Conference Coverage

Anticoagulation therapy after VT ablation yields fewer thrombotic events




San Francisco – Anticoagulation therapy is probably a good idea after ventricular tachycardia ablation in patients with risk factors or stroke, even if they don’t have atrial fibrillation, according to investigators from the University of Kansas Medical Center in Kansas City.

The advice comes from a review of 2,235 ventricular tachycardia (VT) ablation cases from the university and other members of the International VT Ablation Center Collaborative; about a quarter of the patients (604) were prescribed oral anticoagulation therapy at baseline and at discharge, nearly all for atrial fibrillation (AF) and most with warfarin. Over the next year, just 0.3% (2) had a subsequent thromboembolic complication, one of which was an ischemic stroke.

Dr. Rizwan Afzal

Dr. Rizwan Afzal

The remaining patients (1,631) did not have a diagnosis of AF and were not on anticoagulants at baseline or after discharge. They were more likely to have New York Heart Association class I or II heart failure and higher ejection fractions, and to otherwise be in better shape compared with the patients who received anticoagulation therapy. Even so, within a year, 1.3% (21) had a thromboembolic event, almost half of which were ischemic strokes, a substantial increase in relative risk (P = .05).

Maybe those patients had undiagnosed AF at baseline, or perhaps a clot formed over the ablation scar, Dr. Rizwan Afzal said at the annual scientific sessions of the Heart Rhythm Society. Regardless, “this observation has changed our practice. If VT ablation patients have low ejection fractions, if they’re elderly, or have other risk factors for stroke, we put them on blood thinners [afterward] “even if they don’t have atrial fibrillation. We are not sure how long they should be on anticoagulation [therapy] to counteract the increased risk of stroke,” but probably at least for a few weeks, he said.

Dr. Afzal and his colleagues generally opt for warfarin; the use is off label for newer oral anticoagulants, and a tough sell to insurance companies.

There were no predictors of increased thromboembolic risk in the group that was not on anticoagulation therapy. During follow-up, about 2.2% (13) of patients on anticoagulation therapy had bleeding complications, including one intracranial hemorrhage, compared with 2.5% (41) of the patients not treated with an anticoagulant; most of them were on aspirin after the procedure, and the rest were on dual antiplatelet therapy (P = .7), reported Dr. Afzal, a cardiology fellow at the University of Kansas.

The median age of the study patients was 65 years, and 87% were men. In the group on anticoagulation therapy, the mean baseline left ventricular ejection fraction was 31%; 35% had prior cardiac surgery, 29% were on cardiac resynchronization therapy, and 44% had NYHA class III or IV heart failure. The mean baseline ejection fraction among patients who were not on anticoagulation therapy was 35%; 29% had prior heart surgery, 24% were on CRT, and 32.5% had NYHA class III or IV heart failure.

There was no industry funding for the work, and the investigators had no disclosures.

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