The association between serum free fatty acid levels and neurological outcomes in out-of-hospital cardiac arrest patients: A prospective observational study

Abstract

Free fatty acids (FFA) are a known risk factor in the development of sudden cardiac death. However, the relationship between FFA and the outcome of out-of-hospital cardiac arrest (OHCA) patients remains unclear. We aimed to examine the association between FFA and neurological outcomes in OHCA patients. This prospective observational study included adult (≥18 years) OHCA patients between February 2016 and December 2022. We measured serial FFA levels within 1 hour after ROSC and at 6, 12, 24, 48, and 72 hours after the return of spontaneous circulation (ROSC). The primary outcome was neurological outcome at 6 months. A poor neurological outcome was defined by cerebral performance categories 3, 4, and 5. A total of 147 patients were included. Of them, 104 (70.7%) had poor neurological outcomes, whereby the median FFA levels within 1 hour after ROSC (0.72 vs 1.01 mol/L), at 6 hours (1.19 vs 1.90 mol/L), 12 hours (1.20 vs 1.66 mol/L), and 24 hours (1.20 vs 1.95 mol/L) after ROSC were significantly lower than in good outcome group. The FFA levels at 6 hours (odds ratio, 0.583; 95% confidence interval, 0.370-0.919; P = .020), and 12 hours (odds ratio, 0.509; 95% confidence interval, 0.303-0.854; P = .011) after ROSC were independently associated with poor neurological outcomes. The lower FFA levels at 6 hours and 12 hours after ROSC were associated with poor neurological outcomes in patients with OHCA. FFA may reflect oxidative metabolism as well as oxidative stress.