Mandy Fraessdorf

Management and Outcomes of Major Bleeding during Treatment with Dabigatran or Warfarin

Background— The aim of this study was to compare the management and prognosis of major bleeding in patients treated with dabigatran or warfarin. Methods and Results— Two independent investigators reviewed bleeding reports from 1034 individuals with 1121 major bleeds enrolled in 5 phase III trials comparing dabigatran with warfarin in 27 419 patients treated for 6 to 36 months. Patients with major bleeds on dabigatran (n=627 of 16 755) were older, had lower creatinine clearance, and more frequently used aspirin or non-steroid anti-inflammatory agents than those on warfarin (n=407 of 10 002). The 30-day mortality after the first major bleed tended to be lower in the dabigatran group (9.1%) than in the warfarin group (13.0%; pooled odds ratio, 0.68; 95% confidence interval, 0.46–1.01; P=0.057). After adjustment for sex, age, weight, renal function, and concomitant antithrombotic therapy, the pooled odds ratio for 30-day mortality with dabigatran versus warfarin was 0.66 (95% confidence interval, 0.44–1.00; P=0.051). Major bleeds in dabigatran patients were more frequently treated with blood transfusions (423/696, 61%) than bleeds in warfarin patients (175/425, 42%; P<0.001) but less frequently with plasma (dabigatran, 19.8%; warfarin, 30.2%; P<0.001). Patients who experienced a bleed had shorter stays in the intensive care unit if they had previously received dabigatran (mean 1.6 nights) compared with those who had received warfarin (mean 2.7 nights; P=0.01). Conclusions— Patients who experienced major bleeding on dabigatran required more red cell transfusions but received less plasma, required a shorter stay in intensive care, and had a trend to lower mortality compared with those who had major bleeding on warfarin. Clinical Trial Registration— URL: http://www.ClinicalTrials.gov. Unique identifiers: NCT00262600, NCT00291330, NCT00680186, NCT00329238 and NCT00558259.

Perioperative bridging anticoagulation during dabigatran or warfarin interruption among patients who had an elective surgery or procedure. Substudy of the RE-LY trial.

In patients with atrial fibrillation (AF) who require interruption of dabigatran or warfarin for an elective surgery/procedure, the risks and benefits of perioperative bridging anticoagulation is uncertain.We accessed the database from RE-LY, a randomised trial comparing dabigatran with warfarin for stroke prevention in AF, to assess the potential benefits and risks of bridging. In patients who had a first interruption of dabigatran or warfarin for an elective surgery/procedure, we compared the risk for major bleeding (MB), stroke or systemic embolism (SSE) and any thromboembolism (TE) in patients who were bridged or not bridged during the period of seven days before until 30 days after surgery/procedure. We used multivariable Cox regression to adjust for potential confounders.Bridging was used more during warfarin interruption than dabigatran interruption (27.5 % vs 15.4 %; p< 0.001). With dabigatran interruption, bridged patients had more MB (6.5 % vs 1.8 %, p< 0.001) than those not bridged but bridged and not bridged groups did not differ for any TE (1.2 % vs 0.6 %, p=0.16) and SSE (0.5 % vs 0.3 %, p=0.46). With warfarin interruption, bridged patients had more MB (6.8 % vs 1.6 %, p< 0.001) and any TE (1.8 % vs 0.3 %, p=0.007) than those not bridged but bridged and not bridged groups did not differ for SSE (0.5 % vs 0.2 %, p=0.321). In conclusion, in patients who interrupted dabigatran or warfarin for a surgery/ procedure in the RE-LY trial, use of bridging anticoagulation appeared to increase the risk for major bleeding irrespective of dabigatran or warfarin interruption.

Efficacy and augmentation during 6 months of double-blind pramipexole for restless legs syndrome

BACKGROUND Pramipexole is an effective treatment for restless legs syndrome (RLS), but no controlled studies have lasted >12 weeks. METHODS RLS patients (N=331) with pretreatment serum ferritin >30 ng/mL were randomly assigned to take double-blind optimized pramipexole (0.125-0.75 mg/d) or placebo for 26 weeks. The primary efficacy endpoint was change in International RLS Study Group Rating Scale (IRLS) score. Other endpoints assessed global change, symptoms, and QoL. Patients maintained symptom diaries. Cases meeting predefined criteria for suspected augmentation were reviewed by a blinded expert panel, which used a predefined algorithm. RESULTS Among 321 patients providing post-baseline data, of whom 234 completed 26 weeks, pramipexole was more effective than placebo by multiple endpoints, including an adjusted mean IRLS score change of -13.7 vs. -11.1 (p=0.0077) and an IRLS responder rate (≥50% score reduction) of 58.6% vs. 42.8% (p=0.0044). Efficacy showed considerable country-to-country variability. Six-month incidence of confirmed augmentation was 9.2% for pramipexole and 6.0% for placebo. The rate increased with treatment duration for pramipexole but not placebo. Treatment-related adverse events (AEs) were more likely for pramipexole than for placebo, but discontinuation due to AEs was less likely. CONCLUSIONS During a 6-month period, pramipexole was effective, safe, and generally well tolerated. Because risk of augmentation may have increased over 6 months, it should be studied in longer trials. Beginning or mild augmentation is difficult to distinguish from natural RLS fluctuation, at least in a non-iron-deficient population.

