Milvexian for the Prevention of Venous Thromboembolism.

BACKGROUND: Factor XIa inhibitors for the prevention and treatment of venous and arterial thromboembolism may be more effective and result in less bleeding than conventional anticoagulants. Additional data are needed regarding the efficacy and safety of milvexian, an oral factor XIa inhibitor. METHODS: In this parallel-group, phase 2 trial, we randomly assigned 1242 patients undergoing knee arthroplasty to receive one of seven postoperative regimens of milvexian (25 mg, 50 mg, 100 mg, or 200 mg twice daily or 25 mg, 50 mg, or 200 mg once daily) or enoxaparin (40 mg once daily). The primary efficacy outcome was venous thromboembolism (which was a composite of asymptomatic deep-vein thrombosis, confirmed symptomatic venous thromboembolism, or death from any cause). The principal safety outcome was bleeding. RESULTS: Among the patients receiving milvexian twice daily, venous thromboembolism developed in 27 of 129 (21%) taking 25 mg, in 14 of 124 (11%) taking 50 mg, in 12 of 134 (9%) taking 100 mg, and in 10 of 131 (8%) taking 200 mg. Among those receiving milvexian once daily, venous thromboembolism developed in 7 of 28 (25%) taking 25 mg, in 30 of 127 (24%) taking 50 mg, and in 8 of 123 (7%) taking 200 mg, as compared with 54 of 252 patients (21%) taking enoxaparin. The dose-response relationship with twice-daily milvexian was significant (one-sided P<0.001), and the 12% incidence of venous thromboembolism with twice-daily milvexian was significantly lower than the prespecified benchmark of 30% (one-sided P<0.001). Bleeding of any severity occurred in 38 of 923 patients (4%) taking milvexian and in 12 of 296 patients (4%) taking enoxaparin; major or clinically relevant nonmajor bleeding occurred in 1% and 2%, respectively; and serious adverse events were reported in 2% and 4%, respectively. CONCLUSIONS: Postoperative factor XIa inhibition with oral milvexian in patients undergoing knee arthroplasty was effective for the prevention of venous thromboembolism and was associated with a low risk of bleeding. (Funded by Bristol Myers Squibb and Janssen Research and Development; AXIOMATIC-TKR ClinicalTrials.gov number, NCT03891524.).

Research Opportunities in Stroke Prevention for Atrial Fibrillation: A Report From a National Heart, Lung, and Blood Institute Virtual Workshop.

Atrial fibrillation (AF) is one of the strongest risk factors for ischemic stroke, which is a leading cause of disability and death. Given the aging population, increasing prevalence of AF risk factors, and improved survival in those with cardiovascular disease, the number of individuals affected by AF will continue increasing over time. While multiple proven stroke prevention therapies exist, important questions remain about the optimal approach to stroke prevention at the population and individual patient levels. Our report summarizes the National Heart, Lung, and Blood Institute virtual workshop focused on identifying key research opportunities related to stroke prevention in AF. The workshop reviewed major knowledge gaps and identified targeted research opportunities to advance stroke prevention in AF in the following areas: (1) improving risk stratification tools for stroke and intracranial hemorrhage; (2) addressing challenges with oral anticoagulants; and (3) delineating the optimal roles of percutaneous left atrial appendage occlusion and surgical left atrial appendage closure/excision. This report aims to promote innovative, impactful research that will lead to more personalized, effective use of stroke prevention strategies in people with AF.

Patients With Atrial Fibrillation Taking Nonsteroidal Anti-Inflammatory Drugs and Oral Anticoagulants in the ARISTOTLE Trial.

