Admission free-fatty acid level is a predictor of the mid-term worsening renal function in patients with ST-segment elevation myocardial infarction

Whether free fatty acids (FFAs), which are generators of reactive oxygen species and substrates of cytotoxic lipid peroxidation products in proximal tubules of the kidney, can be a predictor of worsening renal function (WRF) is not fully elucidated. A total of 110 patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention within 24 h after symptom onset were included. The exclusion criteria were out-of-hospital cardiac arrest, vasospastic angina, hemodialysis, and/or lack of data. FFAs and serum cystatin C were measured on admission, and urinary liver-type fatty acid-binding protein (L-FABP) was measured 3 h after admission. WRF, defined as an increase in serum creatinine by ≥ 0.3 mg/dL for 2-year follow-up, was observed in 16 patients (15%). A multivariate logistic regression analysis (a stepwise algorithm) revealed that the FFA level was an independent predictor of WRF (P = 0.024). The FFA level was associated with WRF adjusted after serum cystatin C (odds ratio [OR]: 1.378 per 1 mEq/L, P = 0.017), L-FABP (OR: 1.370 per 1 mEq/L, P = 0.016), or the Mehran contrast-induced nephropathy (CIN) risk score (OR: 1.362 per 1 mEq/L, P = 0.021). The FFA level was inversely associated with the change in estimated glomerular filtration rate level for 2 years (R2 = 0.051, P = 0.018). The FFA level on admission was associated with the mid-term WRF in patients with STEMI.