Dabigatran compared with warfarin in patients with atrial fibrillation and symptomatic heart failure: a subgroup analysis of the RE-LY trial

We evaluated the effects of dabigatran compared with warfarin in the subgroup of patients with previous symptomatic heart failure (HF) in the RE‐LY trial.

Urgent surgery or procedures in patients taking dabigatran or warfarin: Analysis of perioperative outcomes from the RE-LY trial

BACKGROUND There is concern about the management of anticoagulated patients with atrial fibrillation (AF) who require an urgent surgery/procedure, especially in those who are receiving a direct oral anticoagulant such as dabigatran. METHODS We accessed the database from RE-LY, a randomized trial comparing dabigatran (110mg and 150mg twice daily) with warfarin for stroke prevention in AF, to assess patients who had an urgent and elective surgery/procedure. We compared the risk for thromboembolism, major bleeding and mortality according to treatment allocation (dabigatran 110mg or 150mg, or warfarin) or surgery/procedure type (urgent or elective). Outcomes were assessed from day-7 to day 30 after a surgery/procedure. RESULTS 353 patients (2.0% of study population) had an urgent surgery/procedure and 4168 patients (23.1% of study population) had an elective surgery/procedure. In patients on dabigatran 110mg, dabigatran 150mg and warfarin who had an urgent surgery/procedure: rates of thromboembolism were 16.1%, 7.4%, and 10.5%; rates of major bleeding were 17.0%, 17.6%, and 22.9%; rates of mortality were 6.3%, 1.5%, and 2.9%, respectively (P>0.50 for all comparisons). Rates of these outcomes were multi-fold higher in patients having an urgent rather than an elective surgery/procedure (P<0.5 for all comparisons). CONCLUSION In anticoagulated patients with atrial fibrillation who require an urgent surgery/procedure, the risks for thromboembolism, major bleeding and mortality did not differ depending on treatment with dabigatran or warfarin, but rates of these outcomes were multi-fold higher than in patients having an elective surgery/procedure.

Dabigatran versus Warfarin for Acute Venous Thromboembolism in Elderly or Impaired Renal Function Patients: Pooled Analysis of RE-COVER and RE-COVER II

Management of acute venous thromboembolism (VTE) with anticoagulants in elderly patients and those with chronic kidney disease poses special challenges. The RE-COVER and RE-COVER II trials showed that dabigatran 150 mg twice daily was as effective as warfarin over 6 months in preventing recurrent VTE, with a lower bleeding risk. We now assess the effects of old age and renal impairment (RI) on pooled trial outcomes in 5,107 patients: 4,504 aged <75 years and 603 aged ≥75 years. The primary efficacy outcome was symptomatic VTE/VTE-related death. Safety outcomes were centrally adjudicated major bleeding events (MBEs), MBEs or clinically relevant non-major bleeding events (MBEs/CRBEs) and any bleeds. Baseline renal function was categorized as normal, mild RI or moderate RI. A total of 3,698 had normal renal function and 1,100 and 237 had mild and moderate RI, respectively (23 patients with severe RI and 49 with missing creatinine clearance data were not included). For dabigatran, VTE/VTE-related death decreased from 3.1% (normal renal function) to 1.9% for mild RI and to 0.0% for moderate RI. For warfarin, the event rates were 2.6, 1.6 and 4.1%, respectively. Overall, major bleeding increased with increasing RI (p = 0.0037) and with age (p = 0.4350), with no apparent difference between the dabigatran and warfarin patients. Dabigatran shows better efficacy than warfarin in RI and in the elderly patients, probably because of an increase in the concentration of dabigatran. However, bleeding risk increases with both dabigatran and warfarin in the presence of RI.

