DENVER — Radiofrequency ablation of atrial fibrillation durably eliminates the arrhythmia in most treated patients but may be just a temporary fix in those with diabetes or another underlying arrhythmogenic substrate unaffected by the procedure, Dr. Anita Wokhlu said at the annual meeting of the Heart Rhythm Society.
Ablation of atrial fibrillation (AF) is a relatively recent development, and most efficacy studies to date are limited to 12 months of follow-up. Dr. Wokhlu is particularly interested in what happens later.
Development of a risk factor profile for AF recurrence would permit patients unlikely to obtain sustained benefit to be spared the expense and risks of ablation, noted Dr. Wokhlu of the Mayo Clinic, Rochester, Minn.
She reported on 428 patients who underwent a first radiofrequency ablation procedure for paroxysmal AF and 379 who were ablated for persistent or permanent AF during 1999–2006 at the Mayo Clinic.
At 2 years of follow-up, 64% of the overall group was free of recurrent AF and off all antiarrhythmic drugs, while 73% were without recurrent AF with or without antiarrhythmic agents. AF was eliminated without need for antiarrhythmic medications in 66% of patients ablated for paroxysmal AF and 54% of those with persistent or permanent AF. Recurrent AF was present in 21% of the paroxysmal and 32% of the persistent or permanent AF group.
Roughly half of all AF recurrences happened more than 6 months after the procedure, and more than 15% occurred after 1 year. Most of these late recurrences were in patients who underwent ablation for persistent or permanent AF.
At 30 months, 25% of patients in the persistent or permanent AF group were in AF, compared with 15% of paroxysmal AF patients, Dr. Wokhlu continued.
Univariate predictors of a first recurrence of AF after more than 1 year were baseline persistent or permanent AF, hypertension, diabetes, left atrial enlargement, and ablation via wide area circumferential ablation as opposed to pulmonary vein isolation.
In a multivariate proportionate hazard analysis, the three independent predictors of late recurrence of AF were diabetes, persistent or permanent AF as the presenting arrhythmia, and wide area circumferential ablation, she reported.