Search Results (8)

Background: Although contemporary stent technology has significantly evolved, a substantial number of patients present with stent failure (SF), the clinical expression of which is either in-stent restenosis (ISR) or stent thrombosis (ST). Methods: In this observational, single-center study, we aimed to compare the clinical characteristics, clinical presentation, angiographic findings and subsequent management of patients who underwent percutaneous coronary intervention (PCI) for SF, either ISR or ST, with patients who had PCI for de novo lesions. Results: Over a period of two years (September 2022–October 2024), 1120 patients underwent PCI, of whom 9% had SF. Of the 101 SF cases, the majority (76 cases, 75%) had ISR, while the rest (25 cases, 25%) had ST. Regarding baseline characteristics, patients who underwent PCI for SF had a higher incidence of diabetes mellitus (53% vs. 29%; p < 0.001), dyslipidemia (88% vs. 50%; p < 0.001) as well as prior coronary artery bypass grafting surgery (7.9% vs. 3.7%; p = 0.043), while they were less likely to be current smokers (33% vs. 52%; p < 0.001). SF PCI patients presented more frequently with unstable angina (17% vs. 8.9%; p = 0.010). A new stent was implanted in less than half of SF cases (i.e., stent implantation, 44% vs. 91%; p < 0.001). On the other hand, in the clinical setting of SF, drug-coated balloons (44% vs. 5.3%; p < 0.001) and plain balloon angioplasty (8.9% vs. 0.7%; p < 0.001) was applied more frequently compared with de novo lesions. Furthermore, the usage of cutting/scoring balloons and lithotripsy was significantly higher in the SF group (8.9% vs. 0.4% and 12% vs. 3%, respectively; p < 0.001 for both). Intracoronary imaging guidance was more commonly used in the SF group (33% vs. 13%; p < 0.001). Stent malapposition (44%) and neoatherosclerosis (67%) were the most common mechanisms of ST and ISR, respectively, as identified by intravascular imaging modalities. Finally, the success rates were comparable (96% vs. 98%; p = 0.150) between the two groups. Conclusions: Approximately one of ten patients underwent PCI because of the failure of a previously implanted stent. Use of intracoronary imaging is significantly higher in the clinical context of SF. While DES implantation remains the standard of practice for de novo lesions, DCBs are a popular alternative, especially for ISR cases. Interventional cardiologists who are involved in the treatment of SF cases should be familiar with interpreting intravascular imaging to guide the use of the adjunctive device required to ensure that optimal procedural results in SF cases are obtained. Full article

Cardiovascular prosthetic devices, stents, prosthetic valves, heart-assist pumps, etc., operate in a wide regime of flows characterized by fluid dynamic flow structures, laminar and turbulent flows, unsteady flow patterns, vortices, and other flow disturbances. These flow disturbances cause shear stress, hemolysis, platelet activation, thrombosis, and other types of blood trauma, leading to neointimal hyperplasia, neoatherosclerosis, pannus overgrowth, etc. Couette-type blood-shearing devices are used to simulate and then clinically measure blood trauma, after which the results can be used to assist in the design of the cardiovascular prosthetic devices. However, previous designs for such blood-shearing devices do not cover the whole range of flow shear, Reynolds numbers, and Taylor numbers characteristic of all types of implanted cardiovascular prosthetic devices, limiting the general applicability of clinical data obtained by tests using different blood-shearing devices. This paper presents the key fluid dynamic parameters that must be met. Based on this, Couette device geometric parameters such as diameter, gap, flow rate, shear stress, and temperature are carefully selected to ensure that the device’s Reynolds numbers, Taylor number, operating temperature, and shear stress in the gap fully represent the flow characteristics across the operating range of all types of cardiovascular prosthetic devices. The outcome is that the numerical data obtained from the presented device can be related to all such prosthetic devices and all flow conditions, making the results obtained with such shearing devices widely applicable across the field. Numerical simulations illustrate that the types of flow patterns generated in the blood-shearing device meet the above criteria. Full article

