Dabigatran Reversal With Idarucizumab in Patients Requiring Urgent Surgery: A Subanalysis of the RE-VERSE AD Study.

OBJECTIVE: To further examine anticoagulation reversal and clinical outcomes in dabigatran treated patients requiring urgent surgery or procedural interventions. BACKGROUND: Idarucizumab, a humanized monoclonal antibody fragment, reverses dabigatran anticoagulation. METHODS: Data from surgical and procedural patients in RE-VERSE AD, a multicenter, open-label, single-arm, prospective cohort of dabigatran reversal were evaluated. A total of 202 patients in this group received 5 g of idarucizumab before surgery or procedures. RESULTS: The interventions included 49 abdominal, 45 orthopedic, 34 vascular, 8 neurologic, and 4 genitourinary surgical procedures, or 29 catheter-based cases, 20 cases for drainage, and 8 diagnostic procedures. Five patients did not undergo their intended intervention after receiving idarucizumab. Complete reversal of the dabigatran anticoagulant effect occurred within minutes in almost all patients, with normal hemostasis in more than 91% of patients. The median time from the first vial of idarucizumab to surgery or procedures was less than 2 hours in all groups except neurosurgery, where it was 3.3 hours. Fresh frozen plasma and packed red cells were the most frequently transfused blood products. Postreversal thromboembolic events occurred in 10 (5%) patients at 30 days, 5 of whom had restarted anticoagulation before the event. Overall 30-day mortality was 12.6%. There were no serious adverse safety signals due to idarucizumab dosing. CONCLUSIONS: Idarucizumab facilitates management of patients requiring urgent procedures by providing rapid dabigatran reversal, and is the only agent of its class studied in surgical patients.

Profile of Patients Diagnosed With Acute Venous Thromboembolism in Routine Clinical Practice: The RE-COVERY DVT/PE™ Study.

BACKGROUND: The safety and efficacy of nonvitamin K antagonist oral anticoagulants (NOACs) for the treatment of venous thromboembolism (VTE) have been established in randomized controlled trials, but limited data are available on their use in clinical practice across geographical regions. METHODS: In the international RE-COVERY DVT/PE observational study (enrollment January 2016 to May 2017), we sought to characterize the patient population and describe the prescribed anticoagulant. Patient characteristics and anticoagulants administered after objective diagnosis of VTE were recorded at the baseline visit and again at hospital discharge or at 14 days after the diagnosis, whichever was later. RESULTS: A total of 6095 patients were included, 50.2% were male, and the mean age was 61.5 years. The most common comorbidities were hypertension (35%), diabetes mellitus (11%), cancer (11%), prior VTE(11%), and trauma/surgery (7%). Overall, 77% of patients received oral anticoagulants, with 54% on NOACs and 23% on vitamin K antagonists (VKAs); 20% received parenteral anticoagulation only. NOACs comprised about 60% of anticoagulant treatment in Europe and Asia but substantially less in Latin America (29%) and the Middle East (21%). For NOAC therapies, the distribution (as a percentage of the total cohort) was rivaroxaban 25.6%, dabigatran 15.5%, apixaban 11.3%, and edoxaban 1.7%. Treatment with NOACs was less frequent in patients who had cancer, chronic renal disease, heart failure, or stroke. CONCLUSIONS: These findings enhance our understanding of baseline characteristics and the initial management of patients with VTE in routine practice.

Global Use of Idarucizumab in Clinical Practice: Outcomes of the RE-VECTO Surveillance Program.