BACKGROUND: The use of nonsteroidal anti-inflammatory drugs (NSAIDs) with oral anticoagulants has been associated with an increased risk of bleeding. We investigated the risk of bleeding and major cardiovascular outcomes in patients with atrial fibrillation taking NSAIDs and apixaban or warfarin. METHODS: The ARISTOTLE trial (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation; n=18 201) compared apixaban with warfarin in patients with atrial fibrillation at an increased risk of stroke. Patients in ARISTOTLE without severe renal (creatine clearance ≤30 mL/min) or liver disease were included in this analysis (n=17 423). NSAID use at baseline, NSAID use during the trial (incident NSAID use), and never users were described. The primary outcome was major bleeding. Secondary outcomes included clinically relevant nonmajor bleeding, gastrointestinal bleeding, heart failure hospitalization, stroke or systemic embolism, and all-cause mortality. NSAID use during the trial, and the interaction between randomized treatment, was analyzed using time-dependent Cox proportional hazards models. RESULTS: Those with baseline NSAID use (n=832 [4.8%]), incident NSAID use (n=2185 [13.2%]), and never users were similar in median age (age [25th, 75th]; 70 [64, 77] versus 70 [63, 75] versus 70 [62, 76]). Those with NSAID use at baseline and incident NSAID use were more likely to have a history of bleeding than never users (24.5% versus 21.0% versus 15.6%, respectively). During a median follow-up (25th, 75th) of 1.8 (1.4, 2.3) years and when excluding those taking NSAID at baseline, we found that incident NSAID use was associated with an increased risk of major bleeding (hazard ratio [HR], 1.61 [95% CI, 1.11-2.33]) and clinically relevant nonmajor bleeding (HR, 1.70 [95% CI, 1.16-2.48]), but not gastrointestinal bleeding. No significant interaction was observed between NSAID use and randomized treatment for any outcome. CONCLUSIONS: A substantial number of patients in the ARISTOTLE trial took NSAIDs. Incident NSAID use was associated with major and clinically relevant nonmajor bleeding, but not with gastrointestinal bleeding. The safety and efficacy of apixaban versus warfarin appeared not significantly to be altered by NSAID use. This study warrants more investigation of the effect of NSAIDs on the outcomes of patients treated with apixaban. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00412984.

Idarucizumab for Dabigatran Reversal - Full Cohort Analysis.

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

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.

Temporal trends in pharmacologic prophylaxis for venous thromboembolism after hip and knee replacement in older adults.

Trends in prescription for venous thromboembolism (VTE) prophylaxis following total hip (THR) and knee replacement (TKR) since the approval of direct oral anticoagulants (DOACs) and the 2012 guideline endorsement of aspirin are unknown, as are the risks of adverse events. We examined practice patterns in the prescription of prophylaxis agents and the risk of adverse events during the in-hospital period (the 'in-hospital sample') and 90 days following discharge (the 'discharge sample') among adults aged ⩾ 65 undergoing THR and TKR in community hospitals in the Institute for Health Metrics database over a 30-month period during 2011 to 2013. Eligible medications included fondaparinux, DOACs, low molecular weight heparin (LMWH), other heparin products, warfarin, and aspirin. Outcomes were validated by physician review of source documents: VTE, major hemorrhage, cardiovascular events, and death. The in-hospital and the discharge samples included 10,503 and 5722 adults from 65 hospitals nationwide, respectively (mean age 73, 74 years; 61%, 63% women). Pharmacologic prophylaxis was near universal during the in-hospital period (93%) and at discharge (99%). DOAC use increased substantially and was the prophylaxis of choice for nearly a quarter (in-hospital) and a third (discharge) of the patients. Aspirin was the sole discharge prophylactic agent for 17% and 19% of patients undergoing THR and TKR, respectively. Warfarin remained the prophylaxis agent of choice for patients aged 80 years and older. The overall risk of adverse events was low, at less than 1% for both the in-hospital and discharge outcomes. The low number of adverse events precluded statistical comparison of prophylaxis regimens.

The importance of adherence and persistence in the elderly atrial fibrillation patient.

Older adults with atrial fibrillation are at the highest risk of ischaemic stroke yet are the least likely to be prescribed anticoagulant therapy, adhere to this therapy, and maintain long-term persistence with this therapy. The reasons for this under treatment are multifactorial and include patient-driven factors, physician-driven factors, medical system complexities, and current unknowns regarding the biology and natural history of AF. Understanding these challenges to stroke prevention and addressing identified barriers to medication adherence and persistence in this vulnerable age group will improve outcomes related to AF.

