SYDNEY, AUSTRALIA. Circumferential anatomical pulmonary vein isolation (CAPVI or Pappone method) is an increasingly popular approach to curing AF via radiofrequency ablation. In this procedure anatomical mapping (CARTO) is used to establish the exact location of the pulmonary veins. Two rings of lesions are then created in the left atrium – one completely encircling the left pulmonary veins and another completely encircling the right pulmonary veins; the two rings are usually joined by a linear lesion.
Researchers at the University of Sydney now report on the long-term success of the procedure in persistent and permanent afibbers. Their study involved 45 (80%) male afibbers and 11 female with either persistent (69.6%) or permanent (30.4%) afib who had failed an average of 2 antiarrhythmic drugs. The mean age of the patients was 56 years and they had suffered from afib from 1 to 12 years (average of 6.4 years). Nine patients (16.1%) had structural heart disease, 3.6% had coronary artery disease, 66.1% had hypertension, and 10% had impaired left ventricular systolic function.
All patients underwent a circumferential PVI guided by the CARTO electroanatomical mapping system with a merged, three-dimensional CT image of the heart. Lesions were positioned about one centimetre from the edge (ostia) of the pulmonary veins where they join the left atrium. The endpoint of the ablation was electrical isolation (from the left atrium) of all the pulmonary veins as measured with a Lasso mapping catheter. A linear ablation (roof line) was added in 57% of patients and 25% also underwent a right atrial flutter ablation. Antiarrhythmics were continued for the first month after the procedure and then discontinued if there were no afib recurrences. Repeat procedures were common with 28.6% undergoing two procedures, 8.9% undergoing 3 procedures, and 1.8% undergoing 4 procedures. Four major complications, one each – stroke, TIA, tamponade, and atrio-esophageal fistula – were observed during the 86 procedures.
After a follow-up of 13 to 30 months (average of 21.6 months), 53.6% of the ablated patients were in normal sinus rhythm (NSR) without the use of antiarrhythmics, 32.1% were in NSR with the aid of antiarrhythmics, and the remaining 14.3% still experienced afib episodes; thus, according to our usual way of grading success, 53.6% of the procedures (including repeats) were complete successes, 32.1% were partial successes, and 14.3% were failures.
Early recurrence (symptomatic episodes within the first 90 days following the procedure) was quite common after the initial procedure (46.4%) as was late recurrence (symptomatic episodes more than 90 days post-procedure), which was experienced by 69.6%. Ten percent developed flutter after the initial PVI and required an extra procedure to correct this. After the final procedure 23.3% had an early recurrence, and 46.4% had a late recurrence. Most late recurrences occurred within 12 months of the procedure. The researchers observed that female afibbers and those with afib of long standing were more likely to experience recurrences. They also noted that experiencing late recurrence was not precluded by the absence of early recurrences.
Seow, SC, et al. Efficacy and late recurrences with wide electrical pulmonary vein isolation for persistent and permanent atrial fibrillation. Europace, Vol. 9, 2007, pp. 1129-33
Editor's comment: A final complete success rate (after repeat ablations) at 53.6% is not impressive, but probably about average for other than top-ranked institutions/EPs.