Outcomes of Warfarin Home INR Monitoring vs Office-Based Monitoring: a Retrospective Claims-Based Analysis.

BACKGROUND: Home INR testing (patient self-testing) is feasible and effective for warfarin patients but little is known about real-world differences in outcomes for patients using PST versus laboratory-based INR monitoring. OBJECTIVE: To compare the safety/efficacy of patient self-testing of real-world warfarin therapy versus office/lab-based monitoring of therapy. DESIGN/SETTING/PARTICIPANTS/EXPOSURE: A retrospective claims-based analysis of warfarin patients enrolled in the MarketScan® Commercial Claims and Encounters and Medicare databases between January 1, 2013, and March 30, 2020. Stratification was based on INR testing method: patient self-testing versus testing at physicians' offices/local laboratory. The probability of adverse events in each cohort was determined after adjusting for demographic and baseline clinical characteristics using a repeated measures analysis. MAIN MEASURES: Rates of all adverse events: deep venous thrombosis, pulmonary embolism, bleeding, and stroke. A secondary outcome of interest was emergency department visits. KEY RESULTS: A total of 37,837 patients were included in the analysis: 1592 patients in the patient self-testing group and 36,245 in the office-based therapy group. After adjusting for demographic and baseline clinical characteristics, patients in the office-based group had statistically significantly higher rates of all adverse events (incidence rate ratio [IRR]=2.07, 95% CI [1.82, 2.36]), and specific adverse events including thromboembolism (IRR=4.38, 95% CI [3.29, 5.84]), major bleed (IRR=1.45, 95% CI [1.28, 1.64]), and stroke (IRR=1.30, 95% CI [1.05, 1.61]) than patients in the patient self-testing group. Office-based patients also had a statistically significant higher rate of emergency department visits than patient self-testing patients (IRR = 1.65, 95% CI [1.47, 1.84]). CONCLUSIONS/RELEVANCE: This analysis of real-world claims data shows lower rates of stroke, thromboembolism, and major bleeding, as well as fewer emergency department visits, with patient self-testing compared to office-based/lab INR monitoring. Our finding that PST is safe and effective among current users suggests that more patients may benefit from its use.

Ciraparantag, an anticoagulant reversal drug: mechanism of action, pharmacokinetics, and reversal of anticoagulants.

Ciraparantag, an anticoagulant reversal agent, is a small molecule specifically designed to bind noncovalently by charge-charge interaction to unfractionated heparin and low-molecular-weight heparin. It shows binding characteristics that are similar to those of direct oral anticoagulants (DOACs). A dynamic light-scattering methodology was used to demonstrate ciraparantag's binding to the heparins and DOACs and its lack of binding to a variety of proteins including coagulation factors and commonly used drugs. Ciraparantag reaches maximum concentration within minutes after IV administration with a half-life of 12 to 19 minutes. It is primarily hydrolyzed by serum peptidases into 2 metabolites, neither of which has substantial activity. Ciraparantag and its metabolites are recovered almost entirely in the urine. In animal models of bleeding (rat tail transection and liver laceration), a single IV dose of ciraparantag given at peak concentrations of the anticoagulant, but before the bleeding injury, significantly reduced the blood loss. Ciraparantag, given after the bleeding injury, also significantly reduced blood loss. It appears to have substantial ability to reduce blood loss in animal models in which a variety of anticoagulants are used and has potential as a useful DOAC reversal agent.

Urgent procedures or surgeries in patients receiving oral anticoagulants: a systematic literature review.

