An emulated target trial analysis based on Medicare data suggested non-inferiority of Dabigatran versus Rivaroxaban.

OBJECTIVES: Rivaroxaban and Dabigatran were the first two non-vitamin K antagonist oral anticoagulants (NOACs) for preventing stroke among non-valvular Atrial Fibrillation patients. This article aimed to evaluate the relative efficacy and safety of Rivaroxaban versus Dabigatran. STUDY DESIGN AND SETTING: An emulated target trial analysis was conducted based on Medicare, in which we constructed three "randomized clinical trials" with well-defined inclusion/exclusion criteria, treatment regimens, and analysis procedures. We analyzed the individual trials, examined temporal variations, and generated unified results via pooled analysis. RESULTS: With a two-year data collection window (2012-2013), 70,129 subjects were enrolled in the three emulated trials, with 36,269 and 34,089 in the Rivaroxaban and Dabigatran arms, respectively. Dabigatran (the reference group for hazard ratio - HR) was superior regarding time to any primary event (including ischemic stroke, other thromboembolic events, major bleeding, and death; HR 1.232, P-value 0.0025), major bleeding (HR 1.187, P-value <0.0001), and mortality (HR 1.488, P-value <0.0001). Differences regarding stroke and other thromboembolic events were not significant. CONCLUSION: Dabigatran was found as superior for the Medicare patients with multiple chronic conditions. Temporal variations, which had been largely neglected in the literature, were observed. This study may provide new insight into treating AF with NOACs.

Comparison of Low-Dose Direct Acting Anticoagulant and Warfarin in patients Aged ≥80 years With Atrial Fibrillation.

Low dose direct acting oral anticoagulants (LDDOACS) were approved for elderly atrial Fibrillation (AF) patients with limited information. A retrospective analysis collecting baseline characteristics and outcomes in AF patients ≥ 80 prescribed LDDOAC or warfarin (W), from a multidisciplinary practice between 1/1/11 (First LDDOAC available) and 5/31/17 was conducted. From 9660 AF patients, 514 ≥ 80 received a LDDOAC and 422 W. A multivariable comparison found LDDOAC patients were older (p <0.001), had lower creatinine clearance (CrCl) (p = 0.006), used more anti-platelet drugs (p <0.001), and more often had new onset AF verses those prescribed W (p <0.001). There were no clinically significant differences among those patients receiving Dabigatran 75 mgs BID (D), Rivaroxaban 15mgs (R) or Apixaban 2.5mgs BID (A). Forty-eight and 50% of the patients remained on their LDDOAC or W for the observation period (p = 0.55). Stroke/systemic embolism (SSE) and CNS bleeds were 1.16 vs 2.22%/yr., (p = 0.143) and 1.46 vs 0.93%/yr., (p = 0.24). Mortality and major bleeds were 6.26 vs 1.67%/yr., and 12.3vs 3.77%/yr. (p <0.001). SSE were 1.1%/yr for D, R, and A (p = 0.94). CNS bleeds were 2.2 for D, 1.7 for R and 0.8%/yr. for A: p = 0.53. Major bleeding was: 14.3 for D, 14.1 for R and 9.1%/yr. for A, p = 0.048 (with A < R, p = 0.01). Mortality was 5.5 for D, 4.2 for R and 9.5% for A, p = 0.031. In conclusion, half the patients remained on their assigned anti-coagulant. SSE and intracranial bleed rates were similar and low. Major bleeds and deaths were different between groups emphasizing the need for prospective randomized trials in this growing population with AF.

Appropriate intraprocedural initial heparin dosing in patients undergoing catheter ablation for atrial fibrillation receiving uninterrupted non-vitamin-K antagonist oral anticoagulant treatment.

