Renal filtration function and early complications after elective coronary artery bypass grafting

Purpose to study the early postoperative complications (EPOCs) depending on the renal filtration function in patients with chronic coronary syndrome (CCS) after elective surgical revascularization. Methods We enrolled 595 consecutive CCS patients (mean age 61±8 years, 508 (85,4 %) males), undergoing isolated coronary artery bypass grafting (CABG). Renal filtration function was calculated by estimated glomerular filtration rate (eGFR) (by CKD-EPI). According to the baseline eGFR value, patients were separated into 3 groups: ≥90 ml/min/1,73 m2 (G1; n=100 [16,8 %]); 60-89 ml/min/1,73 m2 (G2; n=346 [58,2 %]); and <60 ml/min/1,73 m2 (G3; n=149 [25,0 %]). We analyzed perioperative clinical and instrumental data, and EPOCs cases. Totally, EPOCs were registered in 111 (18,7 %) patients. Results G3 was characterized by older age (median, interquartile range: 65 [60-71] years vs. 54 [49-60] years in G1 [p˂0,001] and 62 [56-67] years in G2 [p˂0,001]), higher frequency of females (29,5 % vs. 5,0 % in G1 [p˂0,001] and 11,0 % in G2 [p˂0,001]), atrial fibrillation (17,4 % vs. 4,0 % in G1 [p=0,004] and 8,1 % in G2 [p=0,022]), history of repeated myocardial infarction (vs. [G1+G2]: 22,8 % vs. 13,7 %, respectively; p=0,014), left ventricular systolic dysfunction (vs. [G1+G2]: 35,6 % vs. 24,7 %, respectively; p=0,011), and 3-vessel disease (vs. [G1+G2]: 85,9 % vs. 76,2 %, respectively; p=0,015). EPOCs were more prevalent in G3 (36,9 % vs. 8,0 % in G1 [p˂0,001]; numerically, but non-significantly – vs. 17,9 % in G2 [p=0,082]), namely due to the higher frequency of acute kidney injury (16,8 % vs. 3,0 % in G1 [p=0,002] and 7,5 % in G2 [p=0,020]). Acute postoperative heart failure tended to be more frequent in G3 (vs. [G1+G2]: 12,1 % vs. 7,3 %, respectively; p=0,091). Consequently, the perioperative profile of G3 patients included longer inotropic support and intensive care unit stay. Conclusion The baseline impairment of renal filtration in patients undergoing isolated CABG prolongs the time of intensive care and worsens perioperative profile due to the higher frequency of EPOCs.