Geographic diversity in chronic total occlusion percutaneous coronary intervention: insights from the PROGRESS-CTO registry.

BACKGROUND: There is variability in clinical and lesion characteristics as well as techniques in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed patient and lesion characteristics, techniques, and outcomes in 11 503 CTO-PCI procedures performed in North America (NA) and in the combined regions of Europe, Asia, and Africa from 2017 to 2023 as documented in the PROGRESS-CTO registry. RESULTS: Eight thousand four hundred seventy-nine (74%) procedures were performed in NA. Compared with non-NA patients, NA patients were older, with higher body mass index and higher prevalence of diabetes, hypertension, dyslipidemia, family history of coronary artery disease, prior history of PCI, coronary artery bypass graft surgery and heart failure, cerebrovascular disease, and peripheral arterial disease. Their CTOs were more complex, with higher J-CTO (2.56 ± 1.22 vs 1.81 ± 1.24; P less than .001) and PROGRESS-CTO (1.29 ± 1.01 vs 1.07 ± 0.95; P less than .001) scores, longer length, and higher prevalence of proximal cap ambiguity, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Retrograde (31.0% vs 22.1%; P less than .001) and antegrade dissection and re-entry (ADR) (21.2% vs 9.2%; P less than .001) were more commonly used in NA centers, along with intravascular ultrasound (69.0% vs 10.1%; P less than .001). Procedure and fluoroscopy times were longer in NA, while contrast volume and radiation dose were lower. Technical (86.7% vs 86.8%; P > .90) and procedural (85.4% vs 85.8%; P = .70) success and in-hospital major adverse cardiovascular events (MACE) (1.9% vs 1.7%; P = .40) were similar in NA and non-NA centers. CONCLUSIONS: Compared with non-NA patients, NA patients undergoing CTO PCI have more comorbidities, higher CTO lesion complexity, are more likely to undergo treatment with retrograde and ADR, and have similar technical success and MACE.

Racial disparities in chronic total occlusion percutaneous coronary interventions: insights from the PROGRESS-CTO registry.

OBJECTIVES: There is limited data on race and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The authors sought to evaluate CTO PCI techniques and outcomes in different racial groups. METHODS: We examined the baseline characteristics and procedural outcomes of 11 806 CTO PCIs performed at 44 US and non-US centers between 2012 and March 2023. In-hospital major adverse cardiac events (MACE) included death, myocardial infarction, repeat target-vessel revascularization, pericardiocentesis, cardiac surgery, and stroke prior to discharge. RESULTS: The most common racial group was White (84.5%), followed by Black (5.7%), "Other" (3.9%), Hispanic (2.9%), Asian (2.4%), and Native American (0.7%). There were significant differences in the baseline characteristics between different racial groups. When compared with non-White patients, the retrograde approach and antegrade dissection re-entry were more likely to be the successful crossing strategies in White patients without any significant differences in technical success (86.4% vs 86.4%; P = .93), procedural success (84.8% vs 85.0%; P = .79), and in-hospital MACE (2.0% vs 1.5%; P = .15) between the 2 groups. The technical success rate was significantly higher in the "Other" racial group (91.0% vs 86.4% in White, 86.9% in Asian, 84.5% in Black, 84.5% in Hispanic, and 83.3% in Native American; P = .03) without any significant differences in procedural success or in-hospital MACE rates between the groups. CONCLUSIONS: Despite differences in baseline characteristics and procedural techniques, the procedural success and in-hospital MACE of CTO PCI were not significantly different between most racial groups.

Emergency coronary artery bypass surgery after chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry.

