Left Atrial Functional and Structural Characteristics in Patients After Total and Bicaval Orthotopic Heart...

Background/Objectives: Currently, the most popular techniques for orthotopic heart transplantation (OHTx) are bicaval and total OHTx. Although bicaval OHTx has shown advantages over the biatrial approach, comparisons between bicaval and total OHTx reain limited. To compare the functional and morphological characteristics of the left atrium (LA) in patients after bicaval and total OHTx. Methods: Sixty-six patients (age 51.2 ± 10.5 years) after total OHTx (33 patients) and bicaval OHTx (33 patients) were included in this case-control study. Recipients were matched for sex, age, and time from transplantation and absence of severe graft rejection based on routine endomyocardial biopsies (EMB) performed during follow-up. Echocardiography included standard measurements along with a speckle-tracking assessment of LA strain. Results: Compared with the bicaval OHTx, the total OHTx group showed higher atrial mitral inflow velocity, resulting in a lower E/A ratio, lower LA volume index, and higher LA emptying fraction. Both the reservoir and contraction components of LA function, as assessed by LA deformation, were found to show more favorable profiles in the total OHTx group than in the bicaval group (26.5 ± 6.9 vs. 17.4 ± 4.7, p < 0.001 and 14.8 ± 5.8 vs. 6.0 ± 4.5, p < 0.001, respectively). Multivariable analysis identified surgical technique, left ventricular global longitudinal strain, and the presence of diabetes in the recipient as independent determinants of LA strain. Conclusions: Total OHTx is associated with better LA morphology and function than bicaval OHTx. This may provide better conditions for LA-LV coupling in transplanted hearts and contribute to a more stable electrophysiological environment in atrial tissue.