ACC 2017: Anticoagulant treatment may be unnecessary for stroke prevention following ablation for atrial fibrillation

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For patients with persistent atrial fibrillation or those who are at high risk for recurring atrial fibrillation, catheter ablation is recommended, followed most often by continued use of blood thinners, regardless of whether the ablation procedure was effective. However, little is known about the actual need for these drugs following a successful ablation. In a new study presented at the American College of Cardiology 66th Annual Scientific Sessions (ACC; 17-19 March, Washington, DC, USA), researchers from the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA, have found that patients with persistent atrial fibrillation who are successfully treated with ablation may, in fact, no longer need blood thinners to reduce stroke risk.

“There are two schools of thought when it comes to anticoagulant therapy following catheter ablation for the treatment of atrial fibrillation,” says the study’s presenter Jackson J Liang, a third-year cardiovascular disease fellow at the Perelman School of Medicine. “Those who think all patients with atrial fibrillation should be prescribed blood thinners based on stroke risk scores even after their atrial fibrillation has been ‘cured’ by successful ablation, and those who believe that if there is no evidence of atrial fibrillation recurrence following ablation, then anticoagulants may be unnecessary.”

In this retrospective study, researchers evaluated 400 participants with persistent and longstanding persistent atrial fibrillation who underwent one or more ablations, to determine the patterns of anticoagulation use after ablation based on atrial fibrillation recurrences, as well as likelihood of developing stroke or major bleeds after the procedure.

Participants were instructed to check their pulse two times per day, participate in routine outpatient telemetry monitoring to evaluate for asymptomatic atrial fibrillation, and to have symptom-driven electrocardiograms, when needed. Following the roughly three-year follow-up period, 172 patients were free of atrial fibrillation recurrence, 161 were transformed to paroxysmal atrial fibrillation, and 67 remained in persistent atrial fibrillation. Most interestingly, 207 had discontinued blood thinner use at some point in the three years, and 174 remained off blood thinners at their last follow-up. Participants who no longer experienced atrial fibrillation recurrence after their last ablation were more likely to have been removed from blood thinners as compared to those with whose atrial fibrillation was transformed to paroxysmal atrial fibrillation or those who remained in persistent atrial fibrillation.

“These data show that in certain patients with non-paroxysmal atrial fibrillation who no longer have recurring atrial fibrillation following catheter ablation as confirmed by routine monitoring and daily pulse checks, anticoagulation may be safely discontinued to minimise the risk for major bleeding,” said the study’s senior author, David Callans, the associate director of Electrophysiology for the University of Pennsylvania Health System, Philadelphia, USA.

Patients with recurring atrial fibrillation or those who are high risk for persistent atrial fibrillation are subsequently at higher risk for cerebrovascular such as stroke or transient ischaemic attack. At the same time, those who stay on blood thinners long term, even after successful ablation, have an increased risk of intracranial haemorrhage, gastrointestinal bleeding, and internal bleeding and bruising after falls.

The data collected in this study point to the need for larger, randomised trials examining the relationship between discontinuation of anticoagulation and strokes after successful atrial fibrillation ablation. However at this point, Callans said, “there is enough evidence to support a patient-specific decision making process when evaluating whether anticoagulants following ablation for patients with non-paroxysmal atrial fibrillation is a necessary treatment plan.”