BACKGROUND: Emergency coronary artery bypass surgery (eCABG) is a serious complication of chronic total occlusion (CTO) percutaneous coronary artery intervention (PCI). METHODS: We examined the incidence and outcomes eCABG among 14,512 CTO PCIs performed between 2012 and 2023 in a large multicenter registry. RESULTS: The incidence of eCABG was 0.12% (n = 17). Mean age was 68 ± 6 years and 69% of the patients were men. The most common reason for eCABG was coronary perforation (70.6%). eCABG patients had larger target vessel diameter (3.36 ± 0.50 vs. 2.90 ± 0.52; p = 0.003), were more likely to have moderate/severe calcification (85.7% vs. 45.8%; p = 0.006), side branch at the proximal cap (91.7% vs. 55.4%; p = 0.025), and balloon undilatable lesions (50% vs. 7.4%; p = 0.001) and to have undergone retrograde crossing (64.7% vs. 30.8%, p = 0.006). eCABG cases had lower technical (35.3% vs. 86.7%; p < 0.001) and procedural (35.3% vs. 86.7%; p < 0.001) success and higher in-hospital mortality (35.3% vs. 0.4%; p < 0.001), coronary perforation (70.6% vs. 4.6%; p < 0.001), pericardiocentesis (47.1% vs. 0.8%; p < 0.001), and major bleeding (11.8% vs. 0.5%; p < 0.001). CONCLUSIONS: The incidence of eCABG after CTO PCI was 0.12% and associated with high in-hospital mortality (35%). Coronary perforation was the most common reason for eCABG.

Equipment entrapment/loss during chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There is limited data on equipment loss or entrapment during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and outcomes of equipment loss/entrapment at 43 US and non-US centers between 2017 and 2023. RESULTS: Equipment loss/entrapment was reported in 40 (0.4%) of 10 719 cases during the study period. These included guidewire entrapment/fracture (n = 21), microcatheter entrapment/fracture (n = 11), stent loss (n = 8) and balloon entrapment/fracture/rupture (n = 5). The equipment loss/entrapment cases were more likely to have moderate to severe calcification, longer lesion length, higher J-CTO and PROGRESS-CTO complications scores, and use of the retrograde approach compared with the remaining cases. Retrieval was attempted in 71.4% of the guidewire, 90.9% of the microcatheter, 100% of the stent loss, and 100% of the balloon cases, and was successful in 26.7%, 30.0%, 50%, and 40% of the cases, respectively. Procedures complicated by equipment loss/entrapment had higher procedure and fluoroscopy time, contrast volume and patient air kerma radiation dose, lower procedural (60.0% vs 85.6%, P less than .001) and technical (75.0% vs 86.8%, P = .05) success, and higher incidence of major adverse cardiac events (MACE) (17.5% vs 1.8%, P less than .001), acute MI (7.5% vs 0.4%, P less than .001), emergency coronary artery bypass graft (CABG) (2.5% vs 0.1%, P = .03), perforation (20.0% vs 4.9%, P less than .001), and death (7.5% vs 0.4%, P less than .001). CONCLUSIONS: Equipment loss is a rare complication of CTO PCI; it is more common in complex CTOs and is associated with lower technical success and higher MACE.

Practice differences and knowledge gaps in complex and high-risk interventions between Japan and the USA: A case-based discussion.

Advances in percutaneous coronary intervention (PCI) devices and techniques have expanded the pool of eligible patients for revascularization, including those with comorbidities, reduced left ventricular function, or anatomical complexity (defined as CHIP: complex and high-risk interventions in indicated patients). CHIP interventions are typically performed by selected operators who specialize in complex PCI. This review presents two cases performed in the USA, to discuss the similarities and differences in practice patterns between CHIP operators in Japan and the USA. The first case involves a 58-year-old male presenting with myocardial infarction and cardiogenic shock, and the second case involves a 51-year-old female with a history of coronary artery bypass grafting presenting with a chronic total occlusion and PCI complicated by vessel perforation. The discussion focuses on appropriate patient selection, the role of the heart team approach for decision-making, the use of hemodynamic support devices, and other relevant factors. By comparing practices in Japan and the USA, this review highlights opportunities for knowledge exchange and potential areas for improving patient outcomes.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes.

BACKGROUND: Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach. OBJECTIVES: This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI. METHODS: We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke. RESULTS: The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01). CONCLUSIONS: Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions in Patients With Previous Coronary Artery Bypass Graft Surgery.

