessed an increase in the complexity profile of the patients and lesions treated in the catheterization laboratory. Patients with significant comorbidity burden, left ventricular dysfunction, impaired hemodynamics, and/or complex coronary anatomy often cannot tolerate extensive percutaneous revascularization. Therefore, a variety of MCS devices have been developed and adopted for high-risk PCI. Despite the variety of MCS available to date, a detailed characterization of the patient requiring MCS is still lacking. A precise selection of patients who can benefit from MCS support during high-risk PCI and the choice of the most appropriate MCS device in each case are imperative to provide extensive revascularization and improve patient outcomes. Several new devices are being tested in early feasibility studies and randomized clinical trials and the experience gained in this context will allow us to provide precise answers to these questions in the coming years.

Electrocautery-assisted re-entry to resolve bilateral aorto-ostial chronic total occlusions due to leaflet obstruction following transcatheter aortic valve replacement.

Coronary artery obstruction is a rare but life-threatening complication of transcatheter aortic valve replacement (TAVR). While urgent percutaneous coronary intervention has been described in cases of acute occlusion, little is known about the interventional management of obstruction once it has occurred in the chronic setting. We describe a case in which electrocautery-assisted re-entry was successfully utilized to manage the right coronary artery and left main chronic total occlusion due to leaflet-induced coronary artery obstruction after TAVR.

Chronic total occlusion percutaneous coronary intervention in heart transplant patients.

Cardiac allograft vasculopathy (CAV) is frequently observed after heart transplant (HT), and represents one of the main causes of chronic rejection, graft loss, and death. While the role of percutaneous coronary intervention (PCI) is well established in the management of CAV in cases of nonocclusive stenoses, the outcomes and technical aspects of this procedure in chronic total occlusions (CTOs) are unknown. We describe our experience with three cases in which CTO PCI was indicated to treat CAV in HT recipients, and we discuss the peculiarities and therapeutic approach to this challenging patient population. In particular, all patients were asymptomatic for angina, and CTO PCI was indicated to promote recovery of left ventricular function, extend graft survival, and/or protect from future ischemic events. CTO PCI was performed using hybrid techniques and was successful in all three cases. Intravascular imaging was used in all cases to maximize the durability of the procedure.

Role of the retrograde Carlino technique for chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There is scarce data on the outcomes of the Carlino technique for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to investigate the indications and outcomes of the Carlino technique as performed in the context of the retrograde approach. METHODS: We pooled CTO PCI cases where a retrograde Carlino technique was performed from high-volume operators at four centers. The Carlino technique was characterized according to its indication (achieving plaque/cap modification, clarifying microcatheter location within the vessel, resolving distal cap ambiguity) and was considered successful when it led to the desired outcome. RESULTS: A total of 43 patients were included. Occlusion complexity was very high (mean J-CTO score 3.3 ± 0.8). The two most common indications were understanding the anatomy of the occlusion and clarifying gear location (37.2%) and impenetrable distal cap (34.9%). The Carlino technique was successful in 88.4% of cases. Overall technical and procedural success was 86.0%. The most common successful crossing technique was reverse controlled antegrade and retrograde subintimal tracking (70.3%). No complications were attributed to the Carlino technique. CONCLUSIONS: We observed a high success rate of the retrograde Carlino technique, as well as overall technical and procedural success rates. No Carlino technique-related complications were observed. Additional data from larger registries are warranted to further confirm the safety and efficacy of this technique.

STAR procedure becomes SAFER: First-in-man case series of a new antegrade dissection re-entry technique.

INTRODUCTION: Antegrade dissection and re-entry (ADR) is an integral part of the hybrid algorithm, which has allowed for improved outcomes in chronic total occlusion (CTO) coronary intervention (PCI). METHODS: A new ADR method, Subintimal Antegrade FEnestration and Re-entry (SAFER), is described. The results of a first-in-man series are presented. RESULTS: SAFER was performed on seven consecutive patients with angiographic and clinical success in all patients. CONCLUSIONS: This first-in-man study has shown that the SAFER technique is feasible and effective with the possibility of improving the antegrade PCI CTO success rate.

The contemporary role of protamine in the cardiac catheterization laboratory.

Access to the arterial circulation and full anticoagulation carries a risk of serious bleeding during and after percutaneous coronary intervention. Important sources of bleeding include the arterial access site and coronary artery perforation. Prompt and effective management of hemorrhagic complications is an essential interventional skill. Protamine sulfate is well-known as a heparin reversal agent. Despite this, there is heterogeneity in the use of protamine during interventional procedures. While protamine is generally well-tolerated, it is associated with a risk of hypersensitivity reaction, including anaphylaxis, among others. The purpose of this review is to summarize the existing evidence about and experience with the use of protamine sulfate in the setting of percutaneous coronary and structural interventional procedures.