Idarucizumab was approved for the reversal of dabigatran in 2015. We investigated whether postapproval usage patterns of idarucizumab in a real-world setting reflect those observed in the pivotal trials. No safety or efficacy data were collected in this medical record-based observational study. RE-VECTO, a global postapproval, international, surveillance program, involved hospital pharmacies in countries where idarucizumab was licensed and dispensed (August 2016-June 2018). Characteristics of sites prescribing idarucizumab and of eligible patients (≥ 18 years old and receiving idarucizumab regardless of prior oral anticoagulant use), as well as idarucizumab utilization data, were collected and analyzed descriptively. Sixty-one sites enrolled 359 patients. Most pharmacies (85.2%) were centralized, and the median idarucizumab units stocked per hospital was 2.0 (interquartile range, 1.0-3.0). Almost three-quarters of patients were elderly (74.9% aged > 70 years), and only four (1.1%) had received idarucizumab before. Nearly all patients were treated with dabigatran (97.5%). There was a low frequency of unapproved dabigatran dosage regimens (3.3%). Life-threatening or uncontrolled bleeding was the most frequent indication for idarucizumab (57.7%), followed by emergency surgery/urgent procedure (35.9%). Of the life-threatening bleeding events, the most frequent were gastrointestinal tract (44.4%) and intracranial (38.6%). Most patients (95.0%) were given the full dose of two vials (2 × 2.5 g) of idarucizumab initially, and very few (1.7%) received a second dose. Of those patients requiring emergency or scheduled/planned surgery/procedures, 25.5% underwent gastrointestinal and/or abdominal surgery/procedures. Real-world usage patterns of idarucizumab provide valuable insights into emergency reversal strategies. Off-label use was minimal.

Concomitant Oral Anticoagulant and Nonsteroidal Anti-Inflammatory Drug Therapy in Patients With Atrial Fibrillation.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used medications that can potentially increase the risk of bleeding and thrombosis. OBJECTIVES: This study quantified the effect of NSAIDs in the RE-LY (Randomized Evaluation of Long Term Anticoagulant Therapy) trial. METHODS: This was a post hoc analysis of NSAIDs in the RE-LY study, which compared dabigatran etexilate (DE) 150 and 110 mg twice daily (b.i.d.) with warfarin in patients with atrial fibrillation. Treatment-independent, multivariate-adjusted Cox regression analysis assessed clinical outcomes by comparing NSAID use with no NSAID use. Interaction analysis was obtained from treatment-dependent Cox regression modeling. Time-varying covariate analysis for NSAID use was applied to the Cox model. RESULTS: Among 18,113 patients in the RE-LY study, 2,279 patients used NSAIDs at least once during the trial. Major bleeding was significantly elevated with NSAID use (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.40 to 2.02; p < 0.0001). NSAID use did not significantly alter the risk of major bleeding for DE 150 or 110 mg b.i.d. relative to warfarin (pinteraction = 0.63 and 0.93, respectively). Gastrointestinal major bleeding was significantly elevated with NSAID use (HR: 1.81; 95% CI: 1.35 to 2.43; p < 0.0001). The rate of stroke or systemic embolism (stroke/SE) with NSAID use was significantly elevated (HR: 1.50; 95% CI: 1.12 to 2.01; p = 0.007). The use of NSAIDs did not significantly alter the relative efficacy on stroke/SE for DE 150 or 110 mg b.i.d. relative to warfarin (pinteraction = 0.59 and 0.54, respectively). Myocardial infarction rates were similar with NSAID use compared with no NSAID use (HR: 1.22; 95% CI: 0.77 to 1.93; p = 0.40). Patients were more frequently hospitalized if they used an NSAID (HR: 1.64; 95% CI: 1.51 to 1.77; p < 0.0001). CONCLUSIONS: The use of NSAIDs was associated with increased risk of major bleeding, stroke/SE, and hospitalization. The safety and efficacy of DE 150 and 110 mg b.i.d. relative to warfarin were not altered. (Randomized Evaluation of Long Term Anticoagulant Therapy [RE-LY]; NCT00262600).

Rationale and design of a phase III safety trial of idarucizumab in children receiving dabigatran etexilate for venous thromboembolism.