BACKGROUND: To clarify the appropriate initial dosage of heparin during radiofrequency catheter ablation (RFCA) in patients with atrial fibrillation (AF) receiving uninterrupted nonvitamin K antagonist oral anticoagulant (NOAC) treatment. METHODS: A total of 187 consecutive AF patients who underwent their first RFCA in our center were included. In the warfarin group (WG), an initial heparin dose of 100 U/kg was administered (control group: n = 38). The patients who were on NOACs were randomly divided into 3 NOAC groups (NG: n = 149), NG110, NG120, and NG130, and were administered initial heparin doses of 110 U/kg, 120 U/kg, and 130 U/kg, respectively. During RFCA, the activated clotting time (ACT) was measured every 15 min, and the target ACT was maintained at 250-350 s by intermittent heparin infusion. The baseline ACT and ACTs at each 15-min interval, the average percentage of measurements at the target ACT, and the incidence of periprocedural bleeding and thromboembolic complications were recorded and analyzed. RESULTS: There was no significant difference in sex, age, weight, or baseline ACT among the four groups. The 15 min-ACT, 30 min-ACT, and 45 min-ACT were significantly longer in the WG than in NG110 and NG120. However, no significant difference in 60 min-ACT or 75 min-ACT was detected. The average percentages of measurements at the target ACT in NG120 (82.2 ± 23.6%) and NG130 (84.8 ± 23.7%) were remarkably higher than those in the WG (63.4 ± 36.2%, p = 0.007, 0.003, respectively). These differences were independent of the type of NOAC. The proportion of ACTs in 300-350 s in NG130 was higher than in WG (32.4 ± 31.8 vs. 34.7 ± 30.6, p = 0.735). Severe periprocedural thromboembolic and bleeding complications were not observed. CONCLUSIONS: For patients with AF receiving uninterrupted NOAC treatment who underwent RFCA, an initial heparin dosage of 120 U/kg or 130 U/kg can provide an adequate intraprocedural anticoagulant effect, and 130 U/kg allowed ACT to reach the target earlier. TRIAL REGISTRATION: Registration number: ChiCTR1800016491, First Registration Date: 04/06/2018 (Chinese Clinical Trial Registry http://www.chictr.org.cn/index.aspx ).

Treatment with direct oral anticoagulants or warfarin and the risk for incident diabetes among patients with atrial fibrillation: a population-based cohort study.

BACKGROUND: Diabetes mellitus is a common comorbidity of atrial fibrillation (AF), which can complicate the management of AF. The pharmacology of oral anticoagulants (OACs) have been implicated in pathogenesis of diabetes, but the relationship between different OACs and risk of diabetes remains unexamined. This study aimed to evaluate the risk of diabetes with use of different OACs in AF patients. METHODS: Population-based retrospective cohort study using an electronic healthcare database managed by the Hong Kong Hospital Authority. Patients newly diagnosed with AF from 2014 through 2018 and prescribed OACs were included and followed till December 31, 2019. Inverse probability of treatment weighting based on the propensity score (PS) is used to address potential bias due to nonrandomized allocation of treatment. The risks ofdiabetes were compared between different new OAC users using propensity score-weighted cumulative incidence differences (CID). RESULTS: There were 13,688 new users of OACs (warfarin: n = 3454; apixaban: n = 3335; dabigatran: n = 4210; rivaroxaban: n = 2689). The mean age was 75.0 (SD, 11.2), and 6,550 (47.9%) were women. After a median follow-up of 0.93 years (interquartile range, 0.21-1.92 years), 698 incident diabetes cases were observed. In Cox-regression analysis, dabigatran use was significantly associated with reduced risk of diabetes when compared with warfarin use [HR 0.69 (95% CI 0.56-0.86; P < 0.001)], with statistically insignificant associations observed for use of apixaban and rivaroxaban. The corresponding adjusted CIDs at 2 years after treatment with apixaban, dabigatran, and rivaroxaban users when compared with warfarin were - 2.06% (95% CI - 4.08 to 0.16%); - 3.06% (95% CI - 4.79 to - 1.15%); and - 1.8% (- 3.62 to 0.23%). In head-to-head comparisons between women DOAC users, dabigatran was also associated with a lower risk of diabetes when compared with apixaban and rivaroxaban. CONCLUSIONS: Among adults with AF receiving OACs, the use of dabigatran had the lowest risk of diabetes when compared with warfarin use.

Patterns of anticoagulation therapy in atrial fibrillation: results from a large real-life single-center registry.

AIM: To investigate the differences in the characteristics and clinical outcomes of recently diagnosed patients with atrial fibrillation (AF) receiving different types of anticoagulants in a real-life setting. METHODS: We retrospectively analyzed the charts of 1000 consecutive patients with non-valvular AF diagnosed at our institution or referred it to from 2013 to 2018. RESULTS: Over the observed period, the frequency of direct oral anticoagulation (DOAC) therapy use significantly increased (P = 0.002). Patients receiving warfarin had more unfavorable thromboembolic and bleeding risk factors than patients receiving DOAC. Predetermined stroke and major bleeding risks were similarly distributed among the dabigatran, rivaroxaban, and apixaban groups. Patients receiving warfarin had shorter time-to-major bleeding (TTB), time to thrombosis (TTT), and overall survival (OS) than patients receiving DOACs. After adjustment for factors unbalanced at baseline, the warfarin group showed significantly shorter OS (hazard ratio 2.27, 95% confidence interval 1.44-3.57, P<0.001], while TTB and TTT did not significantly differ between the groups. Only 37% of patients on warfarin had optimal dosing control, and they did not differ significantly in TTB, TTT, and OS from patients on DOACs. CONCLUSION: Warfarin and DOACs are administered to different target populations, possibly due to socio-economic reasons. Patients receiving warfarin rarely obtain optimal dosing control, and experience significantly shorter survival compared with patients receiving DOACs.

