Tzong-Shinn Chu

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.

Acute-on-chronic kidney injury at hospital discharge is associated with long-term dialysis and mortality

Existing chronic kidney disease (CKD) is among the most potent predictors of postoperative acute kidney injury (AKI). Here we quantified this risk in a multicenter, observational study of 9425 patients who survived to hospital discharge after major surgery. CKD was defined as a baseline estimated glomerular filtration rate <45 ml/min per 1.73 m(2). AKI was stratified according to the maximum simplified RIFLE classification at hospitalization and unresolved AKI defined as a persistent increase in serum creatinine of more than half above the baseline or the need for dialysis at discharge. A Cox proportional hazard model showed that patients with AKI-on-CKD during hospitalization had significantly worse long-term survival over a median follow-up of 4.8 years (hazard ratio, 1.7) [corrected] than patients with AKI but without CKD.The incidence of long-term dialysis was 22.4 and 0.17 per 100 person-years among patients with and without existing CKD, respectively. The adjusted hazard ratio for long-term dialysis in patients with AKI-on-CKD was 19.8 compared to patients who developed AKI without existing CKD. Furthermore, AKI-on-CKD but without kidney recovery at discharge had a worse outcome (hazard ratios of 4.6 and 213, respectively) for mortality and long-term dialysis as compared to patients without CKD or AKI. Thus, in a large cohort of postoperative patients who developed AKI, those with existing CKD were at higher risk for long-term mortality and dialysis after hospital discharge than those without. These outcomes were significantly worse in those with unresolved AKI at discharge.

Preoperative Proteinuria Predicts Adverse Renal Outcomes after Coronary Artery Bypass Grafting

Whether preoperative proteinuria associates with adverse renal outcomes after cardiac surgery is unknown. Here, we performed a secondary analysis of a prospectively enrolled cohort of adult patients undergoing coronary artery bypass grafting (CABG) at a medical center and its two affiliate hospitals between 2003 and 2007. We excluded patients with stage 5 CKD or those who received dialysis previously. We defined proteinuria, measured with a dipstick, as mild (trace to 1+) or heavy (2+ to 4+). Among a total of 1052 patients, cardiac surgery-associated acute kidney injury (CSA-AKI) developed in 183 (17.4%) patients and required renal replacement therapy (RRT) in 50 (4.8%) patients. In a multiple logistic regression model, mild and heavy proteinuria each associated with an increased odds of CSA-AKI, independent of CKD stage and the presence of diabetes mellitus (mild: OR 1.66, 95% CI 1.09 to 2.52; heavy: OR 2.30, 95% CI 1.35 to 3.90). Heavy proteinuria also associated with increased odds of postoperative RRT (OR 7.29, 95% CI 3.00 to 17.73). In summary, these data suggest that preoperative proteinuria is a predictor of CSA-AKI among patients undergoing CABG.

The 90-day mortality and the subsequent renal recovery in critically ill surgical patients requiring acute renal replacement therapy.

BACKGROUND Particular attention should be paid to postoperative patients that suffer from severe acute kidney injury (AKI) requiring renal replacement therapy (RRT). METHODS This multicenter prospective observational study included 342 patients with postoperative AKI requiring RRT from January 2002 to December 2006. RESULTS There were 137 (40%) survivors at 90 days after the commencement of RRT. Independent predictors of 90-day mortality were older age, presence of sepsis, status post-cardiopulmonary resuscitation, necessity of continuous renal replacement therapy (CRRT), requirement of total parenteral nutrition, lower body mass index, higher Sequential Organ Failure Assessment score, and higher serum lactate level at the commencement of RRT. Further analysis among the survivors showed that lower serum creatinine at intensive care unit admission, lower Simplified Acute Physiology Score II and inotropic equivalent score at the commencement of RRT, and using CRRT were independent predictors for subsequent renal recovery. CONCLUSIONS The development of AKI requiring RRT in postoperative critical patients represents a substantial risk for mortality and morbidity.

Kidney impairment in primary aldosteronism

BACKGROUND Kidney impairment is noted in primary aldosteronism (PA), and probably initiated by glomerular hyperfiltration. METHODS A prospectively defined survey was conducted on 602 patients who were suspected of PA in the multiple-center Taiwan Primary Aldosteronism Investigation (TAIPAI) database. Estimated glomerular filtration rate (eGFR) was calculated and followed up at 1 yr after treatment. RESULTS The diagnosis of PA was confirmed in 330 patients. Among them 17% of these patients had kidney impairment (eGFR<60 ml/min/1.73 m²). Patients with PA had a higher prevalence of estimated hyperfiltration than those with essential hypertension (EH) (14.5% vs. 7.0%, p=0.005). The eGFR independently predicted PA (OR, 1.017) in the propensity-adjusted multivariate logistic model. In PA, plasma renin activity and lower serum potassium (p=0.018) was correlated with kidney impairment (p=0.001), while this relationship was not significant in patients with EH. Either unilateral adrenalectomy or treatment of spironolactone for PA patients caused a decrease of eGFR (p<0.001). Pre-operative hypokalemia (p=0.013) and the long latency of hypertension (p=0.016) could enhance the significant decrease of eGFR after adrenalectomy. CONCLUSIONS Patients with aldosteronism had relative estimated hyperfiltration than patients with EH. Calculation of eGFR may increase the specificity in identifying patients with PA. Our findings demonstrate the correlation of serum potassium and renin with estimated hyperfiltration in PA and their relationship to kidney damage. These results provide a high priority for future renal protective strategies and methods for the early diagnosis and prompt treatment of PA.