BACKGROUND: The incidence of venous thromboembolism (VTE) in children has been increasing. Anticoagulants are the mainstay of treatment but are associated with bleeding events that may be life-threatening. Idarucizumab is a fragment antigen-binding (fab) that provides immediate, complete, and sustained reversal of dabigatran's anticoagulant effects in adults. OBJECTIVE AND METHODS: This phase III, open-label, single-arm, multicenter, multinational trial will assess the safety of idarucizumab in children participating in two ongoing trials investigating dabigatran etexilate. Eligible patients will be children with VTE (aged 0-≤18 years; n = ~5) with life-threatening or uncontrolled bleeding (group A), and children who require emergency surgery/urgent procedures for a condition other than bleeding (group B). Patients will receive idarucizumab up to 5 g as two consecutive intravenous infusions over 5-10 minutes each, as two 10-15-minute drips or as two bolus injections (15 minutes apart) and will be monitored for 30 days. The primary endpoint will be the safety of idarucizumab assessed by the occurrence of drug-related adverse events (including immune reactions) and all-cause mortality. Secondary endpoints will be the reversal of dabigatran anticoagulant effects assessed by changes in diluted thrombin time and ecarin clotting time, time to achieve complete reversal and the duration of the reversal and bleeding severity (group A). The formation of antidrug antibodies at 30 days post-dose and cessation of bleeding will also be assessed. CONCLUSION: This study will report the safety of idarucizumab in children with VTE who require rapid reversal of the anticoagulant effects of dabigatran. Clinical trial registration: NCT02815670.

Growth-differentiation factor 15 and risk of major bleeding in atrial fibrillation: Insights from the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial.

OBJECTIVE: To evaluate and validate the prognostic value of growth-differentiation factor 15 (GDF-15) beyond clinical characteristics and other biomarkers concerning bleeding and stroke outcomes in patients with atrial fibrillation in the RE-LY trial. METHODS: GDF-15 was measured in samples collected at randomization in 8,474 patients with a median follow-up time of 1.9 years. Patients were stratified based on predefined GDF-15 cutoffs: group 1, <1,200 ng/L (the 90th percentile in healthy individuals); group 2, 1,200-1,800; and group 3, >1,800 ng/L (high-risk individuals). Efficacy and safety outcomes were compared across groups of GDF-15 in Cox models adjusted for baseline characteristics, cardiac (N-terminal pro-b-type natriuretic peptide, high-sensitive troponin T), inflammatory (interleukin 6, C-reactive protein) and coagulation (D-dimer) biomarkers, and randomized treatment. RESULTS: GDF-15 concentrations were <1,200 ng/L in 2,647 (31.2%), between 1,200 and 1,800 ng/L in 2,704 (31.9%), and >1,800 ng/L in 3,123 (36.9%) participants, respectively. Annual rates of stroke, major bleeding, and mortality increased with higher GDF-15 levels. The prognostic value of GDF-15 was independent of clinical characteristics for these outcomes. In models also adjusted for biomarkers, GDF-15 remained significantly associated with major bleeding (hazard ratio [95% CI] group 3 vs group 1 1.76 [1.28-2.42], P < .0005) and all-cause mortality (hazard ratio 1.72 [1.30-2.29], P < .0005). GDF-15 improved the c index of both the HAS-BLED (0.62-0.69) and ORBIT (0.68-0.71) bleeding risk scores. CONCLUSIONS: In patients with atrial fibrillation, GDF-15 is an independent risk indicator for major bleeding and all-cause mortality, but not for stroke. Therefore, GDF-15 seems useful as a specific marker of bleeding in patients with AF on oral anticoagulant treatment.

Idarucizumab for Dabigatran Reversal - Full Cohort Analysis.

BACKGROUND: Idarucizumab, a monoclonal antibody fragment, was developed to reverse the anticoagulant effect of dabigatran. METHODS: We performed a multicenter, prospective, open-label study to determine whether 5 g of intravenous idarucizumab would be able to reverse the anticoagulant effect of dabigatran in patients who had uncontrolled bleeding (group A) or were about to undergo an urgent procedure (group B). The primary end point was the maximum percentage reversal of the anticoagulant effect of dabigatran within 4 hours after the administration of idarucizumab, on the basis of the diluted thrombin time or ecarin clotting time. Secondary end points included the restoration of hemostasis and safety measures. RESULTS: A total of 503 patients were enrolled: 301 in group A, and 202 in group B. The median maximum percentage reversal of dabigatran was 100% (95% confidence interval, 100 to 100), on the basis of either the diluted thrombin time or the ecarin clotting time. In group A, 137 patients (45.5%) presented with gastrointestinal bleeding and 98 (32.6%) presented with intracranial hemorrhage; among the patients who could be assessed, the median time to the cessation of bleeding was 2.5 hours. In group B, the median time to the initiation of the intended procedure was 1.6 hours; periprocedural hemostasis was assessed as normal in 93.4% of the patients, mildly abnormal in 5.1%, and moderately abnormal in 1.5%. At 90 days, thrombotic events had occurred in 6.3% of the patients in group A and in 7.4% in group B, and the mortality rate was 18.8% and 18.9%, respectively. There were no serious adverse safety signals. CONCLUSIONS: In emergency situations, idarucizumab rapidly, durably, and safely reversed the anticoagulant effect of dabigatran. (Funded by Boehringer Ingelheim; RE-VERSE AD ClinicalTrials.gov number, NCT02104947 .).

