Subclinical Aortic Valve Bioprosthesis Thrombosis Assessed With 4D CT
Aortic Valve StenosisTAVR is an increasingly used technique for the treatment of aortic valve stenosis. However, recent clinical experience has suggested that subclinical aortic valve bioprosthesis thrombosis may occur early after valve replacement. The frequency of this potentially ominous phenomenon on both transcatheter and surgical aortic valve bioprosthesis is unknown, as this condition is difficult to detect. The recent development of cardiac 4D computed tomography imaging (4DCT) shows great promise for the evaluation of valve leaflet mobility and morphology. The purpose of this study is in an observational design to assess the frequency of subclinical abnormal leaflet motion and morphology in patients treated with transcatheter or surgical aortic valve bioprosthesis. In addition, the 'natural evolution' of this phenomenon as well as its relation to medical treatment and MACCE will be assessed.
Dabigatran as an Alternative Anticoagulant in Patients With Left Ventricular Assist Device (LVAD)...
ThrombosisBleedingPatients with severe heart failure supported by left ventricular assist device (LVAD) require adequate long-term anticoagulant therapy. New oral anticoagulants such as the direct thrombin inhibitor dabigatran may represent an alternative to Coumarin for long-term anticoagulation. In this pilot single-center study, thirty LVAD patients with stable renal function were scheduled to receive phenprocoumon or dabigatran for long-term anticoagulation after implantation of a HeartWare HVAD system following an open-label balanced parallel group design.
Thrombolysis or Anticoagulation for Cerebral Venous Thrombosis
Sinus ThrombosisIntracranialBackground: Endovascular thrombolysis, with or without mechanical clot removal (ET), may be beneficial for a subgroup of patients with cerebral venous sinus thrombosis (CVT), who have a poor prognosis despite treatment with heparin. Published experience with ET is promising, but only based on case series and not on controlled trials. Objective: The main objective of the TO-ACT trial is to determine if ET improves the functional outcome of patients with a severe form of CVT Study design: The TO-ACT trial will be designed as a multi-centre, prospective, randomized, open-label, blinded endpoint (PROBE) trial. Study population: Patients are eligible if they have a radiologically proven CVT, a high probability of poor outcome (defined by presence of one or more of the following risk factors: mental status disorder, coma, intracranial hemorrhagic lesion or thrombosis of the deep cerebral venous system) and the responsible physician is uncertain if ET or standard anti-coagulant treatment is better. Intervention: Patients will be randomized to receive either ET or standard therapy (therapeutic doses of heparin). ET consists of local application of alteplase or urokinase within the thrombosed sinuses, and/or mechanical thrombectomy. Glasgow coma score, NIH stroke scale and relevant laboratory parameters will be assessed at baseline. Endpoints: The primary endpoint is the modified Rankin scale (mRS) at 12 months. The most important secondary outcomes are the mRS, mortality and recanalization rate at 6 months. Major intra- and extracranial hemorrhagic complications within one week following the intervention are the principal safety outcome. Results will be analyzed according to the "intention-to-treat" principle. Assessment of study endpoints will be carried out according to standardized questionnaires by a blinded neurologist or research nurse who is not involved in the treatment of the patient. Study size: To detect a 50% relative reduction in mRS≥2 (from 40 to 20%), 164 patients (82 in each treatment arm) have to be included (two-sided alpha, 80% power). Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Included patients may benefit directly from ET. Complications of ET, most notably intracranial hemorrhages, constitute the most important risk of the study.
Alteplase for Blood Flow Restoration in Hemodialysis Catheters
ThrombosisWe are investigating a new way of administering alteplase to remove clots from hemodialysis catheters. Currently, alteplase is left to dwell inside the catheter between dialysis treatments to dissolve the clot and restore blood flow through the catheter. We have developed a new way to administer alteplase by advancing it to the tip of the catheter at regular 10 minute intervals. We hypothesize that our new "push" protocol will dissolve clots in hemodialysis catheters better and faster than the current dwell method.
Epidemiology of Venous Thrombosis and Pulmonary Embolism
Cardiovascular DiseasesPulmonary Embolism1 moreTo investigate venous thromboembolism in two carefully conducted prospective epidemiologic studies of African American and white adults -- the Atherosclerosis Risk in Communities (ARIC) Study and the Cardiovascular Health Study (CHS).
Registry of Hospitalized Patients in University Hospital Dubrava Respiratory Center
Covid19Thrombosis4 moreAim of this project is to understand clinical features, clinical outcomes and efficacy and safety profiles of different therapies by analyzing a cohort of COVID-19 patients hospitalized and treated in a tertiary-level institution, University hospital Dubrava. Patients' clinical and laboratory characteristics, drug exposure and outcomes are obtained by analysis of written and electronical medical records.
Venous Thromboembolism in Hematologic Malignancy and Hematopoietic Cell Transplant Patients: a Retrospective...
