Efficacy and Safety Outcomes of Direct Oral Anticoagulants and Amiodarone in Patients with Atrial Fibrillation

BACKGROUND

Direct oral anticoagulants (DOACs) and amiodarone are widely used in the treatment of nonvalvular atrial fibrillation. The DOACs are P-glycoprotein (P-gp) and cytochrome p-450 (CYP3A4) substrates. Direct oral anticoagulant levels may be increased by the concomitant use of potent dual P-gp/CYP3A4 inhibitors, such as amiodarone, which can potentially translate into adverse clinical outcomes. We aimed to assess the efficacy and safety of drug-drug interaction by the concomitant use of DOACs and amiodarone.

METHODS

We performed a systematic review of MEDLINE, the Cochrane Central Register of Clinical Trials, and Embase, limiting our search to randomized controlled trials of patients with atrial fibrillation that have compared DOACs versus warfarin for prophylaxis of stroke or systemic embolism, to analyze the impact on stroke or systemic embolism, major bleeding, and intracranial bleeding risk in patients with concomitant use of amiodarone. Risk ratio (RR) 95% confidence intervals were measured using the Mantel-Haenszel method. The fixed effects model was used owing to heterogeneity (I²) < 25%.

RESULTS

Four trials with a total of 71,683 patients were analyzed, from which 5% of patients (n = 3212) were concomitantly taking DOAC and amiodarone. We found no statistically significant difference for any of the clinical outcomes (stroke or systemic embolism [RR 0.85; 95% CI, 0.67-1.06], major bleeding [RR 0.91; 95% CI, 0.77-1.07], or intracranial bleeding [RR 1.10; 95% CI, 0.68-1.78]) among patients taking DOAC and amiodarone versus DOAC without amiodarone.

CONCLUSION

On the basis of the results of this meta-analysis, co-administration of DOACs and amiodarone, a dual P-gp/CYP3A4 inhibitor, does not seem to affect efficacy or safety outcomes in patients with atrial fibrillation.

Epidemiology of Intracranial Hemorrhage Associated with Oral Anticoagulants in Spain: Trends in Anticoagulation Complications Registry - The TAC 2 Study

Objective

Patients receiving treatment with oral anticoagulants (OACs) are at risk of intracranial hemorrhage (ICH). In this study, we describe the epidemiological and clinical characteristics of patients receiving OACs who experience ICH and compare those receiving vitamin K antagonists (ICH-VKAs) with those receiving direct OACs (ICH-DOACs).

Methods

We performed a national, multicenter, descriptive, observational, retrospective study of all adult patients receiving OACs who were admitted to the neurology department with ICH over a 1-year period. The study population was divided into 2 groups (ICH-VKAs and ICH-DOACs). Epidemiological, clinical, radiological, and therapy-related variables, as well as functional outcome, were compared at 3 months. A total of 366 cases were included (331 ICH-VKAs, 35 ICH- DOACs).

Results

The crude annual incidence of OAC-induced ICH was 3.8 (95% CI, 2.78-3.41) per 100,000 inhabitants/year. The mean (± SD) age was greater for ICH-DOACs (81.5 ± 8.3 vs. 77.7 ± 8.3 years; p = 0.012). The median (IQR) volume of the hemorrhage was lower for ICH-DOACs (11 [30.8] vs. 25 [50.7] mL; p = 0.03). The functional independence rate at 3 months (modified Rankin Scale, mRS < 3) was similar in both groups, although stroke-related mortality was greater in ICH-VKAs (40 vs. 72.7%; p = 0.02). The most frequently indicated poststroke antithrombotic therapy was DOACs (38.7%).

Conclusion

We found that the incidence of OAC-induced ICH was greater than in previous studies. Hemorrhage volume and mortality were lower in ICH-DOACs than in ICH-VKAs. After stroke, DOACs were the most frequently indicated antithrombotic treatment.

A Systematic Review and Meta-analysis

INTRODUCTION AND OBJECTIVES

To assess the effectiveness of direct oral anticoagulants vs vitamin K antagonists in real-life patients with atrial fibrillation.

METHODS

A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA statement. The ROBINS-I tool was used to assess risk of bias.

RESULTS

A total of 27 different studies publishing data in 30 publications were included. In the studies with a follow-up up to 1 year, apixaban (HR, 0.93; 95%CI, 0.71-1.20) and dabigatran (HR, 0.95; 95%CI, 0.80-1.13) did not significantly reduce the risk of ischemic stroke vs warfarin, whereas rivaroxaban significantly reduced this risk (HR, 0.83; 95%CI, 0.73-0.94). Apixaban (HR, 0.66; 95%CI, 0.55-0.80) and dabigatran (HR, 0.83; 95%CI, 0.70-0.97) significantly reduced the major bleeding risk vs warfarin, but not rivaroxaban (HR, 1.02; 95%CI, 0.95-1.10), although with a high statistical heterogeneity among studies. Apixaban (HR, 0.56; 95%CI, 0.42-0.73), dabigatran (HR, 0.45; 95%CI, 0.39-0.51), and rivaroxaban (HR, 0.66; 95%CI, 0.49-0.88) significantly reduced the risk of intracranial bleeding vs warfarin. Reduced doses of direct oral anticoagulants were associated with a slightly better safety profile, but with a marked reduction in stroke prevention effectiveness.

CONCLUSIONS

Data from this meta-analysis suggest that, vs warfarin, the stroke prevention effectiveness and bleeding risk of direct oral anticoagulants may differ in real-life patients with atrial fibrillation.

Mechanism and management of cancer-associated thrombosis

Thromboembolism is considered to have a substantial impact on outcomes in patients with cancer. Although progress in cancer therapy and the advent of new anticancer agents such as molecular targeted drugs have improved the outcomes of patients with cancer, the incidence of cancer-therapy-related thromboembolism is increasing, and the management of this adverse reaction has become a major problem. Cancer is intimately related to thrombosis. Thrombus formation results from the complex interaction of various factors, such as tissue factors, coagulation abnormalities, activated platelet activation, activated adhesion activation, and endothelial cell dysfunction. Thrombosis has an impact on cancer proliferation and extension. The condition known as "cancer-related thrombosis" must therefore be managed differently from thrombosis in patients without cancer.

Registry of Japanese patients with atrial fibrillation focused on anticoagulant therapy in the new era: The RAFFINE registry study design and baseline characteristics

BACKGROUND

The management of atrial fibrillation (AF) has evolved with the development of direct oral anticoagulants (DOACs), but data on their clinical effectiveness and safety outside clinical trial settings are limited.

METHOD

The RAFFINE registry is an observational, multicenter, prospective registry of Japanese patients with AF, designed to follow clinical events over 3 years. Patient enrollment was conducted from 2013 to 2015 at university hospitals, general hospitals, and private clinics to ensure inclusion of a broad spectrum of representative AF patients. The primary outcome events in this study will be ischemic stroke, systemic embolism, and major bleeding.

RESULT

We enrolled 3901 ambulatory patients with AF from 4 university hospitals and 50 general hospitals/clinics in Japan. The mean patient age was 72.6 years and 68.5% were male. The type of AF was paroxysmal in 37.8%, persistent in 9.3%, and permanent in 51.7%. Major coexisting diseases were hypertension (72.7%), diabetes mellitus (30.3%), congestive heart failure (23.8%), history of ischemic stroke or transient ischemic attack (15.1%), and coronary artery disease (13.7%). Of the entire cohort, 44.6% were treated with warfarin and 43.0% were treated with DOACs. The prescription of DOACs exceeded that of warfarin in the general hospitals and clinics. Risk scores such as CHADS₂ score, CHA₂DS₂-VASc score, and HAS-BLED score were higher in patients at university hospitals than in patients at general hospitals or clinics.

CONCLUSION

The RAFFINE registry at baseline described the current status of anticoagulation therapy in Japan and long-term follow-up data will identify how outcomes vary between stratified groups in patients with AF in the DOAC era (UMIN Clinical Trials Registry UMIN000009617).

Clinical characteristics and management of patients with atrial fibrillation treated with direct oral anticoagulants according to blood pressure control

OBJECTIVE

To determine the clinical characteristics and management of hypertensive patients with nonvalvular atrial fibrillation (AF) treated with direct oral anticoagulants (DOACs) according to blood pressure (BP) control.

METHODS

For this purpose, data from two observational, cross-sectional and multicenter studies were combined. In both studies, patients on chronic treatment with anticoagulants and that were on current treatment with DOACs at least for 3 months were included. Adequate BP was defined as a systolic BP<140mmHg and a diastolic BP<90mmHg (<140/85mmHg if diabetes).