In-stent restenosis (ISR) remains the primary cause of target lesion failure following percutaneous coronary intervention (PCI), resulting in 10-year incidences of target lesion revascularization at a rate of approximately 20%. The treatment of ISR is challenging due to its inherent propensity for recurrence and varying susceptibility to available strategies, influenced by a complex interplay between clinical and lesion-specific conditions. Given the multiple mechanisms contributing to the development of ISR, proper identification of the underlying substrate, especially by using intravascular imaging, becomes pivotal as it can indicate distinct therapeutic requirements. Among standalone treatments, drug-coated balloon (DCB) angioplasty and drug-eluting stent (DES) implantation have been the most effective. The main advantage of a DCB-based approach is the avoidance of an additional metallic layer, which may otherwise enhance neointimal hyperplasia, provide the substratum for developing neoatherosclerosis, and expose the patient to a persistently higher risk of coronary ischemic events. On the other hand, target vessel scaffolding by DES implantation confers relevant mechanical advantages over DCB angioplasty, generally resulting in larger luminal gain, while drug elution from the stent surface ensures the inhibition of neointimal hyperplasia. Nevertheless, repeat stenting with DES also implies an additional permanent metallic layer that may reiterate and promote the mechanisms leading to ISR. Against this background, the selection of either DCB or DES on a patient- and lesion-specific basis as well as the implementation of adjuvant treatments, including cutting/scoring balloons, intravascular lithotripsy, and rotational atherectomy, hold the potential to improve the effectiveness of ISR treatment over time. In this review, we comprehensively assessed the available evidence from randomized trials to define contemporary interventional treatment of ISR and provide insights for future directions. Full article

Background and Objectives: Endovascular technologies have significantly improved the outcome of patients with critical limb ischemia (CLI). Drug eluting stents (DES) have documented their efficacy against percutaneous transluminal angioplasty (PTA) and bare metal stents (BMS) in infrapopliteal arterial occlusive disease. However, late in-stent neoatherosclerosis may lead to vascular lumen loss and eventually thrombosis. Polymer free DES constitute a new technology aiming to improve long term patency which their action is still under investigation. The purpose of this study is to report the mechanism of action and to provide a literature review of a novel polymer free amphilimus eluting stent (Cre8, Alvimedica, Instabul, Turkey) in infrapopliteal arterial disease. Methods: Publications listed in electronic databases, European Union Drug Regulating Authorities Clinical Trials Database, as well as scientific programmes of recent interventional vascular conferences were searched. Three studies were included. We analyzed primary and secondary patency, major amputation rate, freedom from CD-TLR, and mortality. Results: Cre8 was implanted in 79 patients with CLI. Most of the patients (n = 65) were Rutherford class 5–6 (82.3%), and diabetes mellitus (DM) was present in 66 patients (83.5%). Mean primary patency was 82.5% at 12 months. Mean lesion stented length was 20 mm and 35 mm in two studies. Mean limb salvage was 91.3% at 12 months. Freedom from CD-TLR was reported in two out of the three studies and was 96% and 83.8%. Mortality was 15% and 23.8% in the same studies, whilst it was not reported in one study. Conclusion: Stenting of infrapopliteal arteries with Cre8 is safe and feasible in patients with CLI and diabetes. All studies have shown very good primary patency and freedom from CD-TLR at 12 and 24 months. Larger observational prospective studies and randomized trials are necessary to establish long term effectiveness and clinical outcomes using the non-polymer Cre8 DES. Full article

Objective: The aim of this study was to evaluate the mid-term efficacy of drug-coated balloons (DCB) in percutaneous coronary intervention (PCI) in two different pathophysiologic scenarios. Background: There are different underlying pathological processes in coronary artery disease. Mid-term safety and efficacy of DCB approach is still limited. Methods: Medical records of all consecutive patients undergoing DCB were evaluated. The primary endpoint was the rate of clinically driven target lesion revascularization (TLR) after 24 months. Results: Between January 2011 and December 2017, 442 patients were included, representing 4.4% of all PCIs in our institution. A total of 460 DCB lesions were treated, of which 328 (71.3%) were de novo and 132 (28.7%) were combined bare metal or drug-eluting stents with in-stent restenosis (ISR). The patients’ mean age was 66.2 ± 11.7 years with a diabetes prevalence of 45.3%. The TLR rate was lower in the de novo group (5.3%) compared to the ISR group (9.4%) (p = 0.04). No differences were observed in major adverse cardiovascular events (MACE) between the de novo group (38.9%) and ISR group (42.5%) (p = 0.47). No significant differences were detected in the TLR occurrence in the subgroup analysis. Conclusion: Our extended experience demonstrates that the mid-term DCB approach in these two pathophysiologic settings represent a reasonable option, with low TLR rate. Full article

