RHEDAR study: Determination of the risk of gastrointestinal hemorrhage in treatment with dabigatran, acenocoumarol and rivaroxaban.

BACKGROUND AND AIM: Atrial fibrillation is a major cause of death and disability due to stroke. Vitamin K antagonist drugs are effective for prevention, but they have a narrow therapeutic range and multiple pharmacological interactions. In recent years, new therapeutic alternatives have been searched to minimize complications. The main objective is to evaluate the risk of gastrointestinal bleeding in anticoagulated patients and compare the classic treatment with new anticoagulants. METHODS: We conducted a retrospective cohort study to determine the risk of gastrointestinal bleeding in patients treated with acenocoumarol/dabigatran/rivaroxaban, between 2012 and 2016. We compared the classic with the new anticoagulant group, and a multivariate logistic regression analysis was used to determinate the risk factors of gastrointestinal bleeding. RESULTS: A total of 1213 patients were selected, 52.7% male patients, a mean age of 72.6 years old (± 14.563). 73.6% had atrial fibrilation. 14.5% of patients used acetylsalicylic acid, and 4% clopidogrel. 67.2% had a high-risk CHADS-2 Score, and 36.9% a high-risk HAS-BLED Score. We determined a 5.6% (68) of gastrointestinal bleeding, without differences according to anticoagulant used. The multivariate model showed a greater risk for digestive hemorrhage in patients with a previous hemorrhagic event (odds ratio [OR] = 2.422 95% confidence interval [CI]: 1.101-5.327) and the concomitant therapy with clopidogrel (OR = 2.373 95% CI: 0.996-5.652). CONCLUSIONS: No differences were found in the risk of gastrointestinal bleeding between the different anticoagulants. A previous gastrointestinal bleeding were considered independent risk factor. The HAS-BLED score should be taken into account to make clinical decisions about to prescribe anticoagulant treatment.

Unintentional ingestion of a high dose of acenocoumarol in a young child.

Acute intoxication with a vitamin K antagonist may cause serious coagulopathy. We report the accidental ingestion of a high dose of acenocoumarol in a young child. Two intravenous administrations of 5 mg of vitamin K, in combination with fast and repeated administration of activated charcoal and sodium sulfate, were sufficient to prevent coagulopathy and related symptoms, despite a confirmed elevated blood acenocoumarol concentration (260 µg/L).

Effectiveness and Safety of Rivaroxaban Compared to Acenocumarol after Infrainguinal Surgical Revascularization.

BACKGROUND: Optimal antithrombotic therapy after lower limb infrainguinal revascularization remains a controversial topic. The use of anticoagulants, alone or in combination with antiplatelet drugs, can potentially improve patency rate and limb salvage, particularly in patients with risk factors for early thrombosis. Bleeding is the main complication of long-term anticoagulant use. New oral anticoagulants can represent an attractive alternative to the standard vitamin K antagonists. The objective of the study is to evaluate the effectiveness (bypass occlusion and major amputation) and safety (major bleeding and all-cause mortality) of rivaroxaban compared to acenocumarol after infrainguinal lower limb surgical revascularization. MATERIAL AND METHODS: Retrospective cohort study of patients with peripheral arterial disease submitted to lower limb infrainguinal bypass revascularization with vein or expanded polytetrafluoroethylene conduit, who were anticoagulated with acenocumarol or rivaroxaban after hospital discharge. Patients with proximal revascularization, revascularization due to any pathology other than peripheral arterial disease, coagulation disorder, stroke or acute myocardial infarction in less than 30 days, glomerular filtration rate <15 mL/min, or on hemodialysis were excluded. RESULTS: One hundred nine patients were included (78.9% male), with a mean age of 64.8 years. After hospital discharge, 40 patients (36.7%) were medicated with rivaroxaban and 69 patients (63.3%) with acenocumarol. At 1 year of follow-up, patients under rivaroxaban and acenocumarol presented comparable major amputation rates (12.5 % vs. 10.1%, P = 0.756), bypass occlusion (22.5% vs. 24.6 %, P = 0.769), and mortality rate (10% vs. 8.7%, P = 0.756). Major bleeding occurred in 13.8% of patients. Patients with renal dysfunction had significantly higher bleeding risk with acenocumarol (45.5% vs. 0%, P = 0.028) compared to rivaroxaban, while patients with normal renal function presented similar bleeding rates with both anticoagulants (6.1% vs. 6.4%, P = 0.953). CONCLUSIONS: Rivaroxaban has equivalent effectiveness to acenocumarol after infrainguinal bypass revascularization, with similar occlusion, major amputation, and mortality rates. Rivaroxaban has an improved safety profile in patients with moderate renal dysfunction due to a significantly lower incidence of major bleeding. In patients with normal renal function, rivaroxaban and acenocumarol present equivalent major bleeding rates.

