"Very" Very Late Stent Thrombosis: A Detailed Look at Two Cases.

Although percutaneous coronary intervention (PCI) has radically transformed the scope of treating coronary artery disease with stenting, stent thrombosis (STh) remains a feared complication. Very late STh, a rare complication after PCI, refers to STh occurring greater than one year after post-stent implantation. An even rarer phenomenon, "very" very late stent thrombosis (VVLST), is described in the literature as STh occurring more than five years post-stent implantation. To our knowledge, there are only 10 case reports and one case series describing VVLST. We discuss two additional complex clinical cases of VVLST presenting as ST-elevation myocardial infarction. We highlight epidemiology, pathophysiology, presentation, diagnostic methods, treatment approach, associated complications, and the need for more extensive future work to minimize the risk of VVLST.

Improved stent sharpness evaluation with super-resolution deep learning reconstruction in coronary CT angiography.

OBJECTIVES: This study aimed to assess the impact of super-resolution deep learning reconstruction (SR-DLR) on coronary CT angiography (CCTA) image quality and blooming artifacts from coronary artery stents in comparison to conventional methods, including hybrid iterative reconstruction (HIR) and deep learning-based reconstruction (DLR). METHODS: A retrospective analysis included 66 CCTA patients from July to November 2022. Major coronary arteries were evaluated for image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Stent sharpness was quantified using 10%-90% edge rise slope (ERS) and 10%-90% edge rise distance (ERD). Qualitative analysis employed a 5-point scoring system to assess overall image quality, image noise, vessel wall, and stent structure. RESULTS: SR-DLR demonstrated significantly lower image noise compared to HIR and DLR. SNR and CNR were notably higher in SR-DLR. Stent ERS was significantly improved in SR-DLR, with mean ERD values of 0.70 ± 0.20 mm for SR-DLR, 1.13 ± 0.28 mm for HIR, and 0.85 ± 0.26 mm for DLR. Qualitatively, SR-DLR scored higher in all categories. CONCLUSIONS: SR-DLR produces images with lower image noise, leading to improved overall image quality, compared with HIR and DLR. SR-DLR is a valuable image reconstruction algorithm for enhancing the spatial resolution and sharpness of coronary artery stents without being constrained by hardware limitations. ADVANCES IN KNOWLEDGE: The overall image quality was significantly higher in SR-DLR, resulting in sharper coronary artery stents compared to HIR and DLR.

An Aspirin-Free Strategy for Immediate Treatment Following Complex Percutaneous Coronary Intervention.

BACKGROUND: There was no study evaluating the effects of an aspirin-free strategy in patients undergoing complex percutaneous coronary intervention (PCI). OBJECTIVES: The authors aimed to evaluate the efficacy and safety of an aspirin-free strategy in patients undergoing complex PCI. METHODS: We conducted the prespecified subgroup analysis based on complex PCI in the STOPDAPT-3 (ShorT and OPtimal duration of Dual AntiPlatelet Therapy after everolimus-eluting cobalt-chromium stent-3), which randomly compared low-dose prasugrel (3.75 mg/d) monotherapy to dual antiplatelet therapy (DAPT) with low-dose prasugrel and aspirin in patients with acute coronary syndrome or high bleeding risk. Complex PCI was defined as any of the following 6 criteria: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation with 2 stents implanted, total stent length >60 mm, or a target of chronic total occlusion. The coprimary endpoints were major bleeding events (Bleeding Academic Research Consortium 3 or 5) and cardiovascular events (a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke) at 1 month. RESULTS: Of the 5,966 study patients, there were 1,230 patients (20.6%) with complex PCI. Regardless of complex PCI, the effects of no aspirin relative to DAPT were not significant for the coprimary bleeding (complex PCI: 5.30% vs 3.70%; HR: 1.44; 95% CI: 0.84-2.47; P = 0.18 and noncomplex PCI: 4.26% vs 4.97%; HR: 0.85; 95% CI: 0.65-1.11; P = 0.24; P for interaction = 0.08) and cardiovascular (complex PCI: 5.78% vs 5.93%; HR: 0.98; 95% CI: 0.62-1.55; P = 0.92 and noncomplex PCI: 3.70% vs 3.10%; HR: 1.20; 95% CI: 0.88-1.63; P = 0.25; P for interaction = 0.48) endpoints without significant interactions. CONCLUSIONS: The effects of the aspirin-free strategy relative to standard DAPT for the cardiovascular and major bleeding events were not different regardless of complex PCI. (ShorT and OPtimal duration of Dual AntiPlatelet Therapy after everolimus-eluting cobalt-chromium stent-3 [STOPDAPT-3]; NCT04609111).