The outcomes of chronic total occlusion (CTO) percutaneous coronary interventions (PCIs) in patients with previous coronary artery bypass graft (CABG) surgery have received limited study. We examined the baseline characteristics and outcomes of CTO PCIs performed at 47 United States and non-United States centers between 2012 and 2023. Of the 12,164 patients who underwent CTO PCI during the study period, 3,475 (29%) had previous CABG. Previous CABG patients were older, more likely to be men, and had more comorbidities and lower left ventricular ejection fraction and estimated glomerular filtration rate. Their CTOs were more likely to have moderate/severe calcification and proximal tortuosity, proximal cap ambiguity, longer lesion length, and higher Japanese CTO scores. The first and final successful crossing strategy was more likely to be retrograde. Previous CABG patients had lower technical (82.1% vs 88.2%, p <0.001) and procedural (80.8% vs 86.8%, p <0.001) success, higher in-hospital mortality (0.8% vs 0.3%, p <0.001), acute myocardial infarction (0.9% vs 0.5%, p = 0.007) and perforation (7.0% vs 4.2%, p <0.001) but lower incidence of pericardial tamponade and pericardiocentesis (0.1% vs 1.3%, p <0.001). At 2-year follow-up, the incidence of major adverse cardiac events, repeat PCI and acute coronary syndrome was significantly higher in previous CABG patients, whereas all-cause mortality was similar. In conclusion, patients with previous CABG who underwent CTO PCI had more complex clinical and angiographic characteristics and lower success rate, higher perioperative mortality, and myocardial infarction but lower tamponade, and higher incidence of major adverse cardiac events with similar all-cause mortality during follow-up.

Impact of calcium on the procedural techniques and outcomes of chronic total occlusion percutaneous coronary intervention.

BACKGROUND: Coronary calcification is common and increases the difficulty of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined the impact of calcium on procedural outcomes of 13,079 CTO PCIs performed in 12,799 patients at 46 US and non-US centers between 2012 and 2023. RESULTS: Moderate or severe calcification was present in 46.6% of CTO lesions. Patients whose lesions were calcified were older and more likely to have had prior coronary artery bypass graft surgery. Calcified lesions were more complex with higher J-CTO score (3.0 ± 1.1 vs. 1.9 ± 1.2; p < 0.001) and lower technical (83.0% vs. 89.9%; p < 0.001) and procedural (81.0% vs. 89.1%; p < 0.001) success rates compared with mildly calcified or non-calcified CTO lesions. The retrograde approach was more commonly used among cases with moderate/severe calcification (40.3% vs. 23.5%; p < 0.001). Balloon angioplasty (76.6%) was the most common lesion preparation technique for calcified lesions, followed by rotational atherectomy (7.3%), laser atherectomy (3.4%) and, intravascular lithotripsy (3.4%). The incidence of major adverse cardiovascular events (MACE) was higher in cases with moderate or severe calcification (3.0% vs. 1.2%; p < 0.001), as was the incidence of perforation (6.5% vs. 3.4%; p < 0.001). On multivariable analysis, the presence of moderate/severe calcification was independently associated with lower technical success (odds ratio, OR = 0.73, 95% CI: 0.63-0.84) and higher MACE (OR = 2.33, 95% CI: 1.66-3.27). CONCLUSIONS: Moderate/severe calcification was present in nearly half of CTO lesions, and was associated with higher utilization of the retrograde approach, lower technical and procedural success rates, and higher incidence of in-hospital MACE.

Aortocoronary dissection during percutaneous coronary interventions for chronic total occlusion: Insights from the PROGRESS-CTO registry.

