Efficacy and Safety of Different Dose of Tirofiban in Interventional Treatment of Complex Coronary Artery Disease

Inclusion Criteria: * Patients were recruited from those undergoing PCI with a planned placement of an intracoronary stent * Including patients with unstable angina pectoris, acute coronary syndrome or NSTEMI * Experienced ischaemic pain at rest * Lasting 10 minutes and occurring within 7 days before enrollment * As well as one of the following: ECG changes: New or presumably new ST-segment depression greater than or equal to 0.1 mV (1 mm), or transient (\< 30 minutes) ST-segment elevation greater than or equal to 0.1 mV (1 mm) in at least 2 contiguous leads -Abnormal cardiac enzymes within the 24 hours before enrollment, defined as elevated Troponin I defined as elevated Troponin I (above the normal reference - * High-risk angiographic features :lesion/anatomy related bifurcation lesion, left main lesion, multiple vessel disease, intracoronary thrombus, SYNTAX score \> 26 and chronic total occlusion disease. Exclusion Criteria: * Increased bleeding risk: ischaemic stroke within the last year or any previous haemorrhagic stroke, tumour or intracranial aneurysm; * Recent (\<1 month) trauma or major surgery (including bypass surgery); * Active bleeding * Unexplained clinically significant bleeding, thrombocytopenia (platelet count \< 100 x 109/L) or history of thrombocytopenia with GP IIb/IIIa, heparin or enoxaparin therapy * Angina from secondary causes such as severe uncontrolled hypertension (systolic blood pressure \> 180 mm Hg despite treatment) * Valvular disease, congenital heart disease, hypertrophic cardiomyopathy, - Thrombolytic therapy within preceding 24 hours * Receiving antiIIb/IIIa therapy * Creatinine clearance of \<30 mL/min