Diastolic echocardiographic parameters identify pediatric kidney transplant recipients with structural myocardial alterations

BACKGROUND: Cardiac complications are among the most common causes of death in patients after pediatric kidney transplantation (KTx), but defined diagnostic procedures identifying young patients at risk are not established. Cardiovascular magnetic resonance (CMR) imaging with native T1 mapping allows detection of diffuse myocardial alterations but is not routinely available for cardiovascular screening. Whether abnormalities detected by echocardiography reflect underlying myocardial structural changes remains unclear. METHODS: Pediatric KTx recipients underwent comprehensive transthoracic echocardiography and CMR imaging with native T1 mapping. Associations between echocardiographic measures and T1 values were analyzed using multivariable linear regressions. Receiver operating characteristics analyses assessed the ability of septal E/e' to identify elevated T1 values, with area under the curve (AUC) and optimal cut-offs determined using positive likelihood ratios (LR +). RESULTS: Forty-six pediatric KTx recipients (16 ± 3.5 years old; time since KTx 7.9 ± 5.3 years) were included. Diastolic echocardiographic abnormalities were common, with 87% exhibiting at least one abnormal diastolic parameter. Septal T1 was associated with septal E/e', A-wave, and pulmonary venous atrial reversal, while lateral T1 was associated only with septal E/e'. Optimal septal E/e' cut-offs were 10.550 for detecting an elevated septal T1 (LR + = 7.143) and 10.630 for detecting an elevated lateral T1 (LR + = 9). CONCLUSIONS: Pediatric KTx recipients with structural myocardial alterations on CMR imaging exhibit detectable abnormalities in routine echocardiographic diastolic parameters. Especially a markedly elevated septal E/e' could identify patients at increased risk for underlying myocardial involvement and justify the use of CMR imaging in post-transplant follow-up.