P5980Etiology of perioperative myocardial injuries after non-cardiac surgery and associated outcomes

Abstract

Abstract Background Perioperative myocardial injuries (PMI) are a common complication following non-cardiac surgery associated with significantly increased postoperative mortality. Due to its mostly asymptomatic presentation it is currently often missed in clinical routine. With the advent of routine screening PMI will be an increasingly recognised. Therefore, a more detailed understanding of the different etiologies causing PMI is needed to guide management. Methods We included consecutive high-risk patients (defined as known cardiovascular disease or aged ≥65 years) undergoing major non-cardiac surgery at two hospitals into this prospective multicenter observational study. All patients received a systematic screening using cardiac troponin (cTn) in clinical routine for detection of PMI, defined as an absolute cTn-rise from baseline values within 3 days of surgery. Patients were contacted to assess occurrence of major adverse events (MACE) including all-cause death at 30-days. First, we identified preoperative existing comorbidities as well as perioperative factors associated with PMI by multivariable regression analysis. Second, PMI were centrally adjudicated to identify predefined subtypes (“type I myocardial infarction (T1MI)”, “acute heart failure” (AHF), “tachyarrhythmia”, “extra-cardiac” triggers, “unknown”) by two independent reviewers using all clinical information available, and subtypes tested for association with 30-day (MACE). Results From 2014 to 2016 we enrolled 4250 patients undergoing 5375 surgeries. PMI occurred after 785 (14,5%) surgeries. Occurrence of PMI was more frequent with older age and cardiovascular comorbidities, especially insulin-dependent diabetes mellitus and chronic kidney disease. Perioperatively multiple known type II triggers (hypotension, bleeding, hypoxemia, tachycardia, length of surgery) were associated with PMI. Only 5,0% of PMI were adjudicated as “T1MI”, 4,3% as “AHF”, 4,3% as “tachyarrhythmia”, 12,0% “extra-cardiac” and the majority of 74,4% as “unknown”. The subtypes were associated increased MACE-rates (24% for T1MI, 40% for “AHF”, 22% for “tachyarrhythmia”, 24% for “extra-cardiac”, 7,1% for “unknown”) compared to non-PMI patients (1,8%, p<0,001 see Figure). MACE within 30 days following surgery Conclusion PMI occurs more likely in patients with preoperative existing comorbidities, PMI are associated with type II triggers in the intra- as well as postoperative period. We identified subtypes allowing a risk-stratification to identify high-risk types and guide clinical management. Acknowledgement/Funding Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, Roche