Asymptomatic and symptomatic deep venous thrombosis in hospitalized acutely ill medical patients: risk factors and therapeutic implications.

BACKGROUND: Acutely ill medical patients experience deep venous thrombosis (DVT) during the hospitalization, however the time course of DVT is still unclear. OBJECTIVES: To evaluate risk factors in acutely ill hospitalized medical patients for proximal asymptomatic DVT (ADVT) and symptomatic DVT (SDVT) at admission and discharge. PATIENTS/METHODS: In this prospective observational study, consecutive acutely ill medical patients (hospitalized mainly for acute medical disease as infections, neoplasm, anemia, heart failure) underwent compression ultrasonography (CUS) of proximal lower limb veins within 48 h from admission and at discharge to diagnose ADVT and SDVT. Covid-19 patients, anticoagulant therapy, surgical procedures, acute SDVT, and acute pulmonary embolism, were exclusion criteria. Biographical characteristics at hospitalization, D-Dimer (assessed by ELISA)) and DD-improve score. RESULTS: Of 2,100 patients (1002 females, 998 males, age 71 ± 16 years) 58 (2.7%) had proximal ADVT at admission. Logistic regression analysis showed that age, and active cancer were independently associated with ADVT at admission. The median length of hospitalization was 10 days [interquartile range: 6-15]. During the hospital stay, 6 patients (0.3%) with a negative CUS at admission experienced DVT (2 SDVT and 4 ADVT). In the subgroup of patients (n = 1118), in whom D-dimer was measured at admission, D-Dimer and IMPROVE-DD score were associated with ADVT at admission (n = 37) and with all DVT (n = 42) at discharge. ROC curve defined an IMPROVE-DD score of 2.5 as the optimal cut-off for discriminating patients with and without thrombotic events. CONCLUSIONS: We provide evidence of early development of ADVT in unselected acutely ill medical patients suggesting the need of investigating patients by CUS immediately after hospital admission (within 48 h). Advanced age, active cancer, known thrombophilia and increased IMPROVE-DD score may identify patients at risk. The benefit of anticoagulation needs to be investigated in patients with these specific risk factors and negative CUS at admission. TRIAL REGISTRATION: NCT03157843.

COVID-19: progression of disease and intravascular coagulation - present status and future perspectives.

The timely and accurate diagnosis of infection with severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), remains the cornerstone of efforts to provide appropriated treatment for patients, to limit further spread of the virus and ultimately to eliminate the virus from the human society. We focus this article on (a) developments for improvement of diagnosis of specific SARS-CoV-2 virus, (b) laboratory changes in the immunologic and coagulation system, (c) therapeutic options for anticoagulant treatment of seriously affected patients and (d) on the perspectives through improvement of diagnostic and therapeutic medical procedures.

Detecting Anti-IIa and Anti-Xa Direct Oral Anticoagulant (DOAC) Agents in Urine using a DOAC Dipstick.

The assessment of the anticoagulant effect of direct oral anticoagulants (DOACs) can be important for rapid medical decision-making, especially in patients needing immediate management. An assay that screens for the absence or presence of a DOAC would help accelerate treatment in these situations. Chromogenic and coagulation methods have several limitations, including limited accuracy, long turnaround time, and their need of specialized laboratories. Oral factor Xa and thrombin inhibitors are also eliminated by the kidneys and can be detected in patient urine samples using a single, rapid, sensitive, and patient-specific qualitative assay. In these tests, the presence or absence of a DOAC in urine can be identified by visually observing specific colors after a few minutes. Several studies have demonstrated the robustness and repeatability of these assays. The specific colors of the test strip also detect creatinine in the urine, which shows whether DOAC excretion is reduced, thus suggesting renal impairment. Persons with amblyopia may use a specific reader. Current indications for using the DOAC Dipstick test include emergency medical situations with severe bleeding and thrombotic events or before urgent major surgical interventions to accelerate medical decision-making.

Measurement of dabigatran, rivaroxaban and apixaban in samples of plasma, serum and urine, under real life conditions. An international study.