RESULTS

Overall, 1036 patients were included. Of these, 881 (85%) had hypertension that were finally analyzed. The presence of other risk factors and cardiovascular disease was common. Mean BP was 132.6±14.3/75.2±9.2mmHg and 70.5% of patients achieved BP goals. Those patients with a poor BP control had more frequently diabetes, and a history of prior labile INR. Patients had a high thromboembolic risk, but without significant differences according to BP control. By contrast, more patients with a poor BP control had a higher bleeding risk (HAS-BLED ≥3: 24.0% vs 35.4%; P<0.001). HAS-BLED score was an independent predictor of poor BP control (odds ratio 1.435; 95% confidence interval 1.216-1.693; P<0.001). Satisfaction with anticoagulant treatment was independent of BP control.

CONCLUSIONS

More than two thirds of our patients with hypertension and AF anticoagulated with DOACs achieve BP targets, what is clearly superior to that reported in the general hypertensive population.

New Trends in Anticoagulation Therapy

Anticoagulation pharmacy has been dramatically altered with US Food and Drug Administration (FDA) approval of 5 direct oral anticoagulants, 1 novel reversal agent and, a second designated for fast-track approval. Trial data surrounding current trends in anticoagulant choice for VTE, reversal, and bridging are constantly redefining practice. Extended therapy for unprovoked VTE has expanded to include low-dose direct oral anticoagulants, aspirin, and the use of the HERDOO2 system to identify women who can stop anticoagulant therapy without increased risk of recurrent VTE. Trends in thromboprophylaxis include extended duration low-dose direct oral anticoagulants to prevent VTE in high-risk patients.

Better clinical outcome with direct oral anticoagulants in hospitalized heart failure patients with atrial fibrillation

Background

Atrial fibrillation (AF) is common in patients with heart failure and is associated with higher mortality. Although previous studies have reported that direct oral anticoagulants (DOACs) reduce the risk of cardiovascular events in out-patients with AF, it remains unclear whether DOACs reduce mortality in hospitalized heart failure (HHF) patients with AF. Therefore, we examined the impact of DOACs on mortality in this group of patients.

Methods

Consecutive 497 HHF patients with AF were retrospectively registered and divided into three groups on the basis of the presence of anticoagulant therapy: non-anticoagulant group (Non, n = 90), Vit K antagonists (VKAs) group (n = 257) and DOACs group (n = 150). We followed up all the patients for mortality.

Results

In the Kaplan-Meier analysis (mean follow-up of 1093 days), all-cause mortality was significantly lower in the VKAs and DOACs groups than in the Non group (31.1% and 15.3% vs. 43.3%, log-rank P < 0.001). In the multivariable Cox proportional hazard analysis after adjusting for other potential confounding factors, usage of DOACs and VKAs were independently associated with lower mortality in HHF patients AF (DOACs, HR 0.356, P = 0.001; VKAs, HR 0.472, P = 0.002). Furthermore, the propensity-matched 1:1 cohort was assessed based on the propensity score (DOACs, n = 114 and VKAs, n = 114). All-cause mortality was significantly lower in the DOACs group than in the VKAs group in the post-matched cohort (12.3% vs. 35.1%, log-rank P = 0.038). In the Cox proportional hazard analysis, the use of DOACs was associated with lower mortality in the post-matched cohort (HR 0.526, P = 0.041).

Conclusion

Appropriate use of anticoagulants in HHF patients with AF is important, and DOACs potentially improve all-cause mortality in such patients.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0746-z) contains supplementary material, which is available to authorized users.

[Not Available]

Zusammenfassung. Die direkten oralen Antikoagulanzien (DOAK) gelten als Medikamente der Wahl in der Behandlung der tiefen Beinvenenthrombose und Lungenembolie. Aus der Patientenperspektive wäre es wünschenswert, diese oralen Substanzen auch in der Behandlung der krebsassoziierten Thrombose (Cancer-Associated Thrombosis, CAT) als Alternative zu der Standardtherapie mit niedermolekularen Heparinen (NMH) einzuführen. Da prospektive Daten zur Wirksamkeit und Sicherheit der DOAK im Vergleich zu NMH noch nicht zur Verfügung stehen, sollten DOAK vorerst für Patienten mit CAT reserviert werden, die eine subkutane Therapie mit NMH nicht tolerieren oder nach der initialen Behandlung mit NMH eine Langzeitantikoagulation erfordern. Die Interaktionen, möglich veränderte Bioverfügbarkeit und Organfunktionen müssen auch bei einer späteren breiteren Einführung der DOAK bei Krebspatienten berücksichtigt werden.

ESC position paper on cardiovascular toxicity of cancer treatments: challenges and expectations

The recent position paper of the European Society of Cardiology (ESC) on cardiovascular toxicity of cancer treatments has attracted considerable interest by healthcare professionals, since it is the first concrete help in the difficult task of monitoring and approaching cardiovascular side effects of anticancer treatments. The ESC expert opinion was not intended as a clinical practice guideline; however, it reports major cardiovascular complications grouped into nine categories, addressing current clinical strategies for prevention and mitigation. In this point of view, we discuss key challenges emerging from critical appraisal of the ESC position paper: (1) the wide spectrum of cardiovascular toxicities associated with oncological drugs, focusing on targeted agents, (2) managing strategies in patients with cardiac implantable devices, (3) the underappreciated (but emerging) immune-related cardiovascular toxicities of checkpoint inhibitors, which may also result in severe heart failure and fulminant myocarditis, (4) the evolving role of anticoagulation in oncology, and the evidence supporting (or not) the use of direct-acting oral anticoagulants in cancer-associated thrombosis.

Drug-induced thrombocytopenia after anticoagulation with rivaroxaban

A 66-year-old man presented to the emergency department with complaints of dark-colored stool and rash developing over the last couple of days. The patient was started on rivaroxaban and flecainide for months prior for atrial fibrillation. Upon arrival, he was awake, alert, and oriented with a blood pressure of 111/63mmHg, heart rate of 68 beats per minute, and oxygen saturation of 96% on room air. A review of systems was unremarkable with the exception of skin rash and light-headedness. The patient's initial laboratory results were significant for red blood cell (RBC) count of 4.05×10⁶/mcL, hemoglobin of 12.1g/dL, hematocrit of 35.6%, and platelet count of 1×103/mcL. Aggressive hydration was started in the ED, initially with two 1-L boluses of normal saline followed by an infusion of 10mL/h. One unit of platelets was transfused. Rivaroxaban and flecainide were held on admission. Twenty-four hours after admission, the patient was initiated on immune globulin (IVIG) Gammagard (Baxter, West Lake, CA), 75g on 3 consecutive days and steroids for possible immune thrombocytopenia. His platelet count steadily improved over the 6-day period to 119×103/mcL on the day of hospital discharge. This is the second reported case of possible rivaroxaban-induced thrombocytopenia.

Acute haemorrhagic tamponade in cancer patients receiving direct oral anticoagulant: case series

The use of direct oral anticoagulants (DOACs) is on the rise in the general population. However, data related to the safety of DOACs in patients with malignancy are limited. In this brief report, we present a series of three cases of haemorrhagic pericardial effusions and tamponade in patients receiving DOACs while undergoing cancer therapy. These three cases were all observed within a period of 6 weeks at a single institution and occurred shortly after the initiation of anticoagulation with one of the DOACs. Two of these patients had evidence of neoplastic pericardial process and were being treated with immunotherapy. The third patient was receiving targeted cancer therapy with a drug known to be associated with increased bleeding risks. Haemorrhagic pericarditis may represent a unique type of DOACs-related complications in subgroups of cancer patients with neoplastic pericardial disease and/or complex pharmacodynamics drug–drug interaction. The purpose of this report is to raise awareness of the lack of conclusive safety data of DOACs in certain cancer patients and to remind clinical providers of the National Comprehensive Cancer Network guidelines recommending against their use in patients with malignancy on the basis of limited safety data in patients undergoing cancer therapies.

Impact of age, comorbidity, and polypharmacy on the efficacy and safety of edoxaban for the treatment of venous thromboembolism: An analysis of the randomized, double-blind Hokusai-VTE trial

BACKGROUND

Many patients with venous thromboembolism (VTE) are elderly, have multiple comorbidities and take several concomitant medications. Physicians may prefer warfarin over direct oral anticoagulants (DOACs) in such patients because comparative data are lacking. This analysis was designed to determine the effects of advanced age, comorbidities, and polypharmacy on the efficacy and safety of edoxaban and warfarin in patients with VTE.

