A clinician’s perspective: novel oral anticoagulants to reduce the risk of stroke in nonvalvular atrial fibrillation – full speed ahead or proceed with caution?

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Over the past few years, three novel oral anticoagulants, dabigatran, rivaroxaban, and apixaban, have been approved in the USA and Europe to reduce the risk of stroke or systemic embolism in patients with nonvalvular atrial fibrillation, and the results of a Phase III trial for a fourth novel oral anticoagulant, edoxaban, have recently been published. The aim of this review is to examine this indication from a clinician’s perspective, highlighting efficacy and safety results from the major trials with these novel oral agents. Clinical issues regarding bleeding, monitoring, and reversal are discussed, along with requirements to consider when interrupting treatment with a novel oral anticoagulant for the purpose of transitioning to another anticoagulant and prior to cardioversion, ablation, percutaneous coronary intervention, or emergency surgery. The cost-effectiveness of each of the approved novel oral anticoagulants is reviewed, and the author provides recommendations for selecting appropriate patients for these agents.

Related collections

Most cited references 65

Record: found
Abstract: found
Article: not found

Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials.

S Connolly, MD Ezekowitz, RG Hart … (1994)

Atrial fibrillation is associated with an increased risk of ischemic stroke. Data on individual patients were pooled from five recently completed randomized trials comparing warfarin (all studies) or aspirin (the Atrial Fibrillation, Aspirin, Anticoagulation Study and the Stroke Prevention in Atrial Fibrillation Study) with control in patients with atrial fibrillation. The purpose of the analysis was to (1) identify patient features predictive of a high or low risk of stroke, (2) assess the efficacy of antithrombotic therapy in major patient subgroups (eg, women), and (3) obtain the most precise estimate of the efficacy and risks of antithrombotic therapy in atrial fibrillation. For the warfarin-control comparison there were 1889 patient-years receiving warfarin and 1802 in the control group. For the aspirin-placebo comparison there were 1132 patient-years receiving aspirin and 1133 receiving placebo. The daily dose of aspirin was 75 mg in the Atrial Fibrillation, Aspirin, Anticoagulation Study and 325 mg in the Stroke Prevention in Atrial Fibrillation Study. To monitor warfarin dosage, three studies used prothrombin time ratios and two used international normalized ratios. The lowest target intensity was a prothrombin time ratio of 1.2 to 1.5 and the highest target intensity was an international normalized ratio of 2.8 to 4.2. The primary end points were ischemic stroke and major hemorrhage, as assessed by each study. At the time of randomization the mean age was 69 years and the mean blood pressure was 142/82 mm Hg. Forty-six percent of the patients had a history of hypertension, 6% had a previous transient ischemic attack or stroke, and 14% had diabetes. Risk factors that predicted stroke on multivariate analyses in control patients were increasing age, history of hypertension, previous transient ischemic attack or stroke, and diabetes. Patients younger than 65 years who had none of the other predictive factors (15% of all patients) had an annual rate of stroke of 1.0%, 95% confidence interval (CI) 0.3% to 3.0%. The annual rate of stroke was 4.5% for the control group and 1.4% for the warfarin group (risk reduction, 68%; 95% CI, 50% to 79%). The efficacy of warfarin was consistent across all studies and subgroups of patients. In women, warfarin decreased the risk of stroke by 84% (95% CI, 55% to 95%) compared with 60% (95% CI, 35% to 76%) in men. The efficacy of aspirin was not as consistent. The risk reduction with 75 mg of aspirin in the Atrial Fibrillation, Aspirin, Anticoagulation Study was 18% (95% CI, 60% to 58%), and with 325 mg of aspirin in the Stroke Prevention in Atrial Fibrillation Study the risk reduction was 44% (95% CI, 7% to 66%). When both studies were combined the risk reduction was 36% (95% CI, 4% to 57%). The annual rate of major hemorrhage (intracranial bleeding or a bleed requiring hospitalization or 2 units of blood) was 1.0% for the control group, 1.0% for the aspirin group, and 1.3% for the warfarin group. In these five randomized trials warfarin consistently decreased the risk of stroke in patients with atrial fibrillation (a 68% reduction in risk) with virtually no increase in the frequency of major bleeding. Patients with atrial fibrillation younger than 65 years without a history of hypertension, previous stroke or transient ischemic attack, or diabetes were at very low risk of stroke even when not treated. The efficacy of aspirin was less consistent. Further studies are needed to clarify the role of aspirin in atrial fibrillation.

0 comments Cited 241 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Reversal of rivaroxaban and dabigatran by prothrombin complex concentrate: a randomized, placebo-controlled, crossover study in healthy subjects.

