A stepwise selection analysis (combining forward selection with backward elimination) was performed on the variables, and the results showed that age, NIHSS score, hyperlipidemia, hyperhomocysteinemia, cardiac insufficiency, CRP, WBC, NE%, Hb, FBG, PA, BNP, and Na+ were independent influencing factors for the occurrence of AP in PSD patients (P < 0.05), as shown in Table 1. This evidence concerns the gene NPPB and hyperhomocysteinemia.