Does preoperative homocysteine level influence the kidney functions after coronary artery bypass grafting?

Elevated homocysteine (Hcy) has been linked to endothelial dysfunction and adverse cardiovascular outcomes. However, its specific role as a risk factor for postoperative complications, especially acute kidney injury (AKI), in patients undergoing coronary artery bypass grafting (CABG), remains insufficiently defined. What’s more we took into consideration presence of diabetes mellitus as an independent risk factor of AKI or the exacerbation of pre-existing chronic kidney disease (CKD), what can modify the prevalence of this complication.

We conducted a prospective analysis of 66 patients (27 with T2DM, 39 controls) who underwent elective CABG with extracorporeal circulation. The study population consisted mainly of men (82,5%), the median age was 69 years. The majority of patients had preserved good left ventricle function. The primary outcome was the occurrence of postoperative AKI or the exacerbation of pre-existing CKD after CABG. We also analyzed the correlation of preoperative homocysteine level with perioperative myocardial injury, infections, neurological or respiratory complications. Clinical, biochemical, and postoperative data were collected for all participants. Spearman’s correlation assessed associations between Hcy and laboratory parameters, while univariable and multivariable logistic regression examined relationships with complications.

Preoperative median Hcy levels were similar in T2DM patients and controls (12.6 vs. 12.1 µmol/L, p = 0.24). In the total cohort, Hcy showed positive correlations with triglycerides (r = 0.39, p = 0.0018), C-peptide (r = 0.33, p = 0.0086), and CRP (r = 0.29, p = 0.0210), and a negative correlation with HDL cholesterol (r = − 0.31, p = 0.0149). Higher Hcy levels were significantly associated with acute kidney injury (AKI) or exacerbation of chronic kidney disease (CKD) after CABG (b = 7.14, SE = 2.11, b⁎ = 0.40, p = 0.0013).

Elevated preoperative Hcy levels were associated with postoperative renal complications after CABG. Therefore, Hcy may serve as a potential biomarker of AKI or exacerbation of CKD after CABG.