A 75-year-old man presented with symptomatic paroxysmal atrial fibrillation and hypertension. He did well on sotalol 120 mg twice daily and warfarin for six months, but then complained of frequent paroxysms which left him drained. He subsequently underwent catheter ablation of his fibrillation. He returned to your office 12 months later feeling quite well, with a well-controlled INR and reported no paroxysms. The EKG performed in the office confirmed sinus rhythm. The patient and his wife ask about discontinuing warfarin, since he has been "cured." To be cautious, you order a three-week Holter monitor, which shows no evidence of atrial fibrillation.
What would be your decision regarding anticoagulation for this patient?
The correct answer is: 4. Continue lifelong warfarin
For patients diagnosed with atrial fibrillation who meet the CHADS2 or CHA2DS2VASc threshold, lifelong anticoagulation is the only true evidence-based management. This has been established through the SPAF (stroke prevention in atrial fibrillation) trials.1
The other three options are often employed by clinicians, but are not evidence-based. However, this question gets at the very etio-pathology of atrial fibrillation-related stroke risk. While the burden of atrial fibrillation plays a large role in the risk of stroke, the pathogenic left atrium which leads to atrial fibrillation is an important consideration. Strategies that address the rhythm universally fail to address the underlying left atrial pathology, and hence atrial fibrillation is never really cured. In the recently presented IMPACT trial, the authors showed that most patients were in fact not in atrial fibrillation when they suffered a stroke. 2
Option 1 assumes that the patient is "cured" of his atrial fibrillation. The late recurrence of paroxysmal atrial fibrillation after a first ablation procedure is around 20-25% (30-35% for non-paroxysmal AF). Even after a second ablation procedure, the recurrence of the rhythm is around 8-10% for paroxysmal and 10-15% for non-paroxysmal AF. 3-5
Option 2 utilizes Holter monitoring as means to establish the absence of AF. Holter monitoring is a relatively ineffective way of attempting to detect the presence of atrial fibrillation. Implanted devices such as REVEAL™ or LINQ™ may provide a more accurate estimate. However, discontinuation of anticoagulation based on such monitoring is not considered evidence-based.6, 7
Option 3 incorrectly suggests that warfarin may be replaced with aspirin. For patients who meet the CHADS2 or CHA2DS2VASc threshold, aspirin is a significantly inferior medication for stroke protection. The concept that patients who have a lower burden of AF can be managed with aspirin is not based in evidence, but rather anecdotal experience.1, 8
With the advent of novel oral anticoagulants, which are at least as efficacious as warfarin, safer than warfarin, and do not require cumbersome monitoring, physicians may be able to move away from the misplaced idea that discontinuing anticoagulation is an option for patients with atrial fibrillation who meet the CHADS2 or CHA2DS2VASc threshold.9
January, C.T., et al., 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: Executive SummaryA Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2014. [Epub Ahead of Print].
Martin, D., etal. Randomized Trial of Anticoagulation Guided by Remote Rhythm Monitoring in Patients With Implanted Cardioverter-Defibrillator and Resynchronization Devices. Presented at the American College of Cardiology Scientific Session, Washington, DC. 2014.
Oral, H., et al., Prevalence of asymptomatic recurrences of atrial fibrillation after successful radiofrequency catheter ablation. J Cardiovasc Electrophysiol 2004;15:920-4.
Steven, D., et al., What is the real atrial fibrillation burden after catheter ablation of atrial fibrillation? A prospective rhythm analysis in pacemaker patients with continuous atrial monitoring. Eur Heart J 2008;29:1037-42.
Wokhlu, A., et al., Long-term outcome of atrial fibrillation ablation: impact and predictors of very late recurrence. J Cardiovasc Electrophysiol 2010;21:1071-8.
Hindricks, G., et al., Performance of a new leadless implantable cardiac monitor in detecting and quantifying atrial fibrillation: Results of the XPECT trial. Circ Arrhythm Electrophysiol 2010;3:141-7.