Wire entanglement to retrieve a dislodged stent from the proximal right coronary artery.

A 70-year-old woman who was a known diabetic and had hypertension presented with non-ST-elevation myocardial infarction. A coronary angiogram showed a significant lesion in the mid-portion of right coronary artery (RCA) followed by distal cut-off.

The use of a homemade 'BAG' repositioning system to salvage complete coronary stent dislodgement.

A 71-year-old man who had undergone percutaneous transluminal coronary angioplasty (PTCA) in 2013 was admitted for unstable angina.

Coronary stent migration to aorta with successful recovery during aortobifemoral bypass.

We present with full and proper consent of the patient, the case of a 64-year-old man with severe peripheral arterial disease and a known chronic infrarenal aortic occlusion causing severe short-distance claudication. Preoperative computed tomography angiography was significant for a new "cylindrical" calcified lesion. During the elective surgery, the lesion was confirmed to be a coronary stent. The coronary stent was confirmed to be from the patient's prior percutaneous coronary intervention to the left anterior descending artery 1 year prior. The stent was removed without complications by the surgical team. To the best of our knowledge, this is the first such case to be described in current literature. This patient is currently alive, and a revision of his left anterior descending artery intervention was found to be unwarranted on repeat coronary angiography.

Impact of Sex Differences on the Outcomes of Coronary Invasive Physiological Assessment: Long-Term Follow-Up in a Brazilian Population.

Objective: This study aimed to evaluate the rate of major adverse cardiac events (MACEs; the sum of death, myocardial infarction, and revascularization rates) according to interventional strategies guided by invasive physiological methods in both sexes in a Brazilian population during long-term follow-up for an average of 2 years. Methods: This retrospective single-center study included 151 consecutive patients (232 lesions) between January 2018 and January 2022. The participants were divided into two groups: the female group (FG), comprising 59 patients with 88 lesions, and the male group (MG), comprising 92 patients with 144 lesions. Results: The FG had a greater mean age (FG: 67.96 ± 13.12 vs. MG: 62.36 ± 12.01 years, p = 0.009) and lower mean creatinine clearance (FG: 79.35 ± 38.63 vs. MG: 92.02 ± 38.62 mL/min, p = 0.02) than did the MG. The percentage of lesions in the left main coronary artery was higher in the FG than in the MG (12.5% vs. 2.78%, p = 0.006). The mean follow-up time was longer in the MG than in the FG (795.61 ± 350 vs. 619.19 ± 318 days, respectively; p = 0.001). MACE occurred in 11.86% and 13.04% of patients in the FG and MG, respectively (p = 0.850). Secondary outcomes, such as death, reinfarction, and the need for new revascularization, showed no significant between-sex differences. Conclusions: Our study demonstrated the safety of invasive physiological methods to determine coronary revascularization in both male and female patients in a Brazilian population, as evidenced by the low rates of adverse cardiac events and death after a long-term follow-up.

Enhanced in-stent luminal visualization and restenosis diagnosis in coronary computed tomography angiography via coronary stent decomposition algorithm from dual-energy image.

