Che-Hsiung Wu

Long-Term Risk of Coronary Events after AKI

The incidence rate of AKI in hospitalized patients is increasing. However, relatively little attention has been paid to the association of AKI with long-term risk of adverse coronary events. Our study investigated hospitalized patients who recovered from de novo dialysis-requiring AKI between 1999 and 2008 using patient data collected from inpatient claims from Taiwan National Health Insurance. We used Cox regression with time-varying covariates to adjust for subsequent CKD and ESRD after discharge. Results were further validated by analysis of a prospectively constructed database. Among 17,106 acute dialysis patients who were discharged, 4869 patients recovered from dialysis-requiring AKI (AKI recovery group) and were matched with 4869 patients without AKI (non-AKI group). The incidence rates of coronary events were 19.8 and 10.3 per 1000 person-years in the AKI recovery and non-AKI groups, respectively. AKI recovery associated with higher risk of coronary events (hazard ratio [HR], 1.67; 95% confidence interval [95% CI], 1.36 to 2.04) and all-cause mortality (HR, 1.67; 95% CI, 1.57 to 1.79) independent of the effects of subsequent progression to CKD and ESRD. The risk levels of de novo coronary events after hospital discharge were similar in patients with diabetes alone and patients with AKI alone (P=0.23). Our results reveal that AKI with recovery associated with higher long-term risks of coronary events and death in this cohort, suggesting that AKI may identify patients with high risk of future coronary events. Enhanced postdischarge follow-up of renal function of patients who have recovered from temporary dialysis may be warranted.

The Impact of Acute Kidney Injury on the Long-term Risk of Stroke

Background The incidence of acute kidney injury (AKI) requiring dialysis in hospitalized patients is increasing; however, information on the long‐term incidence of stroke in patients surviving to discharge after recovering from AKI after dialysis has not been reported. Methods and Results Patients that survived after recovery from dialysis‐requiring AKI during index hospitalizations from 1999 to 2008 were identified in nationwide administrative registries. The risk of de novo stroke and death were analyzed with time‐varying Cox proportional hazard models. The results were validated by a critical care database. We enrolled 4315 patients in the AKI‐recovery group (men, 57.7%; mean age, 62.8±16.8 years) and matched 4315 control subjects as the non‐AKI group by propensity scores. After a median follow‐up period of 3.36 years, the incident stroke rate was 15.6 per 1000 person‐years. The AKI‐recovery group had higher risk (hazard ratio: 1.25; P=0.037) and higher severity of stroke events than the non‐AKI group, regardless of progression to subsequent chronic kidney disease. The rate of incident stroke was not statistically different in those with diabetes alone (without AKI) and in those with AKI alone (without diabetes) after hospital discharge (P=0.086). Furthermore, the risk of mortality in the AKI‐recovery group was higher than in the non‐AKI group (hazard ratio: 2.4; P<0.001). Conclusions The patients who recovered from AKI had a higher incidence of developing incident stroke and mortality than the patients without AKI, and the impact was similar to diabetes. Our results suggest that a public health initiative is needed to enhance postdischarge follow‐up of renal function and to control the subsequent incidence of stroke among patients who recover from AKI after dialysis.

Prevalence and clinical correlates of somatic mutation in aldosterone producing adenoma-Taiwanese population

Primary aldosteronism (PA) is a common form of secondary hypertension and has significant cardiovascular consequences. Mutated channelopathy due to the activation of calcium channels has been recently described in aldosterone-producing adenoma (APA). The study involved 148 consecutive PA patients, (66 males; aged 56.3 ± 12.3years) who received adrenalectomy, and were collected from the Taiwan PA investigator (TAIPAI) group. A high rate of somatic mutation in APA was found (n = 91, 61.5%); including mutations in KCNJ5 (n = 88, 59.5%), ATP1A1 (n = 2, 1.4%), and ATP2B3 (n = 1, 0.7%); however, no mutations in CACNA1D were identified. Mutation-carriers were younger (<0.001), had lower Cyst C (p = 0.042), pulse wave velocity (p = 0.027), C-reactive protein (p = 0.042) and a lower rate of proteinuria (p = 0.031) than non-carriers. After multivariate adjustment, mutation carriers had lower serum CRP levels than non-carriers (p = 0.031. Patients with mutation also had a greater chance of recovery from hypertension after operation (p = 0.005). A high incidence of somatic mutations in APA was identified in the Taiwanese population. Mutation-carriers had lower CRP levels and a higher rate of cure of hypertension after adrenalectomy. This raises the possibility of using mutation screening as a tool in predicting long-term outcome after adrenalectomy.

