Tuesday, June 13, 2006

Don't Have Afib Ablation Just to Stop Warfarin

I am seeing increased numbers of patients for atrial fibrillation ablation, particularly in light of the favorable results displayed in recent trials in patients for intermittent episodes of atrial fibrillation and chronic atrial fibrillation. The most common reason for referral: "I want to get off coumadin."

But this is the wrong reason to have a afib ablation, I believe.

First and foremost, it is important to remember the patient population decribed in the studies above: generally healthy population without other coexistant cardiovascular disease, those under the age of 75, and with small left atria (< 5.0 cm on echocardiogram). Hence it is difficult to apply these studies to the larger subset of patients with structural heart disease.

Secondly, atrial fibrillation ablation carries very real, significant procedural risks (like stroke, cardiac perforation, gastroparesis (stomach paralysis), development of other atrial arrhythmias caused by the lesions applied within the heart, etc., etc.) and even a risk of mortality (usually from the rare complication of perforation of the esophagus.)

Finally, it is quite common (some would say even expected) that an episode of atrial fibrillation is likely to occur in the first month after the ablation procedure, so most physicians advocate continuing warfarin for 3 to 6 months after the procedure. And not all stroke comes from atrial fibrillation. Remember that stroke can be caused by hypertension, atherosclerotic plaque that flies from the ascending aorta or carotids up to the brain, or carotid narrowing. Hence, strokes come from other areas outside the heart and prevention often requires a systemic approach including blood pressure control and systemic anticoagulation in patients at high risk of stroke (those with hypertension, age over 75, diabetics, people with weak heart muscles, or prior stroke).

Atrial fibrillation ablation should be performed, I believe, in those who are highly symptomatic despite therapy with more conventional means. Warfarin (coumadin) should be discontinued only if patients do not have one of the risk factors outlined above and have been treated for at least 6 months after their catheter ablation procedure and monitored to assure no asymptomatic episodes of atrial fibrillation are ocurring after the ablation. Remember, there is no long-term, prospective, randomized trial demonstrating a survival advantage of catheter ablation over more conventional medical therapies. Symptoms despite conventional therapies are the trump card that moves us toward recommending catheter ablation, NOT the desire to stop anticoagulation.


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