Purpose Early posttransplant atrial fibrillation (AF) has been associated with worse clinical outcomes after heart transplantation (HTX). factors for AF. Conclusion Early posttransplant AF was associated with increased mortality (P<0.0001). Total orthotopic HTX showed the lowest rate of AF compared to biatrial or bicaval HTX (P=0.0012). Keywords: atrial fibrillation, biatrial heart transplantation, bicaval heart transplantation, mortality, surgical technique, total orthotopic heart transplantation Introduction Atrial fibrillation (AF) BI 2536 in the early posttransplant period is usually a common phenomenon in patients after heart transplantation (HTX) with a previously explained incidence of 7.9%C18.2%.1,2 Although several risk factors, such as immunosuppressive drug therapy, acute rejection, or ischemic time, may have an influence around the occurrence of AF, the type of surgical technique could play a key role in the development of posttransplant AF within 30 days after HTX.1C7 A number of different cardiac transplantation techniques currently exist. In clinical routine, three types are commonly used: biatrial (BA), bicaval (BC), and total orthotopic (TO) HTX. The initial standard technique for HTX, also known as biatrial technique (BA), was MADH3 developed by Lower and Shumway.3 It consists of two long anastomoses of donor and recipient atria resulting in enlarged cavities with distorted anatomy, long suture lines with potentially proarrhythmic scar tissue, and possible sinus node injury.4,5 An alternative is the bicaval technique (BC), also known as bicaval, left atrial technique, clinically introduced by Sievers et al.6 Here, the right donor atrium is preserved via donor-to-recipient venae cavae anastomoses resulting in unaltered properties of the right atrial geometry and conduction system.4,5 However, the left atrial anastomosis is still performed via donor-to-recipient atrial anastomosis as explained by Lower and Shumway.3,4 Total orthotopic (TO) HTX, also known as bicaval, bipulmonary venous technique, was clinically introduced by Dreyfus et al.7 This technique comprises the total excision of the recipient atria, except for two small pulmonary vein cuffs, which are separately integrated into the left donor atrium.4,8,9 The right donor atrium is connected via BC anastomosis as reported by Sievers et al.6 In this way, the anatomic integrity and physiology of both atria are preserved. 9 Disadvantages of this technique are prolonged ischemic time as a result of complex anastomoses and pulmonary venous stenosis.4 Therefore, the aim of this study was to determine whether the type of surgical technique (BA, BC, or TO) has an influence on early posttransplant AF. Patients and methods Patients This study was performed in accordance with the ethical requirements of the Declaration of Helsinki and was approved by the Ethics Committee of the University or college of Heidelberg, Heidelberg, Germany. It included all patients (18 years) receiving HTX at the Heidelberg Heart Center, Heidelberg, Germany, between June 1989 and December 2012. Patients with repeated HTX were excluded. Data were retrieved from your clinical routine. Written informed consent was obtained for the Heidelberg HTX register.10,11 As only clinical program data were used for this study, no additional written informed consent was required from your patients. Patients were stratified by BI 2536 surgical technique (BA, BC, or TO) and according to posttransplant heart rhythm within 30 days after HTX. The decision of which surgical technique to be used had not been preselected. Factors influencing the choice of HTX technique were surgeons preference, anatomical characteristics, and previous open heart medical procedures. Follow-up Patients were routinely followed-up according to the center standard. The minimum follow-up period was 30 days after HTX. During the early posttransplant period, heart rhythm was BI 2536 constantly assessed by monitor telemetry. Furthermore, 12-lead electrocardiography was routinely performed and in case of arrhythmias on monitor telemetry. Additionally, 24-hour-Holter recording was performed. All available BI 2536 source files pertaining to heart rhythm in the early posttransplant period (30 days after HTX) were analyzed. Early posttransplant AF (AF 30 days after HTX) was defined as AF lasting 30 seconds or longer. Atrial flutter or other supraventricular tachyarrhythmias were not included. Cardiac rejection episodes were diagnosed and treated according to the revised International Society for Heart and Lung Transplantation classification.12 Posttransplant medication Patients after HTX received an immunosuppressive induction treatment with anti-thymocyte globulin since 1994. The initial immunosuppressive regimen of cyclosporine A (CsA) and azathioprine (AZA) was.