Use of Biomarkers to Predict Specific Causes of Death in Patients With Atrial Fibrillation.

BACKGROUND: Atrial fibrillation is associated with an increased risk of death. High-sensitivity troponin T, growth differentiation factor-15, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and interleukin-6 levels are predictive of cardiovascular events and total cardiovascular death in anticoagulated patients with atrial fibrillation. The prognostic utility of these biomarkers for cause-specific death is unknown. METHODS: The ARISTOTLE trial (Apixaban for the Prevention of Stroke in Subjects With Atrial Fibrillation) randomized 18 201 patients with atrial fibrillation to apixaban or warfarin. Biomarkers were measured at randomization in 14 798 patients (1.9 years median follow-up). Cox models were used to identify clinical variables and biomarkers independently associated with each specific cause of death. RESULTS: In total, 1272 patients died: 652 (51%) cardiovascular, 32 (3%) bleeding, and 588 (46%) noncardiovascular/nonbleeding deaths. Among cardiovascular deaths, 255 (39%) were sudden cardiac deaths, 168 (26%) heart failure deaths, and 106 (16%) stroke/systemic embolism deaths. Biomarkers were the strongest predictors of cause-specific death: a doubling of troponin T was most strongly associated with sudden death (hazard ratio [HR], 1.48; P<0.001), NT-proBNP with heart failure death (HR, 1.62; P<0.001), and growth differentiation factor-15 with bleeding death (HR, 1.72; P=0.028). Prior stroke/systemic embolism (HR, 2.58; P>0.001) followed by troponin T (HR, 1.45; P<0.0029) were the most predictive for stroke/ systemic embolism death. Adding all biomarkers to clinical variables improved discrimination for each cause-specific death. CONCLUSIONS: Biomarkers were some of the strongest predictors of cause-specific death and may improve the ability to discriminate among patients' risks for different causes of death. These data suggest a potential role of biomarkers for the identification of patients at risk for different causes of death in patients anticoagulated for atrial fibrillation. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00412984.

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.

Outcomes of apixaban versus warfarin in patients with atrial fibrillation and multi-morbidity: Insights from the ARISTOTLE trial.

BACKGROUND: Patients with atrial fibrillation (AF) often have multi-morbidity, defined as ≥3 comorbid conditions. Multi-morbidity is associated with polypharmacy, adverse events, and frailty potentially altering response to anticoagulation. We sought to describe the prevalence of multi-morbidity among older patients with AF and determine the association between multi-morbidity, clinical outcomes, and the efficacy and safety of apixaban compared with warfarin. METHODS: In this post-hoc subgroup analysis of the ARISTOTLE trial, we studied enrolled patients age ≥ 55 years (n = 16,800). Patients were categorized by the number of comorbid conditions at baseline: no multi-morbidity (0-2 comorbid conditions), moderate multi-morbidity (3-5 comorbid conditions), and high multi-morbidity (≥6 comorbid conditions). Association between multi-morbidity and clinical outcomes were analyzed by treatment with a median follow-up of 1.8 (1.3-2.3) years. RESULTS: Multi-morbidity was present in 64% (n = 10,713) of patients; 51% (n = 8491) had moderate multi-morbidity, 13% (n = 2222) had high multi-morbidity, and 36% (n = 6087) had no multi-morbidity. Compared with the no multi-morbidity group, the high multi-morbidity group was older (74 vs 69 years), took twice as many medications (10 vs 5), and had higher CHA2DS2-VASc scores (4.9 vs 2.7) (all P < .001). Adjusted rates per 100 patient-years for stroke/systemic embolism, death, and major bleeding increased with multi-morbidity (Reference no multi-morbidity; moderate multi-morbidity 1.42 [1.24-1.64] and high multi-morbidity 1.92 [1.59-2.31]), with no interaction in relation to efficacy or safety of apixaban. CONCLUSIONS: Multi-morbidity is prevalent among the population with AF; efficacy and safety of apixaban is preserved in this subgroup supporting extension of trial results to the most complex AF patients.