There are limited data about the frequency of urgent surgical emergencies among patients receiving oral anticoagulants (OACs). We conducted a systematic literature review of Medline and EMBASE for published English-language articles of adult patients receiving oral anticoagulant treatment (vitamin K antagonists, apixaban, dabigatran, edoxaban, rivaroxaban) that reported on patients experiencing unplanned emergent or urgent surgery/procedure or trauma. Randomized trials, observational studies, and case series (50-100 cases) were included. The primary outcome was the frequency of unplanned urgent surgery or invasive procedures among OAC-treated patients with a focus on those not precipitated by the presence of major bleeding. The protocol was not registered. Funding was provided by Covis Pharmaceuticals. The search yielded 1367 potential studies of which 34 were included in the final review. One study reported the rate of urgent surgery/procedures among a large cohort of patients treated with dabigatran or warfarin for atrial fibrillation (~ 1% per year). Another study reported the rate of bleeding or urgent surgery among OAC-treated patients experiencing a fracture or trauma (0.489% per patient-year). The remaining 32 studies were cohorts of OAC-treated patients who received reversal or hemostatic therapies for major bleeding or urgent surgery. A median of 28.8% of these patients underwent surgery or invasive procedure. Urgent surgery appears to be a common, yet understudied complication during OAC treatment potentially associated with high rates of adverse outcomes. With increased eligibility for OACs, future studies evaluating the management and outcomes in this setting are needed.

Ciraparantag reverses the anticoagulant activity of apixaban and rivaroxaban in healthy elderly subjects.

AIMS: Ciraparantag is a reversal agent for anticoagulants including direct oral anticoagulants. The aim was to evaluate the efficacy and safety of ciraparantag to reverse anticoagulation induced by apixaban or rivaroxaban in healthy elderly adults. METHODS AND RESULTS: Two randomized, placebo-controlled, dose-ranging trials conducted in healthy subjects aged 50-75 years. Subjects received apixaban (Study 1) 10 mg orally twice daily for 3.5 days or rivaroxaban (Study 2) 20 mg orally once daily for 3 days. At steady-state anticoagulation subjects were randomized 3:1 to a single intravenous dose of ciraparantag (Study 1: 30, 60, or 120 mg; Study 2: 30, 60, 120, or 180 mg) or placebo. Efficacy was based on correction of the whole blood clotting time (WBCT) at multiple timepoints over 24 h. Subjects and technicians performing WBCT testing were blinded to treatment. Complete reversal of WBCT within 1 h post-dose and sustained through 5 h (apixaban) or 6 h (rivaroxaban) was dose related and observed with apixaban in 67%, 100%, 100%, and 17% of subjects receiving ciraparantag 30 mg, 60 mg, 120 mg, or placebo, respectively; and with rivaroxaban in 58%, 75%, 67%, 100%, and 13% of subjects receiving ciraparantag 30 mg, 60 mg, 120 mg, 180 mg, or placebo, respectively. Adverse events related to ciraparantag were mild, transient hot flashes or flushing. CONCLUSIONS: Ciraparantag provides a dose-related reversal of anticoagulation induced by steady-state dosing of apixaban or rivaroxaban. Sustained reversal was achieved with 60 mg ciraparantag for apixaban and 180 mg ciraparantag for rivaroxaban. All doses of ciraparantag were well tolerated.

Thromboembolic prevention and anticoagulant therapy during the COVID-19 pandemic: updated clinical guidance from the anticoagulation forum.

Thromboembolism is a common and deadly consequence of COVID-19 infection for hospitalized patients. Based on clinical evidence pre-dating the COVID-19 pandemic and early observational reports, expert consensus and guidance documents have strongly encouraged the use of prophylactic anticoagulation for patients hospitalized for COVID-19 infection. More recently, multiple clinical trials and larger observational studies have provided evidence for tailoring the approach to thromboprophylaxis for patients with COVID-19. This document provides updated guidance for the use of anticoagulant therapies in patients with COVID-19 from the Anticoagulation Forum, the leading North American organization of anticoagulation providers. We discuss ambulatory, in-hospital, and post-hospital thromboprophylaxis strategies as well as provide guidance for patients with thrombotic conditions who are considering COVID-19 vaccination.

Discontinuation rates of warfarin versus direct acting oral anticoagulants in US clinical practice: Results from Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II (ORBIT-AF II).