METHODS

Using data from the Hokusai-VTE study, we report rates of recurrent VTE and of clinically relevant bleeding by age category (<65, 65-75, and ≥75; <80 versus ≥80years), and by number of comorbidities (0, 1-2, >2) and concomitant medications (<3, 3-5, >5). Hazard ratios (HR) and corresponding 95% confidence intervals (CI) for edoxaban versus warfarin were determined and Kaplan-Meier methodology was used to construct time-to-event curves. At 3months, pre- and postdose levels of edoxaban were measured using mass spectrometry. For warfarin-treated patients, the time in therapeutic range was calculated. The study was approved by institutional review boards; informed consent was obtained.

RESULTS

Recurrent VTE increased with advanced age, multiple comorbidities, and polypharmacy in warfarin-treated patients but not with edoxaban. Edoxaban was more effective than warfarin in patients ≥75years of age and in those with multiple comorbidities. In the 517 patients over 80years of age, recurrent VTE occurred in 2.8% given edoxaban and in 5.7% given warfarin (HR 0.51, 95% CI 0.21-1.24). Bleeding increased with age, comorbidity, and polypharmacy regardless of treatment, but the relative safety of edoxaban versus well-managed warfarin was maintained. Age, comorbidity, and polypharmacy did not impact edoxaban concentrations.

CONCLUSIONS

These data suggest that a once-daily fixed dose of edoxaban is more effective and at least as safe as warfarin in high-risk VTE patients identified by older age, more comorbidities, and polypharmacy.

CLINICAL TRIAL REGISTRATION

NCT00986154.

Current evidence of oral anticoagulant reversal: A systematic review

INTRODUCTION

Approximately 4-6% of patients treated with oral anticoagulants (OAC) will suffer from major hemorrhage or be in need of urgent surgery necessitating anticoagulant reversal therapy. Several new oral anticoagulants and reversal agents have been introduced that make it difficult for physicians to stay updated on the current evidence of reversal management. This study aims to review the recent literature on oral anticoagulation reversal therapy and to present the current evidence in an easily approachable manner.

MATERIALS AND METHODS

A systematic literature search was conducted using PubMed and EMBASE to identify the latest publications on both vitamin K antagonist (VKA) and direct oral anticoagulant (DOAC) reversal strategies. All studies on humans who received any acute reversal management of VKA treatment were included, except case studies. Since only two studies on acute reversal of DOAC treatment have been published, clinical trials on healthy volunteers were also included.

RESULTS

Twenty-one studies with a total of 4783 VKA treated patients, and 12 studies with a total of 529 DOAC treated patients were included. Elevated INR values due to VKA treatment could be reversed (INR≤1.5) in 63.1% (95% CI: 61.0-65.2) of study subjects after treatment with 4F-PCC, as compared with 12.2% (95% CI: 8.2-16.2) after treatment with fresh frozen plasma (FFP), (p<0.001). Thromboembolism occurred in 1.6% (95% CI: 1.2-2.1) of VKA-patients treated with 4F-PCC, and in 4.5% (95% CI: 2.3-6.7) of FFP-treated patients. To date, reversal of laboratory parameters has been demonstrated for two reversal agents specific to DOACs: idarucizumab for dabigatran reversal and andexanet-alfa for factor Xa-inhibitor reversal.

CONCLUSIONS

This review supports the use of PCC for VKA reversal, specifically for 4F-PCC over FFP for laboratory reversal. There are no studies on clinical efficacy of non-specific agents for DOAC reversal and the evidence for laboratory reversal is not consistent.

The role of direct oral anticoagulants in cancer-related venous thromboembolism: a perspective beyond the guidelines

Cancer-related venous thromboembolism (Wickham et al., Intern Med J 42(6):698-708, 2012) is an important source of morbidity and mortality in that population. The standard of care for the treatment of cancer-related venous thromboembolism (VTE) is a low molecular weight heparin (LMWH) for long periods of time. The favorable clinical trial results for efficacy and safety and availability of direct oral anticoagulants (DOAC) have remodeled the care and options for treatment of venous thromboembolism in the adult population. The data of cancer population-subgroup analysis of those studies have shown that DOAC are as effective and safe as conventional long-term oral anticoagulation with vitamin K antagonists (VKA). Additionally, non-controlled retrospective and prospective cohort data have been published describing efficacy and safety outcomes for the use of DOAC in cancer-related VTE. Altogether, the results from clinical studies have shown that direct oral anticoagulants may represent a treatment option for cancer-related VTE and an alternative to anticoagulation with VKA. Little is known about the patient-centered and system-based variables that determine the use of DOAC outside consensus guidelines, neither is known the impact of different anticoagulant modalities in adherence and quality of life in cancer patients. The objectives of this manuscript are to summarize the clinical trial-based and cohort data of cancer patients treated with DOAC for VTE and to highlight the aspects that may influence adherent to therapy, effectiveness, and safety outcomes in the treatment of cancer-related VTE.

Readmissions in Patients with Anticoagulated Intracranial Hemorrhage: A Retrospective Review

OBJECTIVE

To determine the effect of direct oral anticoagulants (DOACs) compared with warfarin on the 30-day readmission rates in patients with traumatic intracranial hemorrhage (ICH).

METHODS

We conducted a retrospective review of patients from our hospital's trauma database admitted between June 2011 and October 2015 to our level II trauma center after sustaining a traumatic ICH while receiving anticoagulant therapy. Patients were stratified based on the anticoagulation drug (DOAC or warfarin) prescribed on admission. The readmission rates between the 2 groups were compared using χ² analysis and multivariate logistic regression. Patients who died during their initial admission were excluded.

RESULTS

Over the 4-year period, 160 patients were admitted with traumatic ICH. Seventy-nine were receiving warfarin and 57 were receiving a DOAC at admission. Data collected included age, sex, injury severity score, admission Glasgow Coma Score, Abbreviated Injury Scale (head), mechanism of injury, hospital and intensive care unit lengths of stay, discharge destination (eg, home, rehabilitation facility, nursing facility), comorbidities, operative interventions, readmissions, and reasons for the readmissions. The rate of readmission for rebleeding of ICH was significantly lower in the DOAC group compared with the warfarin group (5.3% vs. 17.7%; P = 0.04). Multivariate logistic regression suggests that warfarin use, but not DOAC use, is associated with increased readmission both for all causes and for ICH rebleeding.

CONCLUSIONS

Warfarin use is associated with higher readmission rates in patients with intracranial bleeding for both all-cause readmissions and for intracranial rebleeding.

[Evaluation about patient's knowledge on their direct oral anticoagulants treatment]

AIM OF THE STUDY

Patient's knowledge about their treatment is poor, generally speaking. New oral anticoagulants are easier to use compared to antivitamin K, and they are going to increase. This simplification can underestimate their high potential risk. We have assessed patient's knowledge about their direct oral anticoagulants.

METHODS

It was a quantitative, observational, multicentric, prospective study, on 50 patients on Direct Oral Anticoagulants. They have been included from November 2015 to February 2017, in Île-de-France. They were needed to be aged more than 18years old, whatever was: the reason of this treatment, the beginning of it, the molecule, the existence or not of antivitamin K before. Their knowledge was assessed by a survey, realised by a unique investigator. The primary outcome was to reach more than 80% good answers to the survey. Secondary outcomes were to identify factors than can influence knowledge.

RESULTS

Among fifty patients, nine (18%) reached a goal over or equal to 80%. They knew the name of their medicament in 58% of cases, and the indication in 72% of cases. They could identify hemorragic signs in more than 70% of cases. In case of hemorragic sign, 94% of them were going to see a doctor. Thrombosis signs were less knew. None of the factors, excepted their profession, was different in the two populations (P=0,01).

CONCLUSION

This study showed the few rate of patient knowing their oral anticoagulants treatment perfectly, and their need to improve it. It could make professional healthcare aware to this problematic.

Successful treatment of a massive pulmonary embolism using rivaroxaban in a patient with antithrombin III deficiency

We report a case of acute massive pulmonary embolism in a patient with antithrombin III deficiency. The patient was treated with rivaroxaban. The patient responded well to the therapy, and contrast-enhanced computed tomography showed nearly complete disappearance of the pulmonary embolism. Patients with low antithrombin III activity may have resistance to heparin therapy, leading to insufficient anticoagulation during the acute phase of thromboembolism. This case suggests that direct oral anticoagulants, such as rivaroxaban, may be effective first-line agents for treating venous thromboembolism in patients with antithrombin III deficiency. .