Increased prescription dose for large vessel intravascular brachytherapy.

BACKGROUND: Most randomized studies testing the effectiveness of IVBT were limited to vessels less than 4 mm diameter. In fact, it is now common to treat vessels larger than 4 mm. Accordingly, the authors instituted a prescription dose increase to 34 Gy at 2 mm from source center for vessels greater than 4.0 mm. The increase in prescription dose to 34 Gy at 2 mm from center is substantial, being 50% higher than the conventional maximum of 23 Gy. AIM: To take a close look at group of patients treated to 34 Gy, and for whom follow-up angiograms are available. METHODS: Ten patients treated for ISR with a prescription dose of 34 Gy and for whom follow-up angiograms were available were studied. Beta-radiation brachytherapy was performed with a Novoste Beta-Cath System using a strontium-90 (beta) source (Best Vascular, Springfield, VA). Source lengths of 40 or 60 mm were used. A dose of 34 Gy was prescribed at 2 mm from the source center. RESULTS: Patients were re-catheterized from 2 to 21 months (median: 16 months) following IVBT, all for symptoms suggested of restenosis. All patients had some degree of ISR of the target vessel, but no IVBT-treated vascular segment showed angiographic signs of degeneration, dissection or aneurysm. CONCLUSION: The authors' clinical impression, along with detailed review of the 10 cases, suggest that using a 34 Gy prescription dose at 2 mm from source center does not result in increased toxicity.

Validation of the new PROGRESS-CTO complication risk scores in the OPEN-CTO registry.

BACKGROUND: Risk stratification before chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is important to inform procedural planning as well as patients and their families. We sought to externally validate the PROGRESS-CTO complication risk scores in the OPEN-CTO registry. METHODS: OPEN-CTO is a prospective registry of 1000 consecutive CTO PCIs performed at 12 experienced US centers using the hybrid algorithm. Endpoints of interest were in-hospital all-cause mortality, need for pericardiocentesis, acute myocardial infarction (MI), and major adverse cardiovascular events (MACE) (a composite of all-cause mortality, stroke, periprocedural MI, urgent repeat revascularization, and tamponade requiring pericardiocentesis). Model discrimination was assessed with the area under the curve (AUC) method, and calibration with the observed-versus-predicted probability method. RESULTS: Mean age was 65.4 ± 10.3 year, and 36.5% of patients had prior coronary artery bypass graft. Overall, 41 patients (4.1%) suffered MACE, 9 (0.9%) mortality, 26 (2.6%) acute MI, and 11 (1.1%) required pericardiocentesis. Technical success was achieved in 86.3%. Patients who experienced MACE had higher anatomic complexity, and more often required antegrade dissection/reentry and the retrograde approach. Increasing PROGRESS-CTO MACE scores were associated with increasing MACE rates: 0.5% (score 0-1), 2.4% (score 2), 3.7% (score 3), 4.5% (score 4), 7.8% (score 5), 13.0% (score 6-7). The AUC were as follows: MACE 0.72 (95% confidence interval [CI]: 0.66-0.78), mortality 0.79 (95% CI: 0.66-0.95), pericardiocentesis 0.71 (95% CI: 0.60-0.82), and acute MI 0.57 (95% CI: 0.49-0.66). Calibration was adequate for MACE and mortality, while the models underestimated the risk of pericardiocentesis and acute MI. CONCLUSIONS: In a large external cohort of patients treated with the hybrid algorithm by experienced CTO operators, the PROGRESS-CTO MACE, mortality, and pericardiocentesis risk scores showed good discrimination, while the acute MI score had inferior performance.

Balloon-assisted subintimal entry (BASE) in chronic total occlusion percutaneous coronary interventions.

BACKGROUND: There is limited data on the use of the balloon-assisted subintimal entry (BASE) technique in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and outcomes of 155 CTO PCIs that utilized the BASE technique at 31 US and non-US centers between 2016 and 2023. RESULTS: The BASE technique was used in 155 (7.9%) of 1968 antegrade dissection and re-entry (ADR) cases performed during the study period. The mean age was 66 ± 10 years, 88.9% of the patients were men, and the prevalence of diabetes (44.6%), hypertension (90.5%), and dyslipidemia (88.7%) was high. Compared with 1813 ADR cases that did not use BASE, the target vessel of the BASE cases was more commonly the RCA and less commonly the LAD. Lesions requiring BASE had longer occlusion length (42 ± 23 vs. 37 ± 23 mm, p = 0.011), higher Japanese CTO (J-CTO) (3.4 ± 1.0 vs. 3.0 ± 1.1, p < 0.001) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention chronic total occlusion) (1.8 ± 1.0 vs. 1.5 ± 1.0, p = 0.008) scores, and were more likely to have proximal cap ambiguity, side branch at the proximal cap, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Technical (71.6% vs. 75.5%, p = 0.334) and procedural success (71.6% vs. 72.8%, p = 0.821), as well as major adverse cardiac events (MACE) (1.3% vs. 4.1%, p = 0.124), were similar in ADR cases that used BASE and those that did not. CONCLUSIONS: The BASE technique is used in CTOs with longer occlusion length, higher J-CTO score, and more complex angiographic characteristics, and is associated with moderate success but also low MACE.

