tRNA-derived fragments are altered in diabetes.

AIMS: Maternally inherited diabetes and deafness (MIDD) is a rare form of adult-onset diabetes that can be difficult to diagnose due to its variable clinical phenotype. Transfer RNA-derived small fragments are a novel, emerging class of small non-coding RNAs (sncRNAs) that have significant potential as serum biomarkers due to their stress-induced generation, abundance, stability and ease of detection. METHODS: We investigated the levels of tiRNA 5'ValCAC (alone and in combination with miR-23b-3p) identified from small RNA sequencing studies in serum samples from healthy controls, type 1 diabetes, type 2 diabetes and MIDD subjects. RESULTS: Serum levels of 5'ValCAC were reduced in MIDD and type 2 diabetes subjects compared to controls. Type 2 diabetes subjects had higher serum levels of miR-23b-3p compared to all other subjects. Receiver Operating Characteristic analysis showed the potential of 5'ValCAC and miR-23b-3p as MIDD biomarkers, with the combination showing excellent separation from type 2 diabetes subjects. CONCLUSIONS: This is the first report showing altered serum levels of tiRNAs in diabetes subjects. The combined use of 5'ValCAC and miR-23b-3p as serum biomarkers could potentially differentiate between MIDD subjects and type 2 diabetes subjects.

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.

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.

Application of Weak-Beam Dark-Field STEM for Dislocation Loop Analysis †.

Nanoscale dislocation loops formed by irradiation can significantly contribute to both irradiation hardening and embrittlement of materials when subjected to extreme nuclear reactor environments. This study explores the application of weak-beam dark-field (WBDF) scanning transmission electron microscopy (STEM) methods for quantitative irradiation-induced defect analysis in crystalline materials, with a specific focus on dislocation loop imaging and analysis. A high-purity Fe-5 wt% Cr model alloy was irradiated with 8 MeV Fe2+ ions at 450°C to a fluence of 8.8 × 1019 m-2, inducing dislocation loops for analysis. While transmission electron microscopy (TEM) has traditionally been the primary tool for dislocation imaging, recent advancements in STEM technology have reignited interest in using STEM for defect imaging. This study introduces and compares three WBDF STEM methods, demonstrating their effectiveness in suppressing background contrasts, isolating defect information for dislocation loop type classification, providing finer dislocation line images for small loop analysis, and presenting inside-outside contrast for identifying loop nature. Experimental findings indicate that WBDF STEM methods surpass traditional TEM approaches, yielding clearer and more detailed images of dislocation loops. The study concludes by discussing the potential applications of WBDF STEM techniques in defect analysis, emphasizing their adaptability across various material systems beyond nuclear materials.

Targeting neural correlates of placebo effects.

Harnessing the placebo effects would prompt critical ramifications for research and clinical practice. Noninvasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation and multifocal transcranial electric stimulation, could manipulate the placebo response by modulating the activity and excitability of its neural correlates. To identify potential stimulation targets, we conducted a meta-analysis to investigate placebo-associated regions in healthy volunteers, including studies with emotional components and painful stimuli. Using biophysical modeling, we identified NIBS solutions to manipulate placebo effects by targeting either a single key region or multiple connected areas. Moving to a network-oriented approach, we then ran a quantitative network mapping analysis on the functional connectivity profile of clusters emerging from the meta-analysis. As a result, we suggest a multielectrode optimized montage engaging the connectivity patterns of placebo-associated functional brain networks. These NIBS solutions hope to provide a starting point to actively control, modulate or enhance placebo effects in future clinical studies and cognitive enhancement studies.

Impact of proximal cap ambiguity on the procedural techniques and outcomes of chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO Registry.

