Ablation news from Australia

MELBOURNE, AUSTRALIA. Several studies have reported a major complication rate of 4 – 6 % associated with pulmonary vein isolation (PVI) procedures for the purpose of curing atrial fibrillation. Now a group of electrophysiologists from the Royal Melbourne Hospital reports that the incidence of major complications associated with PVI procedures is less than 1% among lone afibbers.

Their study covered 500 consecutive procedures involving 424 patients during the period July 2006 to September 2009 (repeat rate of 15%). The average age of patients was 55 years (44 to 66 years), 79% were male, and 95% were lone afibbers (80% paroxysmal, 20% persistent). All patients were at low risk for stroke with 64% having a CHADS2 score of zero and 28% having a score of 1 (primarily due to hypertension). After checking for thrombi in the left atrium and left atrial appendage (none were found) all patients underwent a standard pulmonary vein antrum isolation (PVAI) procedure using the CARTO mapping system, a circular mapping catheter, and further guidance by transesophageal echocardiography (TEE) and selective angiography. All procedures were carried out under general anesthesia by one of four electrophysiologists.

Complete isolation (after a 30-minute waiting period) was observed in 99% of the targeted veins. Additional ablations (linear ablation or ablation of fractionated electrograms) were performed in 24% of patients – the majority of whom had persistent AF. Antiarrhythmic therapy was restarted immediately after the procedure and continued for 3 months. All patients had a minimum hospital stay of 2 nights post-procedure.

The incidence of major procedure-related complications was 0.8% consisting of two cases of esophageal hematoma caused by the TEE probe, a pharyngeal trauma also related to the TEE probe, and one case of retroperitoneal hematoma requiring blood transfusion. There were no cases of death, stroke, transient ischemic attack (TIA), tamponade, atrioesophageal fistula, or pulmonary vein stenosis (screening was performed at 3, 6, 9 and 12 months and at least every 6 months thereafter). The authors of the study conclude that PVAI procedures can be performed safely in AF patients without structural heart disease.

Lee, G, et al. Low risk of major complications associated with pulmonary vein antral isolation for atrial fibrillation. Journal of Cardiovascular Electrophysiology, August 19, 2010 [Epub ahead of print]

Editor’s comment: The findings of this study add to the evidence that PVI procedures are very safe for lone afibbers. It is unfortunate that the study did not include data on long-term success rates as these are generally not predictable from the immediate success rates (complete PVI at time of procedure).