The Unmeasured Ischemic Burden of Non-Cardiac Surgery: A Systematic Review of Postoperative Myocardial Injury

Abstract

Background: Myocardial injury after non-cardiac surgery (MINS) is increasingly recognized as a major contributor to postoperative morbidity and mortality. Despite its impact, MINS remains grossly under-diagnosed because the majority of affected patients are asymptomatic, and routine postoperative troponin surveillance is rarely performed outside specialized centers. Over the past decade, evidence has accumulated regarding its definition, mechanisms, clinical outcomes, and potential treatment approaches, yet clinical implementation remains limited.

Objective: To systematically review contemporary evidence (2010–2023) on the definition, detection, prognosis, surveillance strategies, and therapeutic approaches for MINS, with emphasis on the persistent lack of awareness and poor implementation of guideline-recommended monitoring.

Methods: Following PRISMA-2020 guidelines, a systematic search was performed in PubMed/Medline and major cardiology and perioperative guideline sources. Eligible evidence included randomized trials, prospective cohorts, and expert guidelines discussing postoperative myocardial injury. Due to significant heterogeneity across assays, endpoints, and patient populations, a narrative synthesis was conducted.

Results: Across large prospective cohorts, MINS is common and associated with a substantially increased risk of 30-day and 1-year mortality. Most cases have no ischemic symptoms, and diagnosis relies solely on troponin measurement. Clinical guidelines from AHA (2021) and ESC (2022) recommend postoperative troponin testing for 48–72 hours in high-risk surgical patients; however, adoption remains limited. The MANAGE randomized trial provides the strongest therapeutic evidence to date, suggesting that dabigatran may reduce major vascular events in carefully selected MINS patients. Observational data reinforce the prognostic significance of even small troponin elevations.