Stent implantation is a principal therapeutic approach for coronary artery diseases. Nonetheless, the presence of stents significantly interferes with in-stent luminal (ISL) visualization and complicates the diagnosis of in-stent restenosis (ISR), thereby increasing the risk of misdiagnoses and underdiagnoses in coronary computed tomography angiography (CCTA). Dual-energy (DE) CT could calculate the volume fraction for voxels from low- and high-energy images (LHEI) and provide information on specific three basic materials. In this study, the innovative coronary stent decomposition algorithm (CSDA) was developed from the DECT three materials decomposition (TMD), through spectral simulation to determine the scan and attenuation coefficient for the stent, and preliminary execution for an in vitro sophisticated polyether ether ketone (PEEK) 3D-printed right coronary artery (RCA) replica. Furthermore, the whole-coronary-artery replica with multi-stent implantation, the RCA replica with mimetic plaque embedded, and two patients with stent further validated the effectiveness of CSDA. Post-CSDA images manifested no weakened attenuation values, no elevated noise values, and maintained anatomical integrity in the coronary lumen. The stents were effectively removed, allowing for the ISL and ISR to be clearly visualized with a discrepancy in diameters within 10%. We believe that CSDA presents a promising solution for enhancing CCTA diagnostic accuracy post-stent implantation.

Association of Periprocedural Inflammatory Activation With Increased Risk for Early Coronary Stent Thrombosis.

BACKGROUND: Stent thrombosis is a rare but deleterious event. Routine coronary angiography with percutaneous coronary intervention (PCI) is often deferred in the presence of laboratory markers of acute inflammation to prevent complications. The aim of this study was to investigate whether an acute inflammatory state is associated with an increased risk of early stent thrombosis. METHODS AND RESULTS: Within a prospective single-center registry, the association between preprocedural acute inflammatory activation, defined as C-reactive protein plasma levels >50 mg/L or a leukocyte count >12 g/L, and occurrence of early (≤30 days) stent thrombosis was evaluated. In total, 11 327 patients underwent PCI and of those, 6880 patients had laboratory results available. 49.6% of the study population received PCI for an acute coronary syndrome and 50.4% for stable ischemic heart disease. In patients with signs of acute inflammatory activation (24.9%), PCI was associated with a significantly increased risk for stent thrombosis (hazard ratio, 2.89; P<0.00001), independent of age, sex, kidney function, number and type of stents, presence of multivessel disease, choice of P2Y12 inhibitor, and clinical presentation. Elevated laboratory markers of acute inflammation were associated with the occurrence of stent thrombosis in both patients with acute coronary syndrome (hazard ratio, 2.63; P<0.001) and in patients with stable ischemic heart disease (hazard ratio, 3.57; P<0.001). CONCLUSIONS: An acute inflammatory state at the time of PCI was associated with a significantly increased risk of early stent thrombosis. Evidence of acute inflammation should result in deferred PCI in elective patients, while future studies are needed for patients with acute coronary syndrome.

Hybrid interpenetrating network of polyester coronary stent with tunable biodegradation and mechanical properties.

Poly(l-lactide) (PLLA) is an important candidate raw material of the next-generation biodegradable stent for percutaneous coronary intervention, yet how to make a polyester stent with sufficient mechanical strength and relatively fast biodegradation gets to be a dilemma. Herein, we put forward a hybrid interpenetrating network (H-IPN) strategy to resolve this dilemma. As such, we synthesize a multi-functional biodegradable macromer of star-like poly(d,l-lactide-co-ɛ-caprolactone) with six acrylate end groups, and photoinitiate it, after mixing with linear PLLA homopolymer, to trigger the free radical polymerization. The resultant crosslinked polymer blend is different from the classic semi-interpenetrating network, and partial chemical crosslinking occurs between the linear polymer and the macromer network. Combined with the tube blow molding and the postprocessing laser cutting, we fabricate a semi-crosslinked-polyester biodegradable coronary stent composed of H-IPN, which includes a physical network of polyester spherulites and a chemical crosslinking network of copolyester macromers and a part of homopolymers. Compared with the currently main-stream PLLA stent in research, this H-IPN stent realizes a higher and more appropriate biodegradation rate while maintaining sufficient radial strength. A series of polymer chemistry, polymer physics, polymer processing, and in vitro and in vivo biological assessments of medical devices have been made to examine the H-IPN material. The interventional implanting of the H-IPN stent into aorta abdominalis of rabbits and the follow-ups to 12 months have confirmed the safety and effectiveness.