While oral anticoagulation is a cornerstone of stroke prevention therapy in atrial fibrillation (AF), few studies have evaluated comparative discontinuation rates in clinical practice. The objective of this study is to evaluate discontinuation rates among patients on warfarin and direct oral anticoagulants (DOACs) in clinical practice. METHODS: The ORBIT-AF II Registry enrolled 10,005 total AF patients with a CHA2DS2VASc score of ≥2 on warfarin or DOACs from 235 clinical practices across the US from February 13, 2013 and July 12, 2017. Descriptive statistics and multivariable Cox regression modeling were used to describe baseline characteristics and predictors of discontinuation. Unadjusted and adjusted discontinuation rates and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and propensity score adjustment, respectively. RESULTS: At baseline, 16.4% (N = 1642/10,005) were treated with warfarin, 83.6% (N = 8363/10,005) with DOACs and 1498/10,005 patients (15.0%) discontinued therapy [warfarin = 236/1642 (14.4%) vs DOACs = 1262/8363 (15.1%)]. At 6 and 12 months respectively, among 7049 patients with a new diagnosis of AF within 6 months, adjusted discontinuation rates for warfarin versus DOACs were as follows: [6 months: 7.9%, 95%CI (6.8%-9.0%) vs 9.6% (8.4%-10.7%), P = .16]; [12 months: 12.7% (11.0%-14.3%) vs 15.3% (13.6%-16.9%), P = .02)]. Patients who discontinued therapy with warfarin or DOACs had higher risk of adverse clinical outcomes including: all-cause mortality and cardiovascular death (CV) than those who continued treatment. CONCLUSION: In a community based AF cohort, adjusted rates of discontinuation at 12-months were higher in DOAC-treated versus VKA-treated patients. Discontinuation of oral anticoagulation was associated with increased absolute risk of all-cause mortality and CV death. CLINICAL TRIAL REGISTRATION: URL:https://clinicaltrials.gov. Unique Identifier: NCT01701817.

Prognostic Significance of Nuisance Bleeding in Anticoagulated Patients With Atrial Fibrillation.

BACKGROUND: Bleeding is commonly cited as a reason for stopping oral anticoagulants (OACs). Whether minor bleeding events (nuisance bleeding, NB) in patients with atrial fibrillation on OACs are associated with OAC discontinuation, major bleeding, and stroke/systemic embolism (SSE) is unknown. METHODS: Within the ORBIT-AF prospective, outpatient registry (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation), we identified 6771 patients ≥18 years of age at 172 sites with atrial fibrillation and eligible follow-up visits. NB was ascertained from the medical record and was defined as minor bleeding that did not require medical attention (eg, bruising, hemorrhoidal bleeding). We used multivariable pooled logistic regression modeling to evaluate the associations between NB and major bleeding and SSE in the 180 days after documentation of NB. Our unit of analysis was the patient visit, occurring at ≈6-month intervals for a median of 1.5 years following enrollment. Changes in anticoagulation treatment satisfaction after NB were examined descriptively in a subset of patients. RESULTS: The median age of the overall population was 75.0 (interquartile range, 67.0-81.0); 90.0% were white and 42.5% were female. Among 6771 patients (18 560 visits), n=1357 (20.0%) had documented NB, for an incidence rate of 14.8 events per 100 person-years. Over 96.4% of patients remained on OAC therapy after the NB event. Overall, 287 (4.3%) patients experienced major bleeding and 64 (0.96%) had a SSE event during follow-up. NB was not associated with a significant increased risk of major bleeding over 6 months in models adjusting for the ATRIA bleeding score (Anticoagulation and Risk Factors in Atrial Fibrillation) (odds ratio, 1.04; 95% confidence interval, 0.68-1.60; P=0.86). NB was also not associated with increased SSE risk over 6 months in models adjusting for the CHA2DS2-VASc risk score (odds ratio, 1.24; 95% confidence interval, 0.53-2.91; P=0.62). CONCLUSIONS: NB is common among patients with atrial fibrillation on OACs. However, NB was not associated with a higher risk of major bleeding or SSE over the next 6 months, suggesting its occurrence should not lead to changes in anticoagulation treatment strategies in OAC-treated patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01165710.

Association of frailty and cognitive impairment with benefits of oral anticoagulation in patients with atrial fibrillation.