BACKGROUND: Aortocoronary dissection is a potentially serious complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined the incidence, mechanisms, treatment, and outcomes of aortocoronary dissection among 12,117 CTO PCIs performed between 2012 and 2022 in a large multicenter CTO PCI registry. RESULTS: The incidence of aortocoronary dissection was 0.2% (n = 27). Most aortocoronary dissections occurred in the right coronary artery (96.3%, n = 26). The baseline clinical characteristics of patients with and without aortocoronary dissection were similar, except for dyslipidemia, which was less common in patients with aortocoronary dissection (70.4% vs. 86.0%; p = 0.019). The retrograde approach was used more commonly among cases complicated by aortocoronary dissection (59.3% vs. 31.0%; p = 0.002). Technical (74.1% vs. 86.6%; p = 0.049) and procedural (70.4% vs. 85.2%; p = 0.031) success rates were lower among aortocoronary dissection cases, with a similar incidence of in-hospital major adverse cardiovascular events (3.7% vs. 2.0%; p = 0.541). Of the 27 patients with aortocoronary dissection, 19 (70.4%) were treated with ostial stenting and 8 (29.6%) were treated conservatively without subsequent adverse clinical outcomes. No patients required emergency surgery. Follow-up was available for 22 patients (81.5%): during a mean follow up of 767 (±562) days, the incidence of in-stent restenosis was 11.1% (n = 3). CONCLUSIONS: Aortocoronary dissection occurred in 0.2% of CTO PCIs performed by experienced operators, was associated with lower technical and procedural success, and was treated most commonly with ostial stenting. None of the patients required emergency cardiac surgery.

Angiographic Features and Clinical Outcomes of Balloon Uncrossable Lesions during Chronic Total Occlusion Percutaneous Coronary Intervention.

Background: Balloon uncrossable lesions are defined as lesions that cannot be crossed with a balloon after successful guidewire crossing. Methods: We analyzed the association between balloon uncrossable lesions and procedural outcomes of 8671 chronic total occlusions (CTOs) percutaneous coronary interventions (PCIs) performed between 2012 and 2022 at 41 centers. Results: The prevalence of balloon uncrossable lesions was 9.2%. The mean patient age was 64.2 ± 10 years and 80% were men. Patients with balloon uncrossable lesions were older (67.3 ± 9 vs. 63.9 ± 10, p < 0.001) and more likely to have prior coronary artery bypass graft surgery (40% vs. 25%, p < 0.001) and diabetes mellitus (50% vs. 42%, p < 0.001) compared with patients who had balloon crossable lesions. In-stent restenosis (23% vs. 16%. p < 0.001), moderate/severe calcification (68% vs. 40%, p < 0.001), and moderate/severe proximal vessel tortuosity (36% vs. 25%, p < 0.001) were more common in balloon uncrossable lesions. Procedure time (132 (90, 197) vs. 109 (71, 160) min, p < 0.001) was longer and the air kerma radiation dose (2.55 (1.41, 4.23) vs. 1.97 (1.10, 3.40) min, p < 0.001) was higher in balloon uncrossable lesions, while these lesions displayed lower technical (91% vs. 99%, p < 0.001) and procedural (88% vs. 96%, p < 0.001) success rates and higher major adverse cardiac event (MACE) rates (3.14% vs. 1.49%, p < 0.001). Several techniques were required for balloon uncrossable lesions. Conclusion: In a contemporary, multicenter registry, 9.2% of the successfully crossed CTOs were initially balloon uncrossable. Balloon uncrossable lesions exhibited lower technical and procedural success rates and a higher risk of complications compared with balloon crossable lesions.

Incidence, Mechanisms, Treatment, and Outcomes of Coronary Artery Perforation During Chronic Total Occlusion Percutaneous Coronary Intervention.

Coronary artery perforation is a feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Our objective was to describe the incidence, mechanisms, treatment, and outcomes of coronary artery perforation during CTO PCI. We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 10,454 CTO PCIs performed in 10,219 patients between 2012 and 2022. The incidence of coronary perforation was 4.9% (n = 503). Patients who experienced coronary perforation were older and were more likely to have had previous coronary artery bypass graft surgery. Procedures that resulted in perforation were more complex, with higher Japanese CTO and Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) scores. Technical (66% vs 87%, p <0.001) and procedural (55% vs 87%, p <0.001) success rates were lower in perforation cases. The CTO target vessel was the most common perforation site (66%). The retrograde approach was responsible for the perforation in 47% of cases, and guidewire exit was the most common perforation mechanism. The proportion of Ellis class 1, 2, 3, and 3 -"cavity spilling" coronary perforations was 20%, 41%, 28%, and 11%, respectively. In 52% of perforations, 1 or more interventions were required: prolonged balloon inflation (23%), covered stent deployment (21%), coil embolization (6%), and/or autologous fat embolization (4%). Tamponade requiring pericardiocentesis occurred in 69 patients (14%). The incidence of major adverse cardiovascular events was higher in perforation cases (18% vs 1.3%, p <0.001). In conclusion, coronary artery perforation occurred in 4.9% of CTO PCIs performed by experienced operators and was associated with lower technical success and higher in-hospital major adverse cardiovascular events.