Estimated Effectiveness and Safety of Nonvitamin K Antagonist Oral Anticoagulants Compared With Optimally Acenocoumarol Anticoagulated "Real-World" in Patients With Atrial Fibrillation.

Nonvitamin K antagonist oral anticoagulants (NOACs) have been proposed as an alternative to vitamin K antagonists in atrial fibrillation (AF) patients but the comparative benefits between NOACs and optimally anticoagulated patients is unknown. We estimated the absolute benefit in clinical outcomes rates of real-world effect of NOACs in optimally anticoagulated AF patients with acenocoumarol. We included 1,361 patients stable on acenocoumarol with time in therapeutic range of 100% and 6.5 years of follow-up. Estimation of clinical events avoided was calculated applying hazard ratio, absolute and relative risk reduction from the real-world meta-analysis. Compared with an optimally anticoagulated population, dabigatran 110 mg had the highest estimated stroke reduction (0.97%/year vs 1.47%/year; p = 0.002), and the benefit was higher than in RE-LY trial. For major bleeding, apixaban showed the highest estimated reduction (1.81%/year vs 2.83%/year; p <0.001). For mortality, the largest estimated reduction was with apixaban (2.68%/year). For gastrointestinal bleeding, only apixaban had a significant reduction compared with acenocoumarol (0.69%/year vs 1.10%/year; p = 0.004), and the reduction was significantly higher than in ARISTOTLE trial. All NOACs showed significantly lower rates for intracranial hemorrhage and had a positive Net Clinical Benefit compared with acenocoumarol. Apixaban showed the highest extended estimated Net Clinical Benefit 2.64 (95%CI 2.34 to 2.96). In conclusion, in optimally acenocoumarol anticoagulated AF patients, estimated reductions in all clinical outcomes with various NOACs are evident, with the best effectiveness and safety profile with apixaban. Indeed, the estimated effect with "real world" NOACs would probably be higher than that seen in phase-III clinical trials.

Comparison of clinical characteristics of real-life atrial fibrillation patients treated with vitamin K antagonists, dabigatran, and rivaroxaban: results from the CRAFT study.

BACKGROUND: The first-line drugs for the treatment of non-valvular atrial fibrillation (AF) are non-vitamin K antagonist oral anticoagulants (NOACs), which are preferred over vitamin K antagonists (VKAs). There is some evidence that there are dis-crepancies between everyday clinical practice and the guidelines. AIM: The study aimed to compare the characteristics of patients on VKAs, dabigatran, and rivaroxaban in everyday practice (i.e. baseline characteristics, drug doses, risk factors for bleeding and thromboembolic events). Additionally, we assessed the frequency of prescription of different oral anticoagulants (OACs) in recent years. METHODS: This study consisted of data from the multicentre CRAFT (MultiCentre expeRience in AFib patients Treated with OAC) study (NCT02987062). This was a retrospective analysis of hospital records of AF patients (hospitalised in the years 2011-2016) treated with VKAs (acenocoumarol, warfarin) and NOACs (dabigatran, rivaroxaban). A total of 3528 patients with non-valvular AF were enrolled in the CRAFT study. RESULTS: The total cohort consisted of 1973 patients on VKA, 504 patients on dabigatran, and 1051 patients on rivaroxaban. Patients on rivaroxaban were older (70.5 ± 13.1 years) and more often female (47.9%), compared with those on VKAs (67.0 ± 12.8 years, p < 0.001; 35.5%, p < 0.001) and on dabigatran (66.0 ± 13.9 years, p < 0.001; 38.9%, p = 0.001). Among NOACs, patients with persistent and permanent AF were more likely to receive rivaroxaban (54.7% and 73.4%, re-spectively) than dabigatran (45.3%, p < 0.001 and 26.6%, p = 0.002, respectively). Patients on rivaroxaban had higher risk of thromboembolic events (CHA2DS2VASc 3.9 ± 2.0, CHADS2 2.2 ± 1.4) than those on VKAs (3.3 ± 2.0, 1.9 ± 1.3) and on dabigatran (3.1 ± 2.0, 1.8 ± 1.3). Patients on rivaroxaban had also a higher rate of prior major bleeding (11.2%) than those on VKAs (6.7%, p < 0.001) and on dabigatran (7.3%, p = 0.02). Patients on lower doses of dabigatran and rivaroxaban had a significantly higher risk of thromboembolic and bleeding events. Use of VKAs in the year 2011 was reported in over 96% of patients on OACs, but this proportion decreased to 34.6% in 2016. In the last analysed year (2016) AF patients were treated mainly with NOACs - dabigatran (24.2%) and rivaroxaban (41.3%). CONCLUSIONS: The prescription of VKAs declined significantly after the introduction of NOACs. Patients treated with different OACs demonstrated a distinct baseline clinical profile. The highest risk of thromboembolic events and incidence of major bleedings was observed in patients on rivaroxaban, in comparison to patients on VKAs and dabigatran. Among NOACs, patients treated with lower doses of dabigatran and rivaroxaban were older and had a significantly higher risk of thromboembolic and bleeding events.