BACKGROUND: Proximal cap ambiguity is a key parameter in the global chronic total occlusion (CTO) percutaneous coronary intervention (PCI) crossing algorithm. METHODS: We examined the baseline characteristics and procedural outcomes of 9718 CTO PCIs performed in 9498 patients at 41 US and non-US centers between 2012 and 2022. RESULTS: Proximal cap ambiguity was present in 35% of CTO lesions. Patients whose lesions had proximal cap ambiguity were more likely to have had prior coronary artery bypass graft surgery (37% vs. 24%; p < 0.001). Lesions with proximal cap ambiguity were more complex with higher J-CTO score (3.1 ± 1.0 vs. 2.0 ± 1.2; p < 0.001) and lower technical (79% vs. 90%; p < 0.001) and procedural (77% vs. 89%; p < 0.001) success rates compared with nonambiguous CTO lesions. The incidence of major adverse cardiovascular events (MACE) was higher in cases with proximal cap ambiguity (2.5% vs. 1.7%; p < 0.001). The retrograde approach was more commonly used among cases with ambiguous proximal cap (50% vs. 21%; p < 0.001) and was more likely to be the final successful crossing strategy (29% vs. 13%; p < 0.001). The antegrade dissection and re-entry (ADR) "move-the-cap" techniques were also more common among cases with proximal cap ambiguity. CONCLUSIONS: Proximal cap ambiguity in CTO lesions is associated with higher utilization of the retrograde approach and ADR, lower technical and procedural success rates, and higher incidence of in-hospital MACE.

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.

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.

Same day discharge versus overnight observation following chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry.

BACKGROUND: Same day discharge (SDD) following chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We evaluated the clinical, angiographic, and procedural characteristics of patients discharged the same day versus those kept for overnight observation in the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO, NCT02061436). RESULTS: Of the 7181 patients who underwent CTO PCI, 943 (13%) had SDD. The SDD rate increased from 3% in 2015 to 21% in 2022. Patients with SDD were less likely to have a history of heart failure (21% vs. 26%, p = 0.005), chronic lung disease (10% vs. 15%, p = 0.001), or anemia (12% vs. 19%, p < 0.001). Technical success (87% vs. 88%, p = 0.289) was similar, but in-hospital major adverse cardiovascular events (0.0% vs. 0.4%, p = 0.041) were lower in SDD. In multivariable logistic regression analysis, prior myocardial infarction odds ratio (OR): 0.71 (95% confidence interval [CI]: 0.59-0.87, p = 0.001), chronic lung disease OR: 0.64 (95% CI: 0.47-0.88, p = 0.006), and increasing procedure time OR: 0.93 (95% CI: 0.91-0.95, p < 0.001, per 10-min increase) were associated with overnight observation, while radial-only access OR: 2.45 (95% CI: 2.03-2.96, p < 0.001) had the strongest association with SDD. In the SDD, 2 (0.4%) of 514 patients were readmitted, due to retroperitoneal bleeding (n = 1) and ischemic stroke (n = 1). CONCLUSION: The overall frequency of SDD after CTO PCI was 13% and has been increasing over time. SDD is feasible in select patients following CTO PCI, and radial-only access had the strongest association with SDD.

Single vs. multiple operators for chronic total occlusion percutaneous coronary interventions: From the PROGRESS-CTO Registry.

BACKGROUND: There is limited data on the impact of a second attending operator on chronic total occlusion (CTO) percutaneous coronary intervention (PCI) outcomes. METHODS: We analyzed the association between multiple operators (MOs) (>1 attending operator) and procedural outcomes of 9296 CTO PCIs performed between 2012 and 2021 at 37 centers. RESULTS: CTO PCI was performed by a single operator (SO) in 85% of the cases and by MOs in 15%. Mean patient age was 64.4 ± 10 years and 81% were men. SO cases were more complex with higher Japan-CTO (2.38 ± 1.29 vs. 2.28 ± 1.20, p = 0.005) and Prospective Global Registry for the Study of Chronic Total Occlusion Intervention scores (1.13 ± 1.01 vs. 0.97 ± 0.93, p < 0.001) compared with MO cases. Procedural time (131 [87, 181] vs. 112 [72, 167] min, p < 0.001), fluoroscopy time (49 [31, 76] vs. 42 [25, 68] min, p < 0.001), air kerma radiation dose (2.32 vs. 2.10, p < 0.001), and contrast volume (230 vs. 210, p < 0.001) were higher in MO cases. Cases performed by MOs and SO had similar technical (86% vs. 86%, p = 0.9) and procedural success rates (84% vs. 85%, p = 0.7), as well as major adverse complication event rates (MACE 2.17% vs. 2.42%, p = 0.6). On multivariable analyses, MOs were not associated with higher technical success or lower MACE rates. CONCLUSION: In a contemporary, multicenter registry, 15% of CTO PCI cases were performed by multiple operators. Despite being more complex, SO cases had lower procedural and fluoroscopy times, and similar technical and procedural success and risk of complications compared with MO cases.

