Trajectory of Diastolic Function after Heart Transplantation as Assessed by Left Atrial Deformation Analysis

Diastolic dysfunction (DD) is a prevalent and clinically significant complication after heart transplantation (HTX). We aimed to characterize the diastolic function of HTX recipients with both short-term and long-term follow-ups by applying left atrial (LA) deformation analysis. We consecutively enrolled and followed up with 33 HTX patients. Three assessments were performed one month, 3-5 months, and 3-5 years after surgery. Beyond conventional echocardiographic measurements, apical four-chamber views optimized for speckle tracking analysis were acquired and post-processed by dedicated software solutions (TomTec AutoStrain LA and LV). Left atrial phasic functions were characterized by reservoir, conduit, and contraction strains. We categorized diastolic function according to current guidelines (normal diastolic function, indeterminate, DD). At the first assessment, nine (27%) patients were in the DD category, and eleven (33%) were indeterminate. At the second assessment, only one patient (3%) remained in the DD category and six (18%) were indeterminate. At the third assessment, 100% of patients were categorized as having normal diastolic function. LA reservoir strain gradually increased over time. LA contraction strain significantly improved from the second to the third assessment. We found a correlation between the LA reservoir strain and NT-proBNP (r = 0.40, p < 0.05). DD is prevalent immediately after HTX but rare until the end of the first postoperative quarter. Speckle tracking analysis enables the characterization of LA phasic functions that may reflect both short- and long-term changes in diastolic function and correlate with NT-proBNP.