Background: Perioperative myocardial damage and infarction (MI) is associated with increased mortality and other postoperative complications.
Objectives: To assess the incidence of perioperative myocardial damage in patients undergoing major elective noncardiac surgery, to elucidate any association with postoperative MI and mortality and to estimate the impact of preoperative risk factors and intraoperative hypotension.
Design: Observational cohort study.
Setting: Karolinska University Hospital, Stockholm, Sweden, from October 2012 to May 2013.
Patients: In this single-centre study, all adult patients undergoing major elective noncardiac surgery who were scheduled for an overnight admission to the postoperative unit were included. Patients undergoing phaeochromocytoma surgery were excluded. Preoperative risk factors (co-morbidities), intraoperative events (hypotension defined as a 50% decrease in SBP relative to each patient's baseline and lasting >5 min) and postoperative data were collected from medical records. Levels of high-sensitivity cardiac troponin T (hs-cTnT) were measured on postoperative day 1. Myocardial damage was defined as an increase in the hs-cTnT value above 14 ng l. A cardiologist reviewed all cases of MI occurring within 30 days after surgery.
Main outcome measures: Myocardial damage, MI and mortality within 30 days after surgery.
Results: Of the final cohort of 300 patients, 90 (30%) had myocardial damage on postoperative day 1 and 15 (5%) developed postoperative MI within 30 days. Multivariate logistic regression analysis demonstrated that an intraoperative reduction in SBP more than 50% from baseline lasting more than 5 min was an independent predictor of postoperative hs-cTnT elevation (odds ratio, 4.4; 95% confidence interval, 1.8 to 11.1).
Conclusions: In a cohort of 300 patients undergoing major elective noncardiac surgery, there was a high incidence of myocardial damage and an association between an intraoperative reduction in SBP more than 50% from baseline lasting more than 5 min and myocardial damage.