Renal insufficiency is an independent predictor of in-hospital mortality for patients with acute myocardial infarction receiving primary percutaneous coronary intervention

Objective:To investigate the relationship between renal function and clinical outcomes among patients with acute ST-segment elevation myocardial infarction (ASTEMI), who were treated with emergency percutaneous coronary intervention (PCI). Methods: 420 patients hospitalized in Peking University First Hospital, diagnosed with ASTEMI treated with emergency (PCI) from January 2001 to June 2011 were enrolled in this study. Estimated glomerular filtration rate (eGFR) was used as a measure of renal function. We compared the clinical parameters and outcomes between ASTEMI patients combined renal insufficiency and the patients with normal renal function. Results:There was a significant increase in the concentrations of fibrinogen and D-Dimer (P<0.05) and a much higher morbidity of diabetes mellitus in the group of patients with chronic kidney disease (CKD; eGFR<60 ml/(min·1.73 m2)) (P<0.01). CKD (eGFR<60 ml/(min·1.73 m2)) was an independent predictor of in-hospital mortality for patients hospitalized with ASTEMI receiving PCI therapy rapidly (P=0.032, odds ratio (OR) 4.159, 95% confidence interval (CI) 1.127-15.346). Conclusions:Renal insufficiency is an independent predictor of in-hospital mortality for patients hospitalized with ASTEMI treated with primary PCI.     

Underestimation of Impaired Kidney Function with Serum Creatinine

Serum creatinine (SCr) levels are frequently used as a screening test to assess impaired renal function; however, patients can have significantly decreased glomerular filtration rate (GFR) with normal SCr values and making the recognition of kidney dysfunction more difficult. Hence, this study was designed to determine the extent of misclassification of the patients who have significantly reduced GFR as calculated by reexpressed four variable modification of diet in renal disease (MDRD) equation but, normal range of SCr. The study included 1040 in and out patients referred by physicians for serum creatinine measurement. When an exclusion criterion was applied 928 patients were qualified for the study. SCr was measured in 928 patients by a Roche kinetic compensated Jaffe’s assay. GFR was calculated using reexpressed four variable MDRD study equation. Of the 928 patients 270 (29.1%) had renal dysfunction on the basis of eGFR (<60 ml/min/1.73 m²). However, with SCr only 162 (17.5%) patients had abnormal renal function (>1.5 mg/dl) and SCr values misrepresented (108) 11.6% patients with impaired kidney function. In addition, more females, about 15% were failed to detect by SCr method in contrast to males of 9%. This study documented that, a large proportion of patients with impaired renal function are not diagnosed if clinicians rely solely on normal SCr as evidence of normal renal function. Inclusion of eGFR calculated by re-expressed 4 variable MDRD equation may facilitates the early identification and intervention of patients with renal impairment.     

Correlation of Microalbuminuria with Estimated GFR (eGFR) by Cockcroft–Gault and MDRD Formula in Type 2 Diabetics and Hypertensives

Increase in urine albumin excretion rate (AER) precede a fall in glomerular filtration rate in patients developing diabetic chronic kidney disease (CKD). Our results have shown that 7 (50 %) of diabetic and hypertensive individuals with decreased GFR do not have increased AER. In this cross-sectional study, we measured AER of 75 patients with type 2 diabetes and hypertension by immunoturbidimetric method. We correlated the results with eGFR values obtained by Cockcroft–Gault and MDRD method. The method used was not a compensated method. We measured serum creatinine by modified Jaffe’s kinetic method in autoanalyzer XL-600. Analysis of data showed positive correlation between eGFR and microalbuminuria by both the methods with eGFR <60 mL/min/1.73 m². Pearson’s correlation co-efficient (r) was 0.9 (p = 0.0001) by Cockcroft–Gault formula and 0.69 (p = 0.0063) by MDRD formula. Our results concluded that there was positive correlation between AER and eGFR <60 mL/min/1.73 m². We have recognized that these two parameters provide a complimentary benefit in management of cases with CKD.     

The Uncertainty of the eGFR

The estimated glomerular filtration rate (eGFR) is a parameter derived from the serum creatinine, patient age and gender and is used to ascertain renal function. It is subject to variation because of the analytical error of the creatinine measurement and biological variation. The widespread use of the eGFR to classify renal disease has led to the identification of more patients with marginal chronic kidney disease but because of the uncertainty of the eGFR it has also led to over-diagnosis of some kidney disease. There is a well described age relation with eGFR.The uncertainty of the eGFR at the critical decision level of 60 mL/min/1.73 m² is calculated to be 11. Caution needs to be exercised when interpreting an eGFR between 49 and 71 mL/min/1.73 m².     

Nonalcoholic fatty liver disease associated with impairment of kidney function in nondiabetes population

Background

Nonalcoholic fatty liver disease (NAFLD) is associated with the increased burden of kidney. However, there is still no large population study to explore the potential relationship between NAFLD and mild kidney function damage (MKFD) after adjusted for confounding factors. This study is to test the hypothesis that NAFLD is associated with MKFD under controlling the effects of confounding factors.

Materials and methods:

Levels of serum fasting glucose, creatinine, cholesterol, triglyceride, alanine aminotransferase and aspartate aminotransferase were analyzed from 1412 Chinese Han adults. Questionnaire and physical examination were performed to explore the potential association of NAFLD with kidney function.

Results:

NAFLD was associated with impairment of kidney function. Multivariate-adjusted odds ratio illustrated that, compared to subjects with normal liver, NAFLD subjects had a significantly higher risk of MKFD with or without adjusted for blood glucose and other covariates (P = 0.041). Further results from multi-interaction analysis demonstrated that the underlying mechanisms linked NAFLD with impaired kidney function may be that they share common risk factors and similar pathological processes.

Conclusions:

The most striking finding of this study is that NAFLD is negatively associated with kidney function, in nondiabetic population. NAFLD and MKFD may share similar risk factors and/or pathological processes.