[Appropriateness of the prescriptions of conventional versus new oral anticoagulants at discharge from a department of internal medicine]. / Pertinence des prescriptions d'anticoagulants oraux à la sortie d'un service de médecine interne d'un hôpital régional suisse.

BACKGROUND: The recently introduced oral direct anticoagulants (ODAs), presumably safer, and with comparable efficacy to the vitamin K antagonists (VKAs), may reshape the world of anticoagulation medicine. This study aimed to assess the prescription appropriateness of ODAs and VKAs at discharge from hospital. METHODS: We performed a one year retrospective study between August 2012 and July 2013 in the department of internal medicine of a regional hospital (HVs Sion) using Electronic Medical Records. All patients receiving an ODA were included and matched to a patient treated with a VKA. The appropriateness of prescription at discharge was defined by an adequate indication and dosing, the absence of contraindication, a minimal risk of drug-drug interactions and no major bleeding or venous thromboembolism during the hospitalization. The bleeding risk was evaluated with the HAS-BLED score when the indication was atrial fibrillation (AF). RESULTS: Out of the 44patients included (22 with an ODA and 22 with a VKA), 38 received an appropriate prescription according to all criteria. Two patients had an inadequate dosing. A potential drug-drug interaction was detected in 3patients receiving a VKA and in 1patient receiving an ODA. No major contraindication was found, but a relative contraindication was discussed in 3cases. The majority of patients receiving an ODA for an AF had a minor bleeding risk. CONCLUSION: No significant difference was ascertained between the two groups regarding the appropriateness of prescription. Our results suggest that ODAs were cautiously used in our setting.

Possible drug-drug interaction between high-dose esomeprazole and phenprocoumon.

PURPOSE: It is established that omeprazole increases (R)+ warfarin levels with around 10 %. Whether (es)omeprazole also increase the plasma levels of acenocoumarol or phenprocoumon is still uncertain. We analyzed whether addition of (es)omeprazole to acenocoumarol or phenprocoumon increases the international normalized ratio (INR) levels and the risk of overanticoagulation. METHODS: We analyzed all hospital admissions in four teaching hospitals. Patients who used coumarins and pantoprazole or (es)omeprazole simultaneously for at least four consecutive days were included in the study. We analyzed the highest INR level and whether patients had an INR level above six. We compared patients using omeprazole or esomeprazole with patients using pantoprazole, because for pantoprazole, no interaction has been reported. RESULTS: We analyzed 5747 admissions with 4540 patients using one of the drug combinations. For acenocoumarol (4578 admissions), no significant differences were found between users of esomeprazole, omeprazole, and pantoprazole. For phenprocoumon (1169 admissions), the highest INR measured was significantly higher in users of esomeprazole than in users of pantoprazole (4.7 versus 4.3; p = 0.035). No significant difference was found with omeprazole versus pantoprazole (4.3 versus 4.3; p = 0.66). A non-significant association was found between the esomeprazole dose and the highest INR level (p = 0.055). The risk of an INR above six did not differ significantly between esomeprazole and pantoprazole (27.7 % versus 22.9 %; p = 0.34). CONCLUSIONS: The use of esomeprazole simultaneously with phenprocoumon during hospital admissions might increase the anticoagulant effect. The clinical relevance seems to be limited, because no statistically significant increased risk of overanticoagulation was found.

Management of anticoagulation in patients with acute gastrointestinal bleeding.