Comparison of residual renal function in patients undergoing twice-weekly versus three-times-weekly haemodialysis

Aim:  Patients with end‐stage renal disease (ESRD) often start long‐term haemodialysis (HD) thrice weekly, regardless of the level of residual renal function (RRF). In this study, we investigated whether ESRD patients having sufficient RRF can be maintained on twice‐weekly HD, and how they fare compared to patients without RRF on thrice‐weekly HD.

To evaluate the effectiveness of health care ethics consultation based on the goals of health care ethics consultation: a prospective cohort study with randomization

BackgroundThe growing prevalence of health care ethics consultation (HCEC) services in the U.S. has been accompanied by an increase in calls for accountability and quality assurance, and for the debates surrounding why and how HCEC is evaluated. The objective of this study was to evaluate the effectiveness of HCEC as indicated by several novel outcome measurements in East Asian medical encounters.MethodsPatients with medical uncertainty or conflict regarding value-laden issues, and requests made by the attending physicians or nurses for HCEC from December 1, 2009 to April 30, 2012 were randomly assigned to the usual care group (UC group) and the intervention group (HCEC group). The patients in the HCEC group received HCEC conducted by an individual ethics consultant. Data analysis was based on the intention-to-treat principle. Mann–Whitney test and Chi-squared test were used depending on the scale of measurement.ResultsThirty-three patients (53.23%) were randomly assigned to the HCEC group and 29 patients were randomly assigned to the UC group. Among the 33 patients in the HCEC group, two (6.06%) of them ultimately did not receive a HCEC service. Among the 29 patients in the UC group, four (13.79%) of them received a HCEC service. The survival rate at hospital discharge did not differ between the two groups. Patients in the HCEC group showed significant reductions in the entire ICU stay and entire hospital stay. HCEC significantly facilitated achieving the goal of medical care (p < .01). Furthermore, patients in the HCEC group had a shorter ICU stay and shorter hospital stay after the occurrence of medical uncertainty or conflict regarding value-laden issues than those in the UC group.ConclusionsOur findings demonstrated that HCEC were associated with reduced consumption of medical resources as indicated by shorter entire ICU stay, entire hospital stay, and shorter ICU and hospital stay after the occurrence of the medical uncertainty or conflict regarding value-laden issues. This study also showed that HCEC facilitated achieving a consensus regarding the goal of medical care, which conforms to the goal of HCEC.

Clinical characteristics of patients with segmental renal infarction

Background:  Renal infarction is usually an underestimated disease due to its rare and non‐specific presentations; the renal survival of these patients is not well studied. The aim of the present analysis is to study the clinical features and outcome in patients who had documented renal infarction.

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.

Primary aldosteronism: changes in cystatin C-based kidney filtration, proteinuria, and renal duplex indices with treatment.

Objectives To obtain information about the effect of prolonged aldosterone excess on kidney function. Methods We determined kidney function changes defined by cystatin C-based estimations of glomerular filtration rate (CysC-GFR). Pretreatment proteinuria and intrarenal Doppler velocimetric indices in primary aldosteronism were examined and followed after adrenalectomy or spironolactone treatment. Results This prospective, multicenter study included 130 primary aldosteronism patients (56 men; age, 49.9 ± 13.4 years: 100 with adenoma and 30 with idiopathic hyperaldosteronism) and 73 essential hypertension patients (36 men; age, 51.4 ± 14.8 years) as controls. Patients with primary aldosteronism had higher CysC-GFR (P < 0.05) and heavier proteinuria (0.042) than those with essential hypertension. With primary aldosteronism, a higher aldosterone–renin ratio (odds ratio, OR = 7.85, P = 0.008) was independently related to pretreatment CysC-GFR. The factors related to pretreatment proteinuria included CysC-GFR (OR, −0.006, P = 0.001), plasma aldosterone concentration (OR, 0.004, P = 0.002), and duration of hypertension (OR, 0.016, P = 0.032). Duration of hypertension was also independently correlated with the pretreatment resistive index among primary aldosteronism patients (OR, 0.004, P = 0.035). CysC-GFR (all, P < 0.05), proteinuria (P < 0.001), and resistive index (P < 0.001) decreased 1 year after adrenalectomy but not with spironolactone treatment. Conclusion Our data suggest that prolonged hyperaldosteronism will cause relative kidney hyperfiltration and reversible intrarenal vascular structural changes, which disguise the consequent renal injury, including declining GFR and proteinuria. Adrenalectomy and spironolactone treatment exert different clinical impacts toward kidney damage even with a similar blood pressure-lowering effect.