IMPORTANCECoronary plaques that are prone to rupture and cause adverse cardiac events are characterized by large plaque burden, large lipid content, and thin fibrous caps. Statins can halt the progression of coronary atherosclerosis; however, the effect of the proprotein convertase subtilisin kexin type 9 inhibitor alirocumab added to statin therapy on plaque burden and composition remains largely unknown.OBJECTIVE To determine the effects of alirocumab on coronary atherosclerosis using serial multimodality intracoronary imaging in patients with acute myocardial infarction. DESIGN, SETTING, AND PARTICIPANTSThe PACMAN-AMI double-blind, placebo-controlled, randomized clinical trial (enrollment: May 9, 2017, through October 7, 2020; final follow-up: October 13, 2021) enrolled 300 patients undergoing percutaneous coronary intervention for acute myocardial infarction at 9 academic European hospitals.INTERVENTIONS Patients were randomized to receive biweekly subcutaneous alirocumab (150 mg; n = 148) or placebo (n = 152), initiated less than 24 hours after urgent percutaneous coronary intervention of the culprit lesion, for 52 weeks in addition to high-intensity statin therapy (rosuvastatin, 20 mg).MAIN OUTCOMES AND MEASURES Intravascular ultrasonography (IVUS), near-infrared spectroscopy, and optical coherence tomography were serially performed in the 2 non-infarct-related coronary arteries at baseline and after 52 weeks. The primary efficacy end point was the change in IVUS-derived percent atheroma volume from baseline to week 52. Two powered secondary end points were changes in near-infrared spectroscopy-derived maximum lipid core burden index within 4 mm (higher values indicating greater lipid content) and optical coherence tomography-derived minimal fibrous cap thickness (smaller values indicating thin-capped, vulnerable plaques) from baseline to week 52. RESULTS Among 300 randomized patients (mean [SD] age, 58.5 [9.7] years; 56 [18.7%] women; mean [SD] low-density lipoprotein cholesterol level, 152.4 [33.8] mg/dL), 265 (88.3%) underwent serial IVUS imaging in 537 arteries. At 52 weeks, mean change in percent atheroma volume was −2.13% with alirocumab vs −0.92% with placebo (difference, −1.21% [95% CI, −1.78% to −0.65%], P < .001). Mean change in maximum lipid core burden index within 4 mm was −79.42 with alirocumab vs −37.60 with placebo (difference, −41.24 [95% CI, −70.71 to −11.77]; P = .006). Mean change in minimal fibrous cap thickness was 62.67 μm with alirocumab vs 33.19 μm with placebo (difference, 29.65 μm [95% CI,]; P = .001). Adverse events occurred in 70.7% of patients treated with alirocumab vs 72.8% of patients receiving placebo.CONCLUSIONS AND RELEVANCE Among patients with acute myocardial infarction, the addition of subcutaneous biweekly alirocumab, compared with placebo, to high-intensity statin therapy resulted in significantly greater coronary plaque regression in non-infarct-related arteries after 52 weeks. Further research is needed to understand whether alirocumab improves clinical outcomes ...
These results suggest an enhanced ability to withstand high loads when using the monocortical screw fixation technique with angular stability. A higher elastic deformation of LISS compared with conventional plating systems in distal femoral fractures can be explained by the lower bending stiffness caused by different design and material properties.
Objectives The OVID study will demonstrate whether prophylactic-dose enoxaparin improves survival and reduces hospitalizations in symptomatic ambulatory patients aged 50 or older diagnosed with COVID-19, a novel viral disease characterized by severe systemic, pulmonary, and vessel inflammation and coagulation activation. Trial design The OVID study is conducted as a multicentre open-label superiority randomised controlled trial. Participants Inclusion Criteria 1. Signed patient informed consent after being fully informed about the study’s background. 2. Patients aged 50 years or older with a positive test for SARS-CoV2 in the past 5 days and eligible for ambulatory treatment. 3. Presence of respiratory symptoms (i.e. cough, sore throat, or shortness of breath) or body temperature >37.5° C. 4. Ability of the patient to travel to the study centre by private transportation, performed either by an accompanying person from the same household or by the patient themselves 5. Ability to comply with standard hygiene requirements at the time of in-hospital visit, including a face mask and hand disinfectant. 6. Ability to walk from car to study centre or reach it by wheelchair transport with the help of an accompanying person from the same household also complying with standard hygiene requirements. 7. Ability to self-administer prefilled enoxaparin injections after instructions received at the study centre or availability of a person living with the patient to administer enoxaparin. Exclusion Criteria 1. Any acute or chronic condition posing an indication for anticoagulant treatment, e.g. atrial fibrillation, prior venous thromboembolism (VTE), acute confirmed symptomatic VTE, acute coronary syndrome. 