Cardiorenal syndrome in the early stages of coronary bypass surgery.

Aim: Evaluate the frequency and risk factors of postoperative atrial fibrillation (pAF) in patients with chronic coronary artery disease (CHD) with acute kidney injury (AKI) developed in connection with coronary artery bypass grafting (CABG).
Materials and Methods: The study involved 90 patients (pts) undergoing CABG at age 58±7 years, duration of CHD - 6±6 years. 80% of pts had previous myocardial infarction. Chronic heart failure, functional class II was detected in 53.3% pts, functional class III - in 46.7% pts. Multi-vessel coronary lesions had 75.6% pts. CABG with cardiopulmonary bypass was performed in 88.9% pts, operation on a beating heart was fulfilled in 11.1% pts. Creatinine was determined by Jaffe method, the glomerular filtration rate (GFR) was calculated with the СКD-EPI formula. AKI was diagnosed according to KDIGO criteria, 2012.
Results: The frequency of transient AKI after CABG was 33.3%, pAF - 17.8 %, pAF among those with AKI was 20%. The development of AKI was associated with higher levels of troponin T after CABG (Me [25; 75 percentiles] - 0.36 [0.24; 0.99] versus 0.28 [0.11; 0.50] ng/ml; p=0.037), with more frequent use of inotropic drugs (60% and 25%; p=0.002), longer duration of inotropic therapy (2.0 [1.0; 2.5] versus 1.0 [0; 1.0] days; p=0.001). The proportion of patients who had pAF among those with AKI and without it were not significantly different (20% and 16.7%; p=0.7). Decrease in GFR less than 39 [29.8; 45.7] ml/min/1.73 m2 after CABG was the most important risk factor of pAF in pts with CHD and AKI.