<p>Worldwide, more than 2 million patients die within 30 days after noncardiac surgery anually. Postoperative ischemic myocardial injury is frequent, however, no consensus exists about its definition.</p> <p><strong>Objective: </strong>to develop a term Myocardial Injury after Noncardiac Surgery (MINS) caused by myocardial ischemia, requiring at least, troponin T (TnT) elevation, and with prognostic relevance at 30 days after surgery.</p> <p><strong>Methods: </strong>we performed a prospective study including 15,167 patients ³45 years-old undergoing noncardiac surgery, who had fourth-generation TnT measurements during the first 3 postoperative days. We undertook Cox regression analyses with 30-day mortality after surgery as the dependent variable, using different TnT thresholds, clinical features and several perioperative variables. Non-ischemic etiologies were excluded. Furthermore, we developed a scoring system to predict risk in MINS patients.</p> <p><strong>Results:</strong> MINS was defined as TnT ≥0.03 ng/mL with or without clinical features, and it was an independent predictor of 30-day mortality (adjusted HR 3.82, CI 95% 2.84-5.10). We determined that MINS incidence was 8%, its population attributable risk 33.7%, and 30-days mortality rate 9.6%. Patients did not experience ischemic symptoms in 84% of MINS cases. Additionally, we developed a scoring system in patients suffering MINS with 3 independent predictors of death (age ≥75 years, new ST elevation or left bundle branch block, and anterior location of ECG changes),</p> <p><strong>Conclusion: </strong>Among patients undergoing noncardiac surgery, we defined MINS based on a TnT threshold ≥0.03 ng/mL. Mostly, MINS patients were asymptomatic. Therefore, this strongly suggests the importance of a troponin monitoring during the first few days after surgery.</p> / Master of Health Sciences (MSc)

<p>Introduction: Globally, more than 200 million patients undergo major non-cardiac surgery each year and more than 10 million patients will be exposed to postoperative myocardial ischemia, a condition strongly associated with 30-day mortality. The majority of these events go undetected without postoperative Troponin screening. Methods: We conducted a model-based cost-consequence analysis comparing a postoperative Troponin T screening vs. standard care in patients undergoing noncardiac surgery. In a first model, we evaluated the incremental number of detected perioperative myocardial infarctions and the incremental costs. A second model assessed the effect of the screening and consequent treatment on 1-year survival and the related cost. Model inputs based on the Vascular events In Non-cardiac Surgery patIents cOhort evaluatioN (VISION) Study, a large international cohort. We run probability sensitivity analyses with 5,000 iterations. We conducted extensive sensitivity analyses.</p> <p>Results: The cost to avoid missing an event amounted to CAD$ 5,184 for PMI and CAD$ 2,983 for isolated Troponin T. The cost-effectiveness of the postoperative Troponin screening was higher in patients’ subgroups at higher risk for PMI, e.g. patients undergoing urgent surgery. The incremental costs at 1 year of a postoperative PMI screening by 4 Troponin T measurements were CAD$ 169.20 per screened patient. The cost to prevent a death at 1 year amounted to CAD$ 96,314; however, there was relevant model uncertainty associated with the efficacy of the treatment in the 1-year model.</p> <p>Conclusion: Based on the estimated incremental cost per health gain, the implementation of a postoperative Troponin T screening after noncardiac surgery seems appealing, in particular in patients at high risk for perioperative myocardial infarction. However, decision-makers will have to consider it in terms of opportunity costs, i.e. in relation to the cost-effectiveness of other potential programs within the broader health care context.</p> / Master of Science (MSc)