Risk of developing severe sepsis after acute kidney injury: a population-based cohort study

IntroductionSepsis has been a factor of acute kidney injury (AKI); however, little is known about dialysis-requiring AKI and the risk of severe sepsis after survival to discharge.MethodsWe conducted a population-based cohort study based on the Taiwan National Health Insurance Research Database from 1999 to 2009. We identified patients with AKI requiring dialysis during hospitalization and survived for at least 90 days after discharge, and matched them with those without AKI according to age, sex, and concurrent diabetes. The primary outcome was severe sepsis, defined as sepsis with a diagnosis of acute organ dysfunction. Individuals who recovered enough to survive without acute dialysis were further analyzed.ResultsWe identified 2983 individuals (mean age, 62 years; median follow-up, 3.96 years) with dialysis-requiring AKI and 11,932 matched controls. The incidence rate of severe sepsis was 6.84 and 2.32 per 100 person-years among individuals with dialysis-requiring AKI and without AKI in the index hospitalization, respectively. Dialysis-requiring AKI patients had a higher risk of developing de novo severe sepsis than the non-AKI group. In subgroup analysis, even individuals with recovery from dialysis-requiring AKI were at high risk of developing severe sepsis.ConclusionsAKI is an independent risk factor for severe sepsis. Even patients who recovered from AKI had a high risk of long-term severe sepsis.

Urinary π-glutathione S-transferase Predicts Advanced Acute Kidney Injury Following Cardiovascular Surgery.

Urinary biomarkers augment the diagnosis of acute kidney injury (AKI), with AKI after cardiovascular surgeries being a prototype of prognosis scenario. Glutathione S-transferases (GST) were evaluated as biomarkers of AKI. Urine samples were collected in 141 cardiovascular surgical patients and analyzed for urinary alpha-(α-) and pi-(π-) GSTs. The outcomes of advanced AKI (KDIGO stage 2, 3) and all-cause in-patient mortality, as composite outcome, were recorded. Areas under the receiver operator characteristic (ROC) curves and multivariate generalized additive model (GAM) were applied to predict outcomes. Thirty-eight (26.9%) patients had AKI, while 12 (8.5%) were with advanced AKI. Urinary π-GST differentiated patients with/without advanced AKI or composite outcome after surgery (p < 0.05 by generalized estimating equation). Urinary π-GST predicted advanced AKI at 3 hrs post-surgery (p = 0.033) and composite outcome (p = 0.009), while the corresponding ROC curve had AUC of 0.784 and 0.783. Using GAM, the cutoff value of 14.7 μg/L for π-GST showed the best performance to predict composite outcome. The addition of π-GST to the SOFA score improved risk stratification (total net reclassification index = 0.47). Thus, urinary π-GST levels predict advanced AKI or hospital mortality after cardiovascular surgery and improve in SOFA outcome assessment specific to AKI.

Comparison of 24-h Urinary Aldosterone Level and Random Urinary Aldosterone-to-Creatinine Ratio in the Diagnosis of Primary Aldosteronism

Background Historically, urinary aldosterone level measurement was a commonly employed confirmatory test to detect primary aldosteronism (PA). However, 24-h urine collection is inconvenient and cumbersome. We hypothesized that random urinary aldosterone measurements with correction for creatinine concentration might be comparable to 24-h urinary aldosterone levels (Uald-24 h) in the diagnosis of PA. Methods The non-concurrent prospective study was conducted between June 2006 and March 2008 in patients admitted for confirmation of aldosteronism by salt loading test. A 24-h urine sample, which was collected during hospitalization on the day before saline infusion testing after restoration of serum hypokalemia, was collected from all subjects. Moreover, participants were asked to collect a first bladder voiding random urine sample during clinic visits. Uald-24 h and the random urinary aldosterone-to-creatinine ratio (UACR) were calculated accordingly. Results A total of 102 PA patients (71 patients diagnosed of aldosterone-producing adenoma, 31 with idiopathic hyperaldosteronism) and 65 patients with EH were enrolled. The receiver operating characteristic curve showed comparable areas under the curves of UACR and Uald-24 h. The Bland-Altman plot showed mean bias but no obvious heteroscedasticity between the two tests. When using random UACR >3.0 ng/mg creatinine as the cutoff value, we obtained a specificity of 90.6% to confirm PA from essential hypertension. Conclusions Our study reinforce that the diagnostic accuracy of random UACR was comparable to that of Uald-24 h in PA patients. With the quickness and simplicity of the UACR method and its equivalence to Uald-24 h, this assay could be a good alternative diagnostic tool for PA confirmation.

Hemojuvelin Modulates Iron Stress During Acute Kidney Injury: Improved by Furin Inhibitor