Meta-analysis of safety and efficacy for direct oral anticoagulation treatment of non-valvular atrial fibrillation in relation to renal function

INTRODUCTION

We performed a meta-analysis of the safety and efficacy of anticoagulation treatment for atrial fibrillation (AF) in relation to renal function. We also examined the change in estimated glomerular filtration rate (eGFR) from baseline and compared the outcomes for patients with stable and worsening renal function.

MATERIALS AND METHODS

We selected studies that used randomized controlled trials in which outcomes for direct oral anticoagulants (DOACs) (dabigatran, rivaroxaban, apixaban, or edoxaban) were compared with those for warfarin in AF patients with normal, mild or moderate renal function, except the severe one (creatinine clearance<30).

RESULTS

We assessed five clinical trials, involving 72,608 patients. Pooled analysis indicated that the risk of stroke was lower for DOACs than for warfarin among patients with mild renal impairment (Risk ratio, 0.79; 95% confidence interval, 0.68-0.91) and moderate renal impairment (0.80, 0.69-0.92). No major differences were found in patients with normal renal function. Additionally, DOACs were associated with fewer major bleeds among patients with normal (0.77, 0.70-0.84), mild (0.86, 0.77-0.95), and moderate renal impairment (0.73, 0.65-0.82). Among those treated with DOACs, a lower dosage was associated with lower risk of major bleeding (0.75, 0.68-0.83) and higher risk of stroke or systemic embolism (1.28, 1.12-1.47). Further, DOACs tended to be associated with a lower estimated glomerular filtration rate (eGFR) than warfarin even after 30months. Finally, we found significant differences in the risk of stroke (2.09, 1.64-2.68) and major bleeding (2.01, 1.66-2.42) between patients with stable and worsening renal function.

CONCLUSIONS

DOACs have a greater clinical benefit than warfarin with respect to renal function. They are associated with a comparatively lower risk of stroke and major bleeding, as well lower eGFR. This suggests these agents are a better choice in patients with renal disease.

Real-world monitoring of direct oral anticoagulants in clinic and hospitalization settings

Background:

The monitoring of the effects of direct oral anticoagulants may be beneficial during emergencies and adverse events. We aimed to explore direct oral anticoagulant monitoring in “real-world” settings, in which monitoring methods are limited and loading time can be estimated based on only patient reports.

Methods:

In 164 patients, plasma anti-Xa activity was assessed using a STA^®-Liquid Anti-Xa reagent (Diagnostica Stago, Asnieres, France), and prothrombin time was measured using HemosIL^® RecombiPlasTin 2G (Instrumentation Laboratory, Bedford, MA, USA). The loading time was calculated according to the previous dosing time reported by the patient. In the clinic setting, rivaroxaban and apixaban were administered to 103 patients with atrial fibrillation and a blood sample was tested once during a clinic visit. In the hospitalization setting, edoxaban was administered to 61 patients undergoing arthroplasty for prophylaxis of a venous thrombosis and blood samples were tested 3 and 18 h after the last intake.

Results:

Plasma Xa activity in the clinical setting ranged widely (rivaroxaban: 1.1–424.4 ng/mL, apixaban: 15.4–469.2 ng/mL) during the 11.7 ± 7.0 h following the previous dose. The values varied over a wide range (up to a factor of 2) at the same loading time, especially around the peak period. The plasma anti-Xa activity of rivaroxaban and apixaban showed linear correlations with prothrombin time (R² = 0.828 and 0.717, respectively). Edoxaban administration prolonged the prothrombin time by only 1.6 ± 1.1 s from the trough to the peak, to a degree that was negatively correlated with age, but not with plasma creatinine level, creatinine clearance, or body mass index.

Conclusion:

In real-world settings, plasma anti-Xa monitoring should be interpreted considering the wide variations in data, reflecting the variability in patient-reported loading time and interpatient variability.

Indications and Methods of Anticoagulation Reversal

The use of anticoagulation in the prevention of strokes due to atrial fibrillation or the treatment of venous thromboembolic disease has been on the rise. With the advent and proliferation of direct oral anticoagulation medications, the management of anticoagulation reversal has become increasingly complex, especially when urgent or emergent reversal is required. This review details the commonly used parenteral and oral anticoagulants, the treatment strategies necessary for their reversal, and therapies still in development.

Renal Function and Direct Oral Anticoagulant Treatment for Venous Thromboembolism

Because differences in renal function can affect the efficacy and safety of direct oral anticoagulants, prescribing an appropriate dose based on renal function is critical, especially in patient populations with a high incidence of renal impairment. In patients with nonvalvular atrial fibrillation and mild or moderate renal impairment, direct oral anticoagulants are associated with a better risk-benefit profile compared with warfarin. However, less is known regarding outcomes in patients with venous thromboembolism and renal impairment. The efficacy and safety of direct oral anticoagulants in patients with venous thromboembolism and renal impairment are primarily derived from prespecified subgroup analyses of the phase 3 clinical trials. We summarize the available data on direct oral anticoagulant use in patients with venous thromboembolism and renal impairment. Clinicians are encouraged to follow study inclusion/exclusion criteria and perform renal dose adjustments based on the Cockcroft-Gault equation using actual body weight when indicated to avoid adverse events.

Adherence and outcomes to direct oral anticoagulants among patients with atrial fibrillation: findings from the veterans health administration

Background

The direct oral anticoagulants (DOACs) reduce the risk of stroke in moderate to high-risk patients with non-valvular atrial fibrillation (AF). Yet, concerns remain regarding its routine use in real world practice. We sought to describe adherence patterns and the association between adherence and outcomes to the DOACs among outpatients with AF.

Methods

We performed a retrospective cohort study of patients in the VA Healthcare System who initiated pharmacotherapy with dabigatran, rivaroxaban, or apixaban between November 2010 and January 2015 for non-valvular AF with CHA₂DS₂-VASc score ≥ 2. Adherence was determined using pharmacy refill data and estimated by the proportion of days covered (PDC) over the first year of therapy. Clinical outcomes, including all-cause mortality and stroke, were measured at 6 months and used to assess measures of adherence for each DOAC.

Results

A total of 2882 patients were included. Most were prescribed dabigatran (72.7%), compared with rivaroxaban (19.8%) or apixaban (7.5%). The mean PDC was 0.84 ± 0.20 for dabigatran, 0.86 ± 0.18 for rivaroxaban, and 0.89 ± 0.14 for apixaban (p < 0.01). The proportion of non-adherent patients, PDC <0.80, was 27.6% for all and varied according DOAC. Lower adherence to dabigatran was associated with higher risk of mortality and stroke (HR 1.07; 1.03–1.12 per 0.10 decline in PDC).

Conclusions

In a real-world VA population being prescribed anticoagulation for AF, more than one quarter had sub-optimal adherence. Lower adherence was associated with a higher risk of mortality and stroke. Efforts identifying non-adherent patients, and targeted adherence interventions are needed to improve outcomes.

Renal Function Considerations for Stroke Prevention in Atrial Fibrillation

Renal impairment increases risk of stroke and systemic embolic events and bleeding in patients with atrial fibrillation. Direct oral anticoagulants (DOACs) have varied dependence on renal elimination, magnifying the importance of appropriate patient selection, dosing, and periodic kidney function monitoring. In randomized controlled trials of nonvalvular atrial fibrillation, DOACs were at least as effective and associated with less bleeding compared with warfarin. Each direct oral anticoagulant was associated with reduced risk of stroke and systemic embolic events and major bleeding compared with warfarin in nonvalvular atrial fibrillation patients with mild or moderate renal impairment. Renal function decrease appears less impacted by DOACs, which are associated with a better risk-benefit profile than warfarin in patients with decreasing renal function over time. Limited data address the risk-benefit profile of DOACs in patients with severe impairment or on dialysis.

Single-center, retrospective evaluation of safety and efficacy of direct oral anticoagulants versus low-molecular-weight heparin and vitamin K antagonist in patients with cancer

INTRODUCTION

The safety and efficacy of direct oral anticoagulants in cancer patients is currently unclear. Low-molecular-weight heparin remains the standard of care for cancer patients with venous thromboembolism, with warfarin, a vitamin K antagonist, as an alternative. Clear recommendations do not exist for patients with both active cancer and non-valvular atrial fibrillation. The objectives of this study were to report safety and efficacy outcomes of direct oral anticoagulants, low-molecular-weight heparin, and vitamin K antagonist in cancer patients with venous thromboembolism or non-valvular atrial fibrillation.