Therapeutic Drug Monitoring of Direct Oral Anticoagulants May Increase Their Benefit-Risk Ratio.

The attractiveness of direct oral anticoagulants (DOACs) over vitamin K antagonists, in addition to a better benefit-risk ratio, stems from the fact that no therapeutic drug monitoring is deemed necessary. This has been recently mitigated by the fact that increased dabigatran (D) plasma levels have been associated with hemorrhages, and is currently under scrutiny of the European Medicines Agency. We aimed to evaluate, in real conditions of use, whether patients with out-of-range DOAC blood concentrations (too high or too low) were associated with bleeding or thrombosis. Patients treated with D or rivaroxaban (R) were prospectively included in a hospital cohort. D and R plasma levels were measured by high-pressure liquid chromatography-tandem mass spectrometry-at the physician's demand. We defined concentration range as "expected" within the 95% confidence interval of the mean concentration obtained from pivotal trials, and "out of range" when concentrations were outside of that interval. A blind assessment of concentrations versus occurrence of bleeding or thrombosis was performed by means of univariate and multivariate analysis. Three hundred and twenty-two patients (mean age 78.5 years ± 13.1), treated with D or R were included consecutively. They had a mean CHA2DS2-VASc at 4.4 ± 1.7 and a mean HAS-BLED score at 1.7 ± 0.9. Irrespective of the DOAC prescribed, patients presenting with out-of-range concentrations had significantly more bleeding or thrombosis than patients with expected concentrations (P < 0.001). Patients with bleeding were more prone to have concentrations beyond the 95 percentile (N = 62, P < 0.001), whereas patients with thrombosis were more likely to have concentrations below the fifth percentile (N = 26, P < 0.05). The main risks associated with hemorrhages were abnormal concentrations, a high HAS-BLED score, the patient's age, and the creatinine blood level. For thrombosis, a concentration below the fifth percentile was the only risk factor that was significant in our cohort. While D and R under current recommendation have a better benefit-risk ratio than warfarin, their safe usage could be further optimized by some degree of therapeutic monitoring.

[Peculiarities of the treatment of venous thromboembolism with direct oral anticoagulants in challenging patients: senile age, renal failure, fragility]. / Osobennosti terapii venoznykh tromboembolicheskikh oslozhnenii pryamymi oral'nymi antikoagulyantami u oslablennykh patsientov: starcheskii vozrast, pochechnaya nedostatochnost', khrupkost'.

The paper is a narrative review of the literature on the use of direct oral anticoagulants (DOACs) for the VTE treatment in challenging patients: senile age (≥75 years), impaired renal function (estimated glomerular filtration rate ≤50 ml/min), fragility (one of the previous characteristics and/or bodyweight ≤50 kg). The paper discusses the studies of EINSTEIN DVT and PE (rivaroxaban), AMPLIFY (apixaban), HOKUSAI-VTE (edoxaban), RE-COVER I and II (dabigatran) in the focus of the secondary analysis in the pre-specified patient's subgroups, as well as their pooled analyzes and meta-analyzes. Based on the results of this review, it was concluded that in a subgroup of senile age patients, dabigatran increases the risk of major bleeding by 4.8 times and has no advantages over vitamin K antagonists (VKA); rivaroxaban and apixaban retain superiority over VKA on the safety outcomes and reduce the risk of major bleeding by 73% and 77%. In the subgroup of patients with impaired renal function, the use of apixaban and dabigatran is associated with an increase in the risk of major bleeding by 6.5 and 7.3 times, and these DOACs do not have advantages over VKA; rivaroxaban retains its superiority over VKA and reduces the risk of major bleeding by 78%. For fragile patients, a secondary analysis is available only for rivaroxaban, which remains superior to VKA on safety endpoints and reduces the risk of major bleeding by 73%. In the absence of direct comparisons between the available DOACs, the presented data can be used as a rational approach for the choice of appropriate treatment for VTE in challenging patients.

Comparison of the Efficacy and Safety of Direct Oral Anticoagulants and Warfarin After Bioprosthetic Valve Replacements.

