Oral Anticoagulant Therapy (oral + anticoagulant_therapy)

Distribution by Scientific Domains

Selected Abstracts

Low-molecular-weight heparin as bridging therapy during interruption of oral anticoagulation in patients undergoing colonoscopy or gastroscopy

M. Constans
Summary Nowadays, most patients under oral anticoagulant therapy (OAT) require invasive procedures such as colonoscopy (CC) or gastroscopy (GC). The goals of the management of OAT are to minimise the risk of thromboembolism and bleeding. We have performed the first prospective, observational study to evaluate these parameters using fixed-dose high-risk thromboprophylactic therapy with sodic bemiparin (Hibor®) as bridging therapy. From January 2004 to January 2005, patients under OAT were included. Periprocedure prophylaxis consisted of: Acenocumarol patients: Day ,3: withdrawal acenocumarol. Days ,2,,1,0: Hibor ®3500 UI/d sc and days +1,+2,+3: Hibor® 3500 U/I + acenocumarol. And day +5: acenocumarol only. Warfarin patients: Days ,5,,4: withdrawal warfarin, ,3,,2,,1, 0; Hibor® 3500 UI/day sc, days +1,+2,+3,+4: Hibor® 3500 UI/day sc and warfarin and day +5; warfarin only. Thromboembolic complications and bleeding were recorded in a 3 month follow-up. We included 100 consecutive patients in the intention-to-treat group. The remaining 98 patients were 50 women and 48 men. Mean age of women was 71.1 (range: 46,87) years and 70.7 (range: 39,86) years in men. Eighty-three took acenocumarol, and 15 warfarin. Thirty-two gastroscopies and 61 colonoscopies were performed and in five patients both were performed. No thromboembolic and bleeding complications related to bemiparin were observed in the 103 endoscopies. Two patients developed pruritus at the punction site. Fixed-dose high-risk thromboprophilactic therapy with bemiparin (Hibor®) is safe and effective as a bridging therapy in patients under OAT who require GC or CC. [source]

Establishing an oral anticoagulant monitoring service in a multiethnic developing country

Summary We describe the establishment of an International Normalized Ratio (INR)-based system for monitoring oral anticoagulant therapy in a multiethnic developing country. There was significant variation in geometric mean normal prothrombin time among ethnic groups: 12.7 s for Indians, 13.4 s for Africans and 13.7 s for subjects of mixed ancestry. About 4129 INR measurements were performed in the first 2 years. The majority (55.2%) of achieved INRs were subtherapeutic. We found 31 (0.8%) instances of severe overanticoagulation (INR > 8.0). There were no bleeding manifestations in 24 (77%) of them. Only two experienced life-threatening haemorrhage. The management of bleeding and excessive anticoagulation was not always in accordance with international recommendations. The high incidence of underanticoagulation in Trinidad and Tobago may be due to genetically determined warfarin resistance or underdosing. Oral anticoagulant monitoring in Trinidad and Tobago could benefit from the centralization of such services to designated clinics with specialized staff and computer-assisted dosing which adopt internationally accepted guidelines for practice. [source]

Protein C and protein S levels can be accurately determined within 24 hours of diagnosis of acute venous thromboembolism

Summary In the 50% of cases of acute idiopathic venous thromboembolism, laboratory testing for inherited causes is often performed. Most physicians are under the impression that assays for protein C and protein S should not be measured at the time of diagnosis because of a high false positive rate. We performed a prospective cohort study from two outpatient thromboembolism clinics on consecutive patients with an objectively confirmed diagnosis of first acute idiopathic venous thromboembolism. Assays for protein C and protein S were performed prior to the initiation of oral anticoagulation therapy and within 24 h of diagnosis of venous thromboembolism. Abnormal results were repeated when patients discontinued oral anticoagulant therapy. Of 253 patients tested for both protein C and protein S, 229 (91%; 95% confidence interval 87,94%) were negative and 484 of 508 (95%) tests were normal. Of the 24 initial abnormal results, 21 were repeated and 10 (48%; 95% confidence interval 26,70%) were still abnormal. Overall, 97.8% of initial protein C and protein S results were accurate. If protein C and protein S are measured at the time of diagnosis of acute venous thromboembolism, the majority of the results will be normal and false positives are uncommon. [source]