BACKGROUND: The utility of measuring non-vitamin K antagonist oral anticoagulants (NOACs) in plasma, serum and urine samples and with the point-of-care test (POCT) on urine samples should be analysed in an international laboratory study. METHODS: The study was performed to determine the inter-laboratory variance of data from two chromogenic assays each for the NOACs rivaroxaban, apixaban and dabigatran, and to analyse the sensitivity and specificity of the POCT assays for factor Xa- and thrombin inhibitors. Plasma, serum and urine samples were taken from six patients in each group on treatment with a NOAC. RESULTS: The inter-laboratory variances, which can be identified best by the coefficient of variation, ranged from 46% to 59% for apixaban, 63% to 73% for rivaroxaban and 39% to 104% for dabigatran using plasma, serum or urine samples and two chromogenic assays for each NOAC. The concentrations were about 20% higher in serum compared to plasma samples for apixaban and rivaroxaban, and 60% lower for dabigatran. The concentration in urine samples was five-fold (apixaban), 15-fold (rivaroxaban) and 50-fold (dabigatran) higher. Sensitivity and specificity of POCT for apixaban, rivaroxaban, and dabigatran were all >94%. CONCLUSIONS: The inter-laboratory study showed the feasibility of measurement of apixaban, rivaroxaban, and dabigatran in plasma, serum and urine samples of patients on treatment. Dabigatran was determined at far lower levels in serum compared to plasma samples. Concentrations of NOACs in urine were much higher compared to plasma. The POCT was highly sensitive and specific for all three NOACs.

Arterial and venous thrombosis following trauma and major orthopedic surgery: molecular mechanisms and strategies for intervention.

A variety of harmful effects can be triggered by trauma and major orthopedic surgery. One of the key players involved in this process is thrombin. The clinical consequence of this process has, for several decades, been considered to be formation of deep vein thrombosis and pulmonary embolism. Controlling thrombin generation and activation has therefore been the goal of thromboprophylaxis regimens administered to patients suffering from trauma or undergoing major surgery. Protecting patients from venous thromboembolism has, for many years, been the main goal of preventive strategies. However, our knowledge of cell destruction and release of substances that may cause organ damage has expanded in recent years. Release of molecules such as RNA and histones from destroyed tissues may cause cell destruction and organ damage at distal sites if released in huge amounts and disseminated systemically. This new knowledge points toward an unmet need for therapies that prevent both vascular events and organ deterioration. This article briefly reviews molecular mechanisms associated with the occurrence of vascular events and cellular destruction in patients with major bone damage caused by trauma.

Next generation antithrombotic therapy: focus on antisense therapy against coagulation factor XI.

Although the current therapeutic armamentarium of venous thrombosis encompasses the use of vitamin K antagonists, heparins, and direct oral anticoagulants, these drugs have several important drawbacks. Antisense oligonucleotides are relatively short single-stranded nucleic acid sequences, which hybridize with a target messenger RNA (mRNA) and suppress protein synthesis. Coagulation factor XI is a key player in blood coagulation, and thus represents a potential target for antisense therapy. The available evidence reviewed in this article suggests that factor XI antisense oligonucleotides may be more effective than conventional anticoagulants in preventing the onset and propagation of thrombosis, do not require factor measurement since the reduction of mRNA synthesis appears dose-dependently, robustly, and stably decreased for 3 to 5 weeks after the end of administration, with an incidence of major bleeding that is at least not greater than that associated with warfarin or low-molecular-weight heparin therapy. Despite conceptual simplicity, rational design, and relatively inexpensive cost, the preliminary findings in animal models and in patients undergoing knee surgery need to be validated in other prospective trials and cost-effective analyses before this attractive treatment option can be advocated as a new paradigm in prevention and treatment of venous thrombosis.

Patients' serum and urine as easily accessible samples for the measurement of non-vitamin K antagonist oral anticoagulants.

Measurement of the anticoagulant effect of non-vitamin K antagonist oral anticoagulants (NOAC) may be desirable, in particular in patients with acute medical conditions. Useful methods should give results rapidly within minutes, should be easy to perform, specific, and sensitive. Using plasma samples, chromogenic assays can be made to be specific for the two types of NOAC (factor Xa and thrombin inhibitors), and also hemoclot and ecarin clotting time specific for dabigatran. If plasma samples anticoagulated with sodium citrate are not available, blood samples anticoagulated with ethylene diamine tetraacetic acid or serum samples may be regarded as alternatives for the determination of NOAC. At present, dabigatran cannot be determined from serum samples because it may be consumed during the clotting process to obtain serum. NOAC can be determined in urine samples due to their renal elimination. Quantitative methods are preferable to qualitative methods, although the latter may be advantageous in some situations, being developed as point-of-care tests for oral factor Xa and thrombin inhibitors. In these tests, the presence and absence of NOAC in urine can be identified with the naked eye after a few minutes and these tests are highly specific and sensitive. New assays such as a semiquantitative determination in urine samples and measurement using other sample matrices are currently under development.

