Comparison between three different equations for the estimation of glomerular filtration rate in predicting mortality after coronary artery bypass

Race-modified estimated glomerular filtration rate underestimates chronic kidney disease prevalence in Black patients undergoing partial and radical nephrectomy: Implications for surgical planning

Introduction

In estimated glomerular filtration rate equations (eGFR), the race multiplier (RM) yields greater eGFR values and may assign less severe chronic kidney disease (CKD) stages to black individuals. When deciding on appropriateness for partial nephrectomy (PN), patients with CKD are often considered a relative or absolute indication. We hypothesize that the eGFR RM may have ramifications for patients being counseled for radical nephrectomy (RN) versus PN to manage their renal tumor.

Methods

We utilized prospective and retrospective, IRB-approved single-center databases to select patients who underwent PN or RN between 2016 and 2022. Demographics, preoperative risk factors, preoperative eGFR, and surgical management were collected. Descriptive statistics and two-tailed difference of proportion tests compared the percentage of patients with CKD who underwent nephrectomy.

Results

This cohort included 1137 patients who underwent RN or PN, including 74 (6.5%) Black patients and 93.5% (n = 1063) non-Black patients. There was no statistically significant difference between the eGFR of Black and non-Black individuals using the Modification of Diet in Renal Disease equation (P = 0.24) or Chronic Kidney Disease Epidemiology Collaboration 2009 (CKD-EPI 2009) (P = 0.45); however, there was statistically significant difference in eGFR between sample populations when using CKD-EPI 2021 (P = 0.0055). Of the Black patient cohort, 16.2% of patients reclassified to a worse CKD class using CKD-EPI 2021, including 9.5% of Black patients reclassified to CKD3a or worse, and 14.6% of all patients (Black and non-Black) reclassified to a different CKD class under the CKD-EPI 2021 equation.

Conclusions

There are quantitative differences in the evaluation of eGFR when utilizing different equations that may impact clinical considerations and health equity outcomes for nephrectomy across racial groups.

Evaluation of Six eGFR Equations in Predicting Acute Kidney Injury in Patients after Off-Pump Coronary Artery Bypass Grafting: A Case Control Study

Background

There are six widely used equations to calculate the estimated glomerular filtration rate (eGFR) of patients. We aimed to assess the predictive power of preoperative eGFR calculated by these equations for the occurrence of postoperative acute kidney injury (AKI).

Methods

Patients who underwent isolated coronary surgery from January 2016 to January 2021 were continuously enrolled. Serum creatinine and cystatin C used to calculate eGFR were both measured within 1 week before surgery. The eGFR was calculated using six equations: Cockcroft Gault (CG) equation, Chinese abbreviated modification of diet in renal disease (MDRD) equation, chronic kidney disease-epidemiology (CKD-EPI) equation, and full age spectrum (FAS) equation. Postoperative AKI was diagnosed by Kidney Disease Improving Global Outcomes criteria (KDIGO) (① urine volume < 0.5 mL/kg/h for 6 h; ② an increase in serum creatinine by ≥ 26.5 µmol/L within 48 h; ③ an increase in serum creatinine to ≥ 1.5 times baseline levels, which is known or presumed to have occurred within the prior 7 days), and the occurrence of AKI within 7 days after surgery was followed.

Results

A total of 1428 patients were included, of which 319 patients (25.5%) developed postoperative AKI. After adjustment, all eGFRs (CG OR = 0.983, MDRD OR = 0.983, CKD-EPI crea OR = 0.97, CKD-EPI cys OR = 0.955, FAS crea OR = 0.978, FAS cys OR = 0. 941, all p < 0.001) were significantly associated with AKI. The area under the receiver operating characteristic curve (AUC) was 0.621 for CG, 0.614 for MDRD, 0.643 for CKD-EPI crea , 0.739 for CKD-EPI cys , 0.643 for FAS crea , 0.744 for FAS cys , respectively. There was no difference in predictive power between FAS cys and CKD-EPI cys (p = 0.33, DeLong's test).

Conclusions

Preoperative eGFR calculated by FAS cys and CKD-EPI cys equations have better performance in predicting AKI after off-pump coronary artery bypass grafting than other equations.