The cost-effectiveness of computer-assisted anticoagulant dosage: results from the European Action on Anticoagulation (EAA) multicentre study

Summary. Background: Increased demand for oral anticoagulation has resulted in wider adoption of computer-assisted dosing in anticoagulant clinics. An economic evaluation has been performed to investigate the cost-effectiveness of computer-assisted dosing in comparison with manual dosing in patients on oral anticoagulant therapy. Methods: A trial-based cost-effectiveness analysis was conducted as part of the EAA randomized study of computer-assisted dosage vs. manual dosing. The 4.5-year multinational trial was conducted in 32 centres with 13 219 anticoagulation patients randomized to manual or computer-assisted dosage. The main outcome measures were total health care costs, clinical event rates and cost-saving per clinical event prevented by computer dosing compared with manual dosing. Results: Mean dosing costs per patient were lower (difference: ,47) for computer-assisted dosing, but with little difference in clinical event costs. Total overall costs were ,51 lower in the computer-assisted dosing arm. There were a larger number of clinical events in the manual dosing arm. The overall difference between trial arms was not significant (difference in clinical events, ,0.003; 95% CI, ,0.010,0.004) but there was a significant reduction in events with DVT/PE, suggesting computer-assisted dosage with the two study programs (dawn ac or parma 5) was at least as effective clinically as manual dosage. The cost-effectiveness analysis indicated that computer-assisted dosing is less costly than manual dosing. Conclusions: Results indicate that computer-assisted dosage with the two programs (dawn ac and parma 5) is cheaper than manual dosage and is at least as effective clinically, indicating that investment in this technology represents value for money. [source]

The quality of oral anticoagulant therapy and recurrent venous thrombotic events in the Leiden Thrombophilia Study

Summary.,Background:,The International Normalized Ratio (INR) target range is a relatively narrow range in which the efficacy of oral anticoagulant treatment, i.e. prevention of extension and recurrence of thrombosis, is balanced with the risk of hemorrhagic complications. Over the years, different INR target ranges have been implemented for individual indications, depending on their thrombotic potential. In most of the studies defining these INR targets, the treatment of the patients was aimed at a certain INR range, but in the analysis no account was taken of the time that the patients spent within this range in reality. Methods:,The Leiden Thrombophilia Study (LETS) is a population-based case-control study on risk factors for venous thrombosis, in which many genetic and acquired factors have been investigated. Our aim was to investigate the effect of the quality of the oral anticoagulant therapy for the initial venous thrombosis and its relationship with recurrence of thrombosis. Quality of anticoagulation was defined as the time spent at various INR levels during treatment, and we focused on the effect of sustained intensities above a certain INR in preventing recurrences later on. Results:,Two hundred and sixty-six patients with a total follow-up of 2495 patient-years were studied. The mean duration of the initial anticoagulant therapy was 194.5 days (range 48,4671). During follow-up, 58 recurrences were diagnosed (cumulative recurrence rate of 21.8% over 9 years). The mean INR during initial therapy was 2.90, with 90.3% [95% confidence interval (CI) 88.4,92.3%] of the time being spent above an INR of 2.0, and 39.1% (95% CI 35.5,42.7%) above an INR of 3.0. Patients who spent more time below the target range, or who had a shorter duration of anticoagulation, did not experience a higher risk of recurrence after the initial period of anticoagulation had passed. Conclusion:,Provided that oral anticoagulant treatment is adequately managed, according to international guidelines, recurrent thrombosis cannot be ascribed to variation in the primary treatment. Further attempts to reduce the risk of recurrence should therefore be aimed at identifying other explanatory factors, and subsequently fine-tuning the target ranges. [source]

Oral surgery in patients on oral anticoagulant therapy: a randomized comparison of different INR targets


Thromboembolic risk and bleeding in patients maintaining or stopping oral anticoagulant therapy during dental extraction


Moderate dose oral anticoagulant therapy in patients with the antiphospholipid syndrome?


