The Impact of Current Various Definitions of Perioperative Myocardial Infarction after Coronary Artery Bypass Grafting on Long-Term Prognosis

Background: The correct and therefore most appropriate definition of perioperative myocardial infarction (PMI) after CABG is more controversial than ever, especially with recent findings of prominent clinical trials. We aimed to (1) analyze the incidence of PMI depending on various current definitions in a ‘real-life’ setting of CABG surgery and (2) determine the long-term prognosis of patients with PMI depending on current definitions.

Method: A consecutive cohort of 2,829 patients undergoing CABG from two tertiary university centers with presence of serial perioperative cardiac biomarker measurements (cardiac troponin and creatine kinase MB) were retrospectively analyzed. The incidence and prognostic impact of PMI according to the 4th Universal Definition of Myocardial Infarction (4UD), the definition of the Society for Cardiovascular Angiography and Intervention (SCAI), and the Academic Research Consortium (ARC) was assessed. Primary endpoint of this study was defined as a combined endpoint including myocardial infarction, cardiac-related death and repeat revascularization (MACE-free survival).

Results: Depending on the definition, there was a significant difference in the occurrence of PMI (52.5% SCAI vs. 2.9% 4UD vs. 2.6% ARC). Patients with PMI according to 4UD or ARC had a significant higher rate of MACE during median follow-up time of 3.92 years (interquartile range: 2.26–5.88) compared with patients without PMI (long-rank both p < 0.001). PMI according to EXCEL/SCAI had no impact on 5-year MACE rates (long-rank p = 0.961). PMI according to 4UD and ARC myocardial infarction definition was associated with higher all-cause mortality at 5 years (long-rank: 4UD: p = 0.006; ARC: p = 0.005). No significant association between PMI according to the EXCEL/SCAI definition and all-cause mortality was observed. 4UD and ARC criteria remained strong independent predictors for all-cause mortality at 5 years and 30 days (4UD: HR: 12.52; CI: 5.3–29.7; p < 0.001; ARC: HR: 13.44; CI: 5.7–31.7; p < 0.001). New occurrence of Q or R waves or ST segment elevations were associated with increased all-cause mortality within 5 years (long-rank: Q or R: p = 0.013; ST segment elevation: p = 0.016).

Conclusion: Isolated enzyme release is not feasible to detect prognostically relevant PMI after surgery. Combined occurrence of enzyme increase and additional signs of ischemia including angiography, echocardiography or ECG changes should result in rapid action in daily clinical practice.

Publication History

Article published online:
03 February 2022