Development of recommendations to continue anticoagulation with one of the two types of oral anticoagulants based on the identification of patients' preference.

Patients with indication for anticoagulation may prefer treatment with a vitamin K antagonist (VKA) or non-vitamin K antagonist oral anticoagulant (NOAC). A questionnaire may help to identify the preference of patients for one of the two types of oral anticoagulants and to develop a score for the recommendation to continue or to change the anticoagulant. A score was developed using a questionnaire containing biographic data and eight statements on attitudes on anticoagulation and was derived to trigger continuation or change the type of anticoagulant by defining ranges of terms and weighting of the significant statements identified by logistic regression analysis. Participating patients received either anticoagulation with VKA (group 1, n = 690), were transferred from VKA to NOAC (group 2, n = 158), received NOAC de novo (group 3, n = 137) or were transferred from NOAC to VKA (group 4, n = 19). Four statements were significantly (p values between 0.0347 and < 0.0001) associated with recommendations to maintain or to change the type of anticoagulant for patients in groups 1, 2, or 3 with predictive values of c = 0.83 between groups 1 and 2 and c = 0.71 between groups 1 and 3. From the total number of replies to the statements a score of three grades and two strengths (A = strong, B = moderate) was derived for the recommendations. This tool supports recommendations as to continue or to change the presently used type of oral anticoagulant based on the identification of patients' preferences.

The impact of residual thrombosis on the long-term outcome of patients with deep venous thrombosis treated with conventional anticoagulation.

The impact of residual vein thrombosis (RVT) on the long-term outcome of patients with deep vein thrombosis (DVT) is unknown. We assessed the incidence of recurrent venous thromboembolism (VTE), postthrombotic syndrome (PTS), arterial thrombotic events, and cancer in patients with DVT with and without RVT. For this purpose, we evaluated up to 3 years 869 consecutive patients with acute proximal DVT who had conventional anticoagulation. RVT, defined as ultrasound incompressibility of at least 4 mm in the common femoral and/or the popliteal vein after 3 months, was detected in 429 (49.4%) patients, and was more likely in males (adjusted odds ratio [OR], 1.82; 95% confidence interval [CI], 1.37-2.04), in patients with previous VTE (OR, 1.64; 95% CI, 1.06-2.54), and in those with extensive thrombosis (OR, 3.58; 95% CI, 2.19-5.86). During the 3-year follow-up, recurrent VTE developed in 84 (19.6%) patients with RVT and 43 (9.8%) patients without RVT (adjusted hazard ratio [HR], 2.03; 95% CI, 1.40-2.94); PTS in 225 (52.4%) and 118 (26.8%), respectively (HR, 2.34; 95% CI, 1.87-2.93); arterial thrombosis in 29 (6.7%) and 14 (3.2%), respectively (HR, 2.05; 95% CI, 1.08-3.88); and cancer in 21 (4.9%) and 8 (1.8%), respectively (HR, 3.09; 95% CI, 1.31-7.28). In conclusion, in patients treated with vitamin K antagonists for prevention of recurrent VTE, RVT doubles the risk of recurrent VTE, PTS, arterial thrombosis, and cancer. Males, patients with previous VTE, and those with extensive thrombosis are independent risk factors of RVT development. Studies addressing the impact of the novel direct anticoagulants on the development of RVT as well as the long-term complications of DVT are needed.

Measurement of Non-Vitamin K Antagonist Oral Anticoagulants in Patient Plasma Using Heptest-STAT Coagulation Method.

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) are approved for several indications for prophylaxis of thromboembolism at fixed oral doses. The analysis of NOAC activity/concentration may be required in special patient populations. Heptest coagulation assay determines both factor Xa and thrombin inhibitors. The objective of investigations is to analyze the effects of both groups of NOACs on this assay. METHODS: The performance of a modified Heptest-STAT clotting assay was compared with specific chromogenic substrate assays for factor Xa (Coamatic, HemosIL) and thrombin (direct thrombin inhibitor assay and S2238 chromogenic assays) for the determination of rivaroxaban, apixaban, and dabigatran in plasma from patients on treatment. RESULTS: For rivaroxaban (n = 74), the concentrations (mean and SD) of Heptest-STAT versus Coamatic and HemosIL assays were 179.3 ± 85.8 ng/mL versus 199.3 ± 105.7 ng/mL and 212.4 ± 115.9 ng/mL (P < 0.0001), and for apixaban (n = 26) 232.8 ± 10.0 ng/mL versus 178.4 ± 64.4 ng/mL (P < 0.0001) and 182.1 ± 73.1 ng/mL (P = 0.0002). For dabigatran (n = 74), the values of Heptest-STAT were 92.3 ± 65.0 ng/mL versus 124.3 ± 85.6 ng/mL (direct thrombin inhibitor assay, P < 0.0001) and 107.5 ± 59.7 ng/mL (S2238 assay, P = 0.0015), respectively. The values of the intraclass coefficient of correlation ranged from 0.64 to 0.91 (Bland-Altman analysis). CONCLUSIONS: The objective of the study was achieved by demonstrating a high correlation of the Heptest-STAT coagulation assay with chromogenic assays for factor Xa inhibiting NOACs and acceptably good correlation with thrombin inhibiting NOACs in plasma samples of patients on treatment.