Evaluation of the immunogenicity of the dabigatran reversal agent idarucizumab during Phase I studies.

AIMS: Idarucizumab, a humanized monoclonal anti-dabigatran antibody fragment, is effective in emergency reversal of dabigatran anticoagulation. Pre-existing and treatment-emergent anti-idarucizumab antibodies (antidrug antibodies; ADA) may affect the safety and efficacy of idarucizumab. This analysis characterized the pre-existing and treatment-emergent ADA and assessed their impact on the pharmacokinetics and pharmacodynamics (PK/PD) of idarucizumab. METHODS: Data were pooled from three Phase I, randomized, double-blind idarucizumab studies in healthy Caucasian subjects; elderly, renally impaired subjects; and healthy Japanese subjects. In plasma sampled before and after idarucizumab dosing, ADA were detected and titrated using a validated electrochemiluminescence method. ADA epitope specificities were examined using idarucizumab and two structurally related molecules. Idarucizumab PK/PD data were compared for subjects with and without pre-existing ADA. RESULTS: Pre-existing ADA were found in 33 out of 283 individuals (11.7%), seven of whom had intermittent ADA. Titres of pre-existing and treatment-emergent ADA were low, estimated equivalent to <0.3% of circulating idarucizumab after a 5 g dose. Pre-existing ADA had no impact on dose-normalized idarucizumab maximum plasma levels and exposure and, although data were limited, no impact on the reversal of dabigatran-induced anticoagulation by idarucizumab. Treatment-emergent ADA were detected in 20 individuals (19 out of 224 treated [8.5%]; 1 out of 59 received placebo [1.7%]) and were transient in ten. The majority had specificity primarily toward the C-terminus of idarucizumab. There were no adverse events indicative of immunogenic reactions. CONCLUSION: Pre-existing and treatment-emergent ADA were present at extremely low levels relative to the idarucizumab dosage under evaluation. The PK/PD of idarucizumab appeared to be unaffected by the presence of pre-existing ADA.

Safety, pharmacokinetics and pharmacodynamics of idarucizumab, a specific dabigatran reversal agent in healthy Japanese volunteers: a randomized study.

BACKGROUND: Idarucizumab is a humanized monoclonal antibody fragment that specifically binds with high affinity to dabigatran. OBJECTIVES: This study investigated the safety, tolerability and pharmacokinetics of idarucizumab alone and with dabigatran at steady state, and the effects of idarucizumab on dabigatran-induced anticoagulation. PATIENTS/METHODS: This was a two-part, phase I, randomized, placebo-controlled, double-blind, rising-dose trial in healthy Japanese males. Part 1: 32 subjects (males) received single idarucizumab doses (1, 2, 4 or 8 g [n=6/dose group]) or placebo (n=2/dose group). Part 2: 48 males received dabigatran (220 mg bid) followed by idarucizumab (n=9/dose group) 1, 2, 4 or 5 g (2×2.5 g), or placebo (n=3/dose group). Anti-idarucizumab antibodies (ADAs) and idarucizumab effect on anticoagulation parameters (diluted thrombin time [dTT], ecarin clotting time [ECT], activated partial thromboplastin time [aPTT] and thrombin time [TT]) were assessed. RESULTS: No adverse events were reported in subjects receiving idarucizumab. After single doses of idarucizumab (alone or at steady state of dabigatran), maximum plasma concentration was achieved around the end of each infusion. Mean all anticoagulation parameters fell below the upper limit of normal immediately after idarucizumab infusion in all dose groups; the effect was sustained at 4 and 2×2.5 g over the entire measurement period until 72 h. At 1- and 2-g doses, partial return of the anticoagulant effect occurred. Idarucizumab alone had no effect on coagulation parameters. Treatment-emergent ADAs occurred in 6/60 males receiving idarucizumab. CONCLUSIONS: Idarucizumab infusion achieved immediate, complete and sustained reversal of dabigatran-induced anticoagulation in Japanese volunteers. Idarucizumab was well tolerated with no procoagulant effects. Trial registration number: ClinicalTrials.gov NCT02028780 (completed).