Incidence, mechanisms, treatment, and outcomes of donor vessel injury during percutaneous coronary interventions for chronic total occlusion.

BACKGROUND: Donor vessel injury is a potentially life-threatening complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). AIMS: Our goal was to examine the incidence, mechanisms, treatment, and outcomes of patients with donor vessel injury in a large multicenter CTO PCI registry. METHODS: We analyzed the baseline clinical and angiographic characteristics, and procedural outcomes of 12,349 CTO PCIs performed between 2012 and 2022 at 44 centers. RESULTS: The incidence of donor vessel injury was 0.35% (n = 43). The baseline clinical characteristics of patients with and without donor vessel injury were similar. Cases complicated by donor vessel injury were more complex with higher Japanese CTO score (2.9 ± 1.1 vs. 2.4 ± 1.3; p = 0.004) and lower procedural success rate (69.8% vs. 85.2%; p = 0.004). The retrograde approach was used more commonly in donor vessel injury cases (68.9% vs. 30.9%; p < 0.001). Most (53.5%) donor vessel injuries were guide catheter-induced, whereas 20.9% were due to donor vessel thrombosis. Of the 43 patients with donor vessel injury, 36 (83.7%) were treated with stenting and seven (16.3%) received a left ventricular assist device. The incidence of major adverse cardiovascular events (MACEs) was significantly higher in cases with donor vessel injury (23.3% vs. 2.0%; p < 0.001). Of the 43 patients with donor vessel injury, five patients (11.6%) experienced acute myocardial infarction and four patients (9.3%) died. CONCLUSIONS: Donor vessel injury, occurred in 0.35% of CTO PCIs performed by experienced operators, was mainly due to guide catheter-induced dissection or thrombosis and was associated with lower procedural success and higher MACE.

Saphenous Vein Graft Failure: From Pathophysiology to Prevention and Treatment Strategies.

Saphenous vein grafts (SVGs) remain the most frequently used conduits in coronary artery bypass graft surgery (CABG). Despite advances in surgical techniques and pharmacotherapy, SVG failure rates remain high, often leading to repeat coronary revascularization. The no-touch SVG harvesting technique (minimal graft manipulation with preservation of vasa vasorum and nerves) reduces the risk of SVG failure, whereas the effect of the off-pump technique on SVG patency remains unclear. Use of buffered storage solutions, intraoperative graft flow measurement, careful selection of the target vessels, and physiological assessment of the native coronary circulation before CABG may also reduce the incidence of SVG failure. Perioperative aspirin and high-intensity statin administration are the cornerstones of secondary prevention after CABG. Dual antiplatelet therapy is recommended for off-pump CABG and in patients with a recent acute coronary syndrome. Intermediate (30%-60%) SVG stenoses often progress rapidly. Stenting of intermediate SVG stenoses failed to improve outcomes; hence, treatment focuses on strict control of coronary artery disease risk factors. Redo CABG is associated with higher perioperative mortality compared with percutaneous coronary intervention (PCI); hence, the latter is preferred for most patients requiring repeat revascularization after CABG. SVG PCI is limited by high rates of no-reflow and a high incidence of restenosis during follow-up. Drug-eluting and bare metal stents provide similar long-term outcomes in SVG PCI. Embolic protection devices reduce no-reflow and should be used when feasible. PCI of the corresponding native coronary artery is associated with better short- and long-term outcomes and is preferred over SVG PCI, if technically feasible.