METHODS

Retrospective chart review of adult cancer patients from 2012 to 2015 who received an antineoplastic agent and an anticoagulant.

RESULTS

A total of 258 patients were reviewed: 80 patients in direct oral anticoagulant group, 95 patients in low-molecular-weight heparin group, and 83 patients in vitamin K antagonist group. Sixty-seven percent of patients were on an anticoagulant for acute or chronic venous thromboembolism. Major bleeding events were similar across the groups (15% direct oral anticoagulant vs 17% low-molecular-weight heparin vs 18% vitamin K antagonist). The most common type of major bleeding event was gastrointestinal bleeding. A total of five fatal bleeding events occurred. Venous thromboembolism recurrence rates were higher in both direct oral anticoagulant (18%) and low-molecular-weight heparin (12%) groups while lower in vitamin K antagonist group (10%) compared to previous studies.

CONCLUSIONS

Cancer patients receiving direct oral anticoagulants, low-molecular-weight heparin, or vitamin K antagonist had similar rates of major bleeding events, with gastrointestinal bleeding being the most common event. Venous thromboembolism recurrence rates were higher in direct oral anticoagulant and low-molecular-weight heparin groups than prior studies. Randomized trials are warranted to establish clear safety and efficacy in this population.

Clinical outcomes of direct oral anticoagulants after lower extremity arterial procedures

Objectives The use of postoperative anticoagulation is not uncommon for patients undergoing lower extremity arterial procedures as adjunctive therapy. Longer postoperative length of stay is necessary to achieve adequate therapeutic international normalized ratio with traditional protocols that call for the use of unfractionated heparin and warfarin therapy. We hypothesized the direct oral anticoagulants are an attractive alternative to provide adequate anticoagulation in patients who undergo lower extremity arterial procedures. Methods We retrospectively studied patients who had lower extremity arterial procedures between 2012 and 2015 to examine the safety and efficacy of the direct oral anticoagulants in a single institution. Patency, freedom from re-intervention, and major adverse limb event were evaluated. The direct oral anticoagulant agents used included dabigatran, rivaroxaban, and apixaban. The primary patency, adverse effects and freedom from re-intervention were then compared to a control group of patients who were treated with traditional heparin-warfarin therapy after lower extremity bypass procedures. Results Direct oral anticoagulants were utilized in a total of 23 patients (48% men; mean age 69 ± 11 years) during the study period. Indication for use of direct oral anticoagulant after procedure included use of polytetrafluoroethylene (PTFE) bypass graft below the knee joint or after lower extremity angioplasty with disadvantaged runoff. Mean follow-up of the drugs was 23 months (SD ± 16 months). At the end of follow-up, the direct oral anticoagulants have been discontinued in four patients, who are currently only on plavix. Among 82.6% of patients who were given direct oral anticoagulants for PTFE bypasses, graft patency, freedom from re-intervention, and major adverse limb event were 100%, 100%, and 0%, respectively. Patients (17.4%) treated with direct oral anticoagulants for disadvantaged runoff after balloon angioplasty of the lower extremity, patency, freedom from re-intervention, and major adverse limb event were 100%, 100%, and 0%, respectively. For the patients who underwent direct oral anticoagulant administration for disadvantaged runoff primary patency was 100%. One patient developed wound dehiscence which was unrelated to direct oral anticoagulant administration. Our control group consisted of 100 patients who were treated with heparin-warfarin therapy for 30 days after lower extremity bypass procedures. The graft patency, freedom from intervention, and major adverse limb event were 93%, 12%, and 0%, respectively. There was however no statistically significant difference in graft patency rate ( P = .34) or freedom from intervention ( P = .07) between the two groups. Conclusions The preliminary data suggest that there may be a role for using the direct oral anticoagulants with patients who undergo lower extremity arterial procedures for prevention of thrombosis and warrants further investigation.

Comparison of different laboratory tests in the evaluation of hemorrhagic risk of patients using rivaroxaban in the critical care setting: diagnostic accuracy study

Background

Rivaroxaban is a direct oral anticoagulant designed to dispense with the necessity of laboratory monitoring. However, monitoring rivaroxaban levels is necessary in certain clinical conditions, especially in the critical care setting.

Methods

This is a diagnostic accuracy study evaluating sensitivity and specificity of prothrombin time (PT), activated partial thromboplastin time (aPTT), and Dilute Russell viper venom time (dRVVT), to evaluate the hemorrhagic risk in patients taking rivaroxaban. The study used a convenience sample of 40 clinically stable patients using rivaroxaban to treat deep vein thrombosis or atrial fibrillation admitted in a private hospital in Brazil, compared to a group of 60 healthy controls. The samples from patients were collected two hours after the use of the medication (peak) and two hours before the next dose (trough).

Results

The correlation with the plasmatic concentration measured by anti-FXa assay was higher for PT and dRVVTS. The PT and aPTT tests presented higher specificity, while dRVVT was 100% sensible.

Conclusions

There was a strong correlation between the tests and the plasma concentration of the drug. Additionally, our results demonstrated the potential use of dRVVT as a screening test in the emergency room and the need of a second test to improve specificity.

Dosing-time-dependent effect of rivaroxaban on coagulation activity in rats

The anticoagulant effect of rivaroxaban, a direct inhibitor of activated factor X (FX), might be influenced by its dosing time because the activity of the coagulofibrinolytic system exhibits daily rhythmicity. In rats, FX activity follows a 24-h rhythm with a peak in the middle of the light phase and a trough at the beginning of the dark phase. Consistent with these findings, a single dose of rivaroxaban had a stronger inhibitory effect on FX activity after dosing at the beginning of the light phase than after dosing at the beginning of the dark phase. A similar chronopharmacological effect was seen in a quantitative model of venous stasis thrombosis. In comparison, the dosing time had minimal influence on the pharmacokinetics of rivaroxaban. These data indicate that the anticoagulant effect of rivaroxaban is influenced by the dosing time. Further studies should confirm this finding in a clinical setting.

The Anticoagulated trauma patient in the age of the direct oral anticoagulants: a Canadian perspective

Background

The anticoagulated trauma patient presents a particular challenge to the critical care physician. Our understanding of these patients is defined and extrapolated by experience with patients on warfarin pre-injury. Today, many patients who would have been on warfarin are now prescribed the Direct Oral Anticoagulants (DOACs) a class of anticoagulants with entirely different mechanisms of action, effects on routine coagulation assays and approach to reversal.

Methods

Trauma registry data from Toronto’s (Ontario, Canada) two Level 1 trauma centres were used to identify patients on oral anticoagulation pre-injury from June 1, 2014 to June 1, 2015. The trauma registry and medical records were reviewed and used to extract demographic and clinical data.

Results

We found 81 patients were on oral anticoagulants pre-injury representing 3.2% of the total trauma population and 33% of the orally anticoagulated patients were prescribed a DOAC prior to presentation. Comparison between the DOAC and warfarin groups showed similar age, mechanisms of injury, indications for anticoagulation, injury severity score and rate of intracranial hemorrhage. Patients on DOACs had higher initial mean hemoglobin vs warfarin (131 vs 120) and lower serum creatinine (94.8 vs 129.5). The percentage of patients receiving a blood transfusion in the trauma bay and total in-hospital transfusion was similar between the two groups however patients on DOACs were more likely to receive tranexamic acid vs patients on warfarin (32.1% vs 9.1%) and less likely to receive prothrombin concentrates (18.5% vs 60%). Patients on DOACs were found to have higher survival to discharge (92%) vs patients on warfarin (72%).

Conclusion

Patients on DOACs pre-injury now represent a significant proportion of the anticoagulated trauma population. Although they share demographic and clinical similarities with patients on warfarin, patients on DOACs may have improved outcomes despite lack of established drug reversal protocols and challenging interpretation of coagulation assays.

Level of Evidence: III; Study Type: Retrospective Review.

Current use of direct oral anticoagulants for atrial fibrillation in Japan: Findings from the SAKURA AF Registry

BACKGROUND

Large-scale investigations on the use of oral anticoagulants including direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) have not included Japanese patients.