Idarucizumab, a specific reversal agent for dabigatran: mode of action, pharmacokinetics and pharmacodynamics, and safety and efficacy in phase 1 subjects.

The direct oral anticoagulants (DOACs) provide a number of clinical advantages over vitamin K antagonists for the treatment of thromboembolism, including improved efficacy and safety, as well as no need for regular monitoring of anticoagulant effect. However, as with all anticoagulants, bleeding complications may occur, and anticoagulant reversal may be required in specific clinical situations, such as in patients experiencing spontaneous or traumatic bleeds, or in anticoagulated patients requiring emergency surgery or other invasive procedures. Therefore, several reversal agents for the DOACs are in development. This includes the specific reversal agent idarucizumab, which has been approved by the U.S. Food and Drug Administration and the European Medicines Agency for use in patients treated with dabigatran when urgent reversal of its anticoagulant effects is needed. Idarucizumab is a humanized monoclonal antibody fragment that binds with high affinity to free and thrombin-bound dabigatran, resulting in an almost irreversibly bound idarucizumab-dabigatran complex and thereby neutralizing dabigatran's anticoagulant activity. The reversal of the anticoagulant effects of dabigatran by idarucizumab has been demonstrated in animal bleeding models, in healthy volunteers with a range of ages and renal function, and in anticoagulated patients. In the phase 1 trials, at doses of 2 g or greater, idarucizumab resulted in immediate and complete reversal of the dabigatran anticoagulant effects and was well tolerated. In the absence of dabigatran, idarucizumab showed no effect on coagulation parameters or thrombin formation. These findings provide initial evidence that idarucizumab could provide a safe and effective means of reversing anticoagulant activity in patients treated with dabigatran in need of emergency surgery or in emergency bleeding situations.

Comparison of Dabigatran and Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease: The RE-LY Trial (Randomized Evaluation of Long-Term Anticoagulant Therapy).

BACKGROUND: The RE-LY trial (Randomized Evaluation of Long-Term Anticoagulant Therapy) compared dabigatran 150 and 110 mg twice daily with warfarin in 18 113 patients with atrial fibrillation. Those with prosthetic heart valves, significant mitral stenosis, and valvular heart disease (VHD) requiring intervention were excluded. Others with VHD were included. METHODS: This is a post hoc analysis of the RE-LY trial. RESULTS: There were 3950 patients with any VHD: 3101 had mitral regurgitation, 1179 with tricuspid regurgitation, 817 had aortic regurgitation, 471 with aortic stenosis, and 193 with mild mitral stenosis. At baseline, patients with any VHD had more heart failure, coronary disease, renal impairment, and persistent atrial fibrillation. Patients with any VHD had higher rates of major bleeds (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.16-1.5) but similar stroke or systemic embolism event rates (HR, 1.09; 95% CI, 0.88-1.33). For patients receiving dabigatran 110 mg, major bleed rates were lower than for patients taking warfarin (HR, 0.73; 95% CI, 0.56-0.95 with VHD; HR, 0.84; 95% CI, 0.71-0.99 without VHD), and major bleed rates for dabigatran 150 mg were similar to those for warfarin in patients with VHD (HR, 0.82; 95% CI, 0.64-1.06) or without VHD (HR, 0.98; 95% CI, 0.83-1.15). For dabigatran 150 mg, stroke/systemic embolic event rates were lower compared with warfarin in those with VHD (HR, 0.59; 95% CI, 0.37-0.93) and those without VHD (HR, 0.67; 95% CI, 0.52-0.86), and stroke/systemic embolic event rates were similar for warfarin and dabigatran 110 mg regardless of the presence of VHD (HR, 0.97; 95% CI, 0.65-1.45; and HR, 0.88; 95% CI, 0.70-1.10). Intracranial bleeds and death rates for dabigatran 150 and 110 mg were lower compared with warfarin independently of the presence of VHD. CONCLUSIONS: The presence of any VHD did not influence the comparison of dabigatran with warfarin. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00262600.