Clopidogrel vs Aspirin Monotherapy Beyond 1 Year After Percutaneous Coronary Intervention.

BACKGROUND: It remains unclear whether clopidogrel is better suited than aspirin as the long-term antiplatelet monotherapy following dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). OBJECTIVES: This study compared clopidogrel monotherapy following 1 month of DAPT (clopidogrel group) with aspirin monotherapy following 12 months of DAPT (aspirin group) after PCI for 5 years. METHODS: STOPDAPT-2 (Short and Optimal Duration of Dual Antiplatelet Therapy 2) is a multicenter, open-label, adjudicator-blinded, randomized clinical trial conducted in Japan. Patients who underwent PCI with cobalt-chromium everolimus-eluting stents were randomized in a 1-to-1 fashion either to clopidogrel or aspirin groups. The primary endpoint was a composite of cardiovascular outcomes (cardiovascular death, myocardial infarction, stroke, or definite stent thrombosis) or major bleeding (TIMI major or minor bleeding). RESULTS: Among 3,005 study patients (age: 68.6 ± 10.7 years; women: 22.3%; acute coronary syndrome: 38.3%), 2,934 patients (97.6%) completed the 5-year follow-up (adherence to the study drugs at 395 days: 84.7% and 75.9%). The clopidogrel group compared with the aspirin group was noninferior but not superior for the primary endpoint (11.75% and 13.57%, respectively; HR: 0.85; 95% CI: 0.70-1.05; Pnoninferiority < 0.001; Psuperiority = 0.13), whereas it was superior for the cardiovascular outcomes (8.61% and 11.05%, respectively; HR: 0.77; 95% CI: 0.61-0.97; P = 0.03) and not superior for major bleeding (4.44% and 4.92%, respectively; HR: 0.89; 95% CI: 0.64-1.25; P = 0.51). By the 1-year landmark analysis, clopidogrel was numerically, but not significantly, superior to aspirin for cardiovascular events (6.79% and 8.68%, respectively; HR: 0.77; 95% CI: 0.59-1.01; P = 0.06) without difference in major bleeding (3.99% and 3.32%, respectively; HR: 1.23; 95% CI: 0.84-1.81; P = 0.31). CONCLUSIONS: Clopidogrel might be an attractive alternative to aspirin with a borderline ischemic benefit beyond 1 year after PCI.

Diagnosis of Coronary Stent Dislodgement With Transthoracic Echocardiogram: A Case Report.

Coronary stent dislodgment is a rare complication of percutaneous coronary intervention (PCI). Although stent dislodgment typically occurs immediately in the intraoperative or perioperative period, it can infrequently occur subacutely in the post-operative period. Diagnosis of stent dislodgment can be seen with various cardiac imaging modalities, from transthoracic and transesophageal echocardiogram to cardiac computed tomography or magnetic resonance imaging to direct visualization on fluoroscopy during cardiac catheterization. Given the rarity of this entity, there is a lack of established common practice, gold standard for treatment, and/or procedural data. Instances are managed on a case-by-case basis, using the imaging modalities readily available at the institution and treatment modalities the interventionalist or surgeon is most comfortable with. Therefore, management of stent dislodgment consists of conservative, percutaneous, or surgical interventions on a case-by-case basis. We present a case of right coronary artery stent migration that was incidentally diagnosed with routine transthoracic echocardiogram.