BACKGROUND AND OBJECTIVE: Current guidelines recommend anticoagulation with a vitamin K antagonist (warfarin) after a bioprosthetic valve replacement. There is minimal literature evaluating direct oral anticoagulants (DOACs) in patients who have just received a bioprosthetic aortic valve replacement (AVR) or mitral valve replacement (MVR). The purpose of this study was to investigate any differences in efficacy and safety for patients taking a DOAC, compared with warfarin, after a bioprosthetic AVR or MVR. METHODS: A retrospective cohort study was performed to evaluate anticoagulation in patients who received bioprosthetic valve replacements at a large teaching hospital from 2014 to 2018. Patients included in this study received either warfarin or a DOAC following bioprosthetic AVR or MVR, and were maintained on the same agent throughout the 6-month follow-up period. The primary efficacy outcome was the incidence of thromboembolic complications and the primary safety outcome was the incidence of major bleeding within 6 months following surgery. The rate of readmission was assessed as a secondary endpoint. RESULTS: A total of 197 patients were included; 70 patients received warfarin and 127 patients received a DOAC (apixaban, n = 86; rivaroxaban, n = 40; dabigatran, n = 1). Three patients experienced thromboembolic events, all of which occurred in the DOAC group (0% vs. 2.4%; p = 0.20). Major bleeding occurred in 11 patients-two in the warfarin group and nine in the DOAC group (2.9% vs. 7.1%; p = 0.22). Sixty-one patients were readmitted within the 6-month time frame, with 26 readmissions in the warfarin group and 35 readmissions in the DOAC group (37% vs. 27%; p = 0.16). CONCLUSIONS: This small, exploratory study found similar rates of thromboembolic complications and major bleeding events in patients who received a DOAC versus warfarin after a recent bioprosthetic AVR or MVR. This study was limited by its retrospective nature and its sample size. Larger, randomized controlled trials are needed to further determine the efficacy and safety of DOACs in this patient population.

A Structured Literature Review and International Consensus Validation of FORTA Labels of Oral Anticoagulants for Long-Term Treatment of Atrial Fibrillation in Older Patients (OAC-FORTA 2019).

INTRODUCTION: Evidence regarding safety and efficacy of oral anticoagulants for the treatment of atrial fibrillation (AFib) in older adults has been assessed regarding the age appropriateness of oral anticoagulants (OAC) according to the FORTA (Fit fOR The Aged) classification (OAC-FORTA). Three years after its first version (OAC-FORTA 2016), an update was initiated to create OAC-FORTA 2019. METHODS: A structured review of randomized controlled clinical trials and summaries of individual product characteristics was performed to detect newly emerged evidence on oral anticoagulants in older patients with AFib. This review was used by an interdisciplinary panel of European experts (N = 10) in a Delphi process to label OACs according to FORTA. RESULTS: A total of 202 records were identified and 11 studies finally included. We found four new trials providing relevant data on efficacy and safety of warfarin, apixaban, dabigatran or rivaroxaban in older patients with AFib. In the majority of studies comparing the non-vitamin-K oral anticoagulants (NOACs) with warfarin, NOACs were superior to warfarin regarding at least one relevant clinical endpoint. The mean consensus coefficient significantly increased from 0.867 (OAC-FORTA 2016) to 0.931 (p < 0.05) and the proposed FORTA classes were confirmed in all cases during the first round (consensus coefficient > 0.8). Warfarin, dabigatran, edoxaban and rivaroxaban were assigned to the FORTA B label, acenocoumarol, fluindione and phenprocoumon were labeled FORTA C and only apixaban was rated as FORTA A. CONCLUSION: OAC-FORTA 2019 confirms that AFib can be successfully treated with positively labeled antithrombotics at advanced age.

Does the CHA2DS2-VASc scale sufficiently predict the risk of left atrial appendage thrombus in patients with diagnosed atrial fibrillation treated with non-vitamin K oral anticoagulants?