Determination of dabigatran in plasma, serum, and urine samples: comparison of six methods.

BACKGROUND: Assessing the anticoagulant effect of dabigatran may be useful in certain clinical settings. When plasma sampling is not available, serum or urine samples may provide another option for dabigatran determinations. METHODS: Dabigatran was assessed in patients on treatment under real-life conditions in plasma samples by four clotting time-based assays and in plasma, serum, and urine samples by two chromogenic substrate methods. RESULTS: The concentrations of dabigatran in patients' plasma samples were not different for the Hemoclot test (106.8±89.4 ng/mL) and the ecarin clotting time (ECT, 109.5±74.5 ng/mL, p=0.58). Activated partial thromboplastin time and prothrombinase-induced clotting time showed low correlations with the other assays. Chromogenic assays measured similar concentrations as Hemoclot and ECT. For both chromogenic assays, the concentrations of dabigatran were about 70% lower in serum than in plasma samples (p<0.0001). The intra-class coefficient (ICC, Bland-Altman analysis) was strong comparing ECT, Hemoclot thrombin inhibitor (HTI) assay, and the two chromogenic assays (r=0.889-0.737). The ICC was low for comparisons of the chromogenic assays of serum vs. plasma values (ICC, 0.15 and 0.66). The ICC for the determination of dabigatran in urine samples by the two chromogenic assays (5641.6±4319.7 and 4730.0±3770.2 ng/mL) was 0.737. CONCLUSIONS: ECT, HTI, and chromogenic assays can be used to determine dabigatran in plasma samples from patients under real-life conditions. Chromogenic assays require further improvement to reliably measure dabigatran in serum samples. Dabigatran concentrations in urine samples can also be determined quantitatively.

Pharmacokinetics of Certoparin During In Vitro and In Vivo Dialysis.

The efficacy and safety of certoparin in the prophylaxis of clotting during hemodialysis have recently been proven. Different to other low-molecular weight heparins (LMWHs), certoparin does not accumulate in maintenance dialysis patients for unknown reasons. The purpose of the present study was to examine the impact of the dialysis procedure on the removal of certoparin. In a subgroup of the MEMBRANE study consisting of 12 patients, the pharmacokinetics of certoparin during hemodialysis was determined by means of the anti-Xa activity. In addition, the elimination of certoparin into continuously collected dialysate was assessed. Further, in vitro experiments with human blood-simulating high-flux hemodialysis and hemofiltration were performed to quantify the elimination and the sieving coefficients SK of the two LMWHs certoparin and enoxaparin compared with unfractionated heparin (UFH). The surrogate marker middle molecules inulin and myoglobin served as reference solutes during the experiments. Finally, the adsorption of (125) iodine-radiolabeled certoparin onto the synthetic dialysis membrane was quantified. The clinical study reconfirmed the absence of bioaccumulation of certoparin with anti-Xa activities between <0.01 and 0.02 IU/mL after 24 h. A short plasma half-life time of 2.0 ± 0.7 h was determined during hemodialysis. Of the total certoparin dose injected intravenously prior to hemodialysis, only 2.7% was eliminated into dialysate. The in vitro experiments further revealed only 6% of certoparin to be adsorbed onto the dialysis membrane. The anti-Xa activities of certoparin and enoxaparin slowly declined during in vitro hemofiltration to 87.3 ± 5.5 and 82.5 ± 9.4% of baseline, respectively, while inulin and myoglobin concentrations rapidly decreased. The anti-Xa activity of UFH remained unchanged. The SK of both LMWH and UFH was very low in hemofiltration and particularly in hemodialysis with values ≤0.1. The elimination kinetics during hemodialysis suggests strong protein-binding of certoparin. Different from LMWH significantly cleared by the kidneys, the relatively short half-life time of certoparin of only 2 h during hemodialysis allows a more reliable control of the anti-coagulatory effects and decreases the risk of bleeding complications. Dialytic removal does not significantly contribute to the clearance of certoparin in maintenance dialysis patients.

