The goal of this prospective cohort study is to estimate the incidence of myocardial injury after non-cardiac surgery (MINS) in patients undergoing acute high-risk abdominal surgery.

MINS is defined as at least one increased single measurement of plasma troponin I (TnI). TnI-dynamic is defined as either two succeeding measurements of TnI > 59 ng/l with an increase/fall of more than 20%, or by one measurements of TnI > 59 ng/l with a succeeding measurement of TnI < 59 ng/l and a decrease of more than 50%.

Participants will have plasma TnI measured 6-12 hours postoperatively and on each of the following four postoperative days. Follow-up will be minimum one year after surgery.

The aim of the study is to determine:

• The incidence of MINS within the first four postoperative days
• The incidence of dynamic TnI changes
• The association between MINS and dynamic TnI changes respectively and all-course short-term mortality

Gastrointestinal tract perforation, bowel ischemia and bowel obstruction are considered acute high-risk abdominal disorders, often requiring emergency surgery. Myocardial injury after non-cardiac surgery (MINS) is a frequent but often unrecognized postoperative complication. MINS is associated with an increased risk of other cardiac complications and 30-day mortality. However, the literature on MINS is mainly regarding patients undergoing a wide range of elective or acute surgical procedures, and we do not know if the dynamic TnI-criteria used for acute myocardial injury has any association with mortality in patients with MINS.

This study aims to estimate the incidence of MINS in patients undergoing AHA surgery, and the association between the short-term mortality and MINS defined as a single increased measurement of TnI and as TnI dynamics respectively.

Inclusion Criteria:

• 18 years or older
• Patients undergoing acute high-risk abdominal surgery

Exclusion Criteria:

• Patients with microscopic perforations in colonic diverticulitis managed with laparoscopic lavage or drainage
• If further treatment postoperatively was assessed as futile and terminated immediately after surgery

Patients undergoing surgery for gastrointestinal perforation, obstruction due to volvulus, tumour, strangulated hernia or adhesions, mesenterial ischemia or necrosis, or anastomotic leakage after gastrointestinal surgery.