6,963 publications from this institution
The aim of this study was to evaluate the impact of 23-month ticagrelor monotherapy following one-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) on the rates of patient-oriented composite endpoints (POCE) and net adverse clinical events (NACE).The rates of site-reported Academic Research Consortium (ARC)-2 defined POCE (all-cause death, any stroke, any myocardial infarction or any revascularisation) and NACE (POCE or bleeding type 3 or 5 according to the Bleeding ARC [BARC]) were reported up to two years by intention-to-treat principle in the randomised, multicentre, open-label GLOBAL LEADERS study comparing two antiplatelet strategies in 15,991 patients undergoing PCI. The experimental strategy consisted of aspirin with ticagrelor for one month followed by ticagrelor monotherapy for 23 months, whereas the reference treatment consisted of 12-month DAPT followed by 12-month aspirin monotherapy. At two years, POCE occurred in 1,050 (13.2%) patients in the experimental group and in 1,131 (14.2%) in the reference group (HR 0.93, 95% CI: 0.85-1.01, p=0.085). NACE occurred in 1,145 (14.4%) patients in the experimental group and in 1,237 (15.5%) patients in the reference group (HR 0.92, 95% CI: 0.85-1.00, p=0.057). In pre-specified subgroup analyses, no significant treatment-by-subgroup interactions were found for either POCE or NACE at two years.The experimental treatment strategy of one-month DAPT followed by 23 months of ticagrelor alone did not result in a significant reduction in the rates of site-reported POCE or NACE, when compared to the reference treatment. ClinicalTrials.gov Identifier: NCT01813435.
Coronary heart disease (CHD) is a leading cause of death and disability worldwide. Chronic myocardial ischaemia resulting from CHD can cause stable angina and interfere with ordinary activities. Numerous approaches for reducing myocardial ischaemia are currently available. These include lifestyle changes such as weight reduction, exercise, smoking cessation and reduced consumption of salt and fat; pharmacological approaches such as use of anti-platelet agents, statins, angiotensin converting enzyme inhibitors, β-blockers, calcium channel blockers and nitrates; surgical revascularization approaches such as coronary artery bypass grafting and percutaneous methods (balloon angioplasty, bare-metal stents, drug eluting stents). Alternative methods for reducing anginal pain such as external enhanced counterpulsation and spinal cord stimulation are also available. Despite this wide range of choices, patients with ischaemic heart disease usually require a combination of these therapies, and may continue to experience symptoms. While traditional therapies continue to be improved, strategies to increase myocardial circulation by stimulating formation of collateral vessels around obstructed coronary arteries are also in development. These approaches include therapy with recombinant growth factor proteins, transfer of growth factor genes and stem cell therapy. It is hoped that at least one of these approaches will safely and effectively reduce myocardial ischaemia, providing a new option for patients with CHD.
No abstract is provided for this article.
Objectives We sought to assess the efficacy of vascular brachytherapy (VBT) combined with stenting for the primary prevention of restenosis. Background Intravascular brachytherapy after stent implantation for de novo lesions has been abandoned for the present. We revisited this procedure by optimizing all procedural steps—the use of glycoprotein IIb/IIIa blockers, direct stenting, adequate radiation coverage, avoidance of edge damage, source centering, intravascular ultrasound-guided dosimetry, and continuation of a dual anti-platelet regimen for one year. Methods The Beta-Radiation Investigation with Direct stenting and Galileo in Europe (BRIDGE) study is a multicenter, randomized controlled trial evaluating the long-term efficacy of VBT with P-32 (20 Gy at 1 mm in the coronary wall) after direct stenting. The primary end point was angiographic intra-stent late loss; secondary end points were six months binary restenosis and neo-intimal hyperplasia. Patients (n = 112) with de novo lesions (2.5 to 4.0 mm in diameter up to 15 mm long) were randomized to either VBT or no-VBT. Results At six months, intra-stent loss was 0.43 and 0.84 mm (p < 0.001) in the irradiated and control groups, respectively. Intra-stent neo-intimal volume was reduced from 36 mm3to 10 mm3. However, in the irradiated group there were six late occlusions as well as eight restenoses outside the stented and peri-stented area at the fall-off dose edges of the irradiated area. Accordingly, the target vessel revascularization and major adverse cardiac and cerebrovascular events rates at one year in the VBT group (20.4% and 25.9%, respectively) were higher than in the control group (12.1% and 17.2%, respectively). Conclusions Despite the optimization of pre-, peri-, and post-procedural factors and despite the relative efficacy of the brachytherapy for the prevention of the intra-stent neo-intimal hyperplasia, the clinical outcome of the irradiated group was less favorable than that of the control group.
No abstract is provided for this article.
The critical buckling characteristics of hydrostatically pressurized complete spherical shells filled with an elastic medium are demonstrated. A model based on small deflection thin shell theory, the equations of which are solved in conjunction with variational principles, is presented. In the exact formulation, axisymmetric and inextensional assumptions are not used initially and the elastic medium is modelled as a Winkler foundation, i.e., using uncoupled radial springs with a constant foundation modulus that is independent of wave numbers of shell buckling modes. Simplified approximations based on a Rayleigh-Ritz approach are also introduced for critical buckling pressure and mode number with a considerable degree of accuracy. Characteristic modal shapes are demonstrated for a wide range of material and geometric parameters. A phase diagram is established to obtain the requisite thickness to radius, and stiffness ratios for a desired mode profile. The present exact formulation can be readily extended to apply to more general cases of non-axisymmetric buckling problems.