Preprocedural coronary computed tomography angiography in chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry.

BACKGROUND: Preprocedural coronary computed tomography angiography (CCTA) can be useful in procedural planning for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined the clinical, angiographic and procedural characteristics and outcomes of cases with vs. without preprocedural CCTA in PROGRESS-CTO (NCT02061436). Multivariable logistic regression was used to adjust for confounding factors. RESULTS: Of 7034 CTO PCI cases, preprocedural CCTA was used in 375 (5.3%) with increasing frequency over time. Patients with preprocedural CCTA had a higher prevalence of prior coronary artery bypass graft surgery (39% vs. 27%, p < 0.001) and angiographically unfavorable characteristics including higher prevalence of proximal cap ambiguity (52% vs. 33%, p < 0.001) and moderate/severe calcification (59% vs. 41%, p < 0.001) compared with those without CCTA. CCTA helped resolve proximal cap ambiguity in 27%, identified significant calcium not seen on diagnostic angiography in 18%, changed estimated CTO length by >5 mm in 10%, and was performed as part of initial coronary artery disease work up in 19%. CCTA cases had higher J-CTO (2.6 ± 1.2 vs. 2.3 ± 1.3, p < 0.001) and PROGRESS-CTO (1.3 ± 1.0 vs. 1.2 ± 1.0 p = 0.027) scores. After adjusting for potential confounders, cases with preprocedural CCTA had similar technical success (odds ratio [OR]: 1.18, 95% confidence interval [CI], 0.83-1.67) and incidence of major adverse cardiovascular events (OR: 1.47, 95% CI, 0.72-3.00). CONCLUSION: Preprocedural CCTA was used in ~5% of CTO PCI cases. While CCTA may help with procedural planning, especially in complex cases, technical success and MACE were similar with or without CCTA.

Predicting Periprocedural Complications in Chronic Total Occlusion Percutaneous Coronary Intervention: The PROGRESS-CTO Complication Scores.

BACKGROUND: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with increased risk of periprocedural complications. Estimating the risk of complications facilitates risk-benefit assessment and procedural planning. OBJECTIVES: This study sought to develop risk scores for in-hospital major adverse cardiovascular events (MACE), mortality, pericardiocentesis, and acute myocardial infarction (MI) in patients undergoing CTO PCI. METHODS: The study analyzed the PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; NCT02061436) and created risk scores for MACE, mortality, pericardiocentesis, and acute MI. Logistic regression prediction modeling was used to identify independently associated variables, and models were internally validated with bootstrapping. RESULTS: The incidence of periprocedural complications among 10,480 CTO PCIs was as follows: MACE 215 (2.05%), mortality 47 (0.45%), pericardiocentesis 83 (1.08%), and acute MI 66 (0.63%). The final model for MACE included ≥65 years of age (1 point), moderate-severe calcification (1 point), blunt stump (1 point), antegrade dissection and re-entry (ADR) (1 point), female (2 points), and retrograde (2 points); the final model for mortality included ≥65 years of age (1 point), left ventricular ejection fraction ≤45% (1 point), moderate-severe calcification (1 point), ADR (1 point), and retrograde (1 point); the final model for pericardiocentesis included ≥65 years of age (1 point), female (1 point), moderate-severe calcification (1 point), ADR (1 point), and retrograde (2 points); the final model for acute MI included prior coronary artery bypass graft surgery (1 point), atrial fibrillation (1 point), and blunt stump (1 point). The C-statistics of the models were 0.74, 0.80, 0.78, 0.72 for MACE, mortality, pericardiocentesis, and acute MI, respectively. CONCLUSIONS: The PROGRESS-CTO complication risk scores can facilitate estimation of the periprocedural complication risk in patients undergoing CTO PCI.