Development of a tool to identify patients' preference for vitamin K antagonist or direct oral anticoagulant therapy.

Direct oral anticoagulants (DOACs) were developed for the treatment of thromboembolic diseases to overcome limitations of vitamin K antagonists (VKA). International guidelines on atrial fibrillation acknowledge patients' for antiembolic therapy with VKA or DOAC as relevant decision criteria. The objective assessment of patients' preference social interactions and psychological factors are hard to measure albeit representing important contributors. After a series of structured interviews and pilot studies assessing the preparedness to use DOAC as an anticoagulant and the motivation of patients to participate in clinical studies with DOAC, seven items were identified from several questionnaires by regression analysis. Those items were seen the best to describe the willingness to change anticoagulation from VKA to DOAC. By their use, we aim to develop a tool for the objective identification of the patients' preferences for VKA or for DOAC to increase adherence to therapy and to reduce anticoagulant undertreatment. German-speaking patients were asked to fill out a questionnaire consisting of biographic data and the seven selected items, and 180 patients completed the questionnaire so far. Of these, 90 patients were on treatment with VKA (group 1), 57 patients changed anticoagulation from VKA to DOAC (group 2), 29 patients were DOAC naive patients (group 3), and 4 patients changed from DOAC to VKA (group 4). Overall, 94 patients received VKA, 29 patients received dabigatran, 50 patients received rivaroxaban, and 7 patients received apixaban as an anticoagulant. Eight patients were younger than 40 years, 35 patients were aged between 40 and 59 years, 53 patients were aged between 60 and 70 years, and 84 patients were aged older than 70 years. Indication for anticoagulation were atrial fibrillation (n = 106), pulmonary embolism (n = 24), deep vein thrombosis (n = 40), artificial heart valve replacement (n = 8), or other diseases (n = 2). Based on the results of the analysis, a score will be suggested to identify the preference of patients for anticoagulation with VKA or DOAC. This tool may be useful for practitioners and health-care professionals to support patient adherence to therapy, and thereby increase treatment effectiveness.

Glycosaminoglycans: anticoagulant and nonanticoagulant actions: a short history of symposia held at villa vigoni.

Heparin, a sulfated polysaccharide belonging to the family of glycosaminoglycans, was discovered in the beginning of the 20th century and was initially identified as a procoagulant isolated from liver tissue. After the first application in patients approximately 30 years later, further purification identified the major as well as minor, but important, component units of the complex chain mixtures constituting heparin and the multiplex actions became a scientific challenge recently. A series of "Glycosaminoglycan symposium-anticoagulant and nonanticoagulant actions" developed over the past 20 years and focused on this topic has published research data in three issues of Seminars in Thrombosis & Hemostasis and in several other international scientific journals. The latest developments on the methods of analysis, the synthesis, the degradation by heparanases and the nonanticoagulant effects in tumor growth, in anti-inflammatory diseases, and in Alzheimer diseases as presented in the 21st symposium are summarized in the present overview on the occasion of the 40th anniversary of the journal with special reference to the journal's founding Editor in Chief, Eberhard F. Mammen.

Determination of direct oral anticoagulants from human serum samples.

Dabigatran, rivaroxaban, and apixaban are direct oral anticoagulants (DOAC) inhibiting thrombin or factor Xa and effectively preventing thromboembolic complications using fixed doses without need for laboratory-guided dose adjustment. Plasma samples are needed to determine the actual concentration or activity of DOACs, which may be required for special patient populations such as those with acute deterioration of renal function due to any disease, before surgical interventions, during bleeding or thrombotic episodes while on therapy with DOACs, the elderly and youngest populations, unexpected pregnancy, suspicion of overdose and toxication, and to control adherence to therapy. Serum samples have several advantages over plasma samples such as no need of sampling with a specific coagulation tube, reduced pre-analytical errors, and longer storage stability. Determination of rivaroxaban and apixaban from serum samples of patients on treatment performed well and better than samples of patients treated with dabigatran compared with plasma samples. Specific adaption to automated coagulation platforms may improve the performance of the assays from serum samples.

Measurement of rivaroxaban and apixaban in serum samples of patients.

