A comparison of atrial arrhythmias after heart or double-lung transplantation at a single center: insights into the mechanism of post-operative atrial fibrillation.

OBJECTIVES: We compared the incidence of atrial arrhythmias in double-lung transplant patients versus heart transplant patients to gain insight into factors that contribute to post-operative atrial fibrillation (AF).

BACKGROUND: Atrial fibrillation is a common complication after thoracic surgery. Pulmonary vein isolation is an effective treatment for AF. Heart or double-lung transplantation surgery both involve pulmonary vein isolation because of suture lines.

METHODS: We reviewed the records of 174 consecutive heart transplant patients and 122 double-lung transplant patients at the Columbia Presbyterian Medical Center between January 2005 and June 2008. Electrocardiograms during atrial arrhythmia episodes were reviewed by an electrophysiologist. Clinical variables, biopsy results, immunosuppressive regimens, and echocardiographic measurements were collected from the perioperative time period and at the time of arrhythmia occurrence.

RESULTS: In the heart transplant group, 8 (4.6%) patients had AF (group A). In the lung transplant group, 23 (18.9%) patients had AF (group B; p < 0.001). The incidence of AF in a comparison group of 131 patients with normal left ventricular function who underwent coronary artery bypass graft surgery was 19.8%. Immunosuppressive regimens and clinical variables were similar for both groups. Echocardiographic data revealed no significant cardiac abnormalities in 74% of group B compared with 25% of group A (p < 0.05), and 78% of biopsy results in group B were normal, whereas only 25% of group A results were normal (p < 0.05).

CONCLUSIONS: In heart transplant recipients, AF is uncommon and occurs in the setting of myocardial dysfunction and graft rejection. In contrast, AF is more common after lung transplantation despite the absence of graft rejection and cardiac dysfunction. Pulmonary vein isolation alone cannot explain the discrepancy in AF incidence between heart transplant recipients and double-lung transplant recipients. Cardiac autonomic denervation may have a protective effect for heart transplant patients in the post-operative setting.