BACKGROUND: The incidence of cognitive impairment and frailty increase with age and may impact both therapy and outcomes in atrial fibrillation (AF). METHODS: We examined the prevalence of clinically recognized cognitive impairment and frailty (as defined by the American Geriatric Society Criteria) in the Outcomes Registry for Better Informed Care in AF (ORBIT AF) and associated adjusted outcomes via multivariable Cox regression. The interaction between cognitive impairment and frailty and oral anticoagulation (OAC) in determining outcomes was examined. RESULTS: Among 9749 patients with AF [median (IQR) age 75 (67-82) y, 57% male], cognitive impairment and frailty was identified in 293 (3.0%) and 575 (5.9%) patients respectively. Frail patients (68 vs 77%, P < .001) and those with cognitive impairment (70 vs 77%, P = .006) were both less likely to receive an OAC. Both cognitive impairment [HR (95% CI) 1.34 (1.05-1.72), P = .0198] and frailty [HR 1.29 (1.08-1.55), P = .0060] were associated with increased risk of death. Cognitive impairment and frailty were not associated with stroke/transient ischemic attack (TIA) or major bleeding. In multivariable analysis, there was no interaction between OAC use and cognitive impairment or frailty in their associations with mortality, major bleeding and a composite end point of stroke, non-central nervous system systemic embolism, TIA, myocardial infarction or cardiovascular death. CONCLUSION: Those with cognitive impairment or frailty in AF had higher predicted risk for stroke and higher observed mortality, yet were less likely to be treated with OAC. Despite this, the benefits of OAC were similar in patients with and without cognitive impairment or frailty.

A Novel Whole Blood Point-of-Care Coagulometer to Measure the Effect of Direct Oral Anticoagulants and Heparins.

The direct oral anticoagulants (DOACs) currently require no monitoring for routine therapy of atrial fibrillation or venous thromboembolism. Measurement of activity, however, may be important in patients with major and life-threatening bleeding, patients needing emergent surgery, in reversal situations, or in patients at high risk of bleeding or thrombosis due to underlying conditions. For these patients, a widely available and rapid turnaround assay would be optimal. To date, there is no such assay available, especially for the direct factor Xa inhibitors. This report describes the performance of a new, rapid turnaround, point-of-care (PoC) assay for measuring the activity of a range of anticoagulants, including DOACs and heparins, in emergency situations and for routine measurement in high-risk patients. Perosphere Technologies' PoC coagulometer is a handheld instrument that performs individual coagulation tests on samples of fresh whole blood (∼10 µL) with clotting activated by glass contact and endpoint determination performed by infrared spectroscopy. In preclinical studies using rats anticoagulated with therapeutic doses of edoxaban or enoxaparin, the PoC coagulometer showed a strong linear correlation between pharmacokinetic parameters and clotting time with edoxaban (r 2 = 0.994) and with enoxaparin (r 2 = 0.967). These preclinical results suggest that this PoC coagulometer would be ideal to assess the pharmacodynamic effects of anticoagulants and their reversal agents. The PoC bedside instrument delivers results within minutes and requires no more than a drop of whole blood. Studies are underway to confirm these results in humans and to further characterize the performance of the instrument.

Reversal of direct oral anticoagulants: Guidance from the Anticoagulation Forum.

Two specific reversal agents for direct oral anticoagulants (DOACs) have been approved in the United States: idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. Non-specific prohemostatic agents such as prothrombin complex concentrate (PCC) and activated PCC have also been used for DOAC reversal. The goal of this document is to provide comprehensive guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of DOAC reversal agents. We discuss indications for reversal, provide guidance on how the individual reversal agents should be administered, and offer suggestions for stewardship at the health system level.

Early therapeutic persistence on dabigatran versus warfarin therapy in patients with atrial fibrillation: results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry.

