Methods:

The BASEL-PMI study investigators assessed etiologies of PMIs detected within an active surveillance and response program adjudicated by two independent physicians based on all information obtained during clinically indicated PMI workup including cardiac imaging among consecutive high-risk patients undergoing major noncardiac surgery in a prospective multicenter study. PMI etiologies were hierarchically classified into ‘extracardiac’ if caused by a primarily extracardiac disease such as severe sepsis or pulmonary embolism; and ‘cardiac’, further subtyped into type 1 myocardial infarction (T1MI), tachyarrhythmia, acute heart failure (AHF), or likely type 2 myocardial infarction (lT2MI). MACE including acute myocardial infarction, AHF (both only from day 3 to avoid inclusion bias), life-threatening arrhythmia, and cardiovascular death as well as all-cause death were assessed during 1-year follow-up. The primary endpoints were the occurrence of MACE and all-cause death following different PMI etiologies within 1 year. The authors performed multivariable Cox proportional hazards analysis for first MACE and all-cause mortality in patients with PMI adjusted for: age, sex, European Society of Cardiology/European Society of Anesthesiology surgery risk (low, medium, high risk of cardiac events), revised cardiac risk index class, urgency of surgery, postoperative complications (sepsis, stroke, bleeding), center, and surgical specialty.