Patients with atrial fibrillation (AF) who are at high-risk for esophageal injury caused by radiofrequency (RF) ablation can be identified by anatomical features easily seen on pre-acquired CT images, according to a study published in this month's Heart Rhythm Journal.
Martin Martinek, MD, from the Universty of Innsbruck in Austria, and colleagues studied 275 patients admitted to the Elisabethinen University Teaching Hospital in Linz, Austria, for pulmonary vein isolation from September 2007 to June 2009.
A standardized ablation approach using a 25-W energy maximum at the posterior left atrial wall without esophagus visualization, temperature monitoring or intracardiac ultrasound was performed. All patients were screened for evidence of the development of esophageal ulcerations 24 hours after RF ablation.
The investigators classified wall legions as esophageal ulcerations created by RF ablation by means of localization and endosonographic appearance. Anatomical factors included in the multivariate model were left atrial-to-esophageal distance, type of AF and additional left atrial linear lesions.
Within the study population, the total risk of ulcers developing was 2.2 percent. Esophageal ulcerations did not develop in any patient who had pulmonary vein isolation alone.
Additionally, multivariate analysis revealed the anatomical risk factor of a small left atrial-to-esophageal distance as the most important factor in esophageal ulceration development.
"It has been speculated that esophageal ulcerations can lead to atrioesophageal fistula, which is a rare but life-threatening complication of AF," said Martinek. "Our study aimed to discover risk factors that can lead to injuries of the esophagus due to radiofrequency ablation. In doing so, we may better identify high-risk patients to determine the most appropriate course of action for RF ablation and its follow-up."
The authors reported that this is the first study to link anatomical and procedural information to the endpoint of esophageal ulceration creation.
"The combination of this consecutive study with a former randomized trial gives us constant rates of esophageal ulcerations of 2 to 3 percent in mean when using a 25-W maximum at the posterior left atrial wall in a total of more than 400 patients," they wrote.
They said that their data suggest anatomic information from CT showing left atrial-to esophageal distance could be used to stratify high-risk patients.