Interacting medication use and the treatment effects of apixaban versus warfarin: results from the ARISTOTLE Trial.

Warfarin is dependent on multiple hepatic enzymes for metabolism while apixaban is a substrate for P-glycoprotein (P-gp) transport and hepatic CYP3A4 metabolism. The aim of this analysis was to assess the impact of interacting medication use on the treatment effects of apixaban versus warfarin. Outcomes were compared between apixaban and warfarin using Cox proportional hazards modeling according to the use of interacting medications at randomization in ARISTOTLE (n = 18,201). Interacting medications for apixaban were identified as combined P-gp and 3A4 inhibitors or inducers while interacting medications for warfarin were defined as those highly probable for warfarin potentiation or inhibition. At randomization, 5547 (30.5%) patients were on an interacting medication, including 2722 on apixaban and 2825 on warfarin. Patients using an interacting medication were more likely to be female, taking aspirin, and have a history of prior bleeding and were less likely to have a prior stroke or transient ischemic attack. No significant differences were observed on the treatment effect of apixaban compared with warfarin in patients on and off interacting medications for outcomes including the primary efficacy outcome of stroke or systemic embolism (P for interaction = 0.79) or the primary safety outcome of major bleeding (P for interaction = 0.75). Use of interacting medications with anticoagulants occurs often in patients with atrial fibrillation. Despite the potential for altered exposure, interacting medication use was not associated with a significant change in the efficacy or safety of apixaban compared with warfarin in the ARISTOTLE trial.Trial registration ClinicalTrials.gov, NCT00412984.

International normalized ratio control and subsequent clinical outcomes in patients with atrial fibrillation using warfarin.

We explored associations between INR measures and clinical outcomes in patients with AF using warfarin, and whether INR history predicted future INR measurements. We included patients in ARISTOTLE who were randomized to and received warfarin. Among patients who had events, we included those with ≥ 3 INR values in the 180 days prior to the event, with the most recent ≤ 60 days prior to the event, who were on warfarin at the time of event (n = 545). Non-event patients were included in the control group if they had ≥ 180 days of warfarin exposure with ≥ 3 INR measurements (n = 7259). The median (25th, 75th) number of INR values per patient was 29 (21, 38) over a median follow-up of 1.8 years. A total of 87% had at least one INR value < 1.5; 49% had at least one value > 4.0. The last INRs before events (median 14 [24, 7] days) were < 3.0 for at least 75% of patients with major bleeding and > 2.0 for half of patients with ischemic stroke. Historic time in therapeutic range (TTR) was weakly associated with future TTR (R2 = 0.212). Historic TTR ≥ 80% had limited predictive ability to discriminate future TTR ≥ 80% (C index 0.61). In patients with AF receiving warfarin, most bleeding events may not have been preventable despite careful INR control. Our findings suggest that INRs collected through routine management are not sufficiently predictive to provide reassurance about future time in therapeutic range or to prevent subsequent outcomes, and might be over-interpreted in clinical practice.

A biomarker-based risk score to predict death in patients with atrial fibrillation: the ABC (age, biomarkers, clinical history) death risk score.

Aims: In atrial fibrillation (AF), mortality remains high despite effective anticoagulation. A model predicting the risk of death in these patients is currently not available. We developed and validated a risk score for death in anticoagulated patients with AF including both clinical information and biomarkers. Methods and results: The new risk score was developed and internally validated in 14 611 patients with AF randomized to apixaban vs. warfarin for a median of 1.9 years. External validation was performed in 8548 patients with AF randomized to dabigatran vs. warfarin for 2.0 years. Biomarker samples were obtained at study entry. Variables significantly contributing to the prediction of all-cause mortality were assessed by Cox-regression. Each variable obtained a weight proportional to the model coefficients. There were 1047 all-cause deaths in the derivation and 594 in the validation cohort. The most important predictors of death were N-terminal pro B-type natriuretic peptide, troponin-T, growth differentiation factor-15, age, and heart failure, and these were included in the ABC (Age, Biomarkers, Clinical history)-death risk score. The score was well-calibrated and yielded higher c-indices than a model based on all clinical variables in both the derivation (0.74 vs. 0.68) and validation cohorts (0.74 vs. 0.67). The reduction in mortality with apixaban was most pronounced in patients with a high ABC-death score. Conclusion: A new biomarker-based score for predicting risk of death in anticoagulated AF patients was developed, internally and externally validated, and well-calibrated in two large cohorts. The ABC-death risk score performed well and may contribute to overall risk assessment in AF. ClinicalTrials.gov identifier: NCT00412984 and NCT00262600.