Acute gastrointestinal bleeding represents the most common adverse event associated with the use of oral anticoagulant therapy. Due to increasing prescription of anticoagulants worldwide, gastroenterologists are more and more called to deal with bleeding patients taking these medications. Their management is challenging because several issues have to be taken into account, such as the severity of bleeding, the intensity of anticoagulation, the patient's thrombotic risk and endoscopy findings. The recent introduction into the marketplace of new direct oral anticoagulants, for whom specific reversal agents are still lacking, further contributes to make the decision-making process even more demanding. Available evidence on this topic is limited and practice guidelines by gastroenterology societies only marginally address key issues for clinicians, including when and how to reverse coagulopathy, the optimal timing of endoscopy and when and how to resume anticoagulation thereafter. The present paper reviews the evidence in the literature and provides practical algorithms to support clinicians in the management of patients on anticoagulants who present with acute gastrointestinal bleeding.

DRESS syndrome induced by acenocoumarol with tolerance to warfarin and dabigatran: a case report.

Drug reaction with eosinophlia and systemic symptoms (DRESS) syndrome describes a severe medication-induced adverse reaction, which shows skin, blood and solid-organ features. Up to 50 drugs have been described to cause DRESS. The main responsible drugs are carbamazepine and allopurinol. There are no previous reports associated with acenocoumarol. A 85-year-old white male, who was treated with acenocoumarol for the prevention of venous thromboembolism due to atrial fibrillation, presented 6 weeks later a maculopapular exanthema of the trunk and limbs as well as purple lesions and blisters on distal parts of his legs. Elevated creatinine, glucose, urea, International Normalized Ratio, gamma-glutamyl-transpeptidase (GGT) and eosinophilia levels were observed. Acenocoumarol was removed and enoxaparine, systemic corticosteroids, antihistamines were used as treatment with a favorable clinical evolution: 1 month later, the skin lesions had disappeared and laboratory parameters were normalized. Patch tests with warfarin and dabigatran were carried out. Two simple-blind, placebo-controlled oral challenges with warfarin and dabigatran were performed. Patch tests were negative, and single-blind, placebo-controlled oral challenges with warfarin and dabigatran were achieved without immediate or delayed reactions. We firstly describe a DRESS syndrome induced by acenocoumarol. Patch test was useful to assess alternative therapies. Tolerance to other anticoagulants (warfarin and dabigatran) was demonstrated.

Maintenance of anticoagulant and antiplatelet agents for patients undergoing peribulbar anesthesia and vitreoretinal surgery.

PURPOSE: To establish the prevalence of anticoagulation (vitamin K antagonists) and antiplatelet agent therapy in patients undergoing vitreoretinal surgery and to compare the outcome of peribulbar anesthesia and vitreoretinal surgery between users and nonusers. METHODS: We conducted a retrospective case series study in one academic center. No changes in the treatment regimen were made before surgery. Patients were divided into 3 groups: G1, patients with no anticoagulant or antiplatelet therapy; G2, patients treated with anticoagulants; and G3, patients treated with aspirin, clopidogrel, or both. RESULTS: Two hundred and six eyes (206 patients) were included. G1, 144 eyes (69.9%) without any anticoagulant or antiplatelet therapy (69.9%); G2, 12 eyes (5.8%) with anticoagulants; and G3, 44 eyes (21.4%) with antiplatelet agents. Six patients (6 eyes) (2.9%) received both anticoagulant and antiplatelet agents. The incidence of overall and mild postoperative hemorrhagic complications was similar between groups, P = 0.075 and P = 0.127, respectively. However, potential sight-threatening hemorrhagic complications were more frequent in patients receiving antiplatelet agents, P < 0.003. CONCLUSION: Peribulbar anesthesia for vitreoretinal surgery can probably be performed safely in patients receiving anticoagulants. However, retinal surgeons should be aware that severe bleeding complications are more frequent in patients receiving antiplatelet therapy.

Oral rivaroxaban for symptomatic venous thromboembolism.

