February 5, 2014

DynaMed EBM Journal Volume 9, Issue 6

DynaMed Weekly Updates

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Physicians: .25 AMA PRA Category ICreditsTM

Family Physicians: .25 Prescribed credits

Nurse Practitioners: .25 Contact hours

Release Date: January 29, 2014

Expiration Date: January 29, 2015

Estimated Completion Time: 15 minutes

There is no fee for this activity.

To Receive Credit

In order to receive your certificate of participation, you should read the information about this activity, including the disclosure statements, review the entire activity, take the post-test, and complete the evaluation form. You may then follow the directions to print your certificate of participation. To begin, click the CME icon at the end of the article.

Program Overview

Learning Objectives

Upon successful completion of this educational program, the reader should be able to:
1. Discuss the significance of this article as it relates to your clinical practice.
2. Be able to apply this knowledge to your patient's diagnosis, treatment and management.

Faculty Information

Alan Ehrlich, MD - Assistant Clinical Professor in Family Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; Senior Deputy Editor, DynaMed, Ipswich, Massachusetts, USA

Michael Fleming, MD, FAAFP - Assistant Clinical Professor of Family Medicine and Comprehensive Care, LSU Health Science Center School of Medicine, Shreveport, Louisiana, USA; Assistant Clinical Professor of Family Medicine, Department of Family and Community Medicine, Tulane University Medical School, New Orleans, Louisiana, USA; Chief Medical Officer, Amedisys, Inc. & Antidote Education Company


Dr. Ehrlich, Dr. Fleming, DynaMed Editorial Team members, and the staff of Antidote Education Company have disclosed that they have no relevant financial relationships or conflicts of interest with commercial interests related directly or indirectly to this educational activity.

No commercial support has been received for this activity.

Accreditation Statements

ACCME: This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Antidote EducationCompany and EBSCO Publishing. Antidote is accredited by the ACCME to provide continuing medical education for physicians. Antidote Education Company designates this enduring activity for a maximum of 0.25 AMA PRA Category 1 CreditsTM. Physicians should only claim credit commensurate with the extent of their participation in the activity.

AAFP: Enduring Material activity, DynaMed EBM Focus, has been reviewed and is acceptable for up to 13 Prescribed credits by the American Academy of Family Physicians. AAFP certification begins March 7, 2012. Term of approval is for one year from this date with the option of yearly renewal. Each EBM Focus is worth .25 Prescribed credits. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

AANP: This program is approved for 0.25 contact hour of continuing education by the American Academy of Nurse Practitioners.

Program ID: 1304159N


Last week 509 journal articles were evaluated via DynaMed's Systematic Literature Surveillance and summaries of 245 articles were added to DynaMed content.

Based on criteria for selecting "articles most likely to change clinical practice," one article was selected by the DynaMed Editorial Team.

Warfarin May Increase Risk of Bleeding Without Decreasing Risk of Stroke in Elderly Patients With Atrial Fibrillation Receiving Dialysis
Reference: Circulation 2014 Jan 22 early online (level 2 [mid-level] evidence)

Warfarin is widely used for thromboembolic prophylaxis in patients with atrial fibrillation, including patients with chronic kidney disease. A recent randomized trial has shown that adjusted-dose warfarin reduces the risk of ischemic stroke or systemic embolism compared to low-dose warfarin or aspirin in patients with moderate kidney disease (Clin J Am Soc Nephrol 2011 Nov;6(11):2599 full-text). However, the role of warfarin in patients with more advanced kidney disease remains unclear. No randomized trials evaluating warfarin for prevention of cardiovascular outcomes in patients receiving dialysis have been conducted, and observational studies in this population have been conflicting. Now, a new cohort study has evaluated the use of warfarin among elderly patients on dialysis who developed atrial fibrillation.

A total of 1,626 patients aged 65 years or older receiving hemodialysis or peritoneal dialysis prior to hospitalization for atrial fibrillation were retrospectively evaluated for an association between warfarin use and risk of bleeding or stroke. Bleeding events included intracerebral, gastrointestinal, or intraocular bleeding, hematuria, or bleeding at an unspecified location. Stroke events included ischemic stroke, transient ischemic attack, or a retinal infarct. About 46% of patients received warfarin within 30 days of hospital discharge. Comparing the baseline risks for patients receiving warfarin vs. those not receiving warfarin, 84% vs. 86% had a high risk of bleeding (HAS-BLED score ≥ 3) and 77% vs. 69% had a high risk of stroke (CHADS2 score ≥ 2), but p values for these differences were not reported.

In an unadjusted analysis, the rate of bleeding was 10.9 per 100 person-years with warfarin vs. 7.3 per 100 person-years with no warfarin (p < 0.001), with no significant difference in the rate of stroke (3.4 per 100 person-years with warfarin vs. 2.9 per 100 person-years with no warfarin). A separate analysis adjusted for propensity to receive warfarin (with propensity scores based on multiple clinical and demographic factors including baseline risk) had results consistent with those of the unadjusted analysis.

Oral anticoagulation in patients with advanced kidney disease has recently been called into question based on results from several observational studies. Indeed, the routine use of oral anticoagulants in patients with chronic kidney disease requiring dialysis is no longer recommended in guidelines from either Kidney Disease: Improving Global Outcomes (Kidney Int 2011 Sep;80(6):572) or the Canadian Cardiovascular Society (Can J Cardiol 2012 Mar-Apr;28(2):125). The findings from this latest observational study support these updated guidelines, and suggest that warfarin may increase the risk of bleeding with no benefit in primary stroke prevention among patients with atrial fibrillation who require dialysis. Although this study has attempted to account for potential confounders in their statistical analyses, it is nonetheless limited by its observational design, and a randomized trial evaluating oral anticoagulation for primary prevention of stroke in patients with atrial fibrillation who require dialysis is warranted. In the meantime, use of oral anticoagulants in this patient population should be approached with caution.

For more information see the Thromboembolic prophylaxis in atrial fibrillation and Dialysis for chronic kidney disease topics in Dynamed.

Earn CME Credit for reading this e-Newsletter.
For more information on this educational activity, see the CME sidebar.

Call for Peer Reviews

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DynaMed Careers

Looking for a change? The DynaMed editorial team is expanding and looking for talented and driven individuals. Visit the links below to learn about these exciting opportunities.

Deputy Editor of Oncology
Associate Managing Editor