Idarucizumab, a Specific Reversal Agent for Dabigatran: Mode of Action, Pharmacokinetics and Pharmacodynamics, and Safety and Efficacy in Phase 1 Subjects.

The direct oral anticoagulants (DOACs) provide a number of clinical advantages over vitamin K antagonists for the treatment of thromboembolism, including improved efficacy and safety, as well as no need for regular monitoring of anticoagulant effect. However, as with all anticoagulants, bleeding complications may occur, and anticoagulant reversal may be required in specific clinical situations, such as in patients experiencing spontaneous or traumatic bleeds, or in anticoagulated patients requiring emergency surgery or other invasive procedures. Therefore, several reversal agents for the DOACs are in development. This includes the specific reversal agent idarucizumab, which has been approved by the U.S. Food and Drug Administration and the European Medicines Agency for use in patients treated with dabigatran when urgent reversal of its anticoagulant effects is needed. Idarucizumab is a humanized monoclonal antibody fragment that binds with high affinity to free and thrombin-bound dabigatran, resulting in an almost irreversibly bound idarucizumab-dabigatran complex and thereby neutralizing dabigatran's anticoagulant activity. The reversal of the anticoagulant effects of dabigatran by idarucizumab has been demonstrated in animal bleeding models, in healthy volunteers with a range of ages and renal function, and in anticoagulated patients. In the phase 1 trials, at doses of 2 g or greater, idarucizumab resulted in immediate and complete reversal of the dabigatran anticoagulant effects and was well tolerated. In the absence of dabigatran, idarucizumab showed no effect on coagulation parameters or thrombin formation. These findings provide initial evidence that idarucizumab could provide a safe and effective means of reversing anticoagulant activity in patients treated with dabigatran in need of emergency surgery or in emergency bleeding situations.

Long-term evaluation of dabigatran 150 vs. 110 mg twice a day in patients with non-valvular atrial fibrillation.

AIMS: The Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial allowed patients who completed the trial receiving their assigned dabigatran 150 mg (D150) or 110 mg (D110) twice a day to continue into the Long-term Multicenter Extension of Dabigatran Treatment in Patients with Atrial Fibrillation (RELY-ABLE) trial. This permitted assessment of outcomes over a median of 4.6 and a maximum of 6.7 years, respectively. METHODS AND RESULTS: The analysed population included only those patients who completed RE-LY on dabigatran and continued into RELY-ABLE without interruption of assigned dabigatran. Cumulative risk was expressed as Kaplan-Meier plots. Outcomes were compared using Cox proportional hazard modelling. Stroke or systemic embolization rates were 1.25 and 1.54% per year (D150 and D110, respectively); hazard ratio (HR) 0.81 [95% confidence interval (CI): 0.68-0.96] (P = 0.02). Ischaemic stroke was 1.03 (D150) and 1.29%/year (D110); HR 0.79 (95% CI: 0.66-0.95) (P = 0.01). Haemorrhagic stroke rates were 0.11 (D150) and 0.13%/year (D110); HR 0.91 (95% CI: 0.51-1.62) (P = 0.75). Rates of major haemorrhage were 3.34 (D150) and 2.76%/year (D110); HR 1.22 (95% CI: 1.08-1.37) (P = 0.0008). Intracranial haemorrhage rates were 0.32 (D150) and 0.23%/year (D110); HR 1.37 (95% CI: 0.93-2.01) (P = 0.11). Mortality was 3.43 (D150) and 3.55%/year (D110); HR 0.97 (95% CI: 0.87-1.08) (P = 0.54). CONCLUSION: Annualized rates of all outcomes were constant with better efficacy of D150, less major bleeding with D110, and low intracerebral haemorrhage rates for both doses. There were no additional safety concerns. This is the longest continuous randomized experience of a novel anticoagulant.