Anticoagulation is highly effective for the prevention of stroke in patients with atrial fibrillation (AF) but it is dependent on patients continuing therapy. While studies have demonstrated suboptimal therapeutic persistence on warfarin, few have studied persistence rates with non vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran. We examined rates of continued use of dabigatran versus warfarin over 1 year among AF patients in the ORBIT-AF registry between June 29, 2010 and August 09, 2011. Multivariable logistic regression analysis was used to identify characteristics associated with 1-year persistent use of dabigatran therapy or warfarin. At baseline, 6.4 and 93.6% of 7150 AF patients were on dabigatran and warfarin, respectively. At 12 months, dabigatran-treated patients were less likely to have continued their therapy than warfarin-treated patients [Adjusted persistence rates: 66% (95% CI 60-72) vs. 82% (95% CI 80-84), p < .0001]. Predictors of dabigatran persistence included: CHA2DS2-VASc risk scores ≥ 2 OR 5.69, (95% CI 1.50-21.6) and BMI greater than 25 mg/m2 but less than 38 kg/m2 1.05 (1.01-1.09). Predictors of persistence on warfarin included: African American race (vs. White) 1.53 (1.07-2.19), Hispanic ethnicity (vs. White) 1.66 (1.06-2.60), paroxysmal and persistent AF (vs. new-onset) 1.68 (1.21-2.33) and 1.91 (1.35-2.69) respectively, LVH 1.40 (1.08-1.81), and CHA2DS2-VASc risk scores ≥ 2 1.94 (1.18-3.19). While 1-year persistence rates for dabigatran were lower than warfarin, persistence rates for both agents were not ideal. Future studies evaluating contemporary persistence are needed in order to assist in better targeting interventions aimed to improve anticoagulation persistence.

Defining Minimum Necessary Anticoagulation-Related Communication at Discharge: Consensus of the Care Transitions Task Force of the New York State Anticoagulation Coalition.

BACKGROUND: Anticoagulated patients are particularly vulnerable to ADEs when they experience changes in medical acuity, pharmacotherapy, or care setting, and resources guiding care transitions are lacking. The New York State Anticoagulation Coalition convened a task force to develop a consensus list of requisite data elements (RDEs) that should accompany all anticoagulated patients undergoing care transitions. METHODS: A multidisciplinary panel of 15 anticoagulation experts voluntarily completed an iterative Delphi process. Resources were disseminated and deliberated via remote technology, with consensus achieved via blinded electronic polling. RESULTS: The panel reached consensus on a list of 15 RDEs for anticoagulation communication at discharge (the ACDC List). Consensus was rapidly achieved by the full panel on 13 elements, while 3 (2 of which were combined into 1 element) required multiple iterations and achieved consensus with votes from 8 available panelists. The elements encompassed a range of factors, including drug use and indications, previous exposure and duration of therapy, recent drug exposure and laboratory results and expectations for subsequent administration, therapy goals, patient education and comprehension, and expectations for clinical management. Twelve of the elements are applicable to any anticoagulant, and 3 are specific to warfarin. CONCLUSION: The ACDC List identifies specific pieces of clinical information that a panel of anticoagulant experts agree should be communicated to downstream providers for all anticoagulated patients undergoing care transitions. Additional study is needed to objectively evaluate the ability of existing care systems to communicate the elements and to assess possible relationships between communication of the elements and clinical outcomes.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 1.

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic embolism. Today's clinician is faced with the difficult task of selecting a suitable OAC for a patient with a particular clinical profile or a particular pattern of risk factors and concomitant diseases. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. NOACs for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In the first of a two-part review, we discuss the choice of NOAC for stroke prevention in the following subgroups of patients with AF: (i) stable coronary artery disease or peripheral artery disease, including percutaneous coronary intervention with stenting and triple therapy; (ii) cardioversion, ablation and anti-arrhythmic drug therapy; (iii) mechanical valves and rheumatic valve disease, (iv) patients with time in therapeutic range of >70% on warfarin; (v) patients with a single stroke risk factor (CHA2DS2VASc score of 1 in males, 2 in females); and (vi) patients with a single first episode of paroxysmal AF. Although there are no major differences in terms of efficacy and safety between the NOACs for some clinical scenarios, in others we are able to suggest that particular drugs and/or doses be prioritized for anticoagulation.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 2.

