Cardiac adaptation in pediatric kidney transplant recipients with large donor–recipient size discrepancy: a speckle-tracking echocardiography study

Background Pediatric living donor kidney transplantation (KT) with large donor-recipient size mismatch induces a large hemodynamic burden on the child recipient. Although successful KT is known to be beneficial for cardiac function and remodeling, its effects in small recipients with adult donors have not been evaluated. We aimed to describe left ventricular (LV) function and geometry using conventional and speckle-tracking echocardiography in this population. Methods A prospective longitudinal study was performed. Living donor KT recipients with large donor-recipient size mismatch underwent conventional and speckle-tracking echocardiography prior to KT, shortly after KT and at 6 and 12 months post-transplantation. LV global longitudinal strain (GLS), LV ejection fraction, cardiac index, LV mass index (LVMi) and LV dimensions were obtained. Results Ten patients were included with a median [IQR] age of 5.9 years [4.4–8.5]. The median donor–recipient body surface area ratio was 2.36. Prior to transplantation, LV systolic dysfunction was found in 80% of the patients (GLS −18.9% [−19.7–−18.7]). Significant improvement was found after 12 months (change in GLS −1.3% [−1.8–−0.9], p = 0.004). A significant reduction in LVMi was found at 6 months and 12 months of −8.9 g/m 2.7 [−15.6–−5.4], p = 0.01 and −14.3 g/m 2.7 [−15.3–−12.9], p = 0.004, respectively. No significant changes in cardiac index were found at 6 and 12 months. Conclusions Despite the increased hemodynamic demands after pediatric KT with large donor-recipient size mismatch, improved LV function and reduced left ventricular mass were found within 1 year after transplantation. These results suggest reversed cardiac remodeling.