Impact of preprocedural anemia on in-hospital and follow-up outcomes of chronic total occlusion percutaneous coronary intervention.

BACKGROUND: The impact of preprocedural anemia on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We examined the clinical and angiographic characteristics and procedural outcomes of 8633 CTO PCIs performed at 39 US and non-US centers between 2012 and 2023. Anemia was defined as a hemoglobin level of <13 g/dL in men and <12 g/dL in women. RESULTS: Anemia was present in 1652 (19%) patients undergoing CTO PCI. Anemic patients had a higher incidence of comorbidities, such as diabetes mellitus, hypertension, dyslipidemia, heart failure, cerebrovascular disease, and peripheral arterial disease. CTOs in anemic patients were more likely to have complex angiographic characteristics, including smaller diameter, longer length, moderate to severe calcification, and moderate to severe proximal tortuosity. Anemic patients required longer procedure (119 vs. 107 min; p < 0.001) and fluoroscopy (45 vs. 40 min; p < 0.001) times but received similar contrast volumes. Technical success was similar between the two groups. In-hospital major adverse cardiac events (MACE) rates were higher in patients with anemia; however, this association was no longer significant after adjusting for confounding factors. Baseline anemia was independently associated with follow-up MACE (adjusted hazard ratio [HR]: 1.63; 95% confidence interval [CI]: 1.07-2.49; p = 0.023) and all-cause mortality (adjusted HR: 3.03; 95% CI: 1.41-6.49; p = 0.004). CONCLUSIONS: Preprocedural anemia is associated with more comorbidities, higher lesion complexity, longer procedure times, and higher follow-up MACE and mortality after CTO PCI.

External validation of the PROGRESS-CTO perforation risk score: Individual patient data pooled analysis of three registries.

BACKGROUND: Coronary artery perforation is one of the most feared and common complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: To assess the usefulness of the recently developed PROGRESS-CTO (NCT02061436) perforation risk score in independent cohorts. Individual patient-level data pooled analysis of three registries was performed. RESULTS: Of the 4566 patients who underwent CTO PCI at 25 centers, 196 (4.2%) had coronary artery perforation. Patients with perforations were older (69 ± 10 vs. 65 ± 10, p < 0.001), more likely to be women (19% vs. 13%, p = 0.009), more likely to have a history of prior coronary artery bypass graft (34% vs. 20%, p < 0.001), and unfavorable angiographic characteristics such as blunt stump (62% vs. 48%, p < 0.001), proximal cap ambiguity (52% vs. 34%, p < 0.001), and moderate-severe calcification (60% vs. 49%, p = 0.002). Technical success was lower in patients with perforations (73% vs. 88%, p < 0.001). The area under the receiver operating characteristic curve of the PROGRESS-CTO perforation risk model was 0.76 (95% confidence interval [CI], 0.72-0.79), with good calibration (Hosmer-Lemeshow p = 0.97). We found that the CTO PCI perforation risk increased with higher PROGRESS-CTO perforation scores: 0.3% (score 0), 2.3% (score 1), 3.1% (score 2), 5.5% (score 3), 7.5% (score 4), 14.6% (score 5). CONCLUSION: Given the good discriminative performance, calibration, and the ease of calculation, the PROGRESS-CTO perforation score may facilitate assessment of the risk of perforation in patients undergoing CTO PCI.

Iodixanol-associated acute kidney injury and prognosis in patients undergoing elective percutaneous coronary intervention: a prospective, multi-center study.

