Mortality and AF Surgery

Dear Readers, A 60-year-old man with medically refractory idiopathic recurrent persistent and paroxysmal atrial fibrillation (AF) underwent a catheter ablation procedure. He experienced recurrent, refractory, post ablation left atrial flutter well past the recovery phase of the procedure. He was referred to another institution for a catheter ablation of the iatrogenic flutter. Unfortunately, he was found to have a large left atrial appendage thrombus at the time of his pre-procedural transesophageal echocardiogram. The thrombus did not resolve despite months of more aggressive oral anticoagulation, and he continued to be plagued by the atrial flutter. He was then referred to a cardiac surgeon. He subsequently underwent surgical removal of the thrombus, ligation of the appendage, and biatrial radiofrequency ablation. After an uncomplicated postoperative course, he was discharged. He was found dead at home the following week. The cause of death remains unknown. This tragic case raises several questions related to the management of AF, including the risk of post AF ablation left atrial tachycardia, and the role of imaging to exclude a left atrial appendage clot before performing an ablation for AF. However, one of the most important questions that must be asked after a case like this is whether we know the risk of death after an invasive procedure intended to cure a patient of AF. Because the primary objective of nonpharmacological treatments for AF is to improve the quality rather than the duration of life, it is critical to define the mortality rates associated with invasive therapies for AF. In a recent issue of the Journal of the American College of Cardiology, Cappato et al1 published an important paper on the prevalence and causes of a fatal outcome in patients undergoing catheter ablation for AF. Although the retrospective case series of 45,115 procedures in 32,569 patients was limited by the fact that it was based on a physician survey, it found that death as a complication of catheter ablation of AF occurred in only 1 per 1,000 patients. The most common complications were cardiac tamponade in 8 patients, stroke in 5 patients, atrioesophageal fistula in 5 patients, and pneumonia in 2 patients. Other complications, including hemothorax, tracheal compression secondary to subclavian hematoma, and esophageal perforation from an intraoperative transesophageal echocardiographic probe each resulted in additional individual deaths. Studies like these allow for physicians to better inform patients of the risks of a catheter ablation procedure. They also emphasize the importance of having a team in the EP lab prepared to identify and manage the more common potentially lethal complications such as tamponade. The results of this survey may also persuade some physicians to avoid subclavian access for these AF ablation cases that require aggressive periprocedural anticoagulation. An important consideration that was not raised either in the Cappato paper or the accompanying editorial2 is the relative risk of catheter ablation for AF compared to surgical ablation for AF. Although surgical therapy is performed less commonly than catheter ablation and is usually performed when a patient with AF is undergoing cardiac surgery for another indication such as valve surgery, it is a surgery that is being more heavily marketed and promoted. What is the risk of death associated with cardiac surgery for lone AF? This is a difficult question to answer from the literature. In a thorough review on surgical approaches for AF by Gillinov and Saltman in 2008,3 the only mention of the mortality risk is that there have been three published studies that have shown that the addition of a Maze procedure during concomitant cardiac surgery does not appear to increase operative mortality. There is no mention of mortality in the discussion of surgical ablation for lone AF. A paper by Doll et al4 found that esophageal perforation after intraoperative radiofrequency ablation of AF occurred in 4 out of 387 patients. Most non-radiofrequency energy sources such as microwave and high-intensity focused ultrasound were approved by the U.S. Food and Drug Administration for the ablation of soft tissues or cardiac tissues, but not specifically for the treatment of AF. Published data related to these newer devices are limited. In addition, the data that is published is often in the surgical literature, which is read infrequently by the EP community. As more catheter-based techniques and surgical approaches are developed for the management of AF, which is generally not a lethal disease, it will be important that accurate mortality statistics are reported and kept in perspective. Sincerely, Bradley P. Knight, MD, FACC, FHRS Editor-in-Chief, EP Lab Digest