REDWOOD CITY, CALIFORNIA. It is becoming increasingly clear that about 15 to 50% of afibbers undergoing catheter ablation will need two or, in rare cases, more than two procedures in order to achieve lasting freedom from atrial fibrillation (AF). Ablation failure is more common in persistent AF (episodes lasting longer than 7 days or requiring cardioversion) and long-standing persistent AF (permanent) than in paroxysmal (episodes self-converting in less than a week – usually less than 48 hours). An enlarged left atrium, hypertension, diabetes and advanced age are other factors associated with ablation failure. Electrophysiologists at Sequoia Hospital now report that repeat ablations are more successful than initial ablations.
Their study involved 843 patients (72% male) undergoing RF-powered catheter ablations (96% using general anesthesia) during the period October 10, 2003 to December 31, 2009. Thirty-two percent of the study participants had paroxysmal AF, 50% had persistent, and the remaining 18% had permanent AF. Paroxysmal AF was significantly more common among women (43.4%) than among men (27.6%), while permanent AF was more common among males (20.4%) than among females (11.1%) Twenty percent of the group had heart disease, 43% had hypertension, and a sizeable proportion of the group was overweight or obese (average BMI 29).
All patients underwent an initial circumferential pulmonary vein isolation procedure with additional lesion sets as required. The average total procedure and fluoroscopy times were 138 and 71 minutes respectively, and were similar for the initial and repeat procedures. The 1-year AF-free success rates (without antiarrhythmics) after the initial procedure were 66.1% for paroxysmal, 54.5% for persistent and 44.8% for permanent AF. Four-year complete success rates (from Kaplan-Meier curves) were 60.9% for paroxysmal, 42.9% for persistent and 35.2% for permanent AF. Significant predictors of failure were advanced age, enlarged left atrium, and the presence of coronary artery disease.
Twenty-eight percent of the 843 initial patients underwent one repeat procedure and 21 patients (2.5% underwent two repeat ablations. Complete success rates (no AF, no antiarrhythmics) at 1-year from the repeat ablation(s) were 82.9% for paroxysmal, 69.8% for persistent and 66.3% for permanent AF. Corresponding 4-year rates were 81.1%, 58.5% and 59.1% respectively. Thus, the final success rates after one or more procedures were (at 1-year) 85.1% for paroxysmal, 76% for persistent and 65.6% for permanent AF. Corresponding 4-year success rates were 83.6%, 62.2% and 57.3% respectively. At the final follow-up, an additional 24 paroxysmal (2.9%), 58 persistent (6.9%) and 62 permanent (7.33%) afibbers were afib-free with the aid of antiarrhythmic drug therapy. Procedure-related complications at 3.5% were relatively rare with no deaths, atrial-esophageal fistula or pulmonary vein stenosis requiring intervention.
A total of 138 patients whose initial ablation had been unsuccessful did not undergo repeat procedure(s) before the study's termination on December 31, 2009. Of these, 55 underwent a procedure at a later date, 31 were advised by their physician not to undergo a repeat procedure, and 52 decided on their own to forego further treatment. The Sequoia electrophysiologists estimate that if these 138 patients had all undergone repeat procedures, then the final complete success rates at 4 years would have been 94.5% for paroxysmal, 84.9% for persistent, and 78.5% for permanent afibbers. They conclude that repeat ablations are more successful than initial ablations and recommend that prospective ablation patients be advised that a repeat procedure may be required to eliminate their AF.
Winkle, RA, et al. Long-term results of atrial fibrillation ablation: the importance of all initial ablation failures undergoing a repeat ablation. American Heart Journal, Vol. 162, July 2011, pp. 193-200
Editor's comment: The success rate obtained by the EPs at Sequoia Hospital are indeed impressive and should remind all afibbers of the famous quote "If at first you don't succeed try, try again".