Rationale and design of perioperative myocardial ischemia: a protocol for troponin monitoring, prognostic thresholds, economic analysis and further insights into pathophysiology for non-cardiac surgery patients

Introduction: Worldwide, near 200 million adults undergo major non cardiac surgery each year, and 10 million of them are estimated to suffer a myocardial injury after non-cardiac surgery (MINS), defined as an elevated high sensitive troponin T (hs-cTnT) in the first 3 days after surgery. Troponin levels need to be monitored in order to diagnose MINS, high sensitive cardiac Troponin T (hs-cTnT) assays being currently the most frequently used. Perioperative hs-cTnT screening could lead to care decisions that can potentially improve clinical outcomes. However, many of the clinical and economic implications of perioperative hs-cTnT monitoring remain unclear, and need to be elucidated. Methods and analysis: Prospective cohort that will include patients with high cardiovascular risk undergoing major non-cardiac surgery, expected to require at least an overnight hospital admission. Three determinations of hs-cTnT in each patient (before surgery, at 48, and 72 hours after surgery) will be obtained. We will determine the incidence and prognosis of MINS, and calculate prognostically relevant thresholds for pre- and post-operative hs-cTnT. We will also conduct a cost-effectiveness analysis of hs-cTnT screening, compared with usual care. Finally, using computed tomography angiography (CTA) and cardiac magnetic resonance imaging (MRI), we aim to elucidate further the pathophysiology of MINS. Ethics and dissemination: Our center had Ethics approval before including patients. Written informed consent is required for all patients before inclusion. The study will evaluate the feasibility and impact of implementing an hs-cTnT monitoring program at a tertiary hospital, as well as its cost-effectiveness, determine pre and postoperative thresholds of hs-cTnT and finally, evaluate potential mechanisms involved in perioperative ischemic events. The dissemination plan includes publishing the results in a policy-influencing journal, conference presentations, engagement of influential medical organizations, and taking published results to real practice.