D-dimer and factor VIIa in atrial fibrillation - prognostic values for cardiovascular events and effects of anticoagulation therapy. A RE-LY substudy.

Coagulation markers may improve monitoring the risk of stroke and bleeding in patients with atrial fibrillation (AF) during anticoagulant treatment. We examined baseline levels of D-dimer and their association with stroke, cardiovascular death and major bleeding in 6,202 AF patients randomised to dabigatran or warfarin in the RE-LY trial. The effects of treatment on serial levels of D-dimer and coagulation factor (F) VIIa in 2,567 patients were also analysed. Baseline D-dimer levels were related to the rate of stroke/systemic embolism (SEE) with 0.64 % in the lowest quartile (Q1, as reference) (D-dimer < 298 µg/l), 1.38 % Q2 (D-dimer 298-473 µg/l), 1.71 % Q3 (D-dimer 474-822 µg/l) and 2.00 % in Q4 (D-dimer > 822 µg/l) (p=0.0007). Similar associations were shown for cardiovascular death and major bleeding. Addition of baseline D-dimer to established clinical risk factors improved prediction of stroke/SEE, cardiovascular death and major bleeding (C-index increased from 0.66 to 0.68, 0.71 to 0.73 and 0.66 to 0.67, respectively). Dabigatran provided a greater reduction of D-dimer levels than warfarin regardless of baseline anticoagulant treatment. On-treatment levels of FVIIa were markedly reduced by warfarin (median 12.1-13.8 mU/ml) but significantly higher with dabigatran (median 39.4-49.0 mU/ml) at all-time points. Dabigatran is associated with greater reduction in D-dimer without the pronounced reduction of FVIIa seen with warfarin. These different effects on the coagulation system might explain the better efficacy and less intracranial bleeding observed with dabigatran compared with warfarin.

Interleukin-6 and C-reactive protein and risk for death and cardiovascular events in patients with atrial fibrillation.

BACKGROUND: Inflammation has been associated with cardiovascular disease and the burden of atrial fibrillation (AF). In this study we evaluate inflammatory biomarkers and future cardiovascular events in AF patients in the RE-LY study. METHODS: Interleukin-6 (IL-6), C-reactive protein (CRP) (n = 6,187), and fibrinogen (n = 4,893) were analyzed at randomization; outcomes were evaluated by Cox models and C-statistics. RESULTS: Adjusted for clinical risk factors IL-6 was independently associated with stroke or systemic embolism (P = .0041), major bleedings (P = .0001), vascular death (P < .0001), and a composite thromboembolic outcome (ischemic stroke, systemic embolism, myocardial infarction, pulmonary embolism and vascular death) (P < .0001). CRP was independently related to myocardial infarction (P = .0047), vascular death (P = .0004), and the composite thromboembolic outcome (P = .0001). When further adjusted for cardiac (troponin and N-terminal fragment B-type natriuretic peptide [NT-proBNP]) and renal (cystatin-C) biomarkers on top of clinical risk factors IL-6 remained significantly related to vascular death (P < .0001), major bleeding (P < .0170) and the composite thromboembolic outcome (P < .0001), and CRP to myocardial infarction (.0104). Fibrinogen was not associated with any outcome. C-index for stroke or systemic embolism increased from 0.615 to 0.642 (P = .0017) when adding IL-6 to the clinically used CHA2DS2-VASc risk score with net reclassification improvement of 28%. CONCLUSION: In patients with AF, IL-6 is related to higher risk of stroke and major bleeding, and both markers are related to higher risk of vascular death and the composite of thromboembolic events independent of clinical risk factors. Adjustment for cardiovascular biomarkers attenuated the prognostic value, although IL-6 remained related to mortality, the composite of thromboembolic events, and major bleeding, and CRP to myocardial infarction.