METHODS

We established the multicenter SAKURA AF Registry to support prospective observational research on the status of anticoagulation treatment, especially with DOAC, for AF in Japan. We enrolled 3266 AF patients treated with warfarin (n=1577) or any of 4 DOACs (n=1689) from 63 institutions (2 cardiovascular centers, 13 affiliated hospitals or community hospitals, and 48 private clinics) in the Tokyo area.

RESULTS

We conducted our first analysis of the registry data, and although we found equivalent mean age between the DOAC and warfarin users (71.8±9.5 vs. 72.3±9.4 years, p=0.2117), we found a slightly lower risk of stroke (CHADS2 score of 0 or 1 [46.9% vs. 39.4%, p<0.0001]) and significantly better creatinine clearance in DOAC users (70.4±27 vs. 65.6±25.7 mL/min, p<0.0001). Importantly, we documented under-dosing in 32% of warfarin users and inappropriate-low-dosing in 19.7-27.6% of DOAC users.

CONCLUSIONS

Our initial analysis of the SAKURA AF Registry data clarified the real-world use of anticoagulants, which includes DOACs and warfarin in Japan. The DOAC users were at a lower risk for stroke than the warfarin users. In 20-30% of DOAC users, the dose was inappropriately reduced.

The SILVER-AP study]

Objetivo

Describir las características clínicas y el manejo de pacientes con fibrilación auricular no valvular (FANV) tratados con anticoagulantes orales de acción directa (ACOD).

Diseño

Estudio observacional, transversal y multicéntrico.

Emplazamiento

Comunidades autónomas en las que el médico de atención primaria puede prescribir ACOD (n = 9).

Participantes

Un total de 790 pacientes con riesgo de ictus o embolia sistémica que estuviesen en tratamiento crónico con anticoagulantes, que hubiesen modificado su pauta terapéutica, y que actualmente estuviesen en tratamiento con un ACOD durante al menos 3 meses.

Mediciones principales

Recogida de datos sociodemográficos y de manejo clínico.

Resultados

La edad media de los sujetos fue de 78,6 ± 8,4 años; un 50,5% eran varones; CHADS₂: 2,6 ± 1,2; CHA₂DS₂-VASc: 4,3 ± 1,6; HAS-BLED: 2,3 ± 1,0. La duración media del tratamiento con ACOD fue de 15,8 ± 12,5 meses. El ACOD más frecuentemente prescrito fue rivaroxabán (57,8%), seguido de dabigatrán (23,7%) y apixabán (18,5%). De los pacientes que tomaban rivaroxabán, el 70,2% recibieron la dosis de 20 mg/día. En el caso de dabigatrán, el 41,7% tomaban la dosis de 150 mg/12 h, y con respecto a apixabán, el 56,2% tomaban la dosis de 5 mg/12 h. La satisfacción con el tratamiento con ACOD (cuestionario ACTS: 52,0 ± 7,2 puntos en la escala Carga y 12,1 ± 2,2 puntos en la escala Beneficio) y el cumplimiento (97,8% de los pacientes fueron cumplidores) fueron elevados.

Conclusiones

Los pacientes en tratamiento con ACOD en España tienen un elevado riesgo tromboembólico. Una proporción significativa de sujetos reciben una dosis menor de ACOD de la que les correspondería por sus características clínicas. La satisfacción y la adherencia son elevadas.

The representativeness of direct oral anticoagulant clinical trials to hospitalized patients with atrial fibrillation

PURPOSE

Trials of the direct oral anticoagulants (DOACs) dabigatran, rivaroxaban and apixaban provide the basis for prescribing for the prevention of stroke and systemic embolism in atrial fibrillation (AF). The objective of this study was to assess the representativeness of the three pivotal DOAC randomized controlled trials of dabigatran, rivaroxaban and apixaban for unselected hospitalized patients with AF.

METHODS

A cross-sectional study was undertaken. All patients discharged with AF between 2012 and 2015 from a large public hospital network in Melbourne, Australia, were identified. Inclusion and exclusion criteria from the DOAC trials were applied. The proportions of hospitalized patients with AF who would have been eligible for the dabigatran (RE-LY), rivaroxaban (ROCKET-AF) and apixaban (ARISTOTLE) trials were estimated, as was pooled eligibility for all three trials. Characteristics of eligible and ineligible patients were compared.

RESULTS

For the 4734 patients, application of the inclusion and exclusion criteria resulted in 60.5, 52.6 and 35.8% eligibility for the trials of apixaban, dabigatran and rivaroxaban, respectively. Pooled eligibility across all three trials demonstrated that 33.4% of the patients would have been eligible for all three trials but 36.7% ineligible for any trial. Ineligible patients who met exclusion criteria were older and experienced more comorbidities.

CONCLUSIONS

The apixaban and dabigatran trials may be the most representative of hospitalized patients with AF. The DOAC trial results can readily be extrapolated to, and guide prescribing for, at least two thirds of patients discharged from a large metropolitan health service in Australia.

[Misuse and adverse effects of new direct oral anticoagulants: A prospective observational study in patients admitted to an emergency unit of a French university hospital]

INTRODUCTION

The use of direct oral anticoagulants (NOAC) is complex: indications, dosage adjustments and precautions. Emergency departments (ED) are increasingly faced with patients receiving NOAC. The aim of this study was to evaluate the misuse and the adverse effects (AE) of NOAC.

METHODS

All subjects with NOAC admitted to the Limoges University Hospital ED from 1/8/2013 to 1/4/2014 were included in a prospective observational study. Misuse was identified from the NOAC summary of product characteristics and from the 2014 ANSM guideline (indication, dose, co-medications, age, hepatic and renal function); adverse effects were recorded.

RESULTS

A total of 198 subjects were included receiving rivaroxaban (68.7 %), dabigatran (30.8 %) or apixaban (0.5 %). Main indications were embolic prevention in patients with non-valvular atrial fibrillation (78.7 %) and curative treatment of venous thromboembolism (17.2 %). In 16.2 % of the cases, the treatment was not in according to the guidelines: 78 % for prescribing errors (incorrect dosage according to age, renal function, co-medications) and 22 % for wrong initial indication. AE related to NOAC were encountered in 25.8 % patients. Hemorrhagic events were diagnosed in 36 patients with no according to the guidelines in 11.1 % of them. Hemorrhagic events resulted in 3 deaths (8.3 %). Thrombotic events occurred in 15 patients, all these patients were issued with appropriate guidelines.

CONCLUSION

Through the view of an ED, this study confirms a part of misuse and highlights the risk of spontaneous bleeding of NOAC despite appropriate use.

Apixaban for treatment of confirmed heparin-induced thrombocytopenia: a case report and review of literature

Background

Heparin-induced thrombocytopenia (HIT) is a life and limb-threatening condition caused by the binding of platelet-activating antibodies (IgG) to multimolecular platelet factor 4 (PF4)/heparin complexes because of heparin exposure. The by-product of this interaction is thrombin formation which substantially increases the risk of venous and/or arterial thromboembolism. Currently, only one anticoagulant, argatroban, is United States Food and Drug Administration-approved for management of HIT; however, this agent is expensive and can only be given by intravenous infusion. Recently, several retrospective case-series, case reports, and one prospective study suggest that direct oral anticoagulants (DOACs) are also efficacious for treating HIT. We further review the literature regarding current diagnosis and clinical management of HIT.

Case presentation

A 66-year-old male patient developed HIT beginning on day 5 post-cardiovascular surgery; the platelet count nadir on day 10 measured 16 × 10⁹/L. Both the PF4-dependent ELISA and Serotonin-release assay were strongly positive. Despite initial anticoagulation with argatroban (day 6), the patient developed symptomatic Doppler ultrasound-documented bilateral lower extremity deep vein thrombosis on day 14 post-surgery. The patient was transitioned to the DOAC, apixaban, while still thrombocytopenic (platelet count 108) and discharged to home, with platelet count recovery and no further thrombosis at 3-month follow-up.

Conclusions

We report a patient with serologically confirmed HIT who developed symptomatic bilateral lower limb deep vein thrombosis despite anticoagulation with argatroban. The patient was switched to oral apixaban and made a complete recovery. Our patient case adds to the emerging literature suggesting that DOAC therapy is safe and efficacious for management of proven HIT.

Indications for suboptimal low-dose direct oral anticoagulants for non-valvular atrial fibrillation patients

BACKGROUND

Direct oral anticoagulants (DOACs) have been developed for stroke prevention in patients with non-valvular atrial fibrillation (NVAF). We conducted a retrospective cohort study of patients with NVAF who were newly treated with DOACs in a real-world clinical setting.