BACKGROUND: The determination of rivaroxaban and apixaban from serum samples of patients may be beneficial in specific clinical situations when additional blood sampling for plasma and thus the determination of factor Xa activity is not feasible or results are not plausible. MATERIALS AND METHODS: The primary aim of this study was to compare the concentrations of rivaroxaban and apixaban in serum with those measured in plasma. Secondary aims were the performance of three different chromogenic methods and concentrations in patients on treatment with rivaroxaban 10 mg od (n = 124) or 20 mg od (n = 94) or apixaban 5 mg bid (n = 52) measured at different time. RESULTS: Concentrations of rivaroxaban and apixaban in serum were about 20-25% higher compared with plasma samples with a high correlation (r = 0·79775-0·94662) using all assays (all P < 0·0001). The intraclass correlation coefficients were about 0·90 for rivaroxaban and 0·55 for apixaban. Mean rivaroxaban concentrations were higher at 2 and 3 h compared with 1 and 12 h after administration measured from plasma and serum samples (all P-values < 0·05) and were not different between 1 vs. 12 h (plasma and serum). CONCLUSIONS: The results indicate that rivaroxaban and apixaban concentrations can be determined specifically from serum samples.

Global coagulation tests: their applicability for measuring direct factor Xa- and thrombin inhibition and reversal of anticoagulation by prothrombin complex concentrate.

BACKGROUND: Specific mass spectrometry and direct activated factor X (Xa)- and thrombin inhibition assays do not allow determination of the reversal of anticoagulant effects of non-vitamin K direct oral anticoagulants (NOACs) by prothrombin complex concentrate (PCC). The objective of this study was the evaluation of the applicability of a variety of commercially available global coagulation assays in analyzing the reversal of NOAC anticoagulation by PCC. METHODS: Plasma and whole blood were spiked with apixaban or dabigatran and PCC was added to these samples. Prothrombin time (PT), modified PT (mPT), activated partial prothrombin time (APTT), thrombography (CAT method) and thromboelastography (ROTEM, TEG) were performed. RESULTS: Assays triggered by contact activation (APTT, INTEM) did not show inhibitor reversal by PCC. Assays triggered by tissue factor (TF) showed NOAC type and NOAC concentration dependent anticoagulation reversal effects of PCC ranging from partial normalization to overcorrection of the following parameters: clotting or reaction time (PT, mPT TEG-TF, EXTEM, FIBTEM); angle in thromboelastography (TEG-TF); thrombin generation (CAT) lag time, endogenous thrombin potential (ETP) and peak thrombin. Extent of reversal was assay reagent dependent. ETP (5 pM TF) was the only parameter showing complete reversal of anticoagulation by PCC for all NOACs ranging from 200 to 800 µg/L. CONCLUSIONS: ETP fits with the concept that reversal assessment of NOAC anticoagulation by PCC should be based on measurements on the clotting potential or thrombin generating potential of the plasma or whole blood patient sample. Low sensitivity of ETP for NOACs and its correlation with bleeding are issues that remain to be resolved.

Comparison of cost-effectiveness of anticoagulation with dabigatran, rivaroxaban and apixaban in patients with non-valvular atrial fibrillation across countries.

We did a cost-utility analysis for the new oral anticoagulants (NOACs) in the German population based on the quality-adjusted life years (QALY), total costs, and incremental cost-effectiveness ratios (ICER). The aim of our investigation was to examine cost-utility for current German drug market costs and compared to other countries. Outcome data were taken from dabigatran's RE-LY, rivaroxaban's ROCKET AF, and apixaban's ARISTOTLE trials. A Markov decision model, the Monte Carlo simulation (MCS), and further sensitivity analyses were used to simulate comparisons between NOACs over a follow up period of 20 years. The main perspective used for the analyses is from a German public health care insurance perspective. The base-case analyses of a 65 years old person with a CHADS2 score >1 resulted in 7.56-7.64 QALYs gained for warfarin. NOACs added 0.04-0.19 QALYs. Total costs for warfarin ranged from 7622 to 9069 and for NOACs from 19537 to 20048. The sensitivity analysis indicated that current German market costs for the NOACs exceed a willingness-to-pay threshold of (hypothetical) 50000/QALY in all treatment regimen. The MCS showed willingness-to-pay thresholds from 60500/QALY for apixaban to 278000/QALY for dabigatran 110 mg bid, with values for dabigatran 150 mg bid and rivaroxaban in between. In conclusion, from a German public health care insurance perspective current market costs are high in relation to the quality of life gained. These results from clinical studies (efficacy) remain to be confirmed under real life conditions (effectiveness).