Characterization of an Anti-CD70 Half-Life Extended Bispecific T-Cell Engager (HLE-BiTE) and Associated On-Target Toxicity in Cynomolgus Monkeys.

Bispecific T-cell engager (BiTE) molecules have great potential to treat cancer. Nevertheless, dependent on the targeted tumor antigen, the mechanism of action that drives efficacy may also contribute to on-target/off-tumor toxicities. In this study, we characterize an anti-CD70 half-life extended BiTE molecule (termed N6P) which targets CD70, a TNF family protein detected in several cancers. First, the therapeutic potential of N6P was demonstrated using in vitro cytotoxicity assays and an orthotopic xenograft mouse study resulting in potent killing of CD70+ cancer cells. Next, in vitro characterization demonstrated specificity for CD70 and equipotent activity against human and cynomolgus monkey CD70+ cells. To understand the potential for on-target toxicity, a tissue expression analysis was performed and indicated CD70 is primarily restricted to lymphocytes in normal healthy tissues and cells. Therefore, no on-target toxicity was expected to be associated with N6P. However, in a repeat-dose toxicology study using cynomolgus monkeys, adverse N6P-mediated inflammation was identified in multiple tissues frequently involving the mesothelium and epithelium. Follow-up immunohistochemistry analysis revealed CD70 expression in mesothelial and epithelial cells in some tissues with N6P-mediated injury, but not in control tissues or those without injury. Collectively, the data indicate that for some target antigens such as CD70, BiTE molecules may exhibit activity in tissues with very low antigen expression or the antigen may be upregulated under stress enabling molecule activity. This work illustrates how a thorough understanding of expression and upregulation is needed to fully address putative liabilities associated with on-target/off-tumor activity of CD3 bispecific molecules.

Predictors of success in primary retrograde strategy in chronic total occlusion percutaneous coronary intervention: insights from the PROGRESS-chronic total occlusion registry.

BACKGROUND: An upfront (primary) retrograde strategy is often used in complex chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined the clinical, angiographic characteristics, and procedural outcomes of CTO PCIs that were approached with a primary retrograde strategy in the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO, NCT02061436). RESULTS: Of 10,286 CTO PCIs performed between 2012 and 2022, a primary retrograde strategy was used in 1329 (13%) with an initial technical success of 66%, and a final success of 83%. Patients who underwent successful versus unsuccessful primary retrograde cases had similar characteristics: age (65 ± 10 vs. 65 ± 9, years, p = 0.203), men (83% vs. 87%, p = 0.066), prior PCI (71% vs. 71%, p = 0.809), and prior coronary artery bypass graft surgery (52% vs. 53%, p = 0.682). The PROGRESS-CTO score (1.3 ± 0.9 vs. 1.6 ± 0.9, p < 0.001), air kerma radiation (3.9 ± 2.8 vs. 3.4 ± 2.6, gray, p = 0.013), and contrast use (294 ± 148 ml vs. 248 ± 128, ml, p < 0.001) were higher in the unsuccessful group, whereas the presence of interventional collaterals (95% vs. 72%, p < 0.001) and Werner collateral connection grade 2 (43% vs. 31%, p < 0.001) were higher in the successful group. On multivariable logistic regression analysis, the only variable associated with a successful primary retrograde strategy was the presence of interventional collaterals: odds ratio: 6.52 (95% confidence intervals; 3.5-12.1, p < 0.001). CONCLUSION: Presence of interventional collaterals is independently associated with higher success rates with a primary retrograde strategy in CTO PCI.

Prevalence and outcomes of balloon undilatable chronic total occlusions: Insights from the PROGRESS-CTO.

