Myocardial injury after non-cardiac surgery: a perioperative affair?

Myocardial injury after non-cardiac surgery (MINS) is a rather new nosological entity and an unfortunately common perioperative complication. The diagnostic criteria for MINS, also indicated as isolated myocardial injury (IMI), are an elevated postoperative high sensitivity troponin T (hsTnT level ranging between 20 and 65 ng/L with an absolute change of at least 5 ng/L or hsTnT level >65 ng/L), in absence of symptoms and/or EKG findings suggestive of ischemia and without a non-ischemic etiology causing troponin elevation. MINS does not fulfill the universal definition of myocardial infarction even if it is related to ischemic causes and it is independently associated with 30-day postoperative mortality and complications. Nevertheless, mortality at 30 days in MINS patients has been calculated up to 10% and it increases exponentially as a function of peak postoperative troponin concentration. Physician and researchers should discriminate MINS from perioperative myocardial infarction and from not ischemic troponin increases. In the postoperative period, the possibility of missing the diagnosis of an acute coronary syndrome for the paucity of clinical symptoms or because physician failed to evaluate a postoperative EKG recording should always be considered. Physiopathology of MINS is not yet well defined: current hypotheses are surrogated from perioperative myocardial infarction studies. Up to now there are not specific treatments for MINS, even if antithrombotic therapy is under evaluation. Treatment decisions should be tailored to the individual case; potential benefits of troponin screening include a cardiology consultation and consequently, improved patients' information to promote lifestyle changes and enhanced therapy.