Efficacy of dabigatran versus warfarin in patients with acute venous thromboembolism in the presence of thrombophilia: Findings from RE-COVER®, RE-COVER™ II, and RE-MEDY™

It is unclear whether thrombophilia causes resistance to anticoagulant therapy. Post hoc analyses of data from RE-COVER®, RE-COVER™ II, and RE-MEDY™ were performed to compare dabigatran etexilate with warfarin for the treatment and prevention of venous thromboembolism (VTE) in patients with thrombophilia or antiphospholipid antibody syndrome (APS). There were no significant differences in symptomatic VTE/VTE-related deaths between dabigatran etexilate and warfarin in patients with or without thrombophilia. All bleeding event categories were less frequent with dabigatran etexilate than with warfarin, regardless of whether patients had thrombophilia, no thrombophilia, or were not tested. However, these differences did not reach significance in every group. In patients with APS, there was no significant difference in VTE/VTE-related deaths between the two treatment arms. Rates of bleeding events tended to be lower with dabigatran etexilate than with warfarin, reaching statistical significance for any bleeding event. In conclusion, the efficacy and safety of dabigatran etexilate were not significantly affected by the presence of thrombophilia or APS. ClinicalTrials.gov RECOVER Identifier: NCT00291330; RECOVER II Identifier: NCT00680186; RE-MEDY Identifier: NCT00329238

Treatment of acute pulmonary embolism with dabigatran versus warfarin. A pooled analysis of data from RE-COVER and RE-COVER II.

Dabigatran was non-inferior to warfarin for prevention of recurrent venous thromboembolism (VTE), and dabigatran had a lower rate of bleeding compared with warfarin in two large-scale randomised trials, RE-COVER and RE-COVER II. In this study, we investigate the efficacy and safety of dabigatran versus warfarin according to the index event that qualified the patient for enrollment, either symptomatic pulmonary embolism (PE) with or without deep-vein thrombosis (DVT), or DVT alone. We then analyse the anticoagulant effect of dabigatran vs warfarin on patients enrolled with PE. The pooled dataset for the efficacy analysis consisted of 2553 and 2554 patients who were randomised to dabigatran and warfarin, respectively. Recurrent VTE/VTE-related death during the study period and additional 30-day follow-up occurred in 2.7 % of all patients on dabigatran and in 2.4 % on warfarin (hazard ratio [HR] 1.09 [95 % confidence interval 0.77, 1.54]). In patients with PE as their index event, recurrent VTE/VTE-related death occurred in 2.9 % vs 3.1 % of patients (HR 0.93 [0.53, 1.64]). There were significantly fewer major bleeding events in patients treated with dabigatran than with warfarin (HR 0.60 [0.36, 0.99]). The pattern was similar both in patients with PE and in those with DVT alone as the index event. These analyses of the pooled dataset from the RE-COVER and RE-COVER II trials indicate that dabigatran is as effective as warfarin in preventing recurrent VTE, regardless of whether patients present with symptomatic PE (with or without DVT) or with symptomatic DVT alone. Dabigatran was also associated with a lower risk of bleeding than warfarin, regardless of the index event.

Less abnormal uterine bleeding with dabigatran than warfarin in women treated for acute venous thromboembolism

Essentials Factor Xa inhibitors cause more abnormal menstrual bleeding (AUB) than vitamin‐K antagonists (VKA). We analyzed data of AUB in women, evaluating dabigatran versus VKA. We observed a 41% lower risk of AUB in women on dabigatran compared to those on VKA. Our findings of lower AUB risk on dabigatran should be corroborated in future studies.

Rationale, design, and protocol of a randomized controlled trial of the safety and efficacy of dabigatran etexilate versus dose-adjusted warfarin in patients with cerebral venous thrombosis:

Rationale To prevent recurrent venous thrombotic events after acute cerebral venous or dural sinus thrombosis, guidelines recommend long-term oral anticoagulation with vitamin K antagonists. Non-vitamin K oral anticoagulant experience in cerebral venous or dural sinus thrombosis is limited to case reports and series. Aim To compare dabigatran with dose-adjusted warfarin in patients with cerebral venous or dural sinus thrombosis for the prevention of recurrent venous thrombotic event. Sample size One hundred and twenty patients. Methods and design This study is a phase III, prospective, randomized, parallel-group, open-label, multicenter, exploratory trial with blinded endpoint adjudication. Patients with acute cerebral venous or dural sinus thrombosis after 5–15 days of treatment with parenteral heparin are randomized to either dabigatran etexilate 150 mg twice daily or dose-adjusted (international normalized ratio 2–3) warfarin (≤24 weeks). Study outcome The primary endpoint is a composite of patients with new venous thrombotic event (recurring cerebral venous or dural sinus thrombosis, deep venous thrombosis of any limb, pulmonary embolism, and major bleeding (International Society on Thrombosis and Hemostasis definition)) during the treatment period. Statistics will be descriptive (number and frequencies). Study timelines Inclusion started in December 2016. Final results are expected by the end of 2018. Discussion This exploratory trial is the first to compare vitamin K with non-vitamin K antagonists in cerebral venous or dural sinus thrombosis. It will provide evidence to guide physicians and patients in choosing oral anticoagulants to prevent venous thrombotic event after acute cerebral venous or dural sinus thrombosis. ClinicalTrials.gov number: NCT02913326.