The choice of oral anticoagulant (OAC) for patients with atrial fibrillation (AF) may be influenced by individual clinical features or by patterns of risk factors and comorbidities. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. non-vitamin K oral anticoagulants (NOACs) for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In addition, we discuss the timing of initiation of anticoagulation. In the second of a two-part review, we discuss the use of NOAC for stroke prevention in the following subgroups of patients with AF: (vii) secondary stroke prevention in patients after stroke or transient ischaemic attack (TIA), (viii) patients with acute stroke requiring thrombolysis or thrombectomy, (ix) those initiating or restarting OAC treatment after stroke or TIA, (x) those with renal impairment on dialysis, (xi) the elderly, (xii) those at high risk of gastrointestinal bleeding, and (xiii) those with hypertension. In addition, we discuss adherence and compliance. Finally, we present a summary of treatment suggestions. In specific subgroups of patients with AF, evidence supports the use of particular NOACs and/or particular doses of anticoagulant. The appropriate choice of treatment for these subgroups will help to promote optimal clinical outcomes.

Factors associated with non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with new-onset atrial fibrillation: Results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II (ORBIT-AF II).

BACKGROUND: Several non-vitamin K antagonist oral anticoagulant (NOAC) alternatives to warfarin are available for stroke prevention in atrial fibrillation (AF). We aimed to describe the factors associated with selection of NOACs versus warfarin in patients with new onset AF. METHODS: The ORBIT-AF II study is a national, US, prospective, observational, cohort study of anticoagulation treatment in patients with AF receiving NOACs or warfarin in the United States from 2013 to 2016. We measured factors associated with oral anticoagulant selection in 4,670 patients recently diagnosed with AF. RESULTS: At baseline, 1,169 (25%) patients were started on warfarin and 3,501 (75%) on NOACs: of these latter, 259 (6%) were started on dabigatran, 1858 (40%) on rivaroxaban, and 1384 (30%) on apixaban. Those receiving NOACs were slightly younger patients (median age 71 vs 72, P<.0001); were less likely to have prior stroke (5.3% vs 8.6%; P<.0001) or prior bleeding (2.7% vs 4.4%; P=.005); had better kidney function (mean estimated glomerular filtration rate 91 mL/min vs 80 mL/min, P<.0001); and had fewer patients at high stroke risk (CHA2DS2-VASc score [Congestive heart failure, Hypertension, Age ≥75years, Diabetes mellitus, Prior stroke, transient ischemic attack {TIA}, or thromboembolism,Vascular disease, Age 65-74years, Sex category {female}] ≥2 in 86% vs 93%; P<.0001). In multivariable analysis, factors associated with NOAC selection versus warfarin included renal function, prior stroke or valve replacement, rhythm control AF management strategy, treatment by a cardiologist, and higher patient education level. CONCLUSIONS: In contemporary clinical practice, up to three-fourths of patients with new-onset AF are now initially treated with a NOAC for stroke prevention. Those selected for NOAC treatment had lower stroke and bleeding risk profiles, were more likely treated by cardiologists, and had higher socioeconomic status. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01701817.

International trends in clinical characteristics and oral anticoagulation treatment for patients with atrial fibrillation: Results from the GARFIELD-AF, ORBIT-AF I, and ORBIT-AF II registries.

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world. We aimed to provide comprehensive data on international patterns of AF stroke prevention treatment. METHODS: Demographics, comorbidities, and stroke risk of the patients in the GARFIELD-AF (n=51,270), ORBIT-AF I (n=10,132), and ORBIT-AF II (n=11,602) registries were compared (overall N=73,004 from 35 countries). Stroke prevention therapies were assessed among patients with new-onset AF (≤6 weeks). RESULTS: Patients from GARFIELD-AF were less likely to be white (63% vs 89% for ORBIT-AF I and 86% for ORBIT-AF II) or have coronary artery disease (19% vs 36% and 27%), but had similar stroke risk (85% CHA2DS2-VASc ≥2 vs 91% and 85%) and lower bleeding risk (11% with HAS-BLED ≥3 vs 24% and 15%). Oral anticoagulant use was 46% and 57% for patients with a CHA2DS2-VASc=0 and 69% and 87% for CHA2DS2-VASc ≥2 in GARFIELD-AF and ORBIT-AF II, respectively, but with substantial geographic heterogeneity in use of oral anticoagulant (range: 31%-93% [GARFIELD-AF] and 66%-100% [ORBIT-AF II]). Among patients with new-onset AF, non-vitamin K antagonist oral anticoagulant use increased over time to 43% in 2016 for GARFIELD-AF and 71% for ORBIT-AF II, whereas use of antiplatelet monotherapy decreased from 36% to 17% (GARFIELD-AF) and 18% to 8% (ORBIT-AF I and II). CONCLUSIONS: Among new-onset AF patients, non-vitamin K antagonist oral anticoagulant use has increased and antiplatelet monotherapy has decreased. However, anticoagulation is used frequently in low-risk patients and inconsistently in those at high risk of stroke. Significant geographic variability in anticoagulation persists and represents an opportunity for improvement.

