Objective To investigate the relationship between myocardial microcirculation perfusion and the levels of B-type natriuretic peptide (BNP), C-reactive protein (CRP), and atherosclerotic index of plasma (AIP) in patients with recurrent angina pectoris after percutaneous coronary intervention (PCI) in acute myocardial infarction.Methods This study adopted a retrospective approach and selected 120 patients with acute myocardial infarction who underwent PCI treatment at our hospital from June 2020 to June 2023 as the research subjects. They were divided into a recurrence group (n=32) and a non recurrence group (n=88) based on whether angina recurred during the one-year follow-up. Compare the general information of two groups of patients, including postoperative coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) levels, preoperative BNP, CRP, and AIP levels. Use Spearman correlation analysis to investigate the relationship between angina recurrence after PCI and CFR and IMR levels, and use Pearson correlation analysis to investigate the relationship between CFR and IMR levels and BNP, CRP, and AIP levels.Results The proportion of patients with preoperative Killip grade (>Grade II) in the recurrence group (53.12%) was higher than that in the non recurrence group (29.55%), and the difference was statistically significant (P<0.05), The CFR level in the recurrent group was (2.92 ± 0.77) lower than that in the non recurrent group (3.51 ± 0.34), and the IMR level was (32.52 ± 6.68) U higher than that in the non recurrent group (21.27 ± 8.01) U, with statistical significance (P<0.05), The levels of BNP, CRP, and AIP in the recurrent group were (955.14 ± 162.27) ng/L, (8.95 ± 1.43) mg/L, and (0.21 ± 0.06), all higher than those in the non recurrent group (585.55 ± 66.73) ng/L, (6.21 ± 1.52) mg/L, and (0.15 ± 0.03), with statistical significance (P<0.05), Spearman correlation analysis showed that the recurrence of angina pectoris after PCI was negatively correlated with CFR levels (r=-0.394, P<0.05) and positively correlated with IMR levels (r=0.553, P<0.05). Person correlation analysis showed that CFR levels were negatively correlated with BNP, CRP, and AIP levels (r=-0.389, P<0.05), r=-0.211,r=-0.249, The levels of IMR were positively correlated with BNP, CRP, and AIP levels (r=0.460, r=0.595,r=0.303, All P<0.05).Conclusion There is a correlation between the recurrence of angina pectoris after PCI and myocardial microcirculation perfusion, and CFR levels are negatively correlated with BNP, CRP, and AIP levels, while IMR levels are positively correlated with BNP, CRP, and AIP levels.