Incidence, Risk Factors, Prognosis, and Electrophysiological Mechanisms of Atrial Arrhythmias after Lung Transplantation.

OBJECTIVE To investigate incidence and timing, risk factors, prognostic significance, and electrophysiological mechanisms of atrial arrhythmia (AA) after lung transplantation. BACKGROUND Although new-onset AA is common after thoracic surgery and is associated with poorer outcomes, prognostic and mechanistic data is sparse in lung transplant populations. METHOD A total of 293 consecutive isolated lung transplant recipients without known AA were retrospectively reviewed. Mean follow-up was 28±17 months. Electrophysiology studies (EPS) were performed in 25 patients with AA. RESULTS The highest incidence of new-onset AA after lung transplantation occurred within 30 days postoperative AA, (25 % of all patients). In multivariable analysis, postoperative AA was associated with double lung transplantation (OR 2.79; p=0.005) and lower mean pulmonary artery pressure (OR 0.95; p=0.027). Patients with postoperative AA had longer hospital stays (21 days vs 12 days; p<0.001). Postoperative AA was independently associated with late AA (HR 13.52; p<0.001) but not mortality (HR 1.55; p=0.14). In EPS, there were 14 patients with atrial flutter alone and 11 with atrial flutter and fibrillation. Of all EPS patients, 20 (80%) had multiple AA mechanisms, including peritricuspid flutter (48%), perimitral flutter (36%), right atrial incisional reentry (24%), focal tachycardia from recipient pulmonary vein (PV) antrum (32 %), focal PV fibrillation (24%), and left atrial roof flutter (20%). Left atrial mechanisms were present in 80% (20/25) of EPS patients and originated from the anastomotic PV antrum. CONCLUSIONS Postoperative AA was independently associated with longer length of stay and late AA but not mortality. Pleomorphic PV antral arrhythmogenesis from native PV antrum is the main cause of AA after lung transplantation.