Annals of Long Term Care

American Geriatrics Society 2010 Annual Scientific Meeting
Orlando, FL; May 12-15, 2010

Managing Atrial Fibrillation in the Older Patient
Orlando, FL—Atrial fibrillation (AF) has a prevalence of 2.2 million persons in the United States and about 5.5 million worldwide. Individuals predisposed to AF are those with an atrium prone to fibrillate (enlarged, scarred, fibrotic), with a trigger such as frequently firing ectopic atrial foci, frequently found in pulmonary veins. More men than women experience AF in essentially every age group; however, after the age of 85, 60% of AF patients are women. The prevalence of AF rises progressively with age likely due to the cumulative effects of known risk factors such as hypertension, coronary artery disease, diabetes, and valvular heart disease on the atrial myocardium over time. Michael W. Rich, MD, Thomas Burkart, MD, Sean M. Jeffery, PharmD, and Mark A. Supiano, MD, gave a presentation on AF in the older patient at the AGS Annual Meeting.

In the initial clinical evaluation, physicians should exclude structural heart disease and identify correctable secondary causes. The three cornerstones of AF management are rate control, prevention of thromboembolism, and rhythm control. Once rate control is achieved, the need for long-term anticoagulation must be assessed. The CHADS2 system is used to assess embolic risk in nonvalvular AF (Gage et al, JAMA, 2001). Recently published observational studies (Tulner et al, Drugs Aging, 2010) unfortunately confirm that most physicians overestimate the risk of oral anticoagulation in their elderly patients and do not prescribe appropriate anticoagulation, even when no defined contraindications are present. Alternative anticoagulation strategies were reviewed. The ACTIVE-A trial showed that the magnitude of the relative risk for stroke reduction is similar for clopidogrel + aspirin when compared to that of warfarin vs control. The absolute relative risk with warfarin vs control was greater than the difference between clopidogrel + aspirin vs aspirin alone per clinical trial data. The number needed to treat for clopidogrel + aspirin was 111; the number needed to treat was 20-30 for warfarin vs control from the SPAF-1 and SPINAF trials. Aspirin + clopidogrel causes about as much major bleeding as warfarin but it’s less effective for preventing stroke. Clinicians should continue to recommend warfarin for most AF patients, including those with previous stroke or stroke risk factors. For patients unable to take warfarin, clopidogrel plus aspirin may be an alternative to aspirin alone. Suggest aspirin alone for patients at very high risk for bleeding or for those age 75 years or younger with no risk factors. Conclusions from the RE-LY study were that in patients with AF, dabigatran 110 mg was associated with rates of stroke and systemic embolism that were similar to those associated with warfarin, as well as lower rates of major hemorrhage; however, it was not as efficacious as warfarin. Dabigatran 150 mg as compared to warfarin was associated with lower rates of stroke and systemic embolism but similar rates of major hemorrhage and higher rates of major GI hemorrhage. There has not been much information published on rivaroxaban, which has been approved in Canada and Europe for prevention of postoperative venous thromboembolism (and used in the ROCKET AF study; Steffel et al, J Cardiovascular Med, 2009); in 2009, the FDA did not approve it for use in the U.S.

Whether to aggressively pursue rhythm control by means of cardioversion, possibly in combination with antiarrhythmic drug therapy, or to take the more conservative approach of rate control is often a difficult decision. The AFFIRM trial found no mortality benefit to a rhythm-control strategy as compared to a rate-control strategy. However, patient symptoms often dictate a more aggressive approach.