Using GAM and smooth curve fitting while adjusting for various covariates, including sex, age, HDL-c, BMI, LDL-c, HGB, PLT, TG, ALB, BUN, hypertension, DM, smoking, AF, and mRs scores at admission, we observed a nonlinear association between fibrinogen levels in patients with AIS and the risk of unfavorable outcomes(P for log-likelihood ratio test = 0.047) (Fig. 2). This evidence concerns the gene CYGB and atrial fibrillation.