This observational study includes patients at medium-to-high cardiovascular risks undergoing major noncardiac surgery, measures their baseline demographic and clinical characteristics, preoperative cardiac biomarkers and intraoperative surgery/anesthesia related data, and screens them for the occurrence of myocardial injury and major adverse cardiac events after surgery. The primary aim is to develop and validate a pre- and an immediate postoperative prediction model for occurrence of major adverse cardiac events.

Inclusion Criteria:

• Age ≥ 45 years;
• Undergoing major noncardiac surgery (expected procedure duration ≥2 h, expected length of postoperative stay ≥2 d);
• History of at least one cardiovascular disease (i.e., coronary artery disease, stroke, congestive heart failure, or peripheral arterial disease) or with at least two cardiovascular risk factors (i.e., hypertension, diabetes, chronic kidney disease, smoking in the past ≥2 years, ≥65 years of age, hypercholesterolemia, history of TIA, high-risk surgery (intrathoracic, intraperitoneal, or major vascular)).

Exclusion Criteria:

• History of acute cardiovascular events within 30 days prior to surgery;
• American Society of Anesthesiologists (ASA) physical status of 5 or greater;
• Previously enrolled in this study;
• Unable to understand or to sign informed consent.

Patients undergoing major noncardiac suregry with medium-to-high risks for postoperative cardiac complications.