In this newsletter we do want to make you aware of three publications that deal with myocardial injury or myocardial infarction after coronary bypass surgery.
The first publication from Innsbruck, Austria and Essen, Germany investigated which the most appropriate definition of perioperative myocardial infarction (pMI) after coronary artery bypass grafting (CABG) and its impact on clinically relevant long-term events is. The incidence and prognostic impact of pMI were assessed according to (i) the 4th Universal Definition of Myocardial Infarction (4UD), (ii) the definition of the Society for Cardiovascular Angiography and Interventions (SCAI), and (iii) the Academic Research Consortium (ARC). The primary endpoint of this study was a composite of myocardial infarction, all-cause death, and repeat revascularization; secondary end- points were mortality at 30 days and during 5-year follow-up. There was a significant difference in the occurrence of pMI (49.5% SCAI vs. 2.9% 4UD vs. 2.6% ARC). The 4th Universal Definition of Myocardial Infarction and ARC criteria remained strong independent predictors of all-cause mortality at 30 days Moreover, the occurrence of new perioperative electrocardiographic changes was prognostic of both primary and secondary endpoints. In conclusion Isolated biomarker release-based definitions (such as troponin) were not associated with pMI relevant to prognosis. The occurrence of additional signs of ischaemia detected by new electrocardiographic abnormalities, regional wall motion abnormalities, or coronary angiography should result in rapid action in everyday clinical practice.
The second publication from Bad Oyenhausen, Germany investigated what which high sensitive Troponin I cut-offs correlate with clinically meaningful findings in patients after CABG. They found that High-sensitivity cardiac troponin I levels determined 12–16 h after surgery with a cut-off of 8000 ng/L (307× upper reference limit) correlated best with a decision to repeat revascularization, while at earlier time-points, clinical decision should rather be based on electrocardiogram (ECG), echocardiographic, and haemodynamic criteria.
The third recommended reading published by the VISION Cardiac Surgery investigators investigated the impact of periprocedural high sensitive Troponin I on 30 day mortality after cardiac surgery and found that patients undergoing coronary bypass surgery that the threshold troponin level, measured within 1 day after surgery, that was associated with an adjusted hazard ratio of more than 1.00 for death within 30 days was 5670 ng per liter (95% confidence interval [CI], 1045 to 8260), a level 218 times the upper reference limit.
In summary the three publications show that isolated biomarker release alone is not a good marker for periprocedural myocardial infarction unless the values are very high exceeding the upper reverence limit more than 218 to 307 times which should trigger coronary angiography and repeat revascularisation as those values have a significant impact on major adverse cardiovascular events and all-cause mortality.
On behalf of the Working Group nucleus,
Martin Czerny, Chairperson 2020-2022 and Roman Gottardi, Communication Coordinator 2020-2022