MR imaging biomarkers in HCC: outcomes correlation in liver transplant listed patients

PURPOSE

To determine hepatocellular carcinoma (HCC) magnetic resonance imaging (MRI) biomarkers that enable the prediction of delisting from tumor progression versus successful transplantation in patients listed for orthotopic liver transplantation (OLT).

METHODS

With IRB approval and HIPPA compliance, patients with HCC awaiting OLT who were delisted due to HCC progression from 2006 to 2015 were identified. Patients with adequate MR images for review were subsequently matched with a cohort of patients successfully bridged to OLT in the same time period. Matching considered the tumor stage and the dominant treatment strategy adopted to bridge the patient to OLT. Potential MRI features were evaluated by univariable and multivariable analysis using a conditional logistic model.

RESULTS

There were 53 patients included in each cohort. On uni-variable analysis, significant unfavorable MR imaging features included T2 hyperintensity (odds ratio [OR], 19.0), infiltrative border (OR, 7.50), lobulated shape (OR, 4.5), T1 hypointensity (OR, 3.0), heterogeneous arterial enhancement (OR, 7.0), and corona venous enhancement (OR, 4.0). A significant favorable MR imaging feature was the presence of intralesional fat (OR = .36). The best multivariable logistic prediction model derived from the above notable features included only T1 and T2 signal intensity, border definition, and absence of intra-lesional fat as significant variables, with an area under the receiver operating characteristic curve (AUC) of .86 in the prediction of delisting.

CONCLUSION

Select MR imaging features of HCC at presentation before any treatment are significantly associated with the risk of tumor progression regardless of tumor stage and treatment strategy in patients awaiting liver transplantation.

The ViKTORIES trial: A randomized, double-blind, placebo-controlled trial of vitamin K supplementation to improve vascular health in kidney transplant recipients

Premature cardiovascular disease and death with a functioning graft are leading causes of death and graft loss, respectively, in kidney transplant recipients (KTRs). Vascular stiffness and calcification are markers of cardiovascular disease that are prevalent in KTR and associated with subclinical vitamin K deficiency. We performed a single-center, phase II, parallel-group, randomized, double-blind, placebo-controlled trial (ISRCTN22012044) to test whether vitamin K supplementation reduced vascular stiffness (MRI-based aortic distensibility) or calcification (coronary artery calcium score on computed tomography) in KTR over 1 year of treatment. The primary outcome was between-group difference in vascular stiffness (ascending aortic distensibility). KTRs were recruited between September 2017 and June 2018, and randomized 1:1 to vitamin K (menadiol diphosphate 5 mg; n = 45) or placebo (n = 45) thrice weekly. Baseline demographics, clinical history, and immunosuppression regimens were similar between groups. There was no impact of vitamin K on vascular stiffness (treatment effect -0.23 [95% CI -0.75 to 0.29] × 10^-3  mmHg^-1 ; p = .377), vascular calcification (treatment effect -141 [95% CI - 320 to 38] units; p = .124), nor any other outcome measure. In this heterogeneous cohort of prevalent KTR, vitamin K supplementation did not reduce vascular stiffness or calcification over 1 year. Improving vascular health in KTR is likely to require a multifaceted approach.

Perfusion Cardiac Magnetic Resonance Imaging as a Rule-Out Test for Cardiac Allograft Vasculopathy

Cardiac allograft vasculopathy (CAV) is a leading cause of mortality after heart transplantation. Noninvasive imaging techniques used in CAV evaluation have important limitations. In a cross-sectional study, we investigated perfusion cardiac magnetic resonance (CMR) imaging to determine an optimal myocardial perfusion reserve index (MPR) cutoff for detecting CAV using receiver operating characteristic curve analysis. We evaluated CMR performance using sensitivity, specificity and likelihood ratio analysis. We included 29 patients (mean 5 ± 4 years after transplant) scheduled for coronary angiography with intravascular ultrasound (IVUS) who completed CMR. CAV was defined as maximal intimal thickness (MIT) >0.5 mm by IVUS of the left anterior descending artery. CAV was evident in 19 patients (70%) on IVUS (mean MIT 0.82 ± 0.42 mm). MPR was significantly lower in patients with MIT ≥0.50 mm (1.35 ± 0.23 vs. 1.71 ± 0.45, p = 0.013). There was moderate inverse correlation between MPR and MIT (r = -0.36, p = 0.075). The optimal MPR cutoff ≤1.68 for predicting CAV showed sensitivity of 100%, specificity of 63%, a negative predictive value of 100%, a positive predictive value of 86% and a positive likelihood ratio of 2.7. An MPR ≤1.68 has high negative predictive value, suggesting its potential as a test to rule out CAV.

Acute Neurological Illness in a Kidney Transplant Recipient Following Infection With Enterovirus-D68: An Emerging Infection?

We report the first case of enterovirus-D68 infection in an adult living-donor kidney transplant recipient who developed rapidly progressive bulbar weakness and acute flaccid limb paralysis following an upper respiratory infection. We present a 45-year-old gentleman who underwent pre-emptive living-donor kidney transplantation for IgA nephropathy. Eight weeks following transplantation, he developed an acute respiratory illness from enterovirus/rhinovirus that was detectable in nasopharyngeal (NP) swabs. Within 24 h of onset of respiratory symptoms, the patient developed binocular diplopia which rapidly progressed to multiple cranial nerve dysfunctions (acute bulbar syndrome) over the next 24 h. Within the next 48 h, asymmetric flaccid paralysis of the left arm and urinary retention developed. While his neurological symptoms were evolving, the Centers for Disease Control reported that the enterovirus strain from the NP swabs was, in fact, Enterovirus-D68 (EV-D68). Magnetic resonance imaging of the brain demonstrated unique gray matter and anterior horn cell changes in the midbrain and spinal cord, respectively. Constellation of these neurological symptoms and signs was suggestive for postinfectious encephalomyelitis (acute disseminated encephalomyelitis [ADEM]) from EV-D68. Treatment based on the principles of ADEM included intensive physical therapy and other supportive measures, which resulted in a steady albeit slow improvement in his left arm and bulbar weakness, while maintaining stable allograft function.

Cardiovascular MRI predicts 5-year adverse clinical outcome in heart transplant recipients

Imaging recommendations for the follow-up of heart transplant recipients (HTRs) lack evidence justifying their prognostic value. Cardiovascular magnetic resonance imaging (CMRI) can characterize heart structure and function and has prognostic value in many myocardial diseases. We hypothesized that CMRI evaluation of cardiac allografts would predict adverse events. We performed CMRI on 60 HTRs evaluating biventricular size, function and myocardial scar. We performed survival analysis to identify independent predictors of cardiovascular (CV) death or hospitalization. Participants had a mean age of 51 ± 14 years, mean graft age of 3.5 years (±4) and 75% are male. Median follow-up time was 4.9 years with 22 CV hospitalizations and 7 CV deaths. A multivariable survival analysis of imaging and clinical variables identified myocardial scar (hazard ratio [HR] of 10.7, p = 0.005), right ventricular end- diastolic volume index (RVEDVI; 1.1/mL/m(2) , p = 0.001), graft age (HR = 1.2/year, p = 0.004) and previous allograft rejection (HR = 4.4, p = 0.006) as predictive of time to CV death or hospitalization. CMRI-derived myocardial scar and RVEDVI are independently associated with CV outcomes in HTRs.