The Burden of Type 1 Peri-Operative Myocardial Infarction After Non-Cardiac Surgery: Insights From the Myocardial Ischaemia National Audit Project From 2010-2023

OBJECTIVES: To evaluate the prevalence of perioperative myocardial infarction (PMI), the quality-of-care patients receive and their outcomes, and how this varies across different operations. METHODS: We included adults from England with AMI between Jan 2010 and March 2023 from the Myocardial Ischaemia National Audit Project registry, linked to Hospital Episode Statistics (HES). Cox-regression models compared risk of all-cause mortality at thirty-days and five-years, subgroup analyses compared operation type (orthopaedic, vascular, upper (UGI) and lower gastrointestinal (LGI) and urological). RESULTS: We identified 2,821 episodes of type 1 PMI in 533,026 eligible patients (0.5%). Orthopaedics were the largest contributing speciality (45%). Risk of thirty-day mortality was significantly higher in PMI patients at thirty-days (adjusted Hazard Ratio):1.34 [95% CIs 1.21-1.49]) and five-years (1.36 [1.29-1.43]) (both P<0.001). For thirty-day mortality, risk was not significant in orthopaedics and urology but was for vascular (1.75 [1.40-2.18]), UGI (1.95 [1.43-2.66) and LGI surgery (1.94 [1.50-2.51]) (all P<0.001). For those who survived to hospital discharge, PMI patients had higher mortality risk at five-years (1.26 [1.19-1.34), especially high in the UGI (1.76 [1.44-2.13]), LGI (1.34 [1.13-1.59]) and urology groups (1.61 [1.34-1.93]) (all P<0.001). CONCLUSIONS: PMI mortality is significantly higher than AMI all-comers, seen across all subspecialties up to five-years, with variation in the risk of mortality from PMI according to operation type. PMI may identify a high-risk vulnerable group of patients, whose increased mortality risk persists long term, even in those who survive to discharge.