Prognostic value of optical flow ratio for cardiovascular outcomes in patients after percutaneous coronary stent implantation.

Background: The relationship between the optical flow ratio (OFR) and clinical outcomes in patients with coronary artery disease (CAD) after percutaneous coronary stent implantation (PCI) remains unknown. Objective: To examine the correlation between post-PCI OFR and clinical outcomes in patients with CAD following PCI. Methods: Patients who underwent optical coherence tomography (OCT) guided PCI at Guangdong Provincial People's Hospital were retrospectively and continuously enrolled. Clinical data, post-PCI OCT characteristics, and OFR measurements were collected and analyzed to identify predictors of target vessel failure (TVF) after PCI. Results: Among 354 enrolled patients, 26 suffered TVF during a median follow-up of 484 (IQR: 400-774) days. Post-PCI OFR was significantly lower in the TVF group than in the non-TVF group (0.89 vs. 0.93; P = 0.001). In multivariable Cox regression analysis, post-PCI OFR (HR per 0.1 increase: 0.60; 95% CI: 0.41-0.89; P = 0.011), large stent edge dissection (HR: 3.85; 95% CI: 1.51-9.84; P = 0.005) and thin-cap fibroatheroma (TCFA) (HR: 2.95; 95% CI: 1.19-7.35; P = 0.020) in the non-stented segment were independently associated with TVF. In addition, the inclusion of post-PCI OFR to baseline characteristics and post-PCI OCT findings improved the predictive power of the model to distinguish subsequent TVF after PCI (0.838 vs. 0.796; P = 0.028). Conclusion: The post-PCI OFR serves as an independent determinant of risk for TVF in individuals with CAD after PCI. The inclusion of post-PCI OFR assessments, alongside baseline characteristics and post-PCI OCT findings, substantially enhances the capacity to differentiate the subsequent manifestation of TVF in CAD patients following PCI.

Percutaneous Extraction of Deployed Coronary Stent During Retrieval of Jailed Buddy Wire.

Retrieval of a buddy wire following coronary stenting of long, tortuous, and calcified lesions runs the risk of wire entrapment and stent deformation. We report a case of successful percutaneous extraction of a longitudinally deformed coronary stent during retrieval of jailed buddy wire from the left anterior descending artery. (Level of Difficulty: Advanced.).

A novel double arrowhead auxetic coronary stent.

A stent implantation is a standard medical procedure for treating coronary artery diseases. Over the years, various different designs have been explored for the stents which come with a range of limitations, including late in-stent restenosis (due to low radial strength), foreshortening, radial recoil, etc. Contrary, stents with auxetic design, characterized by a negative Poisson's ratio, display unique deformation characteristics that result in enhanced mechanical properties in terms of its radial strength, radial recoil, foreshortening, and more. In this study, we have analysed a novel double arrowhead (DA) auxetic stent that aims to overcome the limitations associated with traditional stents, specifically in terms of radial strength, foreshortening, and radial recoil. The parametric analysis was done initially on the DA's unit ring structure to optimize the design by evaluating the effect of three design parameters (angle, amplitude, and width) on the mechanical characteristics (radial strength and radial recoil) using finite element analysis. The width of the strut was found to be the primary determinant of the stent structure's properties. Consequently, the angle and width were found to have the least effect on altering the stent's mechanical properties. After performing the parametric analysis, optimal design factors were selected to design the full-length DA auxetic stent. The mechanical characteristics of the DA auxetic stent were assessed and compared in a case study with the Cypher™ commercial stent. The radial strength of DA auxetic stent was found to be 7.26 N/mm, which is more than double the Cypher™ commercial stent's radial strength. Additionally, the proposed stent possesses reduced radial recoil property and completely eliminates the stent foreshortening issue, which shows the superior mechanical properties of the proposed auxetic stent and its potential as a promising candidate for future stent designs.

