Comparison of 2D Shear Wave Elastography, Transient Elastography, and MR Elastography for the Diagnosis of Fibrosis in Patients With Nonalcoholic Fatty Liver Disease.

OBJECTIVE. The aim of the present study was to compare the diagnostic accuracy of liver stiffness measurements (LSMs) obtained using MR elastography (MRE), transient elastography (TE), and 2D shear wave elastography (SWE) in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD). SUBJECTS AND METHODS. We prospectively enrolled 62 adult subjects (mean age [± SD], 50 ± 13 years; 58% women; body mass index [weight in kilograms divided by the square of height in meters], 35 ± 7). Two-dimensional SWE, MRE, and TE were performed at a mean of 105 ± 86 days after liver biopsy. The area under the ROC curve (AUROC) values and 95% CIs for the corresponding LSMs (expressed in kilopascals) were calculated, with significant fibrosis (Metavir liver fibrosis score, F2-F4) and advanced fibrosis (F3-F4) used as outcome measures. Pairwise comparisons of AUROC values were conducted using the DeLong test. Statistical significance was set at p < 0.05. RESULTS. For the 62 subjects, valid LSMs were obtained for 57 subjects with the use of 2D SWE, for 59 subjects with TE, for 59 subjects with MRE, and for 54 subjects with all three modalities combined. The AUROC values (95% CIs) of 2D SWE, TE, and MRE for the diagnosis of significant fibrosis were 0.80 (0.67-0.92), 0.77 (0.64-0.89), and 0.85 (0.74-0.95), respectively. The AUROC values (95% CIs) of 2D SWE, TE, and MRE for the diagnosis of advanced fibrosis were 0.89 (0.80-0.98), 0.86 (0.77-0.95), and 0.95 (0.89-1.00), respectively. Pairwise comparisons revealed similar diagnostic accuracy for significant fibrosis (2D SWE vs MRE, p = 0.431; 2D SWE vs TE, p = 0.317; and MRE vs TE, p = 0.052) and advanced fibrosis (2D SWE vs MRE, p = 0.348; 2D SWE vs TE, p = 0.293; and MRE vs TE, p = 0.059). CONCLUSION. For patients with biopsy-proven NAFLD, 2D SWE, MRE and TE exhibited comparable and very good to excellent diagnostic accuracy for advanced fibrosis and comparable but lower accuracy for significant fibrosis.

QT interval prolongation in end-stage liver disease cannot be explained by nonhepatic factors.

INTRODUCTION: QT interval prolongation in patients with end-stage liver disease (ESLD) is common. However, electrolyte abnormalities, renal insufficiency, treatment with QT-prolonging drugs, and other factors known to prolong QT interval independently of liver disease occur frequently in ESLD. Moreover, elevated heart rate may be present in ESLD and result in spurious QTc prolongation if the Bazett formula is used for rate correction. It thus remains unclear whether QT prolongation in ESLD is directly caused by liver failure, or indirectly by these confounding factors. METHODS: Medical records of all patients (n = 437) who received orthotopic liver transplantation (OLTx) at our institution between 2008 and 2011 were reviewed. Data from 51 patients with available pre-OLTx dobutamine stress echo (DSE), post-OLTx ECG and without nonhepatic factors affecting QT interval duration were analyzed. For each patient, QT versus RR regression line was calculated from ECG tracings obtained during DSE. The QT interval on post-OLTx ECG was compared with the pre-OLTx QT predicted by the regression line for the same RR interval. RESULTS: QT interval shortened significantly post-OLTx (from 394 ± 47 to 364 ± 45 ms at RR interval 750 ± 144 ms; P < 0.002) when compared using the regression method. Corrected QT intervals calculated by Bazett and Fridericia formulas also shortened. Patients with prolonged QT pre-OLTx had significantly higher INR and lower serum albumin. CONCLUSION: ESLD impairs ventricular repolarization even in the absence of other known factors affecting repolarization. QT prolongation in ESLD is associated with impaired synthetic liver function.