ThrombosisVenous4 moreVenous thromboembolism (VTE) is the second leading cause of death in patients with cancer, after disease progression. VTE is increasingly recognized as a complication in patients with hematologic malignancies and various studies have reported high rates of VTE. Critically ill patients are at high risk of VTE and should all receive thromboprophylaxis. Given the increasing number of patients with HM (hematologic malignancies) / HCT (Hematopoietic cell transplantation) who develop critical illness, and their often prolonged course, it is imperative to understand the incidence and risk factors for VTE, and to evaluate the efficacy and risks associated with both chemical and mechanical thromboprophylaxis Therefore, the investigators plan to evaluate retrospectively the VTE / PE (pulmonary embolism) incidence in HM /HCT patients at the University of Toronto, and the complications associated with it (including death). In addition, the investigators want to evaluate the use, type (mechanical or pharmacological) and timing of thromboprophylaxis. And lastly, the investigators will determine the incidence of bleeding and of complications associated with chemical and mechanical thromboprophylaxis. The investigators will describe the change in VTE incidence over the last 10 years. The investigators know that patients with COVID-19 infection are at higher risk of thrombosis than non-COVID patients. As such, HM/HCT COVID-19 pts will comprise a subgroup, which will be compared with patients who are not not positive for COVID-19. If these numbers are low, COVID-19 status will be included as a predictive variable in our modelling. The results of this research program will help define indications and safety of VTE prophylaxis; and will inform the development of clinical practice guidelines.
A Study of the Efficacy of Preventive Dosing of Fondaparinux Sodium Versus Placebo for the Prevention...
Deep Vein ThrombosisCoronary Artery Bypass Surgery1 moreThis trial is a prospective, single-center Phase II randomized study to demonstrate the superior efficacy of Fondaparinux Sodium subcutaneous injections in patients undergoing CABG surgery (isolated and redo isolated) versus treatment with placebo. All consecutive patients scheduled for CABG surgery that meet the general inclusion and none of the exclusion criteria will be considered for enrollment in the study. Consecutive patients will be randomized on the day of admission prior to their CABG surgery into one of two groups. One group will be randomized to the placebo while the second group will receive 2.5 mg Fondaparinux Sodium injections. Both groups will receive routine mechanical prophylaxis as determined by the treating physicians. Group randomized to receive Fondaparinux Sodium will receive a 2.5 mg SQ daily drug dose starting 12 +/- 2 hours post-wound closure or the following day in the morning (at the discretion of the cardiothoracic surgeon). The second dose would be administered 24 hours later and the dosing will then be once a day. The group randomized to placebo will receive subcutaneous equivolume isotonic saline at the same time points described above. Patients randomized will receive a 2.5 mg dose of Fondaparinux Sodium or placebo subcutaneously for a total of 3-9 days post CABG with day 1 being the day of surgery. The drug will be discontinued if the patient is discharged before day 9. If the patient stays for more than 9 days inside hospital, a duplex would be obtained per protocol and further DVT prevention measures would be instituted per the discretion of treating physician. Patients will be assessed daily while hospitalized for any symptoms and adverse reactions and will undergo laboratory testing (CBC, PT/INR, PTT and UA) as specified in the protocol. Post-op day 3-9(no later than 2 days after the last preventive drug dose) patients will undergo the protocol specific lower limb venous duplex scan and earlier if symptomatic. Patients will also be contacted (phone/office visit) for follow-up 25-35 days post CABG to assess for signs or symptoms of deep venous thrombosis or thromboembolism and for any potential complications.
Early Versus Late Resumption of Anticoagulation in Patients With Both High Thrombosis Risk and Major...
Major hæmorrhageIn patients with a high thromboembolic risk, withdrawing anticoagulant treatment is recommended in some situations, including when major hæmorrhage occurs. But withdrawing treatment can be risky. In patients on a curative dose of anticoagulant medicine, treatment withdrawal heightens the risk of thromboembolic events occurring, with potentially major consequences. For instance, mechanical valve thrombosis is fatal in 15% of patients. Resumption of anticoagulation is therefore critical in patients at high risk for thromboembolic events. However, in these patients having presented major hæmorrhage, resumption of anticoagulation heightens the risk of hæmorrhage recurrence. This risk is even higher when the original hæmorrhage was not accessible via surgical, endoscopic or endoluminal hemostasis. As far as investigators know, there is no data in the literature to rely on when the major hæmorrhage is not accessible via hemostatic intervention and the risk of thrombosis is high. When confronted with patients who need anticoagulation but have a high risk of hæmorrhage recurrence, the question of when treatment should be resumed has not been resolved. This is why investigators propose to conduct a randomised comparative study to evaluate two treatment strategies - early resumption (H48 to H72) versus late resumption (H120 to H144) of anticoagulation. MAIN OBJECTIVE: The main objective of the present study is to evaluate in terms of bleeding risk, thrombosis risk and mortality at one month, the effect of early vs. late resumption of anticoagulation in patients having presented with serious hæmorrhage while on curative-dose anticoagulants and facing a high thromboembolic risk.
Resection vs. Best Supportive Care for Hepatocellular Carcinoma (HCC) With Portal Venous Thrombus...
Hepatocellular Carcinoma With Portal Vein Tumor ThrombusThe purpose of this study is to evaluate the long-term efficacy and safety of surgical resection compared with best supportive care in patients with resectable hepatocellular carcinoma (HCC) with portal venous thrombus (PVTT) in the first branch of portal vein.