[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100635973":3},{"organization":4,"armGroups":7,"interventions":21,"overallOfficials":42,"centralContacts":46,"locations":56,"responsibleParty":75,"collaborators":51,"id":77,"slug":78,"hasResults":79,"nctId":80,"briefTitle":81,"officialTitle":82,"acronym":83,"eligibilityCriteria":84,"healthyVolunteers":79,"sex":85,"minAge":86,"maxAge":51,"enrollmentInfo":87,"targetDuration":51,"studyType":90,"phases":91,"briefSummary":93,"conditions":94,"keywords":99,"overallStatus":105,"whyStopped":51,"lastUpdateSubmitDate":106,"lastUpdatePostDateStruct":107,"startDateStruct":110,"completionDateStruct":112,"leadSponsor":114,"locationsCount":115},{"fullName":5,"class":6},"University College Dublin","OTHER",[8,15],{"label":9,"type":10,"description":11,"interventionNames":12},"Weight-based Tinzaparin","EXPERIMENTAL","Tinzaparin (Innohep®, LEO Pharma) administered subcutaneously once daily at a dose of 50 anti-Xa IU\u002Fkg total body weight, commencing on post-operative day 1 and continuing for 21 days. Administered via subcutaneous injection into the abdominal wall. Anti-Xa level measured at 4 hours (±30 minutes) after the third consecutive dose on post-operative day 2.",[13,14],"Diagnostic Test: Anti-Xa Activity Monitoring","Drug: Tinzaparin (Leo)",{"label":16,"type":17,"description":18,"interventionNames":19},"Weight-stratified Enoxaparin","ACTIVE_COMPARATOR","Enoxaparin (Clexane®, Sanofi) administered subcutaneously twice daily, commencing on post-operative day 1 and continuing for 21 days. Dose: 40 mg twice daily for patients weighing ≤150 kg; 60 mg twice daily for patients weighing \\>150 kg. Administered via subcutaneous injection into the abdominal wall. Anti-Xa level measured at 4 hours (±30 minutes) after the third consecutive dose on post-operative day 2.",[13,20],"Drug: enoxaparin",[22,29,36],{"type":23,"name":24,"description":25,"armGroupLabels":26,"otherNames":27},"DIAGNOSTIC_TEST","Anti-Xa Activity Monitoring","A single venous blood sample (\\~5 mL, citrated tube) drawn at 4 hours (±30 minutes) after the third consecutive LMWH dose on post-operative day 2, concurrent with routine post-operative bloods. Anti-Xa activity measured using a CE-marked in vitro diagnostic assay at the SVUH Haematology Laboratory. Results are not available in real time and do not influence clinical management. Target prophylactic range: 0.2-0.4 IU\u002FmL per ASMBS 2021 guidance.",[9,16],[28],"Anti-factor Xa assay; chromogenic anti-Xa assay",{"type":30,"name":31,"description":32,"armGroupLabels":33,"otherNames":34},"DRUG","Tinzaparin (Leo)","Tinzaparin sodium administered subcutaneously once daily at 50 anti-Xa IU\u002Fkg total body weight for 21 days post-operatively, commencing on post-operative day 1. Used for pharmacological VTE prophylaxis following laparoscopic bariatric surgery.",[9],[35],"Innohep",{"type":30,"name":37,"description":38,"armGroupLabels":39,"otherNames":40},"enoxaparin","Enoxaparin sodium administered subcutaneously twice daily (40 mg for weight ≤150 kg; 60 mg for weight \\>150 kg) for 21 days post-operatively, commencing on post-operative day 1. Used for pharmacological VTE prophylaxis following laparoscopic bariatric surgery.",[16],[41],"Clexane",[43],{"name":44,"affiliation":5,"role":45},"Helen M Heneghan, PhD, FRCSI","PRINCIPAL_INVESTIGATOR",[47,53],{"name":48,"role":49,"phone":50,"phoneExt":51,"email":52},"Czara A Kennedy, BMBS, MSc, MRCI","CONTACT","00353861933967",null,"czara.kennedy@ucd.ie",{"name":44,"role":49,"phone":54,"phoneExt":51,"email":55},"0035312214000","helen.heneghan@ucd.ie",[57],{"facility":58,"status":51,"city":59,"state":51,"zip":51,"country":60,"countryCode":61,"cosmosGeoPoint":62,"geoPoint":67,"contacts":68},"St Vincent's University Hospital","Dublin","Ireland","IE",{"type":63,"coordinates":64},"Point",[65,66],-6.24889,53.33306,{"lat":66,"lon":65},[69,72],{"name":70,"role":49,"phone":54,"phoneExt":51,"email":71},"Czara A