The CHA2DS2-VASc scale does not include potential risk factors for left atrial appendage thrombus (LAAT) formation such as a form of atrial fibrillation (AF) and impaired kidney function. The real risk of thromboembolic complications in AF patients is still unclear as well as an optimal anticoagulant treatment in males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2.The aim of this study was to compare the predictive value of the CHA2DS2-VASc scale and other scales to estimate the risk of LAAT formation in AF patients treated with non-vitamin K oral anticoagulants (NOACs) and to assess the prevalence of thrombi in patients at intermediate risk of stroke.The observational study included consecutive patients with a diagnosis of non-valvular AF treated with NOACs, admitted to 3 high-reference institutions between 2013 and 2018. All individuals underwent transoesophageal echocardiography before cardioversion or ablation.Out of 1163 enrolled AF patients (62.1% male, mean age 62 years) the LAAT had been detected in 50 individuals (4.3%). Among patients with LAAT, 1 patient (2.0%) was classified as a low-risk category, 9 (18.0%) were at intermediate-risk, and 40 (80.0%) were at high risk of thromboembolic complications according to CHA2DS2-VASc scale. All patients were treated with NOACs: 51.0% rivaroxaban, 47.1% dabigatran, and 1.9% apixaban.Patients at intermediate stroke-risk with detected LAAT had higher R2CHADS2 score (2.1 ±â€Š1.2 vs 1.2 ±â€Š0.8, P = .007), higher CHA2DS2-VASc-RAF score (6.4 ±â€Š4.4 vs 3.7 ±â€Š2.6, P = .027) and more often had an estimated glomerular filtration rate below 56 mL/min/1.73 m (44.4% vs 13.2%, P = .026) compared to patients without LAAT. The receiver operating characteristics revealed that the CHA2DS2-VASc-RAF scale had better predictive ability to distinguish between patients with and without LAAT in the study group than CHA2DS2-VASc (P = .0006), CHADS2 (P = .0006) and R2CHADS2 scale (P = .0140).The CHA2DS2-VASc scale should be supplemented with an assessment of renal function and form of AF to improve stroke risk estimation. The application of additional scales to estimate the risk of LAAT might be especially useful among males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2.

Safe chest tube placement in a patient with tension pneumothorax receiving rivaroxaban therapy for non-valvular atrial fibrillation.

The number of patients treated with direct oral anticoagulants is increasing worldwide. Although bleeding complications associated with direct oral anticoagulants are lower than those associated with vitamin K antagonists, the increased number of patients treated with these anticoagulants suggests that a higher absolute number of patients are at risk. Tube thoracostomy is an invasive procedure with a high risk of bleeding. To date, among direct oral anticoagulants, only dabigatran has a well-studied antidote to reverse its effects during emergency procedure or surgery. This report describes a case in which emergency placement of a tube thoracostomy, in a patient with type 2 respiratory failure due to left tension pneumothorax and receiving the anticoagulant rivaroxaban, in the pharmacokinetics phase with greater anticoagulant effect, did not result in bleeding greater than that typically encountered during such interventions. The procedure ended successfully with no acute complications.

Outcome of non-vitamin K oral anticoagulants in the treatment of left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation.

BACKGROUND: Data comparing dabigatran with rivaroxaban regarding the resolution of left atrial/left atrial appendage (LA/LAA) thrombus in patients with nonvalvular atrial fibrillation (AF) are scarce. This study aimed to compare the efficacy and safety of dabigatran vs rivaroxaban regarding the resolution of LA/LAA thrombus in patients with nonvalvular AF. METHODS: This retrospective study enrolled nonvalvular AF patients scheduled to undergo catheter ablation or cardioversion in Shanghai Ruijin Hospital between January 2014 and January 2019. Altogether, 34 patients with LA/LAA thrombus detected by transesophageal echocardiography (TEE) were enrolled. Among them, 12 patients were treated with dabigatran 150 mg bid and the other 22 with rivaroxaban 20 mg qd. Follow-up TEE was performed within greater than or equal to 3 weeks to less than 6 months of the initial TEE to evaluate the resolution of the LA/LAA thrombus. RESULTS: Baseline patient characteristics were similar in the two groups. Overall, 18 patients (81.8%) in the rivaroxaban group had complete thrombus resolution after 70.3 ± 22.1 treatment days, and 10 patients (83.3%) in the dabigatran group had complete thrombus resolution after 69.3 ± 47.9 treatment days. There was no significant difference between the groups (P = .6). TEE showed that the average length, width, and area of thrombus significantly decreased in both groups after treatment, although there was no significant difference in the amount of change in these parameters between the two groups after treatment (P = .6). Undissolved thrombus in two patients in the rivaroxaban group did dissolve after switching to dabigatran. CONCLUSIONS: The results suggest that both dabigatran and rivaroxaban are potential options for treating LA/LAA thrombus in patients with nonvalvular AF. Dabigatran could be an alternative option for the resolution of LA/LAA thrombus resistant to rivaroxaban.

Use of Direct Oral Anticoagulants in the Treatment of Left Ventricular Thrombus: Systematic Review of Current Literature.