2. Anticoagulant thromboprophylaxis deemed necessary in view of the patient's history, comorbidity or predisposing strong risk factors for thrombosis: a. Any of the following events occurring in the prior 30 days: fracture of lower limb, hospitalization for heart failure, hip/knee replacement, major trauma, spinal cord injury, stroke, b. previous VTE, c. histologically confirmed malignancy, which was diagnosed or treated (surgery, chemotherapy, radiotherapy) in the past 6 months, or recurrent, or metastatic, or inoperable. 3. Any clinically relevant bleeding (defined as bleeding requiring hospitalization, transfusion, surgical intervention, invasive procedures, occurring in a critical anatomical site, or causing disability) within 30 days prior to randomization or sign of acute bleeding. 4. Intracerebral bleeding at any time in the past or signs/symptoms consistent with acute intracranial haemorrhage. 5. Haemoglobin <8 g/dL and platelet count <50 x 109 cells/L confirmed by recent laboratory test (<90 days). 6. Subjects with any known coagulopathy or bleeding diathesis, including known significant liver disease associated with coagulopathy. 7. Severe renal insufficiency (baseline creatinine clearance <30 mL/min calculated using the Cockcroft-Gault formula) confirmed by recent laboratory test (<90 days). 8. Contraindications to enoxaparin therapy, including prior heparin-induced thrombocytopenia and known hypersensitivity. 9. Current use of dual antiplatelet therapy. 10. Participation in other interventional studies over the past 30 days. 11. Non-compliance or inability to adhere to treatment or lack of a family environment or support system for home treatment. 12. Cognitive impairment and/or inability to understand information provided in the study information. Patient enrolment will take place at seven Swiss centres, including five university hospitals and two large cantonal hospitals. Intervention and comparator Patients randomized to the intervention group will receive subcutaneous enoxaparin at the recommended dose of 4,000 IU anti-Xa activity (40 mg/0.4 ml) once daily for 14 days. Patients randomized to the comparator group will receive no anticoagulation. Main outcomes Primary outcome: a composite of any hospitalization or all-cause death occurring within 30 days of randomization. Secondary outcomes: (i) a composite of cardiovascular events, including deep vein thrombosis (including catheter-associated), pulmonary embolism, myocardial infarction/myocarditis, arterial ischemia including mesenteric and extremities, acute splanchnic vein thrombosis, or ischemic stroke within 14 days, 30 days, and 90 days of randomization; (ii) each component of the primary efficacy outcome, within 14 days, 30 days, and 90 days of randomization; (iii) net clinical benefit (accounting for the primary efficacy outcome, composite cardiovascular events, and major bleeding), within 14 days, 30 days, and 90 days of enrolment; (iv) primary efficacy outcome, within 14 days, and 90 days of enrolment; (v) disseminated intravascular coagulation (ISTH criteria, in-hospital diagnosis) within 14 days, 30 days, and 90 days of enrolment. Randomisation Patients will undergo block stratified randomization (by age: 50-70 vs. >70 years; and by study centre) with a randomization ratio of 1:1 with block sizes varying between 4 and 8. Randomization will be performed after the signature of the informed consent for participation and the verification of the eligibility criteria using the electronic data capture software (REDCAP, Vanderbilt University, v9.1.24). Blinding (masking) In this open-label study, no blinding procedures will be used. Numbers to be randomised (sample size) The sample size calculation is based on the parameters α = 0.05 (2-sided), power: 1−β = 0.8, event rate in experimental group, pexp = 0.09 and event rate in control group, pcon = 0.15. The resulting total sample size is 920. To account for potential dropouts, the total sample size was fixed to 1000 with 500 patients in the intervention group and 500 in the control group. Trial Status Protocol version 1.0, 14 April 2020. Protocol version 3.0, 18 May 2020 Recruiting start date: June 2020. Last Patient Last Visit: March 2021. Trial registration ClinicalTrials.gov Identifier: NCT04400799 First Posted: May 26, 2020 Last Update Posted: July 16, 2020 Full protocol The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.
Laser-cladding experiments have been performed with STELLITE 6 powder on mild steel substrates, using a 1.5 kW linearly polarized continuous wave CO 2 laser as a heat source. The clad height, the mass efficiency, the dimensions of the melt pool, as well as the global absorptivity, were measured as functions of the powder feed rate and the scanning speed. A quantitative analytical model of the process is proposed, based on the overall mass and energy balance. It allows the calculation of the mass efficiency and of the global absorptivity, taking into account the incorporation of the powder into the melt pool as well as the energy absorbed by the powder jet and the substrate. It successfully explains the experimental results and demonstrates the role played by the melt pool inclination with respect to the substrate. A processing diagram is given to find rapidly the optimal laser treatment conditions and the desired clad height. It is discussed with respect to the other limiting conditions of the process, the geometrical maximum powder efficiency, the porosity, the dilution, and the maximum power of the laser installation.
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