Hyun Chul Chung

Design and challenges of the Randomized Evaluation of Normal versus Augmented Level Replacement Therapy (RENAL) Trial: high-dose versus standard-dose hemofiltration in acute renal failure

Background/Aims: The optimal dose of renal replacement therapy (RRT) in acute renal failure (ARF) is uncertain. Methods: The Randomized Evaluation of Normal versus Augmented Level Replacement Therapy Trial tests the hypothesis that higher dose continuous veno-venous hemodiafiltration (CVVHDF) at an effluent rate of 40 ml/kg/h will increase survival compared to CVVHDF at 25 ml/kg/h of effluent dose. Results: This trial is currently randomizing critically ill patients in 35 intensive care units in Australia and New Zealand with a planned sample size of 1,500 patients. This trial will be the largest trial ever conducted on acute blood purification in critically ill patients. Conclusion: A trial of this magnitude and with demanding technical requirements poses design difficulties and challenges in the logistics, conduct, data collection, data analysis and monitoring. Our report will assist in the development of future trials of blood purification in intensive care. This study was registered with ClinicalTrials.gov (NCT00221013).

Relationship between Extracellular Water Fraction of Total Body Water Estimated by Bioimpedance Spectroscopy and Cardiac Troponin T in Chronic Haemodialysis Patients

Background/Aims: The ratio of extracellular water to total body water (ECW/TBW) estimated by bioimpedance spectroscopy (BIS) may be a useful volume index in haemodialysis (HD) patients, but its direct relation to cardiovascular (CV) outcomes has been rarely evaluated. Methods: We investigated the relationship between ECW/TBW by BIS and cardiac troponin T (cTnT) level, a biochemical surrogate of CV mortality. Results: Seventy-four HD patients without ischemic heart disease (age 51.6 ± 13.2 years; male:female ratio 36:38; diabetes 37.8%) were recruited. Post-HD ECW/TBW was positively correlated to log cTnT levels (r = 0.60, p < 0.01). In multivariate regression models, male sex (β = 0.23, p = 0.03), diabetes mellitus (β = 0.21, p = 0.04), log high-sensitivity C-reactive protein (β = 0.21, p = 0.04) and post-HD ECW/TBW (β = 0.37, p < 0.01) were independent risk factors for elevated log cTnT levels. Conclusion: Post-HD ECW/TBW by BIS is worthy of further evaluation as a pathophysiological index for reducing CV mortality in HD patients.

Acute Kidney Injury after Transarterial Chemoembolization for Hepatocellular Carcinoma: A Retrospective Analysis

Background: Transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) may result in acute kidney injury (AKI) like other angiographic interventions. Methods: To investigate the incidence, risk factor and outcomes of AKI after TACE, defined by Acute Kidney Injury Network (AKIN) criteria, we retrospectively analyzed 442 TACE treatment sessions in 236 HCC patients. Results: The incidence of AKI in the first 48 h after TACE was 9.8% (23 of 236 patients at risk). Presence of hypertension (OR 3.24, 95% CI 1.21–8.72, p = 0.02), lower baseline serum albumin (OR 0.29, 95% CI 0.15–0.56, p < 0.01) and higher creatinine level (OR 12.02, 95% CI 3.49–41.39, p < 0.01) were independent risk factors of AKI. Prolonged renal insufficiency after 1 month was observed in 24.1% of AKI episodes. Conclusion: AKI is a common complication after TACE and we have to pay attention to the prevention and early recognition of AKI occurrence in high-risk patients.