METHODS

We retrospectively analyzed patients with NVAF newly treated with one of three DOACs-dabigatran, rivaroxaban, or apixaban-between January 1, 2013, and December 31, 2015.

RESULTS

A total of 670 patients with NVAF who were newly prescribed one of the three DOACs were analyzed; 74 patients (10.9%) received dabigatran, 290 (43.3%) received rivaroxaban, and 306 (45.8%) received apixaban. Fifteen patients had thromboembolic events, almost half of which were due to discontinuation of DOACs. Six patients had major bleeding, although almost all were discharged with good neurological prognoses. A total of 129 patients were treated with a suboptimal low-dose DOAC; none experienced a thromboembolic event as long as the DOAC was taken regularly, and none of the patients in any of the three DOAC groups had major bleeding events.

CONCLUSIONS

With good adherence, the clinical course associated with DOACs is comparatively good. In the future, suboptimal low-dose DOAC therapy may serve as an appropriate choice for some patients with a high risk of stroke and bleeding.

A case series and review of the literature

BACKGROUND

To date, very little is known about the effects of direct oral anticoagulants (DOA) use in patients with cervical artery dissection (CAD) and cerebral venous thrombosis (CVT). We present our initial experience with the use of DOA for CAD and CVT and an overview of the published literature.

METHODS

From our database, we identified 4 patients who received DOA after CAD and 4 patients after CVT. Also, we analyzed the data reported for 45 patients who received DOA after CAD and 23 after CVT from review of the literature.

RESULTS

Among patients with CAD, resolved or improved arterial stenosis was noted in 27 (55%), and symptomatic recurrent ischemic stroke in 2 (4%). Among patients with CVT, complete or partial recanalization was noted in 25 (90%), and no significant functional disability in 26 (93%). No patient developed intracranial hemorrhage.

CONCLUSIONS

Although no statistical conclusions can be drawn from these data, DOA could be an alternative in patients with CAD-related embolic infarct and CVT-related hemorrhagic venous infarct. A large-scale clinical trial will be needed to validate these results.

Anticoagulation in chronic liver disease

In this Grand Round presentation, the case of a man with decompensated liver disease is described. He subsequently developed a fatal pulmonary embolism, which may not have occurred if he had been prescribed prophylactic anticoagulation to prevent venous thromboembolic disease. The burden of thrombotic disease in those with chronic liver disease is discussed, before a more detailed analysis of the current evidence, safety data, and clinical dilemmas regarding the use of anticoagulation in patients with chronic liver disease. Finally, the future directions within this field are explored.

The Effects of Indirect- and Direct-Acting Anticoagulants on Lupus Anticoagulant Assays: A Large, Retrospective Study at a Coagulation Reference Laboratory

OBJECTIVES

To investigate the effects of indirect- and direct-acting anticoagulants on the interpretation of lupus anticoagulant (LAC) assays.

METHODS

A retrospective database review was performed to identify all LAC panels from November 2012 to November 2015. The positivity rates for three LAC tests were compared among various anticoagulant medications.

RESULTS

This analysis included 7,721 LAC panels. Direct oral anticoagulants, warfarin, and unfractionated heparin (UFH) were associated with higher LAC positivity rates compared with patients not receiving documented anticoagulation (83% for argatroban, 58% for dabigatran, 72% for rivaroxaban, 53% for apixaban, 56% for warfarin, and 36% for UFH vs 29% for no anticoagulation, P < .025). Direct thrombin inhibitors mainly affected the activated partial thromboplastin time-based assays and the tissue thromboplastin inhibition index (TTI), while direct factor Xa inhibitors mainly affected the TTI and the dilute Russell viper venom ratio.

CONCLUSIONS

Results of LAC testing performed while patients are receiving anticoagulant therapies should be interpreted with caution to avoid misdiagnosing patients with the antiphospholipid syndrome and potentially committing them to long-term anticoagulation therapy.

Oral anticoagulant therapy for older patients with atrial fibrillation: a review of current evidence

Atrial fibrillation is more frequent in older patients, who have a higher risk of cardioembolic stroke and thromboembolism. Oral anticoagulant therapy is the standard of treatment for stroke prevention; however, under-prescription is still very common in older patients. The reasons underlying this phenomenon have not been systematically investigated, and true contraindications only partially account for it. An intimate skepticism on the real benefit-risk balance of oral anticoagulant therapy in the oldest patients seems to derive from the fact that most studies supporting it were conducted decades ago and included younger patients, with overall better functional and clinical status. In this review we will focus on the main barriers to anticoagulant therapy prescription in older patients and summarize the available evidences on the efficacy and safety of vitamin K antagonists and direct oral anticoagulants in this population. The encouraging evidence of a higher net clinical benefit of direct oral anticoagulants compared with warfarin should hopefully widen the treatment options also for frail individuals, thereby allowing a greater number of patients to be treated according to current international guidelines.

Determination of edoxaban equivalent concentrations in human plasma by an automated anti-factor Xa chromogenic assay

INTRODUCTION

This phase I, open-label, multiple-dose, two-treatment study assessed the relationship between edoxaban equivalent concentration derived from an anti-FXa assay with the summed concentration of edoxaban and its active metabolite, M-4, as assessed by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). This study also assessed the relationship between edoxaban plasma concentrations assessed by LC/MS/MS in sodium citrate and lithium heparin tubes.

MATERIALS AND METHODS

Healthy volunteers were randomized to receive once-daily edoxaban 60mg or 90mg for 5days (15 participants per treatment group). Serial blood samples were collected for analysis by LC/MS/MS and by the anti-FXa assay. Edoxaban equivalent levels were assessed using a commercially available anti-FXa activity assay with an edoxaban-specific setup.

RESULTS AND CONCLUSIONS

The day 5 concentration estimates were significantly correlated between the 2 assays (P<0.0001 for both edoxaban doses). The geometric least squares mean (GLSM) ratio (90% confidence interval) for edoxaban equivalent concentrations vs edoxaban + M-4 concentrations was 114.3% (108.2-120.8) for edoxaban 60mg (P<0.0001) and 113.0% (107.1-119.2) for edoxaban 90mg (P=0.0002). The GLSM ratio for edoxaban concentrations in sodium citrate vs lithium heparin tubes for 60-mg and 90-mg edoxaban doses were 82.8% (78.5-87.3) and 83.9% (79.1-89.0), respectively. In this study, an anti-FXa chromogenic assay with edoxaban-specific calibrators and controls demonstrated good accuracy in estimating edoxaban concentrations across a wide range of concentrations relative to LC/MS/MS at steady state following the administration of once-daily edoxaban for 5days.

Incidence and predictors of silent cerebral thromboembolic lesions after catheter ablation for atrial fibrillation in patients treated with direct oral anticoagulants

There are few reports about the incidence and predictors of silent cerebral thromboembolic lesions (SCLs) after atrial fibrillation (AF) ablation in patients treated with direct oral anticoagulants (DOACs). The purpose of this study is to evaluate the incidence and predictors of SCLs after AF ablation with cerebral magnetic resonance imaging (C-MRI) in patients treated with DOACs. We enrolled 117 consecutive patients who underwent first AF ablation and received DOACs, including apixaban, dabigatran, edoxaban, and rivaroxaban. DOACs were discontinued after administration 24 h before the procedure, and restarted 6 h after the procedure. During the procedure, activated clotting time (ACT) was measured every 15 min, and intravenous heparin infusion was performed to maintain ACT at 300-350 s. All patients underwent C-MRI the day after the procedure. SCLs were detected in 28 patients (24%) after AF ablation. Age, female sex, the presence of persistent AF, left atrial volume, procedure time, radiofrequency energy, electrical cardioversion, and mean ACT showed no correlations with the incidence of SCLs. Multivariate analysis revealed independent predictors of SCLs were CHA₂DS₂VASc scores ≥3, left atrial appendage (LAA) emptying velocity ≤39 cm/s, and minimum ACT ≤260 s. Patients with both CHA₂DS₂VASc scores ≥3 and LAA flow velocity ≤39 cm/s had the highest incidence of SCLs 15 of 26 patients (58%). In patients treated with DOACs, CHA₂DS₂VASc score ≥3, minimum ACT ≤260 s, and LAA emptying velocity ≤39 cm/s were independent risk factors for the SCLs after AF ablation.

[Are general practitioners in Paris and surrounding areas reticent about direct oral anticoagulants?]