Complications and failure modes of coronary embolic protection devices: Insights from the MAUDE database.

BACKGROUND: There is limited data on complications associated with the use of coronary embolic protection devices (EPDs). METHODS: We queried the Manufacturer and User Facility Device Experience database between November 2010 and November 2020 for reports on coronary EPDs: Spider FX (Medtronic, Minneapolis, MN) and Filterwire EZ (Boston Scientific, Natick, MA). RESULTS: We retrieved 119 reports on coronary EPD failure (Spider FX n = 33 and Filterwire EZ n = 86), most of which (78.2%) occurred during saphenous vein graft interventions. The most common failure mode was inability to retrieve the EPD (49.6%), with the filter trapped against stent struts in 76.2% of the cases. Other device complications included filter fracture (28.6%), failure to cross (7.6%), failure to deploy (7.6%), and failure to recapture the filter (3.4%). Filter fracture (54.5 vs. 29.1%) and failure to recapture (9.1 vs. 2.1%) were more commonly reported, while failure to deploy the filter (0 vs. 10.5%) was less commonly reported with the Spider-FX. CONCLUSIONS: The most common modes of failure of coronary EPDs are the failure of retrieval (49.6%), followed by the filter fracture (28.6%). When using EPDs, careful attention to the technique is essential to avoid failures and subsequent complications.

Radial versus femoral access in patients with coronary artery bypass surgery: Frequentist and Bayesian meta-analysis.

BACKGROUND: The optimal access site for cardiac catheterization in patients with prior coronary artery bypass surgery (CABG) continues to be debated. METHODS: We performed a random effects frequentist and Bayesian meta-analysis of 4 randomized trials and 18 observational studies, including 60,192 patients with prior CABG (27,236 in the radial group; 32,956 in the femoral group) that underwent cardiac catheterization. Outcomes included (1) access-site complications, (2) crossover to a different vascular access, (3) procedure time, and (4) contrast volume. Mean differences (MD) and 95% confidence interval (CI) were calculated for continuous outcomes and odds ratios (OR) and 95% CI for binary outcomes. RESULTS: Among randomized trials, crossover (OR: 7.63; 95% CI: 2.04, 28.51; p = 0.003) was higher in the radial group, while access site complications (OR: 0.96; 95% CI: 0.34, 2.87; p = 0.94) and contrast volume (MD: 15.08; 95% CI: -10.19, 40.35; p = 0.24) were similar. Among observational studies, crossover rates were higher (OR: 5.09; 95% CI: 2.43, 10.65; p < 0.001), while access site complication rates (OR: 0.52; 95% CI: 0.30, 0.89; p = 0.02) and contrast volume (MD: -7.52; 95% CI: -13.14, -1.90 ml; p = 0.009) were lower in the radial group. Bayesian analysis suggested that the odds of a difference existing between radial and femoral are small for all endpoints except crossover to another access site. CONCLUSION: In a frequentist and Bayesian meta-analysis of patients with prior CABG undergoing coronary catheterization, radial access was associated with lower incidence of vascular access complications and lower contrast volume but also higher crossover rate.

An algorithmic approach to balloon undilatable coronary lesions.

Balloon undilatable lesions are lesions that have been successfully crossed by both a guidewire and a balloon but cannot be expanded despite multiple high-pressure balloon inflations. Balloon undilatable lesions can be de novo or in-stent. We describe a systematic, algorithmic approach to treat both de novo and in-stent balloon undilatable lesions using various techniques, such as high-pressure balloon inflation, plaque modification balloons, intravascular lithotripsy, very high-pressure balloon inflation, coronary atherectomy, laser coronary angioplasty, and extraplaque lesion crossing. Knowledge of the various techniques can increase the efficiency, success and safety of the procedure.

