Elevated glycosylated hemoglobin levels are associated with severe acute kidney injury following coronary artery bypass surgery.

BACKGROUND: Diabetic patients are at increased risk of acute kidney injury (AKI) following surgery. The significance of uncontrolled diabetes on kidney function after coronary artery bypass grafting (CABG) remains controversial. Our aim was to study the association between pre-operative hemoglobin A1c (HbA1c) and severe cardiac surgery-associated AKI (CSA-AKI) following CABG. METHODS: A single-center, retrospective cohort study including patients who underwent isolated CABG from 2010 to 2018 was performed. Patients were grouped into pre-operative HbA1c of <6.5 %, 6.5-8.5 %, and ≥8.5 %. Postoperative serum creatinine levels were queried for up to 30 days, and the 30-day risk of severe AKI was compared among groups. Multivariable logistic regression was used to study factors associated with severe CSA-AKI and the association of severe CSA-AKI with postoperative outcomes. Cox regression was used to study the association between severe CSA-AKI and all-cause mortality from the time of surgery to the last follow-up or death. RESULTS: A total of 2424 patients met the inclusion criteria. Patients were primarily male (70.5 %), with a median age of 64 years (IQR 57-71). Median bypass and cross-clamp times were 95 (IQR 78-116) and 78 min (IQR 63-95). Severe CSA-AKI occurred within 30 days in 5.7 %, 6.7 %, and 9.1 % of patients with pre-op HbA1c of <6.5 %, 6.5-8.5 %, and ≥8.5 %, respectively. After adjusting for covariates, HbA1c >8.5 %, was independently associated with severe CSA-AKI 30 days after CABG (aOR 1.59, 95%CI 1.06-2.40). In addition, severe CSA-AKI was associated with increased 30- (aOR 15.83,95%CI 7.94-31.56) and 90- day mortality (aOR 9.54, 95%CI 5.46-16.67), prolonged length of stay (aOR 3.46,95%CI 2.41-4.96) and unplanned 30-day readmission (aOR 2.64, 95%CI 1.77-3.94). Lastly, severe CSA-AKI was associated with increased all-cause mortality (aHR 3.19, 95%CI 2.43-4.17). CONCLUSION: Elevated preoperative HbA1c (≥8.5 %) was independently associated with an increased 30-day risk of severe CSA-AKI, which is a consistent predictor of adverse outcomes after CABG. Delaying surgery to achieve optimal glycemic control in an elective setting may be reasonable.

Perioperative Cardiometabolic Targets and Coronary Artery Bypass Surgery Mortality in Patients With Diabetes.

Background Coronary artery bypass graft (CABG) surgery represents the preferred revascularization strategy for most patients with diabetes and multivessel disease. We aimed to evaluate the role of optimized, perioperative cardiometabolic targets on long-term survival in patients who underwent CABG. Methods and Results Single-institution retrospective study was conducted in patients with diabetes who underwent CABG between January 2010 and June 2018. Demographic, surgical, and cardiometabolic determinants were identified during the perioperative period. Clinical characteristics and longitudinal survival outcomes data were obtained. A total of 1534 patients with CABG were considered for analysis and 1273 met inclusion criteria. The mean age of patients was 63.3 years (95% CI, 62.7-63.8 years), and most were men (65%) and Hispanic or Latino (47%). Comorbidities included hypertension (95%) and dyslipidemia (88%). In total, 490 patients (52%) had a low-density lipoprotein cholesterol level >70 mg/dL. Furthermore, 390 patients (31%) had uncontrolled systolic blood pressure >130 mm Hg. Last, only 386 patients (29%) had a hemoglobin A1c level between 6% and 7%. At 5 years, 121 patients (10%) died. Failure to achieve goal systolic blood pressure was associated with all-cause (hazard ratio [HR], 1.573; 95% CI, 1.048-2.362 [P=0.029]) and cardiovascular (HR, 2.023; 95% CI, 1.196-3.422 [P=0.009]) mortality at 5 years post-CABG. In contrast, prescription of a statin during the perioperative interval demonstrated a protective effect for all-cause (HR, 0.484; 95% CI, 0.286-0.819 [P=0.007]) and cardiovascular (HR, 0.459; 95% CI, 0.229-0.920 [P=0.028]) mortality. There was no association between achievement of low-density lipoprotein cholesterol, triglycerides, non-high-density lipoprotein cholesterol, or hemoglobin A1c level goals and mortality risk at 5 years. Conclusions Among patients with diabetes, blood pressure control and statin therapy were the most important perioperative cardiometabolic survival determinants 5 years after CABG.