Thrombophilic Evaluation in Patients with Acute Pulmonary Embolism.

Patients with acute pulmonary embolism (PE) are often tested for thrombophilias, which are hereditary and acquired conditions that predispose to thrombosis. If a hereditary condition is identified, then testing is often performed on members of the patient's family. Testing for these conditions can be complex, as the presence of acute thrombosis and antithrombotic therapies can make the results of many tests unreliable. Many risk factors for thrombosis exist that are not routinely assessed by laboratory testing, and it is likely that many hereditary thrombophilia conditions remain to be discovered. Also, various risk factors for thrombosis interact with one another. Therefore, the results of a laboratory thrombophilia evaluation provide a limited ability to assess a patient or family members' risk for future thrombosis, and such testing usually does not provide information that improves a management decision. Thrombophilia testing is expensive and carries potential risks. This article reviews common thrombophilias, their epidemiology and classification, and timing and technical aspects of accurate testing and provides rational suggestions for the use of thrombophilia testing in five clinical situations: (1) following provoked PE (or other venous thromboembolism), (2) following unprovoked venous thromboembolism, (3) in relatives of patients with thrombosis, (4) in female relatives of patients with thrombosis considering estrogen use, and (5) in female relatives of patients with thrombosis who are considering pregnancy. Published guidelines and guidance statements from professional societies and other groups are also reviewed. Clinicians should carefully consider the relevant risks and benefits before testing patients for thrombophilia. When performed, testing should be timed correctly and care should be taken to properly interpret results. New models that incorporate multiple genetic and clinical markers may improve the utility of testing, but these await further research.

Use and outcomes associated with bridging during anticoagulation interruptions in patients with atrial fibrillation: findings from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF).

BACKGROUND: Temporary interruption of oral anticoagulation for procedures is often required, and some propose using bridging anticoagulation. However, the use and outcomes of bridging during oral anticoagulation interruptions in clinical practice are unknown. METHODS AND RESULTS: The Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry is a prospective, observational registry study of US outpatients with atrial fibrillation. We recorded incident temporary interruptions of oral anticoagulation for a procedure, including the use and type of bridging therapy. Outcomes included multivariable-adjusted rates of myocardial infarction, stroke or systemic embolism, major bleeding, cause-specific hospitalization, and death within 30 days. Of 7372 patients treated with oral anticoagulation, 2803 overall interruption events occurred in 2200 patients (30%) at a median follow-up of 2 years. Bridging anticoagulants were used in 24% (n=665), predominantly low-molecular-weight heparin (73%, n=487) and unfractionated heparin (15%, n=97). Bridged patients were more likely to have had prior cerebrovascular events (22% versus 15%; P=0.0003) and mechanical valve replacements (9.6% versus 2.4%; P<0.0001); however, there was no difference in CHA2DS2-VASc scores (scores ≥ 2 in 94% versus 95%; P=0.5). Bleeding events were more common in bridged than nonbridged patients (5.0% versus 1.3%; adjusted odds ratio, 3.84; P<0.0001). The incidence of myocardial infarction, stroke or systemic embolism, major bleeding, hospitalization, or death within 30 days was also significantly higher in patients receiving bridging (13% versus 6.3%; adjusted odds ratio, 1.94; P=0.0001). CONCLUSIONS: Bridging anticoagulation is used in one quarter of anticoagulation interruptions and is associated with higher risk for bleeding and adverse events. These data do not support the use of routine bridging, and additional data are needed to identify best practices concerning anticoagulation interruptions. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01165710.