BACKGROUND: The prevalence, treatment, and outcomes of balloon undilatable lesions encountered in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have received limited study. METHODS: We examined the clinical characteristics and procedural outcomes of balloon undilatable lesions in the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO, NCT02061436). RESULTS: Of 6535 CTO PCIs performed between 2012 and 2022, 558 (8.5%) lesions were balloon undilatable. In this subset, patients were older (mean age 67 ± 10 vs. 64 ± 10, p < 0.001) and had higher prevalence of comorbidities: diabetes mellitus (54% vs. 40%, p < 0.001), prior PCI (71% vs. 59%, p < 0.001), prior myocardial infarction (52% vs. 45%, p = 0.003), and prior coronary artery bypass graft surgery (44% vs. 25%, p < 0.001). The CTO lesion length was estimated to be 34 ± 23 mm, mean J-CTO score was 2.9 ± 1.1 and mean PROGRESS-CTO score was 1.4 ± 1.0. A cutting balloon was used in 27%, a scoring balloon in 15%, laser in 14%, rotational atherectomy in 28%, orbital atherectomy in 10%, intravascular lithotripsy in 1% and other modalities/approaches in 5%. Balloon undilatable lesions had lower technical success (90.9% vs. 93.8%, p = 0.007) and higher incidence of major adverse cardiovascular events (MACE) (composite of in-hospital death, acute myocardial infarction, stroke, re-PCI, emergency CABG, and pericardiocentesis) (5.0% versus 1.3%, p < 0.001). CONCLUSION: Approximately 1 in 12 CTO (8.5%) lesions are balloon undilatable. Treatment of balloon undilatable lesions is associated with lower technical success and higher in-hospital MACE.

Characterization of false positive, contaminant-driven mutagenicity in impurities associated with the sotorasib drug substance.

Sotorasib (Lumakras™) is a first-in-class, non-genotoxic, small molecule inhibitor of KRAS G12C developed as an anticancer therapeutic for treatment of patients that have a high unmet medical need. Anticancer therapeutics are considered out of scope of ICH M7 guidance for control of mutagenic impurities; however, based on ICH S9 Q&A, mutagenicity assessments are needed for impurities that exceed the qualification threshold, consistent with ICH Q3A/B, and non-mutagenic drugs. Here, we carried out hybrid-based mutagenicity assessment of sotorasib drug substance (DS) impurities using in silico quantitative structure-activity relationship (QSAR) modelling and Ames tests (for in silico positive mutagens). We encountered contradictive mutagenicity results for 2 impurities (Beta-Chloride and PAC). PAC was negative initially by QSAR but positive in a GLP full plate Ames test and Beta-Chloride was positive by QSAR, negative in a non-GLP micro-Ames but positive in a GLP full plate Ames assay. Root cause analyses identified and characterized mutagenic contaminants, 3-chloropropionic acid in batches of Beta-Chloride and 3-chloropropionic acid and Chloro-PAC in batches of PAC, used in initial GLP full-plate Ames tests. Significant reduction of these contaminants in re-purified batches resulted in no induction of mutagenicity in follow-up GLP micro-Ames tests. In summary, root-cause analyses led to accurate mutagenicity assessment for sotorasib DS-associated impurities.

GIPR gene expression in testis is mouse specific and can impact male mouse fertility.

BACKGROUND: Glucose-dependent insulinotropic polypeptide receptor (Gipr) gene expression has been reported in mouse spermatids and Gipr knockout male mice have previously been reported to have decreased in vitro fertilization, although the role of Gipr signaling in male mouse fertility is not well understood. OBJECTIVES: The purposes of these studies were to determine the role of glucose-dependent insulinotropic polypeptide receptor in male fertility using Gipr knockout mice and anti-glucose-dependent insulinotropic polypeptide receptor antibody-treated wild-type mice and to determine if the expression of Gipr in mouse testes is similar in non-human and human primates. METHODS AND MATERIALS: Adiponectin promoter-driven Gipr knockout male mice (GiprAdipo-/- ) were assessed for in vitro and in vivo fertility, sperm parameters, and testicular histology. CD1 male mice were administered an anti-glucose-dependent insulinotropic polypeptide receptor antibody (muGIPR-Ab) prior to and during mating for assessment of in vivo fertility and sperm parameters. Expression of Gipr/GIPR mRNA in the mouse, cynomolgus monkey, and human testes was assessed by in situ hybridization methods using species-specific probes. RESULTS: GiprAdipo-/- male mice are infertile in vitro and in vivo, despite normal testis morphology, sperm counts, and sperm motility. In contrast, administration of muGIPR-Ab to CD1 male mice did not impact fertility. While Gipr mRNA expression is detectable in the mouse testes, GIPR mRNA expression is not detectable in monkey or human testes. DISCUSSION: The infertility of GiprAdipo-/- male mice correlated with the lack of Gipr expression in the testis and/or adipocyte tissue. However, as administration of muGIPR-Ab did not impact the fertility of adult male mice, it is possible that the observations in genetically deficient male mice are related to Gipr deficiency during development. CONCLUSION: Our data support a role for Gipr expression in the mouse testis during the development of sperm fertilization potential, but based on gene expression data, a similar role for glucose-dependent insulinotropic polypeptide receptor in non-human primate or human male fertility is unlikely.