Idarucizumab for Dabigatran Reversal.

BACKGROUND: Specific reversal agents for non-vitamin K antagonist oral anticoagulants are lacking. Idarucizumab, an antibody fragment, was developed to reverse the anticoagulant effects of dabigatran. METHODS: We undertook this prospective cohort study to determine the safety of 5 g of intravenous idarucizumab and its capacity to reverse the anticoagulant effects of dabigatran in patients who had serious bleeding (group A) or required an urgent procedure (group B). The primary end point was the maximum percentage reversal of the anticoagulant effect of dabigatran within 4 hours after the administration of idarucizumab, on the basis of the determination at a central laboratory of the dilute thrombin time or ecarin clotting time. A key secondary end point was the restoration of hemostasis. RESULTS: This interim analysis included 90 patients who received idarucizumab (51 patients in group A and 39 in group B). Among 68 patients with an elevated dilute thrombin time and 81 with an elevated ecarin clotting time at baseline, the median maximum percentage reversal was 100% (95% confidence interval, 100 to 100). Idarucizumab normalized the test results in 88 to 98% of the patients, an effect that was evident within minutes. Concentrations of unbound dabigatran remained below 20 ng per milliliter at 24 hours in 79% of the patients. Among 35 patients in group A who could be assessed, hemostasis, as determined by local investigators, was restored at a median of 11.4 hours. Among 36 patients in group B who underwent a procedure, normal intraoperative hemostasis was reported in 33, and mildly or moderately abnormal hemostasis was reported in 2 patients and 1 patient, respectively. One thrombotic event occurred within 72 hours after idarucizumab administration in a patient in whom anticoagulants had not been reinitiated. CONCLUSIONS: Idarucizumab completely reversed the anticoagulant effect of dabigatran within minutes. (Funded by Boehringer Ingelheim; RE-VERSE AD ClinicalTrials.gov number, NCT02104947.).

Anticoagulation reversal in vitamin K antagonist-associated intracerebral hemorrhage: a systematic review.

The effect of rapid anticoagulation reversal on mortality and functional outcome in vitamin K antagonist-associated intracerebral hemorrhage (VKA-ICH) is uncertain. Given the approval of idarucizumab for dabigatran reversal and pending approval for andexanet alfa for reversal of factor Xa inhibitors, a systematic appraisal of the effectiveness of reversal for VKA-ICH would provide a bench mark for current practice. We performed PubMed searches and reviewed current guidelines. Using pre-specified inclusion and exclusion criteria, studies were reviewed by two physicians independently. Data elements abstracted included study design, sample size, inclusion and exclusion criteria; patient characteristics at presentation; time to presentation and therapy; dose and timing of warfarin reversal agents; functional outcome and mortality. Studies were assessed for risk of bias. Twenty-one studies met the selection criteria. The overall quality of the studies was poor with small sample size for the majority and all studies being either case series or retrospective observational in design. Inclusion criteria were not uniform. Interpretation of the effectiveness of vitamin K antagonist reversal on functional outcome was not feasible due to lack of standard protocols in the management of VKA-ICH including choice, dose, and timing of reversal agent, timing of subsequent INR monitoring, and decision for repeat imaging. Confounding by indication, lack of universal reporting of functional outcome, and use of varied scales for the endpoint further limited a summary interpretation. Despite availability of reversal agents, mortality and morbidity remain high following VKA-ICH. Evidence for improvement in neurological outcome is limited.

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.

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.