Acute kidney injury following coronary artery bypass grafting and control angiography: a comprehensive analysis of 221 patients

Postoperative acute kidney injury increases short- and long-term death risks in elderly patients (≥ 75 years old) undergoing coronary artery bypass graft surgery

PURPOSE

To explore the incidence of postoperative acute kidney injury (AKI) after coronary artery bypass grafting (CABG) in elderly Chinese patients (≥ 75 years old) and its impacts on the short- and long-term prognosis.

METHODS

A total of 493 patients aged 75-88 years old who underwent CABG from two medical centers between January 2006 and October 2021 were involved. Perioperative (preoperative and 7 days after operation) serum creatinine (Scr) levels were measured in all the enrolled patients. Univariate and multivariate logistic regression analyses were conducted to explore the independent risk factors of postoperative in-hospital mortality. Kaplan-Meier curves and COX model were used to test the risk factors of all-cause death during follow-up. Propensity score matching was used to balance differences between AKI and control groups. The primary outcome event was in-hospital death, and the secondary outcome was all-cause death during follow-up.

RESULTS

The 198 patients were diagnosed with postoperative AKI. Intra-aortic balloon pump (IABP), cardiopulmonary bypass, and postoperative AKI were independent risk factors of in-hospital death. Gender, New York Heart Association Classification, preoperative eGFR, last eGFR within 7 days after operation, postoperative AKI, and postoperative renal function all impacted long-term prognosis. After 1:1 matching, 190 patients were included in the AKI and control groups. Use of IABP, use of cardiopulmonary bypass, and occurrence of postoperative AKI were still independent risk factors of in-hospital death. Preoperative eGFR, last eGFR within 7 days after operation, postoperative AKI and postoperative renal function all impacted long-term prognosis.

CONCLUSION

The incidence of postoperative AKI in elderly patients undergoing CABG is high, and postoperative AKI is an independent risk factor of both short- and long-term postoperative prognosis.

The association between serum anion gap and acute kidney injury after coronary artery bypass grafting in patients with acute coronary syndrome

BACKGROUND

The purpose of this study was to explore the association between serum anion gap (SAG) and acute kidney injury (AKI) after coronary artery bypass grafting (CABG) in patients with acute coronary syndrome (ACS) in the Intensive Care Unit (ICU).

METHODS

We retrospectively analyzed the clinical data of 2,428 ACS patients who underwent CABG in the Medical Information Mart for Intensive Care IV (Mimic-IV) database. The endpoint of this study was AKI after CABG. The baseline data of the two groups (non-AKI group vs. AKI group) was compared, and the restricted cubic spline (RCS) plot, multivariable logistic regression model, and subgroup analysis were used to explore the relationship between SAG and the risk of AKI after CABG.

RESULTS

In the adjusted multivariate logistic regression model, SAG was an independent predictor of AKI after CABG (OR = 1.12, 95% CI: 1.02-1.23, P = 0.015). The RCS revealed that the relationship between SAG levels and risk of AKI was J-shaped. When the SAG was ≥ 11.58 mmol/L, the risk of AKI increased by 26% for each unit increase in SAG. Additionally, we further divided the SAG into quartiles. In the fully adjusted model, compared with the first quartile of SAG, the odds ratios (ORs) and 95% confidence intervals (CIs) for AKI risk across the SAG quartiles were 0.729 (0.311, 1.600), 1.308 (0.688-2.478), and 2.221 (1.072, 4.576).

CONCLUSIONS

The SAG level was associated with the risk of AKI after CABG in a J-shaped curve in the ICU. However, the underlying causes of the problem need to be investigated.

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.