Outcomes of chronic total occlusion percutaneous coronary intervention in patients with reduced left ventricular ejection fraction.

BACKGROUND: The relationship between left ventricular ejection fraction (LVEF) and the success and safety of coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We examined the clinical characteristics and outcomes of CTO PCI in the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO) after stratifying patients by LVEF (≤35%, 36%-49%, and ≥50%). RESULTS: A total of 7827 CTO PCI procedures with LVEF data were included. Mean age was 64 ± 10 years, 81% were men, 43% had diabetes mellitus, 61% had prior PCI, 45% had prior myocardial infarction, and 29% had prior coronary artery bypass graft surgery. Technical success was similar in the three LVEF strata: 85%, 86%, and 87%, p = 0.391 for LVEF ≤35%, 36%-49%, and ≥50%, respectively. In-hospital mortality was higher in lower LVEF patients (1.1%, 0.4%, and 0.3%, respectively, p = 0.001). In-hospital major adverse cardiovascular events (MACE) were numerically higher in lower EF patients (2.7%, 2.1%, and 1.9%, p = 0.271). At a median follow-up of 2 months (interquartile range: 19-350 days), patients with lower LVEF continued to have higher mortality (4.9%, 3.2%, and 1.4%, p < 0.001) while the MACE rates were similar (9.3%, 9.6%, and 7.4%, p = 0.172). CONCLUSION: CTO PCI can be performed with high technical success in patients with reduced LVEF but is associated with higher in-hospital and post-discharge mortality.

Nonclinical Safety Profile of Sotorasib, a KRASG12C-Specific Covalent Inhibitor for the Treatment of KRAS p.G12C-Mutated Cancer.

Sotorasib is a first-in-class KRASG12C covalent inhibitor in clinical development for the treatment of tumors with the KRAS p.G12C mutation. A comprehensive nonclinical safety assessment package, including secondary/safety pharmacology and toxicology studies, was conducted to support the marketing application for sotorasib. Sotorasib was negative in a battery of genotoxicity assays and negative in an in vitro phototoxicity assay. Based on in vitro assays, sotorasib had no off-target effects against various receptors, enzymes (including numerous kinases), ion channels, or transporters. Consistent with the tumor-specific target distribution (ie, KRASG12C), there were no primary pharmacology-related on-target effects identified. The kidney was identified as a target organ in the rat but not the dog. Renal toxicity in the rat was characterized by tubular degeneration and necrosis restricted to a specific region suggesting that the toxicity was attributed to the local formation of a putative toxic reactive metabolite. In the 3-month dog study, adaptive changes of hepatocellular hypertrophy due to drug metabolizing enzyme induction were observed in the liver that was associated with secondary effects in the pituitary and thyroid gland. Sotorasib was not teratogenic and had no direct effect on embryo-fetal development in the rat or rabbit. Human, dog, and rat circulating metabolites, M24, M10, and M18, raised no clinically relevant safety concerns based on the general toxicology studies, primary/secondary pharmacology screening, an in vitro human ether-à-go-go-related gene assay, or mutagenicity assessment. Overall, the results of the nonclinical safety program support a high benefit/risk ratio of sotorasib for the treatment of patients with KRAS p.G12C-mutated tumors.