Vitamin D Levels and Their Relationship with Cardiac Biomarkers in Chronic Hemodialysis Patients

Vitamin D insufficiency may be associated with cardiovascular (CV) mortality in HD patients. To test this hypothesis, we cross-sectionally measured 25-hydroxyvitamin D (25D), 1,25-dihydroxyvitamin D (1,25D), cardiac troponin T (cTnT), and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) in chronic HD patients. Sixty-five patients (M:F=31:34, age 52.2±13.2 yr, DM 41.5%) were selected. Along with the expected low levels of 1,25D, 59 (90.8%) patients had 25D insufficiency (<30 ng/mL) among whom 15 (23.1%) were 25D deficient (<10 ng/mL). The 25D levels showed a negative correlation with cTnT levels (Spearmans ρ=-0.44, p<0.01) but not with NT-pro-BNP levels (Spearmans ρ=-0.17, p=0.17). The 1,25D levels, however, did not show any relationship with either cTnT or NT-pro-BNP. In multivariate analysis, being male and having low levels of 25D were independent risk factors associated with cTnT elevation (β=0.44, p<0.01 and β=-0.48, p<0.01, respectively). In conclusion, not only 1,25D but also 25D are commonly decreased in HD patients. Lower 25D levels appear to be associated with cTnT elevation, predicting worse CV outcome, and are possible to involve cardiac hypertrophy or coronary artery disease.

Remote ischemic preconditioning in hemodialysis: a pilot study

Hemodialysis (HD)-induced myocardial ischemia is associated with an elevated cardiac troponin T, and is common in asymptomatic patients undergoing conventional HD. Remote ischemic preconditioning (RIPC) has a protective effect against myocardial ischemia–reperfusion injury. We hypothesized that RIPC also has a protective effect on HD-induced myocardial injury. Chronic HD patients were randomized to the control group or the RIPC group. RIPC was induced by transient occlusion of blood flow to the arm with a blood-pressure cuff for 5 min, followed by 5 min of deflation. Three cycles of inflation and deflation were undertaken before every HD session for 1 month (total 12 times). The primary outcome was the change in cardiac troponin T (cTnT) level at day 28 from baseline. Demographic and baseline laboratory values were not different between the control (n = 17) and the RIPC groups (n = 17). cTnT levels tended to decrease from day 2 in the RIPC group through to 28 days, in contrast to no change in the control group. There were significant differences in the change of cTnT level at day 28 from baseline [Control, median; −0.002 ng/ml (interquartile range −0.008 to 0.018) versus RIPC, median; −0.015 ng/ml (interquartile range −0.055 to 0.004), P = 0.012]. RIPC reduced cTnT release in chronic conventional HD patients, suggesting that this simple, cheap, safe, and well-tolerated procedure has a protective effect against HD-induced ischemia.

Remote Ischemic Preconditioning for the Prevention of Contrast-Induced Acute Kidney Injury in Diabetics Receiving Elective Percutaneous Coronary Intervention

Objective Remote ischemic preconditioning (RIPC) induces transient episodes of ischemia by the occlusion of blood flow in non-target tissue, before a subsequent ischemia-reperfusion injury. When RIPC is applied before percutaneous coronary intervention (PCI), the kidneys may be protected against ischemia-reperfusion injury and subsequently contrast-induced acute kidney injury (CI-AKI). The aim of this study was to evaluate the efficacy of RIPC for the prevention of CI-AKI in patients with diabetes with pre-existing chronic kidney disease (CKD) undergoing elective PCI. Methods This randomized, double-blind, sham-controlled study enrolled patients with diabetes scheduled for elective PCI with eGFR ≤60 ml/min/1.73 m2 or urinary albumin creatinine ratio of >300 mg/g to receive either RIPC or the sham ischemic preconditioning. Results One hundred and two patients (68.9 ± 8.2 years old, 47.1% men) were included. Baseline eGFR, creatinine and serum NGAL was similar between RIPC and control groups (48.5 ± 12 ml/min vs. 46.6 ± 10 ml/min, p = 0.391; 1.42 ± 0.58 mg/dl vs. 1.41 ± 0.34 mg/dl, p = 0.924; and 136.0 ± 45.0 ng/ml vs. 137.6 ± 43.3 ng/ml, p = 0.961, respectively). CI-AKI occurred in 13.7% (14/102) of the total subjects, with both RIPC and control groups having an equal incidence of 13.7% (7/51). No significant differences were seen in creatinine, NGAL, cardiac enzymes (troponin T, CKMB) and hs-CRP between the groups post-procedure. Conclusions In this study, RIPC applied prior to elective PCI was not effective in preventing CI-AKI in patients with diabetes with pre-existing CKD. Trial Registration ClinicalTrials.gov NCT02329444

