MD Conference Express AHA 2011 - (Page 21)

AF ablation achieves ≥1 year of freedom from recurrent AF in many patients who are carefully selected to undergo the procedure. However, patients can have recurrent asymptomatic or symptomatic and unrecognized AF at any time after an ablation procedure. Therefore, adherence to anticoagulation is strictly required—in particular, in those with multiple CHADS2 risk factors for stroke that is associated with AF. Ongoing research in patients may reveal more about the long-term success of AF ablation with heart failure and other advanced structural heart disease. Bottom Line for Referring Clinicians to their EP Colleagues: Indications for catheter AF ablation include symptomatic AF that is refractory or intolerant to at least one class I or III antiarrhythmic medication. AF ablation may be performed in selected symptomatic patients with heart failure and/or reduced EF. In rare clinical situations, it may be appropriate as first-line therapy. However, even after a successful AF ablation, it is important to recognize that the ACC/AHA/ ESC 2011 guideline recommendations for anticoagulation at the time of cardioversion apply to patients who are in AF at the time of AF ablation (as AF termination is the goal of the procedure), including recommendations for the duration of therapeutic anticoagulation before and after the procedure. The presence of an LA thrombus, even if a patient is on a therapeutic anticoagulant, is a contraindication for catheter ablation of AF [HRS/EHRA/ECAS Consensus Statement. Heart Rhythm 2007]. The efficacy of the novel oral direct IIa and Xa anticoagulants that are rapidly being approved for use in routine clinical practice in terms of use around the time of AF ablation and cardioversion procedures is actively being explored but not definitively known. In patients with a CHADS2 risk score of 2 or higher, anticoagulation should be continued indefinitely, even after successful ablation. ACCF/AHA/HRS Guideline Recommendation for Duration of Anticoagulation after AF Ablation (2011 ACCF/AHA/ HRS Focused Update on the Management of Patients with AF [Updating the 2006 Guideline]) 1. 2. Therapeutic warfarin (INR goal: 2–3) is recommended for all patients for at least 2 months following an AF ablation. Low-molecular-weight heparin or IV heparin should be used as a bridge to resumption of systemic anticoagulation following AF ablation. Decisions regarding the use of warfarin more than 2 months following ablation should be based on the patient’s risk factors for stroke that is associated with AF and not on the presence or type of AF. Risk determination can be aided by the CHADS2 and CHA2DS2-Vasc scores. 4. Discontinuation of warfarin therapy postablation is generally not recommended in patients who have a CHADS2 score ≥ 2. Anticoagulation for AF Elaine M. Hylek, MD, MPH, Boston University Medical Center, Boston, Massachusetts, USA, discussed anticoagulation for AF. According to Dr. Hylek, five randomized trials in nonrheumatic AF (AFASAK, SPAF, BAATAF, CAFA, and SPINAF) found significant efficacy in the use of warfarin—a 66% overall risk reduction for stroke—however, only about half of high-risk patients with AF receive warfarin therapy in routine clinical practice (Figure 1) [Friberg L et al. Eur Heart J 2006; Waldo AL et al. J Am Coll Cardiol 2005]. Figure 1. Underutilization of Anticoagulation Therapy in AF. Warfarin Therapy No Warfarin Therapy United States Stockholm 47% 53% 46% 54% Age >80 years and perceived bleeding risk were negative predictors of warfarin use. Reproduced with permission from E. Hylek, MD. Novel anticoagulants for stroke prevention in AF include dabigatran (RE-LY), apixaban (ARISTOTLE), rivaroxaban (ROCKET-AF), and edoxaban (ENGAGE AF-TIMI 48; NCT00781391) [Connolly SJ et al. N Engl J Med 2009; Granger CB et al; N Engl J Med 2011; Patel M et al. N Engl J Med 2011; Ruff CT Am Heart J 2010]. All of these trials have been completed, except ENGAGE (estimated end date in 2012). Based on research findings from the pivotal Phase 3 studies, the United States Food and Drug Administration (FDA) approved dabigatran and rivaroxaban as having similar efficacy as therapeutic warfarin to reduce the risk of stroke in patients with nonvalvular AF. The FDA granted a priority review to apixaban in March 2012 for the prevention of stroke and systemic embolism in AF patients, given the positive results in ARISTOTLE that demonstrated reduction in stroke, bleeding, and mortality. ENGAGE AF-TIMI 48 is slated to end in 2012 and may provide for more flexible dosing (two doses studied, dose adjustments made before and after randomization). However, further research is needed to understand how to optimize the effectiveness of these novel agents in routine practice. 21 3. Peer-Reviewed Highlights from the American Heart Association Scientific Sessions 2011 http://www.mdconferencexpress.com

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MD Conference Express AHA 2011

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