BACKGROUND: Left ventricular thrombus (LVT) is an important complication in the setting of systolic dysfunction, particularly after acute myocardial infarction. Current guidelines recommend the vitamin-K antagonist, warfarin, for the treatment of LVT. AREA OF UNCERTAINTY AND STUDY QUESTION: The direct oral anticoagulants (DOACs) are being increasingly used for the management of this entity, despite lack of randomized trials in support of it or knowledge about their efficacy. We aimed to assess the frequency of use and the efficacy of DOACs in the treatment of LVT. DATA SOURCES: We searched published articles in Google Scholar, PubMed, MEDLINE, and Embase from the introduction of DOACs in any therapy until April 2018. Reports describing patients diagnosed with LVT and who were treated with a DOAC were examined. Patient characteristics, comorbidities, pharmacologic treatments, and outcomes were collected. The primary end points of this study were thrombus resolution and time to resolution. Other end points were bleeding and thromboembolic events. RESULTS: Thirty articles describing 41 patients were analyzed. The most common risk factors for LVT formation were male gender, ischemic heart disease, and low ejection fraction. Most patients were treated with rivaroxaban (51.2%), followed by apixaban (26.8%) and dabigatran (22%). Patients were treated with DOAC alone (46.3%), DOAC and aspirin (12.2%), DOAC and clopidogrel (2.4%), and triple therapy (39%). Thrombus resolution success rate was 81%, 100%, and 88.9% for rivaroxaban, apixaban, and dabigatran, respectively. The median time of thrombus resolution was 40 days, 36 days, and 24 days for rivaroxaban, apixaban, and dabigatran, respectively. One nonfatal bleeding event and one stroke event were reported while on a DOAC. CONCLUSIONS: The use of DOACs is a reasonable alternative to vitamin-K antagonists in the management of LVT.

Direct oral anticoagulants for extended treatment of venous thromboembolism: insights from the EINSTEIN CHOICE study.

The risk of recurrence of venous thromboembolism (VTE) persists after interruption of the initial anticoagulation therapy. New evidence shows that direct oral anticoagulants are effective for extended treatment of VTE and may reduce the risk of all-cause mortality. The optimal duration of anticoagulation after VTE is, however, controversial and complicated by the need for individualised assessment and balance between thrombosis and bleeding risks. Three direct oral anticoagulants (rivaroxaban, apixaban and dabigatran) have been studied for extended treatment of VTE. Dabigatran was shown to be safer than vitamin K antagonists and similarly effective for the prevention of recurrent VTE. Dabigatran, apixaban and rivaroxaban resulted in significant decreases in the rate of recurrent symptomatic VTE when compared to placebo, without a statistically significant difference in the risk of major bleeding. The latest guidelines of the American College of Chest Physicians suggest the use of low-dose aspirin to prevent VTE recurrence in patients who want to stop anticoagulation. In the randomised, double-blind, phase 3 EINSTEIN CHOICE trial, once-daily rivaroxaban at doses of 20 mg or 10 mg and 100 mg of aspirin were compared in VTE patients for whom there was clinical equipoise for extended anticoagulation. Either a treatment dose (20 mg) or a prophylactic dose (10 mg) of rivaroxaban significantly reduced the risk of VTE recurrence without a significant increase in bleeding risk compared with aspirin. The EINSTEIN CHOICE trial included patients with provoked or unprovoked VTE. Patients with VTE provoked by minor persistent or minor transient risk factors enrolled in this trial had not-negligible VTE recurrence rates. These new findings on extended therapy suggest the possibility of anticoagulation regimens at intensities tailored to the patients' risk profiles and VTE characteristics, with a shift of the risk-benefit balance in favour of extended treatment.

The contribution of real-world evidence to cost-effectiveness analysis: case study of Dabigatran etexilate in France.