Donor Evaluation of Living Kidney Transplantation in the Aging Society

BACKGROUND

Because of the lack of organ donation, living kidney transplantation (LKT) is increasing worldwide. Recently, the number of elderly donors has been increasing, and the patients with end-stage kidney diseases are older than those in the previous decades. Due to the advanced ages, their glomerular filtration rates (GFR) decrease, and the comorbidities such as hypertension, diabetic condition, and obesity are common. The clinicians now have to give their unwilling consent to the LKT from the donors with expanded criteria.

SUMMARY

For the secure selection of donors, proper GFR measuring is essential. Although directly measured GFR (mGFR) was recommended in the guidelines, estimated GFR (eGFR) is used at the initial evaluation of donor renal function clinically. Many equations calculating eGFR have been published so far. In the selection of eGFR equations, the smaller difference between mGFR and eGFR and the closer relationship to the prevalence rates of comorbidities are requisite points. Therefore, we compared the specificity of the various eGFR equations. The eGFR calculated from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation showed approximate reliability with minimal difference between mGFR and eGFR and the closer relationships to the prevalence rates of comorbidities.

KEY MESSAGE

The CKD-EPI-eGFR presented optimal performance in the donor renal function evaluation. Therefore, eGFR from the CKD-EPI equation is highly recommended in evaluating renal function in LKT donors.

Preoperative renal insufficiency predicts postoperative adverse outcomes in a mixed surgical population: a retrospective matched cohort study using the NSQIP database

BACKGROUND

The incidence of chronic kidney disease is increasing, but most cases are not diagnosed until the accidental finding of abnormal laboratory data or the presentation of severe symptoms. Patients with chronic kidney disease are reported to have an increased risk of postoperative mortality and morbidities, but previous studies mainly targeted populations undergoing cardiovascular surgery. The authors aimed to evaluate the risk of postoperative mortality and complications in a surgical population with preoperative renal insufficiency (RI).

MATERIALS AND METHODS

This retrospective cohort study used data from the National Surgical Quality Improvement Program database between 2013 and 2018 to evaluate the risk of postoperative morbidity and mortality in the surgical population. Patients with estimated glomerular filtration rate less than 60 ml/min/1.73 m 2 were defined as the RI group. Propensity score matching methods and multivariate logistic regression were used to calculate the risk of postoperative morbidity and mortality.

RESULTS

After propensity score matching, 502 281 patients were included in the RI and non-RI groups. The RI group had a higher risk of 30-day in-hospital mortality (odds ratio: 1.54, 95% CI: 1.49-1.58) than the non-RI group. The RI group was associated with a higher risk of postoperative complications, including myocardial infarction, stroke, pneumonia, septic shock, and postoperative bleeding. The RI group was also associated with an increased risk of prolonged ventilator use for over 48 h, readmission, and reoperation.

CONCLUSION

Patients with preoperative RI have an increased risk of postoperative 30-day mortality and complications. RI group patients with current dialysis, estimated glomerular filtration rate less than or equal to 30 ml/min/1.73 m 2 or concomitant anemia had an elevated risk of postoperative mortality.

Coronary Artery Bypass Grafting in Patients with Chronic Kidney Disease: Chronic Kidney Disease Has an Independent Adverse Effect on the Long-Term Outcome of Coronary Artery Bypass Grafting

We examined short- and long-term outcomes of coronary artery bypass grafting (CABG) in patients with ischemic heart disease and the effect of renal function on these outcomes. We included 2783 patients who underwent primary elective CABG at a single institution between 2002 and 2020 (age: 67.6 ± 10.2 years; male: 2281 male). They were stratified based on their preoperative estimated glomerular filtration rate and underwent off-pump CABG (completion rate, 98.1%); 57.6% cases used bilateral internal thoracic arteries (BITA). In-hospital mortality rate was 1.0%. Logistic regression analysis revealed that low left ventricular function (<40%), but not chronic kidney disease (CKD) severity, was an independent predictive risk factor for postoperative hospital mortality. Significant differences existed in respiratory complications, infections, and hospitalization duration according to CKD severity. Deep sternal wound infection rate was 0.5%. The mean follow-up period was 7.1 (0–18.5) years. Estimated 10-year survival rates were negatively correlated with CKD severity; in the Cox hazard model, severe CKD was an independent predictor of long-term survival. We examined the relationship between preoperative and intraoperative factors and their effects on long-term survival using propensity score matching by dividing the renal function severity into G1–2 and G3–5. Renal function severity, age, and operative time were independent risk factors. No prognostic improvement was observed with BITA grafts; graft patency was superior in the right internal thoracic artery (52/52; 100%) than in the great saphenous vein (48/59; 81.4%) in G5. Post-CABG in-hospital mortality was unrelated to renal function, but CKD severity strongly influenced long-term survival. Operation time was an important predictor of long-term prognosis in patients with impaired renal function. Treatment plans, including graft and anastomosis-site selections, should be designed to shorten the operation time. In conclusion, using the right internal thoracic artery in CABG is more beneficial in patients with CKD and cardiovascular comorbidities.

