Effect of Hydration Guided by Vigileo on the Prevention of CIN After PCI for Patients With AMI

Inclusion Criteria: * Clearly diagnosed STEMI or NSTEMI patients: * Patients aged 18-80 years * Patients are scheduled to undergo emergency percutaneous coronary interventions * Estimated glomerular filtration rate eGFR \<120ml / min (according to MDRD formula) * Sign the informed consent to join the group. Exclusion Criteria: * Patients with mechanical complications * Patients with cardiogenic shock * Patients with aortic dissection * Patients who have malignant tumors or short-term progressive diseases that researchers believe improper to be included in the group * Hemodialysis-dependent patients with end-stage renal failure * Patients who had a history of exposure to radioactive contrast media within 1 week before or 72 hours after direct PCI * Patients who are allergic to radioactive contrast agents * Patients diagnosed with right ventricular myocardial infarction with hypotension (defined as systolic blood pressure ≤90 mmHg) on admission.