This Article Extract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ono, A. Articles by Fujita, T. Search for Related Content PubMed Articles by Ono, A. Articles by Fujita, T. Related Collections Coumarins Arrhythmias, clinical electrophysiology, drugs Embolic stroke Anticoagulants

(Circulation. 2007;116:e538.)
© 2007 American Heart Association, Inc.

Correspondence

Letter Regarding Article by Hylek et al, "Major Hemorrhage and Tolerability of Warfarin in the First Year of Therapy Among Elderly Patients With Atrial Fibrillation"

Ayumu Ono, MD, PhD; Ichiko Kawamura, MD

Otsuki Hospital, Kochi, Japan

Toshiro Fujita, MD

Department of Internal Medicine, University of Tokyo, Tokyo, Japan

To the Editor:

We read with great interest the recent publication by Hylek et al¹ in which they concluded that the rate of bleeding complications during warfarin therapy was substantially higher than previously reported in elderly patients with atrial fibrillation. They emphasize that published rates of major hemorrhage derived from younger noninception cohorts underestimate the bleeding that occurs in clinical practice, and the higher rate of bleeding in their study is attributable to the higher risk of bleeding in the early phase of warfarin therapy and the advanced age of their study subjects. However, the results are not necessarily generalizable to other clinical settings, because the patients enrolled in this cohort have more risk factors for bleeding than representative patients receiving warfarin in clinical practice.

First, the patients received aspirin combined with warfarin at a remarkably higher rate (40%) than reported previously.² The frequent use of aspirin may contribute to the higher rate of bleeding in patients receiving warfarin, because previous studies have demonstrated that combined anticoagulant-antiplatelet use increases bleeding risk without additive prevention of thromboembolic events. In recent trials comparing ximelagatron and warfarin, the combination therapy of aspirin with either ximelagatron or warfarin did not reduce the risk of stroke, systemic embolism, or myocardial infarction, but the addition of aspirin to warfarin or ximelagatron was associated with increased risk of bleeding, which was especially obvious when aspirin and warfarin were combined.³

Second, the study included patients receiving warfarin in spite of their potential contraindications for anticoagulation, such as active malignancy, prior bleeding, and dementia. In general, patients with risk factors for bleeding should be considered as ineligible for anticoagulation.

When physicians use warfarin in eligible patients at high risk but without contraindications, thromboembolism-associated atrial fibrillation can be adequately and safely prevented even in elderly patients. In fact, recent inception cohorts in which warfarin was newly started in elderly patients without contraindications or concomitant use of antiplatelets reported lower rates of major bleeding (<3% per 100 person-years)^4,5 than the study by Hylek et al (7.2% per 100 person-years).¹

	Acknowledgments

 
Disclosures

None.

	References

Top References

 

1. Hylek EM, Evans-Molina C, Shea C, Henault LE, Regan S. Major hemorrhage and tolerability of warfarin in the first year of therapy among elderly patients with atrial fibrillation. Circulation. 2007; 115: 2689–2696.[Abstract/Free Full Text]
   
2. Fang MC, Stafford RS, Ruskin JN, Singer DE. National trends in antiarrhythmic and antithrombotic medication use in atrial fibrillation. Arch Intern Med. 2004; 164: 55–60.[Abstract/Free Full Text]
   
3. Gorelick PB. Combining aspirin with oral anticoagulant therapy: is this a safe and effective practice in patients with atrial fibrillation? Stroke. 2007; 38: 1652–1654.[Free Full Text]
   
4. Kalra L, Yu G, Perez I, Lakhani A, Donaldson N. Prospective cohort study to determine if trial efficacy of anticoagulation for stroke prevention in atrial fibrillation translates into clinical effectiveness. BMJ. 2000: 320; 1236–1239.[Abstract/Free Full Text]
   
5. Ruiz Ortiz M, Romo Penas E, Franco Zapata MF, Mesa Rubio D, Anguita Sanchez M, Lopez Granados A, Arizon del Prado JM, Valles Belsue F. Oral anticoagulation in patients aged 75 years or older with chronic non-valvar atrial fibrillation: effectiveness and safety in daily clinical practice. Heart. 2005; 91: 1225–1226.[Free Full Text]
   

This Article Extract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ono, A. Articles by Fujita, T. Search for Related Content PubMed Articles by Ono, A. Articles by Fujita, T. Related Collections Coumarins Arrhythmias, clinical electrophysiology, drugs Embolic stroke Anticoagulants