Impact of glomerular filtration rate estimation on cardiovascular events in elderly patients undergoing coronary angiography

BACKGROUND

Estimation of kidney function by glomerular filtration rate (eGFR) is affected by age and is important for decision making regarding treatment and prognosis of patients with cardiovascular disease. We investigated the impact of eGFR on long-term cardiovascular outcomes in an elderly population undergoing coronary angiography for evaluation or treatment of coronary artery disease.

METHODS

GFR was estimated according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in 3690 elderly patients (aged 70-100 years) undergoing coronary angiography. Patients receiving maintenance dialysis were excluded. The association between eGFR and major adverse cardiovascular events (MACE) including myocardial infarction, ischemic stroke or death, was investigated. GFR was further calculated according to modification of diet in renal disease (MDRD) and the Cockcroft-Gault equations, and compatibility between estimations was analyzed.

RESULTS

Cardiovascular comorbidities were more prevalent with the reduction in kidney function as was the proportion of patients presenting with acute coronary syndromes. The adjusted hazard ratio (95% confidence interval) for MACE during a mean follow-up of 5 years was 0.95 (0.77-1.16), 1.04 (0.84-1.29), 1.56 (1.16-1.84), 2.22 (1.65-2.97) and 3.74 (2.20-6.38) in patients with eGFR 60-89, 45-59, 30-44, 15-29 and <15 ml/min/1.73m2, respectively, compared to >90 ml/min/1.73m2. Reclassification of eGFR stages by MDRD (upward 23.8%, downward 0.4%) and Cockcroft-Gault (upward 4.3%, downward 28.1%) compared to CKD-EPI estimation, was noted. However, the association between eGFR stages and MACE was similar between equations.

CONCLUSIONS

Kidney function, as manifested by eGFR, has a graded inverse association with the burden of cardiovascular comorbidities and long-term adverse events in elderly patients undergoing coronary angiography.

The Modified Chronic Kidney Disease Epidemiology Collaboration Equation for the Estimated Glomerular Filtration Rate Is Better Associated with Comorbidities than Other Equations in Living Kidney Donors in Japan

Objective We studied three types of estimated glomerular filtration rate (eGFR) equations and evaluated which type was strongly associated with comorbidities in living kidney transplantation (LKT) donors. Methods We compared the Japanese modified eGFR, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equations (Jm-eGFR, Jm-MDRD, and Jm-CKD-EPI, respectively) for Japanese LKT donors with respect to their relationships with obesity, hypertension, diabetes, cardiovascular disease, and stroke. Results Of the 8,176 enrolled Japanese LKT donors, the eGFR calculated using Jm-CKD-EPI (eGFR/Jm-CKD-EPI) detected significant differences in 4 of 5 comorbidities between the comorbidity-positive and comorbidity-negative groups, whereas the eGFR calculated using Jm-MDRD (eGFR/Jm-MDRD) and Jm-eGFR (eGFR/Jm-eGFR) detected only 3 and 1 comorbidities, respectively. The area under the receiver operating characteristic curve of Jm-CKD-EPI was larger than those of Jm-eGFR and Jm-MDRD for all five comorbidities. Conclusion We found that the eGFR/Jm-CKD-EPI correlated better with comorbidities than the eGFR/Jm-eGFR and eGFR/Jm-MDRD in Japanese LKT donors. We recommend using the eGFR/Jm-CKD-EPI for the initial assessment of the renal function in LKT donor candidates when evaluating the presence of associated comorbidities.