How well does physician risk assessment predict stroke and bleeding in atrial fibrillation? Results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF).

BACKGROUND: Assessments of stroke and bleeding risks are essential to selecting oral anticoagulation in patients with atrial fibrillation (AF). We aimed to assess outcomes according to physician assessed risk, with comparison to empirical risk scores. METHODS: This was a prospective, observational study of 9,715 outpatients with AF enrolled in ORBIT-AF, a US national registry. Stroke and bleeding risks were quantified by physician assignment, CHADS2 and CHA2DS2-VASc stroke scores, and ATRIA and HAS-BLED bleeding scores. Outcomes were stroke or systemic embolism and major bleeding during a median follow-up of 28 months. RESULTS: Physician-assigned risk was associated with thromboembolic events: low risk (0.71 per 100 patient-years [95% CI 0.56-0.91], n=3,991), intermediate risk (0.98 [95% CI 0.79-1.20], n=4,148), and high risk (1.84 [95% CI 1.43-2.37], n=1,576, P<.0001), and major bleeding: low (3.43 [95% CI 3.07-3.82], n=4,250), intermediate (4.55 [95% CI 4.03-5.15], n=2,702), and high (5.76 [95% CI 4.42-7.50], n=468; P<.0001). Discrimination of stroke risk was similar with CHADS2 (c=0.59, 95% CI 0.57-0.61) vs physician assessment (c=0.58, 95% CI 0.55-0.62). Among patients on oral anticoagulation, bleeding risk discrimination was higher with ATRIA (c=0.63, 95% CI 0.61-0.65) and HAS-BLED (c=0.60, 95% CI 0.59-0.62) than with physician assessment (0.55, 95% CI 0.53-0.57). Physician-assessed risk categories did not add significantly to empirical risk scores, in Cox models for outcomes (Padjusted>.05 for all physician assessments vs Padjusted<.05 for empirical scores). CONCLUSION: Physician-assigned risk showed a graded relationship with outcomes, and both physician-based and empirical scores yielded only moderate discrimination. Although empirical scores provided valuable risk stratification information (with or without physician judgment), physician assessment added little to existing scores. These data support the use of empirical scores for stroke and bleeding risk stratification, and the need for novel approaches to risk stratification in this population.

Management and clinical outcomes in patients treated with apixaban vs warfarin undergoing procedures.

Using data from ARISTOTLE, we describe the periprocedural management of anticoagulation and rates of subsequent clinical outcomes among patients chronically anticoagulated with warfarin or apixaban. We recorded whether (and for how long) anticoagulant therapy was interrupted preprocedure, whether bridging therapy was used, and the proportion of patients who experienced important clinical outcomes during the 30 days postprocedure. Of 10 674 procedures performed during follow-up in 5924 patients, 9260 were included in this analysis. Anticoagulant treatment was not interrupted preprocedure 37.5% of the time. During the 30 days postprocedure, stroke or systemic embolism occurred after 16/4624 (0.35%) procedures among apixaban-treated patients and 26/4530 (0.57%) procedures among warfarin-treated patients (odds ratio [OR] 0.601; 95% confidence interval [CI] 0.322-1.120). Major bleeding occurred in 74/4560 (1.62%) procedures in the apixaban arm and 86/4454 (1.93%) in the warfarin arm (OR 0.846; 95% CI 0.614-1.166). The risk of death was similar with apixaban (54/4624 [1.17%]) and warfarin (49/4530 [1.08%]) (OR 1.082; 95% CI 0.733-1.598). Among patients in ARISTOTLE, the 30-day postprocedure stroke, death, and major bleeding rates were low and similar in apixaban- and warfarin-treated patients, regardless of whether anticoagulation was stopped beforehand. Our findings suggest that many patients on chronic anticoagulation can safely undergo procedures; some will not require a preprocedure interruption of anticoagulation. ARISTOTLE was registered at www.clinicaltrials.gov as #NCT00412984.