Date of Award
Master of Health Sciences (MSc)
Health Research Methodology
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.
Objective: 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.
Methods: 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.
Results: 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),
Conclusion: 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.
Botto, Fernando, "Myocardial Injury after Noncardiac Surgery (MINS)" (2012). Open Access Dissertations and Theses. Paper 7385.
McMaster University Library
Available for download on Saturday, September 28, 2013