Current Endovascular Management of Arterial Complications After Pediatric Liver Transplantation in a Tertiary Center.

PURPOSE: Pediatric liver transplant surgery is burdened by arterial complications whose endovascular treatment is not standardized. We report the outcomes of a cohort of pediatric recipients with hepatic artery complications treated by endoluminal procedures. MATERIALS AND METHODS: From December 2019 to December 2022, consecutive transplanted pediatric patients who underwent endovascular treatment of hepatic artery complications were reviewed. The analysis included: type of complication (occlusion, stenosis, pseudoaneurysm); onset (acute = < 15 days, subacute = 15-90 days, late = > 90 days); endovascular technique (angioplasty, stenting); complications and outcomes. Technical success was defined as the opacification of the hepatic artery at the final angiogram with < 50% residual stenosis and no pseudoaneurysms. Clinical success was defined by graft's and patient's survival. RESULTS: Seventeen patients (8 males; median age 33 months, IQR 9-103) underwent 21 hepatic arteriography procedures for predominantly acute or subacute occlusions (n = 7) or stenosis (n = 11) with concurrent pseudoaneurysms (n = 4). Primary and secondary technical success was achieved in 13/18 and 3/3 procedures, respectively, with overall technical success of 76%. Angioplasty alone was successful in 5/21 procedures; stent-retriever thrombectomy was performed in one occlusion with thrombosis; stenting was required in 9/17 (53%) patients. Clinical success was obtained in 14/17 (82%) patients with hepatic artery patency after a median of 367 days (IQR 114.5-500). Clinical failure occurred in 3 permanent occlusions, with 2 deaths and 1 re-transplantation. Procedure-related complications included minor events in 3/17 (18%) patients and 1/17 (6%) death. CONCLUSION: In liver transplanted children with hepatic artery complications, endovascular treatment may provide clinical success, with stenting often required in acute and subacute conditions. LEVEL OF EVIDENCE: Level 4.

Percutaneous coronary stent implantation in children and young infants following surgical repair of congenital heart disease.

Background: Coronary artery stent implantation (CSI) in the pediatric population is rare. Only a few reports were published on managing postoperative coronary artery obstruction using coronary stents following surgical repair of congenital heart diseases (CHD). This study aimed to analyze the feasibility, indications, procedural technique, risk factors, and short-term outcomes of CSI after pediatric cardiac surgery. Methods: In this retrospective cohort study, we reviewed all pediatric patients who underwent surgical repair of CHD requiring postoperative CSI in two cardiac centers (King Abdulaziz University Hospital and King Faisal Specialist Hospital and Research Center) between 2012 and 2022. Survival to hospital discharge was the study's primary outcome. The secondary outcomes included procedural success, duration of mechanical ventilation, intensive care unit (ICU) stay, hospital stay, need for coronary reintervention, and late mortality. A descriptive analysis was performed for the collected data from the patients' medical records. Results: Eleven patients who underwent postoperative CSI were identified. The most common anatomic diagnosis was congenital aortic valve stenosis. All patients underwent cardiac catheterization on extracorporeal membrane oxygenation support except one patient, who presented with chest pain after cardiac surgery. Procedural success was achieved in all patients with excellent revascularization documented by post-procedural angiograms. Both patients who had late coronary events after cardiac surgery survived hospital discharge. There was no in-hospital mortality among the two patients who required stenting of only the right coronary artery. The four patients who required more than 120 minutes to complete the procedure had early mortality. After CSI, the median duration of mechanical ventilation and ICU stay was 12 and 17 days, respectively. Six patients (54.5%) survived hospital discharge post-CSI; they did not require re-intervention during the follow-up period (38-1,695 days). Conclusions: CSI in pediatric patients can be performed with excellent procedural success for treating coronary artery stenosis after cardiac surgery. It could be considered a potential treatment strategy for this population.