OBJECTIVE: The goal of this study was to assess the differences between an ex ante and an ex post cost-effectiveness analysis of Dabigatran etexilate vs VKAs for the prevention of thromboembolic events in non-valvular atrial fibrillation patients and to draw lessons on the design and use of real-world data for decision making. METHODS: The same model was used to calculate the cost-effectiveness ratio using two sets of parameters. One set included the efficacy and safety outcomes data from RE-LY, the pivotal trial comparing Dabigatran to warfarin; cost data came from an ex ante publication. Outcomes data for the second set came from real-world data studies. Cost data were a mix of real-world data and other sources. Two treatment strategies were compared: treatment initiation by either Dabigatran or VKAs, followed by either VKAs or Dabigatran. A crude comparison of results was performed; the impact of data differences was then assessed. Probabilistic sensitivity results of the two analyses were compared. RESULTS: With real-world evidence, Dabigatran at both dosages was more effective for the prevention of ischemic strokes, intra-cranial haemorrhages, with less major extra-cranial haemorrhages and a similar risk of myocardial infarction. Using clinical trial data, Dabigatran150 mg (resp. Dabigatran110 mg) as a first-line treatment vs VKAs yielded an ICER of € 8077/QALY (resp. € 13,116/QALY). Real-world evidence scenarios were cost-saving and more effective for both dosages. CONCLUSION: The reassessment of outcomes and cost data had an impact on results, improving the efficiency of Dabigatran. We identify methodological issues which should be discussed if post-launch RWE based cost-effectiveness data become a standard in HTA decision making.

Activated clotting time on the day of atrial fibrillation ablation for minimally interrupted and uninterrupted direct oral anticoagulation therapy: Sequential changes, differences among direct oral anticoagulants, and ablation safety outcomes.

BACKGROUND: Activated clotting time (ACT)-guided heparinization is used during atrial fibrillation (AF) ablation. Differences in sensitivity to ACT assays have been identified among different direct oral anticoagulants (DOACs). OBJECTIVE: We aimed to examine ACT just before ablation (pre-ACT) for different ablation start times (9:00, 11:00, 13:00, or 15:00) and ablation safety outcomes in minimally interrupted (min-Int) and uninterrupted (Unint) DOAC regimens and examine differences in pre-ACT values among four DOACs. METHODS: Consecutive patients were randomized into the min-Int (n = 307) or Unint (n = 277) groups. DOACs examined were apixaban, dabigatran, edoxaban, and rivaroxaban. RESULTS: No sequential changes in pre-ACT values were observed for each DOAC used and for all four DOACs combined in the min-Int and Unint groups. There was no meaningful difference in pre-ACT at each ablation start time between the groups. Clinically significant differences in overall pre-ACT were not obtained between the groups (138 ± 24 vs 142 ± 23 seconds). The pre-ACT (baseline) value for dabigatran was on average 29 seconds higher than that for the other three DOACs. The min-Int and Unint groups showed similar thromboembolic (0% vs 0%) and bleeding event rates (major, 1% vs 0%; all, 3.5% vs 2.5%). CONCLUSION: The pre-ACT did not show a sequential change in the min-Int and Unint groups. No notable differences in the time-dependent change in pre-ACT between the groups were observed. Variations in baseline ACT suggest the need for moderate adjustment of ACT for adequate modification of heparin dose for the other three DOACs. Both regimens provided similar acceptable AF ablation safety outcomes.

Safety of direct oral anticoagulants in patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular dysplasia resulting in visceral arteriovenous malformations and smaller mucocutaneous telangiectasia. Most patients experience recurrent nosebleeds and become anemic without iron supplementation. However, thousands may require anticoagulation for conditions such as venous thromboembolism and/or atrial fibrillation. Over decades, tolerance data has been published for almost 200 HHT-affected users of warfarin and heparins, but there are no published data for the newer direct oral anticoagulants (DOACs) in HHT. METHODS: To provide such data, a retrospective audit was conducted across the eight HHT centres of the European Reference Network for Rare Multisystemic Vascular Diseases (VASCERN), in Denmark, France, Germany, Italy, the Netherlands and the UK. RESULTS: Although HHT Centres had not specifically recommended the use of DOACs, 32 treatment episodes had been initiated by other clinicians in 28 patients reviewed at the Centres, at median age 65 years (range 30-84). Indications were for atrial fibrillation (16 treatment episodes) and venous thromboembolism (16 episodes). The 32 treatment episodes used Apixaban (n = 15), Rivaroxaban (n = 14), and Dabigatran (n = 3). HHT nosebleeds increased in severity in 24/32 treatment episodes (75%), leading to treatment discontinuation in 11 (34.4%). Treatment discontinuation was required for 4/15 (26.7%) Apixaban episodes and 7/14 (50%) Rivaroxaban episodes. By a 4 point scale of increasing severity, there was a trend for Rivaroxaban to be associated with a greater bleeding risk both including and excluding patients who had used more than one agent (age-adjusted coefficients 0.61 (95% confidence intervals 0.11, 1.20) and 0.74 (95% confidence intervals 0.12, 1.36) respectively. Associations were maintained after adjustment for gender and treatment indication. Extreme hemorrhagic responses, worse than anything experienced previously, with individual nosebleeds lasting hours requiring hospital admissions, blood transfusions and in all cases treatment discontinuation, occurred in 5/14 (35.7%) Rivaroxaban episodes compared to 3/15 (20%) Apixaban episodes and published rates of ~ 5% for warfarin and heparin. CONCLUSIONS: Currently, conventional heparin and warfarin remain first choice anticoagulants in HHT. If newer anticoagulants are considered, although study numbers are small, at this stage Apixaban appears to be associated with lesser bleeding risk than Rivaroxaban.