Kennedy, BMBS, MRCSI, MSc","czkennedy@svhg.ie",{"name":73,"role":49,"phone":54,"phoneExt":51,"email":74},"Naomi J Fearon, MD, FRCSI","naomifearon@svhg.ie",{"type":76,"investigatorFullName":51,"investigatorTitle":51,"investigatorAffiliation":51,"oldNameTitle":51,"oldOrganization":51},"SPONSOR","100635973","the-oat-trail-the-obesity-anti-coagulation-thromboprophylaxis-trial-100635973",false,"NCT07559643","The OAT Trail: The Obesity Anti-Coagulation Thromboprophylaxis Trial.","A Prospective, Randomised Controlled Trial Comparing Weight-based Tinzaparin Versus Weight-based Enoxaparin for Peri-operative Thromboprophylaxis in Patients Undergoing Bariatric Surgery: Evaluation of Anti-Xa Levels and Clinical Outcomes.","The OAT-RCT","Inclusion Criteria:\n\n* Age ≥18 years\n* BMI ≥40 kg\u002Fm², or BMI ≥35 kg\u002Fm² with at least one obesity-related comorbidity (type 2 diabetes, hypertension, obstructive sleep apnoea, dyslipidaemia, or metabolic dysfunction-associated steatotic liver disease (MASLD))\n* Scheduled to undergo laparoscopic bariatric surgery (sleeve gastrectomy or gastric bypass) at St Vincent's University Hospital, Dublin, Ireland\n* Capacity to provide written informed consent\n\nExclusion Criteria:\n\n* Current therapeutic anticoagulation for any indication Known allergy or hypersensitivity to tinzaparin, enoxaparin, heparin, or any heparin-derived product, including documented heparin-induced thrombocytopaenia (HIT) Any other contraindication to LMWH therapy Severe renal impairment (eGFR \\\u003C30 mL\u002Fmin\u002F1.73m²) Known haematological disorder or coagulopathy Pregnancy, breastfeeding, or planning pregnancy during the study period Active major bleeding or high bleeding risk at the discretion of the treating clinician Inability to provide written informed consent Participation in another interventional clinical study within 30 days prior to enrolment","ALL","18 Years",{"count":88,"type":89},180,"ESTIMATED","INTERVENTIONAL",[92],"NA","Blood clots in the legs or lungs (called venous thromboembolism or VTE) are one of the most serious complications after weight loss surgery. Most blood clots occur after patients go home from hospital, within the first 30 days after surgery. To prevent blood clots, all patients having weight loss surgery receive a daily blood-thinning injection for 21 days after their operation.\n\nTwo blood-thinning injections are currently used at St Vincent's University Hospital for this purpose: enoxaparin (Clexane®) and tinzaparin (Innohep®). Both belong to a group of medicines called low molecular weight heparins (LMWHs). Patients with obesity process these medicines differently to the general population, and previous studies from our hospital have shown that fewer than 53% of patients achieve adequate blood-thinning levels with either injection when measured by a blood test called an anti-Xa level.\n\nPatients will be randomly assigned (like a coin toss) to receive either tinzaparin or enoxaparin for 21 days after their surgery. Both injections are already in routine use at this hospital. A single extra blood sample will be taken on the second day after surgery to measure the anti-Xa level, which tells us whether the injection is providing adequate protection against blood clots. This blood sample will be taken at the same time as routine post-operative blood tests so that no additional blood draws are required.\n\nThe study will also look at rates of blood clots and bleeding events within 30 days of surgery, and will ask patients to complete a short questionnaire at their six-week follow-up appointment about their experience with the injection.",[95,96,97,98],"Bariatric Surgery","Anti-Xa Activity","VTE (Venous Thromboembolism)","Obesity & Overweight",[100,101,102,103,104],"Anti-Xa","Metabolic Bariatric Surgery","Obesity","VTE","DVT","NOT_YET_RECRUITING","2026-05-14",{"date":108,"type":109},"2026-05-18","ACTUAL",{"date":111,"type":89},"2026-08-01",{"date":113,"type":89},"2026-12-01",{"name":5,"class":6},1]