Membranoproliferative glomerulonephritis presenting as arthropathy and cardiac valvulopathy in hypocomplementemic urticarial vasculitis: a case report

IntroductionHypocomplementemic urticarial vasculitis syndrome is a rare disorder characterized by chronic urticarial vasculitis, arthralgia, arthritis, and hypocomplementemia. Previously, only six patients with concomitant hypocomplementemic urticarial vasculitis syndrome, Jaccoud’s arthropathy, and valvular heart disease have been reported.Case presentationA 30-year-old Korean man presented with hypocomplementemic urticarial vasculitis syndrome. In addition to urticarial cutaneous lesions, he experienced polyarthralgia and arthritis that resulted in progressive deformity of the joints of both hands, cardiac valvulopathy with mitral, tricuspid, and aortic regurgitation, and intermittent neck swelling with laryngeal edema. He also developed nephritis with azotemia. His renal biopsy results revealed membranoproliferative glomerulonephritis, type I. He showed a partial response to a combination therapy of steroid, cyclophosphamide, and mycophenolate mofetil.ConclusionsWe describe, to the best of our knowledge, the first case of glomerulonephritis presenting a arthropathy and cardiac valvulopathy in hypocomplementemic urticarial vasculitis syndrome. A combination of corticosteroids, cyclophosphamide, and mycophenolate mofetil appear to be a safe and effective treatment for nephropathy, however are less effective for cutaneous vasculitis, cardiac valvulopathy, and arthropathy.

Serum Phosphorus Concentration and Coronary Artery Calcification in Subjects without Renal Dysfunction

Serum phosphorus (P) concentration is associated with coronary artery calcification (CAC) as well as cardiovascular events in patients with chronic kidney disease. It has been suggested that this relationship is extended to subjects without renal dysfunction, but further explorations in diverse races and regions are still needed. We performed a cross-sectional study of 2,509 Korean subjects (Far Eastern Asian) with an estimated glomerular filtration rate of ≥60 ml/min/1.73m2 and who underwent coronary computerized tomography. Serum P concentration was divided into pre-determined 4 categories: ≤3.2, 3.2< to ≤3.6, 3.6< to ≤4.0 and >4.0 mg/dL. Agatston score (AS), an index of CAC, was divided into 3 categories: 0, 0< to ≤100, and >100. A multinomial logit model (baseline outcome: AS = 0) was applied to estimate the odds ratio (OR) for each serum P category (reference: ≤3.2mg/dL). Mean age of subjects was 53.5±9.1 years and 36.9% were female. In the adjusted model, serum P concentration of 3.6< to ≤4.0 mg/dL and >4.0 mg/dL showed high ORs for AS of >100 [OR: 1.58, 95% confidence interval (CI): 1.04–2.40 and OR: 2.11, 95% CI: 1.34–3.32, respectively]. A unit (mg/dL) increase in serum P concentration was associated with 50% increase in risk of AS >100 (OR: 1.50, 95% CI: 1.16–1.94). A higher serum P concentration, even within a normal range, may be associated with a higher CAC in subjects with normal renal function.

Efficacy of low-dose i.v. iron therapy in haemodialysis patients.

Aim:  i.v. iron therapy is more effective in maintaining adequate iron status in haemodialysis (HD) patients than oral iron therapy (OIT). However, data on lower doses of i.v. iron therapy are insufficient.

ATYPICAL REVERSIBLE POSTERIOR LEUKOENCEPHALOPATHY SYNDROME IN A CHRONIC HAEMODIALYSIS PATIENT WITH SEVERE HYPERTENSION

Reversible posterior leukoencephalopathy syndrome (RPLS) refers to a clinicoradiologic entity characterized by headache, altered mentality, cortical visual disturbance, seizure and transient vasogenic oedema predominantly involving the bilateral subcortical white matter of parietooccipital lobes on neuroimaging. We herein describe an atypical RPLS manifested by chorea with only the bilateral thalamic involvements.