Clinical Research Directory

Inclusion Criteria: * Scheduled for or undergoing elective, urgent, or emergency major abdominal surgery (pancreatectomy, liver resection, gastrectomy, colorectal surgery, or emergency laparotomy) with expected duration \>= 2 hours or major visceral resection. * Possessing established or potential cardiovascular risk defined by meeting AT LEAST ONE of the following: * Age \>= 65 years; OR * Age 45 to 64 years with at least one documented cardiovascular risk factor or comorbidity: documented coronary artery disease, congestive heart failure, prior ischemic stroke or TIA, peripheral arterial disease (resting ABI \<= 0.90), diabetes mellitus requiring treatment, arterial hypertension, dyslipidemia/hypercholesterolemia, active cigarette smoking, overweight/obesity (BMI \>= 25 kg/m\^2), family history of premature cardiovascular disease, unexplained cardiac signs/symptoms, chronic obstructive pulmonary disease (COPD), baseline chronic renal impairment (eGFR \< 60 mL/min/1.73m\^2 or serum creatinine \> 177 umol/L), or Revised Cardiac Risk Index (RCRI) \>= 2 points. * Signed Informed Consent Form permitting electronic medical record (EMR) data extraction and participation in a 30-day follow-up telephone interview. Exclusion Criteria: * Active acute myocardial infarction or acute coronary syndrome within 30 days prior to the index surgical procedure. * End-stage renal disease (ESRD) on maintenance hemodialysis or peritoneal dialysis. * Intraoperative mortality or death within the first 24 hours postoperatively due to acute massive surgical exsanguination. * Incomplete postoperative troponin testing protocol (missing both 24h and 48h postoperative blood samples). * Patient or legal surrogate withdrawal of consent during the 30-day surveillance period.