OBJECTIVE

Determine how familiar general practitioners (GPs) working in Paris and surrounding areas are with prescriptions for direct oral anticoagulants (DOACs).

MATERIAL AND METHOD

A questionnaire sent to 189 GP working in Paris and surrounding areas yielded 100 responses. Data collected included a brief summary of sociodemographic items, comparative knowledge about DOACs and vitamin K antagonists (VKAs), and responses to two clinical situations for DOAC prescriptions (renewal of a first prescription).

RESULTS

The majority (65%) of the responding GPs were over 50. The GPs were knowledgeable about data in the literature concerning the following items: patient quality of life (72% considered it improved); adherence (55% suggested it was improved); rules for DOAC prescription (88% knew the set doses; 81% knew biological monitoring does not exist; 38% were aware of potential interactions). They were not knowledgeable about the following points: main sites for bleeding risks are the gut and the brain; 44% thought risk was lowered for gastrointestinal bleeding and concerning brain hemorrhages 26% thought there was a lesser risk while 40% had no opinion; cost (20% thought it was lower). For prescription modalities, 90% of the GPs renewed the DOAC previously prescribed for non-valvular atrial fibrillation while 76% preferred a LMWH-VKA scheme for the first prescription for deep vein thrombosis.

CONCLUSION

Without being reticent about DOACs, the GPs questioned in this study recognized the usefulness of these medications for their patients' quality of life but were hesitant to use DOACs as the first intention anticoagulant, undeniably due to lack of experience and knowledge about the lower risk of bleeding. Initial training and continuing education should be strengthened on this point with dedicated workshops.

Appropriateness of direct oral anticoagulant dosing for venous thromboembolism treatment

Adherence to FDA-approved dosing for the direct oral anticoagulants (DOACs) based on renal function, hepatic function, and concomitant medications in a real-world setting has not been evaluated. The purpose of this retrospective cohort analysis was to determine the prescribing accuracy of DOAC dosing for venous thromboembolism (VTE) treatment compared with enoxaparin. The secondary outcomes were to describe the incidence of in-hospital VTE recurrence and bleeding on DOAC therapy. The study included 168 patients with 261 admissions for the DOAC group and 639 patients with 841 admissions for the enoxaparin group. Dosing was appropriate in 235/261 (90.0%) of patient admissions in the DOAC group. Among the DOAC doses administered, 233/2246 (10.4%) were contraindicated based on renal function, hepatic function, or drug interactions compared with 322/7293 (4.4%) of administered enoxaparin doses evaluated based on renal function, p < 0.001. Three recurrent VTEs, 3 major bleeding events, 1 probable major bleeding event, and 3 clinically relevant non-major bleeding events were observed during the study period. Although a majority of DOAC doses administered were appropriate, further education and close monitoring of these agents are warranted to increase appropriateness of therapy and improve patient safety.

The use of direct oral anticoagulants in inherited thrombophilia

To review the use of the direct oral anticoagulant (DOAC) agents in inherited thrombophilia based on the literature. MEDLINE, International Pharmaceutical Abstracts, and Google Scholar searches (1970-May 2016) were conducted for case reports, case series, retrospective cohorts, or clinical trials using the key words: protein C deficiency, protein S deficiency, antithrombin deficiency, activated protein C resistance, Factor V Leiden, hypercoagulable, NOACs, dabigatran, apixaban, rivaroxaban, betrixaban, edoxaban, Xa inhibitor, direct thrombin inhibitor. Results were limited to English-only articles. Clinical studies evaluating the use of DOACs for hypercoagulable states related to inherited thrombophilia were selected and evaluated. Thrombophilia, a predisposition to thrombosis, manifests predominantly as venous thromboembolism. Causes of inherited thrombophilia include antithrombin deficiency, deficiencies of proteins C and S, and Factor V Leiden mutation. Many patients with thrombophilia receive anticoagulant therapy for primary or secondary prevention of VTE, historically either warfarin or a heparin product. DOAC's have been considered as potential alternatives to traditional agents based on their pharmacologic activity. Case reports and a post-hoc analysis of a clinical trial have indicated positive results in patients with inherited thrombophilia and VTE. Positive results have been reported for the use of DOACs in inherited thrombophilia. Further robust studies are needed for definitive decision making by clinicians.

Identification of risk factors for inappropriate and suboptimal initiation of direct oral anticoagulants

Direct Oral Anticoagulants (DOACs) require specific dosing and monitoring to ensure safe and appropriate use. The purpose of this evaluation was to identify patient- and process-related factors that correlate with increased risk of inappropriate prescribing of DOACs. A retrospective chart review was conducted in three outpatient clinics within an academic medical center to identify patients started on DOAC therapy and evaluate the appropriateness of DOAC initiation. Data collected included patient demographics, DOAC medication initiated, dose, indication, baseline laboratory values, concomitant medications, type and specialty of prescriber, and initiation setting. Appropriateness of initial dose was assessed and data were analyzed in order to identify factors correlating with inappropriate use. One-hundred sixty-seven patients initiated on a DOAC were identified. Most patients were prescribed anticoagulation for atrial fibrillation (74.9 %) and most commonly prescribed rivaroxaban (62.9 %). An inappropriate dose was prescribed in 24 (14.4 %) patients. Female patients and patients over 75 years were more likely to be prescribed an inappropriate initial dose. Baseline evaluation of blood counts and organ function were often not performed: hemoglobin values had not been drawn within the month prior to initiation in 28.7 % of patients, serum creatinine in 22.8 %, alanine transaminase in 52.1 %, and total bilirubin in 64.1 %. Lack of baseline labs was more pronounced in patients initiated on a DOAC in the outpatient setting. Dosing and baseline lab collection for DOAC initiation were suboptimal in all settings analyzed. Targeted interventions are needed to ensure the safe and appropriate use of DOAC therapy.

Real-life experience with the specific reversal agent idarucizumab for the management of emergency situations in dabigatran-treated patients: a series of 11 cases

Non-vitamin K antagonist oral anticoagulants (NOACs) have a favorable benefit-risk profile compared with vitamin K antagonists. However, the lack of specific reversal agents has made the management of some patients receiving long-term treatment with NOACs problematic in emergency situations such as major bleeding events or urgent procedures. Idarucizumab, a fully humanized Fab antibody fragment that binds specifically and with high affinity to dabigatran, was recently approved for use in adult patients treated with dabigatran when rapid reversal of its anticoagulant effect is required. Clinical experience with idarucizumab is currently limited. We report 11 real-life clinical cases in which idarucizumab was used after multidisciplinary consultation in a variety of emergency situations including severe postoperative bleeding, emergency high-bleeding-risk surgery (hip/spine surgery and neurosurgery), invasive diagnostic testing (lumbar puncture), intracranial bleeding (pre-pontine subarachnoid hemorrhage and lobar intracerebral hemorrhage) and thrombolysis with recombinant tissue plasminogen activator for acute ischemic stroke. This case series illustrates the role of idarucizumab in improving patient safety in rare emergency situations requiring rapid reversal of the anticoagulant effect of dabigatran, while highlighting the importance of information and education about the availability and appropriate use of this recently approved specific reversal agent.

Direct oral anticoagulant use and the incidence of bleeding in the very elderly with atrial fibrillation

Atrial fibrillation (AF) is a major risk factor for stroke in the elderly population. The use of anticoagulation in patients with AF greatly reduces the risk for stroke, but results in an increased risk of bleeding. Over the past several years, direct oral anticoagulants (DOACs, dabigatran, rivaroxaban, and apixaban) have been used in place of warfarin for stroke prevention in AF. We conducted a retrospective cohort study to assess the safety of DOACs in very elderly patients (75+) managed in a health care system encompassing both community and academic settings. We found that 36 % of patients had moderate to severe renal failure (estimated glomerular filtration rate <59 ml/min/1.73 m(2)) at the time of DOAC initiation. 142 patients were followed for a mean of 2.56 years, and five experienced a major bleeding episode while on anticoagulation, for a rate of 1.37 per 100 person years. All major bleeding episodes were associated with a decline in GFR compared to baseline. There were 12 non-major bleeding episodes reported. HAS-BLED scores were similar for those patients who experienced bleeding complications compared to those who did not. 21 % of patients were prescribed an inappropriately low dose of DOAC based on approved recommendations. DOACs appear to be a safe form of anticoagulation in very elderly patients with AF. However, the decline in GFR among patients with major bleeding highlights the importance of routine renal function monitoring.