Elise S Eerenberg, Pieter Kamphuisen, Meertien K Sijpkens … (2011)

Rivaroxaban and dabigatran are new oral anticoagulants that specifically inhibit factor Xa and thrombin, respectively. Clinical studies on the prevention and treatment of venous and arterial thromboembolism show promising results. A major disadvantage of these anticoagulants is the absence of an antidote in case of serious bleeding or when an emergency intervention needs immediate correction of coagulation. This study evaluated the potential of prothrombin complex concentrate (PCC) to reverse the anticoagulant effect of these drugs. In a randomized, double-blind, placebo-controlled study, 12 healthy male volunteers received rivaroxaban 20 mg twice daily (n=6) or dabigatran 150 mg twice daily (n=6) for 2½ days, followed by either a single bolus of 50 IU/kg PCC (Cofact) or a similar volume of saline. After a washout period, this procedure was repeated with the other anticoagulant treatment. Rivaroxaban induced a significant prolongation of the prothrombin time (15.8±1.3 versus 12.3±0.7 seconds at baseline; P<0.001) that was immediately and completely reversed by PCC (12.8±1.0; P<0.001). The endogenous thrombin potential was inhibited by rivaroxaban (51±22%; baseline, 92±22%; P=0.002) and normalized with PCC (114±26%; P<0.001), whereas saline had no effect. Dabigatran increased the activated partial thromboplastin time, ecarin clotting time (ECT), and thrombin time. Administration of PCC did not restore these coagulation tests. Prothrombin complex concentrate immediately and completely reverses the anticoagulant effect of rivaroxaban in healthy subjects but has no influence on the anticoagulant action of dabigatran at the PCC dose used in this study. Clinical Trial Registration- URL: http://www.trialregister.nl. Unique identifier: NTR2272.

0 comments Cited 229 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Prevention of stroke and systemic embolism with rivaroxaban compared with warfarin in patients with non-valvular atrial fibrillation and moderate renal impairment.

Jürgen Becker, Daniel Wojdyla, R. Patel … (2011)

Patients with non-valvular atrial fibrillation (AF) and renal insufficiency are at increased risk for ischaemic stroke and bleeding during anticoagulation. Rivaroxaban, an oral, direct factor Xa inhibitor metabolized predominantly by the liver, preserves the benefit of warfarin for stroke prevention while causing fewer intracranial and fatal haemorrhages. We randomized 14 264 patients with AF in a double-blind trial to rivaroxaban 20 mg/day [15 mg/day if creatinine clearance (CrCl) 30-49 mL/min] or dose-adjusted warfarin (target international normalized ratio 2.0-3.0). Compared with patients with CrCl >50 mL/min (mean age 73 years), the 2950 (20.7%) patients with CrCl 30-49 mL/min were older (79 years) and had higher event rates irrespective of study treatment. Among those with CrCl 30-49 mL/min, the primary endpoint of stroke or systemic embolism occurred in 2.32 per 100 patient-years with rivaroxaban 15 mg/day vs. 2.77 per 100 patient-years with warfarin [hazard ratio (HR) 0.84; 95% confidence interval (CI) 0.57-1.23] in the per-protocol population. Intention-to-treat analysis yielded similar results (HR 0.86; 95% CI 0.63-1.17) to the per-protocol results. Rates of the principal safety endpoint (major and clinically relevant non-major bleeding: 17.82 vs. 18.28 per 100 patient-years; P = 0.76) and intracranial bleeding (0.71 vs. 0.88 per 100 patient-years; P = 0.54) were similar with rivaroxaban or warfarin. Fatal bleeding (0.28 vs. 0.74% per 100 patient-years; P = 0.047) occurred less often with rivaroxaban. Patients with AF and moderate renal insufficiency have higher rates of stroke and bleeding than those with normal renal function. There was no evidence of heterogeneity in treatment effect across dosing groups. Dose adjustment in ROCKET-AF yielded results consistent with the overall trial in comparison with dose-adjusted warfarin.

0 comments Cited 138 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): Vasc Health Risk Manag

Journal ID (iso-abbrev): Vasc Health Risk Manag

Journal ID (publisher-id): Vascular Health and Risk Management

Title: Vascular Health and Risk Management

Publisher: Dove Medical Press

ISSN (Print): 1176-6344

ISSN (Electronic): 1178-2048

Publication date Collection: 2014

Publication date (Electronic): 21 August 2014

Volume: 10

Pages: 507-522

Affiliations

Division of Cardiology, University of Washington Medical Center, Seattle, WA, USA

Author notes

Correspondence: Eugene Yang, Division of Cardiology, University of Washington Medical Center, 1959 NE Pacific Street, Box 356005, Seattle, WA 98195, USA, Tel +1 206 598 6819, Fax +1 206 598 0445, Email eyang01@ 123456uw.edu

Article

Publisher ID: vhrm-10-507

DOI: 10.2147/VHRM.S68117

PMC ID: 4149394

SO-VID: 934a1a84-3b7f-43b1-b8c4-e6a5f0e3145e

License:

The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

History

Comments

Comment on this article

scite_

Smart Citations

Citing PublicationsSupportingMentioningContrasting

View Citations

See how this article has been cited at scite.ai

scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.

Cited by 3

See all cited by

Most referenced authors 1,801

See all reference authors

A clinician’s perspective: novel oral anticoagulants to reduce the risk of stroke in nonvalvular atrial fibrillation – full speed ahead or proceed with caution?

Read this article at

Abstract

Related collections

Cardiovascular Innovations and Applications

Most cited references 65

Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials.

Reversal of rivaroxaban and dabigatran by prothrombin complex concentrate: a randomized, placebo-controlled, crossover study in healthy subjects.

Prevention of stroke and systemic embolism with rivaroxaban compared with warfarin in patients with non-valvular atrial fibrillation and moderate renal impairment.

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 173

Cited by 3

Most referenced authors 1,801