Abstract: AIM To plasminogen activator inhibitor-1; acute myocardial infarction; coronary artery; thrombus; fibrinolytic systemanalyze the relationship between plasminogen activating inhibitor 1 (PAI-1) and acute myocardial infarction (AMI) in patients with coronary artery thrombosis after thrombolytic therapy and explore its clinical significance. METHODSLogistic linear regression analysis was conducted in 41 AMI patients with coronary artery thrombosis who were treated with thrombolytic therapy and 40 healthy controls. Plasma PAI-1 levels were recorded before and after thrombolysis in AMI patients and compared with those in control group. RESULTSCompared with the control group, plasma PAI-1 levels in AMI patients were significantly higher than those in control group (P<0.05). In AMI patients, plasma PAI-1 levels 0.5 h and 1 h after thrombolysis were higher but with no statistical significance compared with those before thrombolysis, whereas plasma PAI-1 levels 1.5 h and 2 h after thrombolysis were significantly higher than before thrombolysis (P<0.05). Plasma PAI-1 levels in patients with coronary recanalization 2 h after thrombolysis were significantly lower than in patients without coronary recanalization (P<0.05). CONCLUSIONPlasma PAI-1 levels gradually decrease within 2 h after thrombolysis, which is related to coronary recanalization.