AIMS Free iron plays an important role in the pathogenesis of acute kidney injury (AKI) via the formation of hydroxyl radicals. Systemic iron homeostasis is controlled by the hemojuvelin-hepcidin-ferroportin axis in the liver, but less is known about this role in AKI. RESULTS By proteomics, we identified a 42 kDa soluble hemojuvelin (sHJV), processed by furin protease from membrane-bound hemojuvelin (mHJV), in the urine during AKI after cardiac surgery. Biopsies from human and mouse specimens with AKI confirm that HJV is extensively increased in renal tubules. Iron overload enhanced the expression of hemojuvelin-hepcidin signaling pathway. The furin inhibitor (FI) decreases furin-mediated proteolytic cleavage of mHJV into sHJV and augments the mHJV/sHJV ratio after iron overload with hypoxia condition. The FI could reduce renal tubule apoptosis, stabilize hypoxic induced factor-1, prevent the accumulation of iron in the kidney, and further ameliorate ischemic-reperfusion injury. mHJV is associated with decreasing total kidney iron, secreting hepcidin, and promoting the degradation of ferroportin at AKI, whereas sHJV does the opposite. INNOVATION This study suggests the ratio of mHJV/sHJV affects the iron deposition during acute kidney injury and sHJV could be an early biomarker of AKI. CONCLUSION Our findings link endogenous HJV inextricably with renal iron homeostasis for the first time, add new significance to early predict AKI, and identify novel therapeutic targets to reduce the severity of AKI using the FI.

Delayed diagnosis of primary aldosteronism in patients with autosomal dominant polycystic kidney diseases

Hypertension is a frequent early manifestation of autosomal dominant polycystic kidney disease (ADPKD). Several mechanisms can cause hypertension in ADPKD patients, although, primary aldosteronism (PA) as a possible manifestation of hypertension in ADPKD is extremely rare. We retrospectively reviewed the Taiwan Primary Aldosteronism Investigation (TAIPAI) database, which listed a total of 346 patients diagnosed with PA. Of these 346 patients, only three cases of concurrent PA and ADPKD were identified. These patients presented with hypertensive crisis and hypokalemia, and subsequent testing revealed aldosterone-producing adenomas (APAs) that were removed by laparoscopic adrenalectomy. Postoperatively, aldosterone-renin ratios (ARRs) and potassium levels normalized, and blood pressure improved. The diagnosis of PA in ADPKD is extremely challenging because multiple renal cysts can obscure the identification of adrenal adenomas, and ADPKD is associated with hypertension in almost all cases.1 Because of frequent delays in the diagnosis of PA in ADPKD patients, future prospective studies to screen PA in hypertensive ADPKD patients may be necessary to evaluate the exact prevalence of coexistence of PA and ADPKD.

Longitudinal assessment of prognostic factors for patients with hepatorenal syndrome in a tertiary center

IntroductionHepatorenal syndrome (HRS) is one of the serious complications in patients with advanced cirrhosis and ascites. In tertiary centers, most patients were classified as having type 1 HRS for their rapid progressive diseases. However, no significant predictors have been assessed previously for patients with type 1 HRS. In addition to the initial model of end-stage liver disease (MELD) scores and biochemistry parameters, we want to further investigate the prognostic importance of changes in MELD scores and biochemistry parameters over time for patients with type 1 HRS.Materials and methodsData from type 1 HRS patients were incorporated, including their demographic, clinical progression, all recording biochemical parameters, therapeutic methods, and outcomes.ResultsA total of 103 patients were included in our study. According to the definition of the International Ascites Club, 67 patients (or 65%) had type 1 HRS whereas 36 (or 35%) had type 2 HRS. According to the multivariate COX proportional hazards regression model, either initial biochemistry parameters or MELD scores were not significantly associated with prognosis. By time-dependent proportional hazards model, each point elevated in creatinine (CRE) and total bilirubin (TBI) levels during the admission increased mortality risk by 29 and 4%, respectively. Increasing albumin level during the admission showed its protective value. Changes in MELD score simple during the admission, which were calculated by CRE and TBI [3.8 × log (bilirubin (mg/dl)] + 9.6 × log [Creatinine (mg/dl) + 6.43], were significant predictor for patients with type 1 HRS.ConclusionIn patients with type 1 HRS, changes in TBI, CRE, and albumin level during the admission were associated with prognosis. Changes in MELD score simple is superior to initial and changes in MELD scores to predict prognosis in patients with type 1 HRS.

Effect of Treatment on Body Fluid in Patients with Unilateral Aldosterone Producing Adenoma: Adrenalectomy versus Spironolactone.

Aldosterone affects fluid retention in the body by affecting how much salt and water that the kidney retains or excretes. There is limited information about the effect of prolonged aldosterone excess and treatment on body fluid in primary aldosteronism (PA) patients. In this study, body composition changes of 41 PA patients with unilateral aldosterone producing adenoma (APA) were assessed by a bio-impedance spectroscopy device. Patients with APA receiving adrenalectomy, as compared with those treated with spironolactone, had significantly lower relative overhydration (OH) and urine albumin excretion, and significantly higher urine sodium excretion four weeks after treatment. These differences dissipated 12 weeks after the initial treatment. Independent factors to predict decreased relative OH four weeks after treatment were male patients and patients who experienced adrenalectomy. Patients who underwent adrenaelctomy had significantly decreased TNF-α and increased serum potassium level when compared to patients treated with spironolactone 4 and 12 weeks after treatment. In this pilot study, we found that adrenalectomy leads to an earlier increase in renal sodium excretion and decreases in body fluid content, TNF-α, and urine albumin excretion. Adrenalectomy yields a therapeutic effect more rapidly, which has been shown to ameliorate overhydration in PA patients.