Challenges and outcomes of the double kissing crush stenting technique: Insights from the PROGRESS-BIFURCATION registry.

BACKGROUND: Although the double kissing (DK) crush stenting technique can provide excellent outcomes in percutaneous coronary intervention (PCI) of bifurcation lesions, it can be challenging to perform. METHODS: We examined the clinical and angiographic characteristics, challenges encountered, and procedural outcomes of bifurcation PCI with DK crush in Prospective Global Registry of Percutaneous Coronary Intervention in Bifurcation Lesions (PROGRESS-BIFURCATION, NCT05100992). RESULTS: DK crush was used in 48 of 435 bifurcation lesions (11%). Technical success was 100%, procedural success was 96%, and the incidence of in-hospital major adverse cardiovascular events was 4%. Challenges while performing DK crush were encountered in 26 lesions (54%): (1) difficulty in side branch (SB) first rewiring (38%) that was overcome with the use of a new guidewire (30%) or a microcatheter (15%); (2) inability to deliver balloon to an SB for the first kiss (54%) that was overcome with the use of a smaller balloon (86%), rewiring (29%), microcatheter (14%), and increased support 7%; (3) difficulty in SB second rewiring (19%) that was overcome with the use of a new guidewire (80%) and/or microcatheter (60%). DK crush was more often performed in left main and proximal left anterior descending artery lesions (70% vs. 50%, p = 0.014). DK crush cases required more contrast (198 ± 84 ml vs. 163 ± 70 ml, p = 0.003), fluoroscopy time (35 ± 20 min vs. 25 ± 21 min, p = 0.004), and lasted longer (137 ± 69 min vs. 99 ± 66 min, p = 0.001) compared with non-DK crush techniques. CONCLUSIONS: While challenges are common when performing DK crush bifurcation stenting, success rates are high and complication rates are low.

Intravascular lithotripsy in chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry.

BACKGROUND: The use of intravascular lithotripsy (IVL) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 82 CTO PCIs that required IVL at 14 centers between 2020 and 2022. RESULTS: During the study period, IVL was used in 82 of 3301 (2.5%) CTO PCI procedures (0.4% in 2020 and 7% in 2022; p for trend < 0.001). Mean patient age was 69 ± 11 years and 79% were men. The prevalence of hypertension (95%), diabetes mellitus (62%), and prior PCI (61%) was high. The most common target vessel was the right coronary artery (54%), followed by the left circumflex (23%). The mean J-CTO and PROGRESS-CTO scores were 2.8 ± 1.1 and 1.3 ± 1.0, respectively. Antegrade wiring was the final successful crossing strategy in 65% and the retrograde approach was used in 22%. IVL was used in 10% of all heavily calcified lesions and 11% of all balloon undilatable lesions. The 3.5 mm lithotripsy balloon was the most commonly used balloon (28%). The mean number of pulses per lithotripsy run was 33 ± 32 and the median duration of lithotripsy was 80  (interquartile range: 40-103) seconds. Technical and procedural success was achieved in 77 (94%) and 74 (90%) cases, respectively. Two (2.4%) Ellis Class 2 perforations occurred after IVL use and were managed conservatively. CONCLUSION: IVL is increasingly being used in CTO PCI with encouraging outcomes.

Mechanism of FIB-Induced Phase Transformation in Austenitic Steel.

The transformation of unstable austenite to ferrite or α' martensite as a result of exposure to Xe+ or Ga+ ions at room temperature was studied in a 304 stainless steel casting alloy. Controlled Xe+ and Ga+ ion beam exposures of the 304 were carried out at a variety of beam/sample geometries. It was found that both Ga+ and Xe+ ion irradiation resulted in the transformation of the austenite to either ferrite or α' martensite. In this paper, we will refer to the transformation product as a BCC phase. The crystallographic orientation of the transformed area was controlled by the orientation of the austenite grain and was consistent with either the Nishiyama­Wasserman or the Kurdjumov­Sachs orientation relationships. On the basis of the Xe+ and Ga+ ion beam exposures, the transformation is not controlled by the chemical stabilization of the BCC phase by the ion species, but is a result of the disorder caused by the ion-induced recoil motion and subsequent return of the disordered region to a more energetically favorable phase.