No abstract is available for this article. [source]

Individualized duration of oral anticoagulant therapy for deep vein thrombosis based on a decision model

R. Vink
Summary.,Background:,The optimal duration of oral anticoagulant therapy for patients with a first episode of deep vein thrombosis (DVT) is still a matter of debate. However, according to the ACCP consensus strategy a limited stratification in treatment duration is advocated, i.e. 3 months for patients with a transient risk factor and 1 year or longer for patients with recurrent disease or a consistent risk factor such as thrombophilia or cancer. This consensus strategy is founded on the mean optimal duration of therapy obtained in large cohorts of patients and is mainly based on the risk of recurrent venous thromboembolism (VTE), with only minimal consideration for the patient's bleeding risk. Objective:,The aim of this study is to optimize the anticoagulant treatment strategy with vitamin K antagonists for the individual patient with DVT. Methods:,Based on an extensive literature study, a mathematical model was constructed to balance the risk of recurrent VTE against the risk of major hemorrhagic complications. The following parameters are incorporated in the model: baseline estimates and risk factors for recurrent VTE and bleeding, clinical course of DVT, and efficacy of treatment with vitamin K antagonists. With the use of these parameters, the risk for a recurrent VTE and a bleeding episode can be calculated for the individual patient. The optimal duration of anticoagulant therapy can be defined as the timepoint at which the benefit of treatment (prevention of VTE) is counterbalanced by its risk (bleeding). Results/conclusions:,How long a patient should receive anticoagulant treatment is a matter of balancing the benefits and risks of treatment. The model shows that the optimal treatment duration varies greatly from patient to patient according to the patient's unique bleeding and recurrence risk. [source]

Incidence of cancer after a first episode of idiopathic venous thromboembolism treated with 3 months or 1 year of oral anticoagulation

M. R. Taliani
Summary.,Background:,A prolonged treatment with oral anticoagulants has been claimed to reduce the incidence of newly diagnosed cancer in the long-term follow-up of patients with venous thromboembolism. Objectives:,In a multicenter prospective study we assessed the incidence of newly diagnosed clinically overt cancer in patients with a first episode of idiopathic venous thromboembolism (VTE) treated with oral anticoagulants for 3 months or 1 year. Patients and methods:,Consecutive patients with an idiopathic venous thromboembolism who had completed 3 months of oral anticoagulant therapy without having a recurrence, bleeding or newly diagnosed cancer were randomized to discontinue oral anticoagulant therapy or to continue it for nine additional months. Idiopathic venous thromboembolism was defined as thrombosis occurring in the absence of known cancer, known thrombophilia, or temporary risk factors for venous thromboembolism. All patients were followed up for at least 1 year after randomization. Results:,A total of 429 patients, 265 patients with DVT and 164 with PE, were followed up for an average of 43.7 months after randomization. A newly diagnosed cancer occurred in 32 patients (7.5%), 13 (6.2%) of the 210 patients treated for 3 months and 19 (8.7%) of the 219 patients treated for 1 year (RR = 0.71, 95% confidence interval 0.36,1.41). Conclusions:,The incidence of newly diagnosed clinically overt cancer is not reduced in patients with idiopathic venous thromboembolism treated with 1-year anticoagulant treatment compared with patients treated for 3 months. [source]

Non-traumatic pulmonary haematoma complicating oral anticoagulation therapy

RESPIROLOGY, Issue 4 2007
Abstract: Several cases of non-traumatic pulmonary haematoma have been reported in the literature. However, very few of them are related to anticoagulation therapy. The authors report two cases of pulmonary haematoma caused by oral anticoagulant therapy without any underlying pathological lesion. The evolution was fatal in the first case, whereas a slow spontaneous resolution of the haematoma was noted in the second. Non-traumatic pulmonary haematoma can be a complication of oral anticoagulation and should be considered in the differential diagnosis of pulmonary densities in this setting. [source]