Early cardiac remodeling in aortic coarctation: insights from fetal and neonatal functional and structural assessment.

OBJECTIVES: Coarctation of the aorta (CoA) is associated with left ventricular (LV) dysfunction in neonates and adults. Cardiac structure and function in fetal CoA and cardiac adaptation to early neonatal life have not been described. We aimed to investigate the presence of cardiovascular structural remodeling and dysfunction in fetuses with CoA and their early postnatal cardiac adaptation. METHODS: This was a prospective observational case-control study, conducted between 2011 and 2018 in a single tertiary referral center, of fetuses with CoA and gestational age-matched normal controls. All fetuses/neonates underwent comprehensive echocardiographic evaluation in the third trimester of pregnancy and after birth. Additionally, myocardial microstructure was assessed in one fetal and one neonatal CoA-affected heart specimen, using synchrotron radiation-based X-ray phase-contrast microcomputed tomography and histology, respectively. RESULTS: We included 30 fetuses with CoA and 60 gestational age-matched controls. Of these, 20 CoA neonates and 44 controls were also evaluated postnatally. Fetuses with CoA showed significant left-to-right volume redistribution, with right ventricular (RV) size and output dominance and significant geometry alterations with an abnormally elongated LV, compared with controls (LV midventricular sphericity index (median (interquartile range; IQR), 2.4 (2.0-2.7) vs 1.8 (1.7-2.0); P < 0.001). Biventricular function was preserved and no ventricular hypertrophy was observed. Synchrotron tomography and histological assessment revealed normal myocyte organization in the fetal and neonatal specimens, respectively. Postnatally, the LV in CoA cases showed prompt remodeling, becoming more globular (LV midventricular sphericity index (mean ± SD), 1.5 ± 0.3 in CoA vs 1.8 ± 0.2 in controls; P < 0.001) with preserved systolic and normalized output, but altered diastolic, parameters compared with controls (LV inflow peak velocity in early diastole (mean ± SD), 97.8 ± 14.5 vs 56.5 ± 12.9 cm/s; LV inflow peak velocity in atrial contraction (median (IQR), 70.5 (60.1-84.9) vs 47.0 (43.0-55.0) cm/s; LV peak myocardial velocity in atrial contraction (mean ± SD), 5.1 ± 2.6 vs 6.3 ± 2.2 cm/s; P < 0.05). The neonatal RV showed increased longitudinal function in the presence of a patent arterial duct. CONCLUSIONS: Our results suggest unique fetal cardiac remodeling in CoA, in which the LV stays smaller from the decreased growth stimulus of reduced volume load. Postnatally, the LV is acutely volume-loaded, resulting in an overall geometry change with higher filling velocities and preserved systolic function. These findings improve our understanding of the evolution of CoA from fetal to neonatal life. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Assessment of the arteries in living kidney donors: correlation of magnetic resonance angiography with intraoperative findings.

Comprehensive imaging evaluation of kidney donor anatomy is crucial for selecting candidates for living kidney transplantation and for determining the surgical technique to procure the renal graft. In 76 living renal donors we compared the results of preoperative magnetic resonance angiography (MRA) with the intraoperative findings of arterial anatomy. Donors were evaluated for the number of main renal arteries and the presence of any polar arteries. A total of 80 main renal arteries and five polar arteries were observed at MRA. At surgery, 90 main renal arteries and eight polar arteries were identified. MRA demonstrated a sensitivity, specificity, and overall accuracy of 18%, 98%, and 87%, respectively, for main arteries and 25%, 96%, and 88% for polar arteries. Eleven (14.5%) kidneys displayed more than one main artery and MRA only detected two cases. Eight kidneys had polar arteries and MRA only detected two cases. MRA is a reliable method for presurgical evaluation of renal arteries in potential donors, providing valuable information required by the surgeon. But, as the technique misses small-diameter vessels, it cannot be recommended as the sole diagnostic tool in unclear cases.

Assessment of cyclosporine therapeutic monitoring with C2 concentrations in stable renal allograft recipients.

The optimal long-term C2 target to minimize the risk of chronic allograft nephropathy (CAN) has not yet been established in a prospective study. Furthermore, it is not known whether the target is the same in patients who also receive mycophenolate mofetil (MMF). We determined the 2-hour postdose concentration (C2) in a cohort of 65 maintenance renal transplant patients. The mean C0 level was 0.12 microg/mL and the C2 was 0.62 microg/mL. The overexposed patients are 14%. There was a good correlation between C0 and C2, and between C2 and the cyclosporine (CsA) dose. Patients receiving MMF display lower levels of C0 and C2, lower dosages of CsA, and higher levels of plasma creatinines. We did not observe significant differences on relating the level of absorption to patient age and sex, creatinine level, CsA dose, or coadministration of MMF. In conclusion, there is a low incidence of overexposed patients. C2 levels of approximately 0.6 microg/mL (and possibly may be sufficient in renal transplant patients. somewhat lower [0.5 microg/mL] in patients receiving MMF) Patients who display slow or fast absorption of CsA do not have any apparent characteristic.