All patients undergoing non-cardiac surgery who met the inclusion criteria underwent a preoperative evaluation using specific assessment tools.

Following surgery, patients were closely monitored in the intermediate care unit for the first 24 hours for the development of acute myocardial infarction (AMI). AMI was diagnosed based on the presence of chest pain, elevated cardiac biomarkers, and specific electrocardiogram (ECG) and echocardiogram findings.

Inclusion Criteria:

• Patients older than 45,
• Patients of ASA-PS grade II-IV,
• Patients who prepared for non-cardiac surgeries of SSS of II-IV,
• Patients free of exclusion criteria,
• Patients signed the written consent for the study precipitation.

Exclusion Criteria:

• Patients of ASA-PS grade I or V,
• Patients younger than 60 years,
• Patients planned to undergo surgeries of SSS >IV,
• Patients were severely frail with CFS>6,
• Patients had abnormal preoperative electrocardiography (ECG),
• Patients had a history of previous major cardiac or cerebrovascular events,
• Patient had disturbed cognitive function, coagulopathy, severe anemia with hemoglobin concentration (HBC) < 7 gm/dl.

All patients assigned for non-cardiac surgeries who fulfilled the inclusion criteria underwent preoperative evaluation using the assessment tools. All patients were admitted to the intermediate care unit for the 1st 24-h PO for follow-up for the possibility of developing acute myocardial infarction (AMI), which was diagnosed according to the 2017 ESC Guidelines and was differentiated as STEMI and NSTEMI.