OBJECTIVE: To evaluate iodixanol-associated acute kidney injury (AKI) and prognosis in patients undergoing elective percutaneous coronary intervention (PCI). METHODS: Patients undergoing elective PCI and iodixanol administration were prospectively enrolled in 8 centers between May 2020 and November 2021. The primary endpoint was AKI, defined as an increase in SCr of ≥ 0.3 mg/dL (26.4 µmol/L) or relative elevation ≥ 50% from baseline in the 48-72 h after PCI. Prognosis evaluations included the major adverse renal and cardiovascular events (MARCE): all-cause mortality, new-onset renal replacement therapy (NRRT), non-fatal myocardial infarction, and non-fatal stroke. AKI predictors were identified using multivariable logistic regression and associations between AKI and outcomes were examined using Cox regression. RESULTS: A total of 3630 patients were included in the final analysis and 2.9% of patients (107/3,630) suffered AKI. Among them, 95.3% (102/107) of AKI were stage 1, and 4.6% (5/107) of stage 2. The multivariable analysis indicated that age over 75-year-old, diabetes, NT-pro-BNP > 300 pg/mL, hemoglobin < 110 g/L, eGFR < 60 mL/min/1.73m2, and diuretics were independently associated with AKI (p < 0.05). After a median follow-up of 13 months, MARCE occurred in 3.6% (131/3630) of the study population, and their incidence was higher in AKI (9.4%, 10/107) vs. non-AKI patients (3.4%, 121/3,523). However, after multivariable adjustment, there was no statistically significant association between AKI and MARCE (p = 0.382). CONCLUSIONS: In patients undergoing elective PCI, cases of iodixanol-associated AKI were mostly mild and, after multivariable adjustment, held no statistically significant association with MARCE on mid-term follow-up. CLINICAL RELEVANCE STATEMENT: The incidence of iodixanol-associated AKI was low and mainly limited to mild renal impairment in patients undergoing elective PCI. Physicians should provide adequate contrast for coronary artery evaluation and, at the same time, minimize the contrast volume. KEY POINTS: • The incidence of iodixanol-associated acute kidney injury was low and mostly limited to mild renal impairment. • Iodixanol administration had no statistically significant impact on the major adverse renal and cardiovascular events in patients undergoing elective percutaneous coronary intervention.

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.

Iso-osmolar versus low-osmolar contrast media and outcomes after percutaneous coronary intervention: Insights from the VA CART Program.

OBJECTIVES: To assess whether contrast media type is associated with outcomes in veterans undergoing percutaneous coronary intervention (PCI). BACKGROUND: There is uncertainty about the impact of iso-osmolar contrast medium (IOCM) versus low-osmolar contrast medium (LOCM) on acute kidney injury (AKI) and other major adverse renal or cardiovascular events (MARCE) after PCI. We assessed the association between contrast media type and MARCE in patients who underwent PCI within the Veterans Administration Healthcare System. METHODS: We reviewed PCIs performed between 2009 and 2019 using data from the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program. The primary endpoint was MARCE, a composite of myocardial infarction, stroke, all-cause death, AKI, and dialysis onset at 30 days. RESULTS: The analysis cohort consisted of 50,389 patients of whom 25,555 received LOCM and 24,834 received IOCM. There was significant variation in contrast type across sites. After adjustment for comorbidities, no significant association between contrast media type and MARCE was observed in both site-unadjusted (odds ratio [OR] for IOCM: 0.99; 95% confidence interval [CI]: 0.92-1.08; p = 0.97) and site-adjusted (OR: 1.06; 95% CI: 0.95-1.18; p = 0.30) analyses. Similar results were obtained when contrast volume was imputed or the data was subset to individuals with available contrast volume. CONCLUSION: In a large cohort of veterans undergoing PCI, we found considerable site variation in the type of contrast media used but no significant association between contrast media type and the incidence of MARCE, both before and after adjustment for the site.

Grade 3 coronary artery perforations in chronic total occlusion-percutaneous coronary intervention: Mechanisms, locations, and outcomes from the G3CAP Registry.

AIM: The impact of Grade III coronary perforations (G3-CP) in the setting of CTO-PCI is not well assessed. METHODS AND RESULTS: We reviewed 7773 CTO-PCI and 98,819 non CTO-PCI performed in 10 European centers: G3 perforation occurred in 87 patients (1.1%) during CTO PCI and 224 patients (0.22%) during non CTO-PCI (p < 0.001). G3-CP involved the CTO segment in 68% of patients and the retrograde channels in 14% of cases. In the CTO PCI group, wire induced G3-CP (50.5% vs. 32.5%, p = 0.02) occurred predominantly when dedicated CTO tapered and highly penetrative wires were used. Intra-procedural and in-hospital death rates were 4.6% vs. 5.8% and 3.6% vs. 7.5% respectively for CTO PCI and non-CTO PCI groups (p = NS). At a median follow up of 24 months, the overall mortality and MAE were respectively 7.8% and MAE 19% without difference among groups. CONCLUSIONS: We showed similar in-hospital and long-term outcomes when G3 perforations occurred during CTO PCI and non CTO-PCI.