Effectiveness and safety of direct oral anticoagulants compared to warfarin in treatment naïve non-valvular atrial fibrillation patients in the US Department of defense population.

BACKGROUND: Clinical trials have demonstrated that direct oral anticoagulants (DOACs) are at least non-inferior to warfarin in reducing the risk of stroke/systemic embolism (SE) among patients with non-valvular atrial fibrillation (NVAF), but the comparative risk of major bleeding varies between DOACs and warfarin. Using US Department of Defense (DOD) data, this study compared the risk of stroke/SE and major bleeding for DOACs relative to warfarin. METHODS: Adult patients with ≥1 pharmacy claim for apixaban, dabigatran, rivaroxaban, or warfarin from 01 Jan 2013-30 Sep 2015 were selected. Patients were required to have ≥1 medical claim for atrial fibrillation during the 12-month baseline period. Patients with a warfarin or DOAC claim during the 12-month baseline period were excluded. Each DOAC cohort was matched to the warfarin cohort using propensity score matching (PSM). Cox proportional hazards models were conducted to evaluate the risk of stroke/SE and major bleeding of each DOAC vs warfarin. RESULTS: Of 41,001 identified patients, there were 3691 dabigatran-warfarin, 8226 rivaroxaban-warfarin, and 7607 apixaban-warfarin matched patient pairs. Apixaban was the only DOAC found to be associated with a significantly lower risk of stroke/SE (hazard ratio [HR]: 0.55; 95% confidence interval [CI]: 0.39, 0.77; p < 0.001) and major bleeding (HR: 0.65; 95% CI: 0.53, 0.80; p < 0.001) compared to warfarin. Dabigatran and rivaroxaban initiation were associated with similar risk of stroke/SE (dabigatran: HR: 0.68; 95% CI: 0.43, 1.07; p = 0.096; rivaroxaban: HR: 0.83; 95% CI: 0.64, 1.09; p = 0.187) and major bleeding (dabigatran: HR: 1.05; 95% CI: 0.79, 1.40; p = 0.730; rivaroxaban: HR: 1.07; 95% CI: 0.91, 1.27; p = 0.423) compared to warfarin. CONCLUSION: Among NVAF patients in the US DOD population, apixaban was associated with significantly lower risk of stroke/SE and major bleeding compared to warfarin. Dabigatran and rivaroxaban were associated with similar risk of stroke/SE and major bleeding compared to warfarin.

Extended treatment with non-vitamin K antagonist oral anticoagulants versus low-molecular-weight heparins in cancer patients following venous thromboembolism. A pilot study.

BACKGROUND: Low-molecular-weight heparins (LMWH) are the drug of choice for treatment of cancer-associated thrombosis (CAT), however non-vitamin K antagonist oral anticoagulants (NOAC) seem to be a reasonable alternative. We investigated the safety and efficacy of NOAC versus LMWH in patients with a history of CAT. METHODS: In a prospective cohort study 128 consecutive patients with active cancer who experienced CAT were enrolled following LMWH treatment for ≥3 months. Symptomatic recurrent venous thromboembolism (VTE), bleeding and death were recorded during follow-up. RESULTS: 65 (50.8%) patients were switched to NOAC and 63 (49.2%) continued with LMWH. During a median follow-up of 17 (interquartile range, 15-21) months, recurrent VTE was observed in 6 (9.2%) patients on NOAC and in 12 (19.0%) on LMWH (hazard ratio [HR] 0.44, 95% confidence interval [CI] 0.16-1.16). The rate of major bleeding was 9.2% and 4.8%, respectively (HR 2.00, 95% CI 0.50-8.00). The median time to bleeding was shorter in patients on NOAC (3 [2.25-5.5] months) versus on LMWH (9 [6.5-13.0] months). The mortality rates were similar in both groups (15.4% versus 15.9%, respectively, HR 0.76, 95% CI 0.32-1.84). CONCLUSIONS: In patients following CAT, extended treatment with NOAC, compared with LMWH, appears to be associated with similar effectiveness and safety.