Despite the dramatic improvements of revascularization therapies occurring in the past decades, a relevant percentage of patients treated with percutaneous coronary intervention (PCI) still develops stent failure due to neo-atherosclerosis (NA). This histopathological phenomenon following stent implantation represents the substrate for late in-stent restenosis (ISR) and late stent thrombosis (ST), with a significant impact on patient’s long-term clinical outcomes. This appears even more remarkable in the setting of drug-eluting stent implantation, where the substantial delay in vascular healing because of the released anti-proliferative agents might increase the occurrence of this complication. Since the underlying pathophysiological mechanisms of NA diverge from native atherosclerosis and early ISR, intra-coronary imaging techniques are crucial for its early detection, providing a proper in vivo assessment of both neo-intimal plaque composition and peri-strut structures. Furthermore, different strategies for NA prevention and treatment have been proposed, including tailored pharmacological therapies as well as specific invasive tools. Considering the increasing population undergoing PCI with drug-eluting stents (DES), this review aims to provide an updated overview of the most recent evidence regarding NA, discussing pathophysiology, contemporary intravascular imaging techniques, and well-established and experimental invasive and pharmacological treatment strategies. Full article

Diabetes mellitus (DM) is a strong risk factor for the development of cardiovascular diseases such as coronary heart disease, cerebrovascular disease, and peripheral arterial disease (PAD). In the population of people living with DM, PAD is characterised by multi-level atherosclerotic lesions as well as greater involvement of the arteries below the knee. DM is also a factor that significantly increases the risk of lower limb amputation. Percutaneous balloon angioplasty with or without stent implantation is an important method of the treatment for atherosclerotic cardiovascular diseases, but restenosis is a factor limiting its long-term effectiveness. The pathogenesis of atherosclerosis in the course of DM differs slightly from that in the general population. In the population of people living with DM, more attention is drawn to such factors as inflammation, endothelial dysfunction, platelet dysfunction, blood rheological properties, hypercoagulability, and additional factors stimulating vascular smooth muscle cell proliferation. DM is a risk factor for restenosis. The purpose of this paper is to provide a review of the literature and to present the most important information on the current state of knowledge on mechanisms and the clinical significance of restenosis and in-stent restenosis in patients with DM, especially in association with the endovascular treatment of PAD. The role of such processes as inflammation, neointimal hyperplasia and neoatherosclerosis, allergy, resistance to antimitotic drugs used for coating stents and balloons, genetic factors, and technical and mechanical factors are discussed. The information on restenosis collected in this publication may be helpful in planning further research in this field, which may contribute to the formulation of more and more precise recommendations for the clinical practice. Full article

The technology of percutaneous coronary intervention (PCI) is constantly being refined in order to overcome the shortcomings of present day technologies. Even though current generation metallic drug-eluting stents (DES) perform very well in the short-term, concerns still exist about their long-term efficacy. Late clinical complications including late stent thrombosis (ST), restenosis, and neoatherosclerosis still exist and many of these events may be attributed to either the metallic platform and/or the drug and polymer left behind in the arterial wall. To overcome this limitation, the concept of totally bioresorbable vascular scaffolds (BRS) was invented with the idea that by eliminating long-term exposure of the vessel wall to the metal backbone, drug, and polymer, late outcomes would improve. The Absorb-bioabsorbable vascular scaffold (Absorb-BVS) represented the most advanced attempt to make such a device, with thicker struts, greater vessel surface area coverage and less radial force versus contemporary DES. Unfortunately, almost one year after its initial approval by the U.S. Food and Drug Administration, this scaffold was withdrawn from the market due to declining devise utilization driven by the concerns about scaffold thrombosis (ScT) seen in both early and late time points. Additionally, the specific causes of ScT have not yet been fully elucidated. In this review, we discuss the platform, vascular response, and clinical data of past and current metallic coronary stents with the Absorb-BVS and newer generation BRS, concentrating on their material/design and the mechanisms of thrombotic complications from the pre-clinical, pathologic, and clinical viewpoints. Full article