MILAN, ITALY. Catheter ablation with the intent of curing atrial fibrillation (AF) is one of the most complex procedures in medical practice. It involves the introduction and manipulation of several catheters in a space smaller than the inside of a golf ball, the puncture of the wall between the right and left atrium without puncturing the heart wall itself in the process (cardiac tamponade), the close control of anticoagulation, and the accurate placing of multiple lesions in the left atrium. One would expect a fairly high casualty rate with such a complex procedure. A team of electrophysiologists from around the world now reports that the mortality rate associated with catheter ablation for AF is less than 0.1% (0.98 per 1000 patients).

Their study included data from 45,115 procedures performed on 32,569 patients in 162 ablation centers between the years 1995 and 2006. During or within 30 days of the procedure 25 patients died (0.077%) and another 7 procedure-related deaths (0.021%) occurred more than 30 days following the procedure. Thirteen of the deaths occurred during the procedure itself of which 5 were due to tamponade, 2 to stroke, and the remaining due to heart attack, torsades des pointes or other causes. During the following 30 days, 5 patients died from atrioesophageal fistula, 2 from cardiac arrest, and another 2 from massive antibiotic-resistant pneumonia.

Somewhat surprisingly, the study group found no difference in fatality rates associated with the volume of procedures performed in a center, nor was there any difference attributable to the type of procedure (segmental or circumferential) or size of the catheter. Overall, the 0.1% procedure-related deaths were most commonly associated with cardiac tamponade, atrioesophageal fistula and stroke or heart attack.

Cappato, R, et al. Prevalence and causes of fatal outcome in catheter ablation of atrial fibrillation. Journal of the American College of Cardiology, Vol. 53, No. 19, May 12, 2009, pp. 1798-803
Belhassen, B. A 1 per 1,000 mortality rate after catheter ablation of atrial fibrillation. An acceptable risk? Journal of the American College of Cardiology, Vol. 53, No. 19, May 12, 2009, pp. 1804-06

Editor�s comment: Although clearly a cause for concern when deciding to undergo an ablation for afib, a 0.1% fatality rate is actually quite low and on par with the rate observed for relatively simple cataract surgery. Appendectomy (removal of the appendix) is associated with a 0.2% mortality rate, hip replacement with a 1% mortality rate, and bypass surgery with a 3% risk of death. It should also be kept in mind that the observed fatality rate for afib ablation is per patient not per procedure. If looking at the rate per procedure, the risk of a fatal tamponade is 0.016% (1.6 deaths per 10,000 procedures), that of atrioesophageal fistula 0.011% (1.1 deaths per 10,000 procedures), and that of stroke and heart attack 0.009% (0.9 deaths per 10,000 procedures). The all-inclusive fatality rate per procedure is 0.07% - really an amazingly low number when considering the complexity of the procedure.