The effects of troponin screening among patients undergoing acute high-risk abdominal surgery: A retrospective cohort study.

Background: Acute high-risk abdominal (AHA) surgery is associated with a high short-term mortality rate. This might be partly attributed to myocardial injury after non-cardiac surgery (MINS) defined by elevated postoperative troponin levels. The myocardial injury is often asymptomatic; thus, troponin screening seems to be the best diagnostic method. We aimed to assess whether implementing troponin screening with subsequent individualised interventions as standard care is associated with reduced mortality after AHA surgery. We also explored the treatment implications in the screening period.

Methods: A retrospective cohort of 558 patients undergoing surgery from February 2018 to March 2021 was included. The patients undergoing surgery before March 2019 served as the historical control group, while the screening group consisted of patients undergoing surgery from March 1, 2019. Troponin I was to be measured 6-12 h postoperatively and in the morning of the succeeding 4 days. Patients with myocardial injury were assessed, and treatment was individualised after multiple disciplinary consultations. The primary outcome was the unadjusted 30-day mortality rates. Inverse probability treatment weighting was used to adjust for selection bias.

Results: We included 558 patients: 382 in the screening group and 176 in the historical control group. In the screening group, 15 patients (3.9%) died before the first blood sampling, and in 31 patients (8.1%), troponin screening was omitted, leaving only 336 patients screened. Myocardial injury was diagnosed in 81 patients (24.1%) of the 336 patients. Of these, 59 (72.8%) had a cardiac consultation. No interventions or alterations in relation to myocardial injury were done in 67 patients (82.7%). The 30-day mortality was 13.8% (95% CI 8.7%-18.9%) in the control group and 11.1% (95% CI 8.0%-14.3%) in the screening group. The absolute risk difference was -2.7% (95% CI -8.7%-3.3%; p = .38), which was unchanged after adjustment. The difference remained unchanged after 90 days and 1 year.

Conclusion: The implementation of postoperative troponin screening was not associated with reduced mortality after AHA surgery. Research on the prevention and treatment of MINS is warranted before the implementation of standard troponin screening.