BACKGROUND: Rivaroxaban, an oral factor Xa inhibitor, may provide a simple, fixed-dose regimen for treating acute deep-vein thrombosis (DVT) and for continued treatment, without the need for laboratory monitoring. METHODS: We conducted an open-label, randomized, event-driven, noninferiority study that compared oral rivaroxaban alone (15 mg twice daily for 3 weeks, followed by 20 mg once daily) with subcutaneous enoxaparin followed by a vitamin K antagonist (either warfarin or acenocoumarol) for 3, 6, or 12 months in patients with acute, symptomatic DVT. In parallel, we carried out a double-blind, randomized, event-driven superiority study that compared rivaroxaban alone (20 mg once daily) with placebo for an additional 6 or 12 months in patients who had completed 6 to 12 months of treatment for venous thromboembolism. The primary efficacy outcome for both studies was recurrent venous thromboembolism. The principal safety outcome was major bleeding or clinically relevant nonmajor bleeding in the initial-treatment study and major bleeding in the continued-treatment study. RESULTS: The study of rivaroxaban for acute DVT included 3449 patients: 1731 given rivaroxaban and 1718 given enoxaparin plus a vitamin K antagonist. Rivaroxaban had noninferior efficacy with respect to the primary outcome (36 events [2.1%], vs. 51 events with enoxaparin-vitamin K antagonist [3.0%]; hazard ratio, 0.68; 95% confidence interval [CI], 0.44 to 1.04; P<0.001). The principal safety outcome occurred in 8.1% of the patients in each group. In the continued-treatment study, which included 602 patients in the rivaroxaban group and 594 in the placebo group, rivaroxaban had superior efficacy (8 events [1.3%], vs. 42 with placebo [7.1%]; hazard ratio, 0.18; 95% CI, 0.09 to 0.39; P<0.001). Four patients in the rivaroxaban group had nonfatal major bleeding (0.7%), versus none in the placebo group (P=0.11). CONCLUSIONS: Rivaroxaban offers a simple, single-drug approach to the short-term and continued treatment of venous thrombosis that may improve the benefit-to-risk profile of anticoagulation. (Funded by Bayer Schering Pharma and Ortho-McNeil; ClinicalTrials.gov numbers, NCT00440193 and NCT00439725.).

[The c.-1639g > A polymorphism of the VKORC1 gene and his influence on the therapeutic response during oral anticoagulants use].

BACKGROUND/AIM: A single nucleotide polymorphism c.-1639G > A in the promoter region of vitamin K-epoxide reductase (VKORC1) gene has been found to account for most of the variability in response to oral anticoagulants (OA). The aim of the study was to determine the incidence and the effect of c.-1639G > A polymorphism on the acenocoumarol dosage requirements in the group of patients under stable anticoagulation, and to estimate the variability in response to OA. METHODS: Our study included 200 consecutive patients requiring low (n = 43), medium (n = 127) and high (n = 30) acenocoumarol dose. RESULTS: Out of 43 low dose patients, 40 (93%) carried the A allele. The A allele was less frequent in the group of 30 patients requiring high dose: among these patients 13 (43.3%) carried the A allele in the heterozygous form and none of them carried AA genotype. The patients with GG genotype required 2.6 times higher dose than the patients carriers of AA genotype (p < 0.0001). In 33 patients (16.5%) the overdose occurred during the initiation of anticoagulant therapy and in 11 patients (5.5%) it was associated with bleeding. Out of the group of 33 overdosed patients, 27 and 6 patients carried AA and GA genotype, respectively (p < 0.000001). CONCLUSION: VKORC1 significantly influenced OA dose and predicted individuals predisposed to unstable anticoagulation. The carriers of AA genotype required 2.6 time lower doses of OA than the carriares of GG genotype. Pharmacogenetic testing could predict a high risk of overdose among 28.5% of our patients--carriers of AA genotype, before anticoagulation therapy initiation.

[Knowledge of patients undergoing long-term acenocumarol treatment about the safety of anticoagulant therapy]. / Wiedza o zasadach bezpiecznego stosowania doustnych antykoagulantów u chorych leczonych przewlekle acenokumarolem.

UNLABELLED: Oral anticoagulation with coumarin derivatives (OAC) has been used for more than 50 years and is being prescribed to a steadily increasing number of patients as a long-term therapy. The aim of our study was to evaluate patients' knowledge about the safety of acenocumarol treatment, the therapeutic range of International Normalized Ratio (INR) and its interactions with other medications and food. MATERIAL AND METHODS: One hundred and forty patients on long-term acenocumarol treatment were included in the study. They were interviewed using a questionnaire specifically prepared by the authors. The questions concerned their understanding of the reasons for the treatment, knowledge of target INR ratio, frequency of INR examination. Additionally the questionnaire contained questions specifically designed to check the patients' knowledge about factors influencing INR values e.g. drugs, food, alcohol and the like. RESULTS: One hundred and fifteen (82.1%) patients declared knowledge of target INR ratio, but only eighty eight (62.9%) answered correctly. Percentages of correct answers for the questions evaluating knowledge about acenocumarol treatment did not exceed 50%. Patients' responses suggested that advice was not always provided by doctors. CONCLUSIONS: Level of patients' knowledge about the safety of OAC treatment was very low. Insufficient knowledge was observed particularly in patients with lower education levels and those over 60 years of age. Those groups require a special attention and longer education to be able to self-manage the treatment. Special anticoagulant clinics do not exist in Poland. So, it seems very appropriate to develop concise guidelines available for patients in practices of family doctors. Education should be systematic and modified according to changing recommendations.