Equipment utilization in chronic total occlusion percutaneous coronary interventions: Insights from the PROGRESS-CTO registry.

BACKGROUND: We examined guidewire and microcatheter utilization during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined device utilization in 2,968 CTO PCIs performed in 2,936 patients at 19 US and two international center between January 2016 and January 2019. RESULTS: The median number of antegrade guidewires used per case declined (5 in 2016 vs 3 in 2019) and was higher in higher complexity lesions (2 in J-CTO 0 vs. 8 in J-CTO 4 or 5 score). In antegrade-only procedures, the most frequently used guidewires were the Pilot 200 (Abbott Vascular, 37%), Fielder XT (Asahi Intecc, 25%) and Gaia third (Asahi Intecc, 18%), while the most commonly used microcatheters were the Turnpike Spiral (Vascular Solutions, 18%) and Turnpike (Vascular Solutions, 16%). Compared with 2012-2015, during 2016-2019 use of novel equipment such as the Gaia guidewires and the Turnpike microcatheters led to decreased use of Confianza Pro 12 (Asahi Intecc) wire and Corsair (Asahi Intecc) family of microcatheters. In retrograde cases, the guidewires most commonly used were the Sion (44%), Pilot 200 (27%) and Fielder FC (26%), while the Corsair/Corsair Pro, Turnpike LP (Vascular Solutions) and Caravel (Asahi Intecc) were the most frequently used microcatheters for collateral crossing (29%, 26% and 22%, respectively). CONCLUSIONS: The most commonly used guidewires during CTO PCI are polymer-jacketed guidewires and the most commonly used microcatheters are torquable microcatheters.

Comparing Xe+ pFIB and Ga+ FIB for TEM sample preparation of Al alloys: Minimising FIB-induced artefacts.

Recently, the dual beam Xe+ plasma focused ion beam (Xe+ pFIB) instrument has attracted increasing interest for site-specific transmission electron microscopy (TEM) sample preparation for a local region of interest as it shows several potential benefits compared to conventional Ga+ FIB milling. Nevertheless, challenges and questions remain especially in terms of FIB-induced artefacts, which hinder reliable S/TEM microstructural and compositional analysis. Here we examine the efficacy of using Xe+ pFIB as compared with conventional Ga+ FIB for TEM sample preparation of Al alloys. Three potential source of specimen preparation artefacts were examined, namely: (1) implantation-induced defects such as amophisation, dislocations, or 'bubble' formation in the near-surface region resulting from ion bombardment of the sample by the incident beam; (2) compositional artefacts due to implantation of the source ions and (3) material redeposition due to the milling process. It is shown that Xe+ pFIB milling is able to produce improved STEM/TEM samples compared to those produced by Ga+ milling, and is therefore the preferred specimen preparation route. Strategies for minimising the artefacts induced by Xe+ pFIB and Ga+ FIB are also proposed. LAY DESCRIPTION: FIB (focused ion beam) instruments have become one of the most important systems in the preparation of site-specific TEM specimens, which are typically 50-100 nm in thickness. TEM specimen preparation of Al alloys is particularly challenging, as convention Ga-ion FIB produces artefacts in these materials that make microstructural analysis difficult or impossible. Recently, the use of noble gas ion sources, such as Xe, has markedly improved milling speeds and is being used for the preparation of various materials. Hence, it is necessary to investigate the structural defects formed during FIB milling and assess the ion-induced chemical contamination in these TEM samples. Here we explore the feasibility and efficiency of using Xe+ PFIB as a TEM sample preparation route for Al alloys in comparison with the conventional Ga+FIB.