Radius Anesthesia Blog
Myocardial injury after non-cardiac surgery, or MINS, is a condition that affects approximately 20% of patients who undergo major surgery . Unfortunately, there is a strong association between MINS and major surgical patients’ short-term and long-term mortalities . Furthermore, it is a common condition . A systematic review pooling outcomes from 530,867 surgeries determined the incidence of MINS to be at 18% . This high level of risk, combined with the fact that most MINS cases are asymptomatic, highlights the importance of preventing, detecting, and treating MINS .
MINS is characterized by post-operative troponin measurements exceeding the 99th percentile of the assay’s upper reference limit [1, 2]. These elevated levels are typically found during or within the first thirty days following a non-cardiac operation . MINS can occur without associated ischemic symptoms or an electrocardiography finding .
The probability of experiencing MINS depends on a variety of factors, such as demographics, cardiac history, and surgery type . For one, older patients and male patients are more likely to suffer from MINS than their younger or female counterparts, respectively . Cardiac conditions, such as prior heart failure, hypertension, and coronary artery disease also make an individual more likely to demonstrate signs of MINS following major surgery . Relatedly, patients with concerning Duke Activity Status Index scores are also at heightened risk . Emergency surgeries also carry a greater risk of the condition compared to elective procedures . Physicians can order tests to ascertain patients’ reticulated platelet concentrations, natriuretic peptide concentrations, and post-exercise heart rate recovery, all of which can indicate a person’s likelihood of developing MINS .
Additionally, some intraoperative and postoperative occurrences can predict a patient’s likelihood of exhibiting MINS. One such occurrence is intraoperative blood loss . An analysis of 15,926 non-cardiac surgical patients discovered an association between significant intraoperative bleeding and myocardial injury . Moreover, postoperative hypotension, bleeding, pain, hypoxia, and tachycardia can all increase the risk that a patient suffers from MINS . As a result, physicians should take the necessary steps to correct those conditions before they result in myocardial injury and be especially vigilant during the post-operative period.
Before surgery, there are a few preventative measures that may reduce the risk of MINS . Aspirin and statins have been shown by some studies to lower the frequency of MINS [3, 6]. While metoprolol can reduce a patient’s risk of myocardial infarction in the perioperative period, it can also contribute to increased risk of stroke and mortality . Angiotensin-converting enzyme inhibitors (ACE) and angiotensin II receptor blockers (ARP) should also be avoided if possible because of their positive correlation with MINS .
If a patient develops MINS following surgery, physicians may wish to initiate dabigatran treatments at a dose of 110 mg to be taken twice daily, along with low-dose aspirin if patients do not face a high risk of bleeding . Statin therapy can also be helpful . Physicians should consider cardiac catheterization if MINS patients exhibit recurring bouts of instability, perhaps because of heart failure or cardiac ischemia .
Myocardial injury after non-cardiac surgery can be a difficult condition to prevent and manage. However, early interventions can reduce patients’ risk of death . To ensure that surgical patients do not suffer from myocardial injury, surveillance is key .
References K. Ruetzler et al., “Diagnosis and Management of Patients With Myocardial Injury After Noncardiac Surgery: A Scientific Statement From the American Heart Association,” Circulation, p. e1-e19, October 2021. [Online]. Available: https://doi.org/10.1161/CIR.0000000000001024.  P. J. Devereaux and W. Szczeklik, “Myocardial injury after non-cardiac surgery: diagnosis and management,” European Heart Journal, vol. 41, no. 32, p. 3083-3091, August 2020. [Online]. Available: https://doi.org/10.1093/eurheartj/ehz301.  N. R. Smilowitz et al., “Myocardial Injury after Non-Cardiac Surgery: A Systematic Review and Meta-analysis,” Cardiology in Review, vol. 27, no. 6, p. 267-273, November 2020. [Online]. Available: https://doi.org/10.1097/CRD.0000000000000254.  J. Park et al., “Intraoperative blood loss may be associated with myocardial injury after non-cardiac surgery,” PLoS One, vol. 16, no. 2, p. 1-11, February 2021. [Online]. Available: https://doi.org/10.1371/journal.pone.0241114.  A. J. L. Jorge, E. T. Mesquita, and W. D. A. Martins, “Myocardial Injury after Non-cardiac Surgery – State of the Art,” Arquivos Brasileiros de Cardiologia, vol. 117, no. 3, p. 544-553, September 2021. [Online]. Available: https://doi.org/10.36660/abc.20200317.  N. Kuthiah and C. Er, “Myocardial injury in non-cardiac surgery: complexities and challenges,” Singapore Medical Journal, vol. 61, no. 1, p. 6-8, January 2020. [Online]. Available: https://doi.org/10.11622/smedj.2020004.  A. Hua et al., “Early cardiology assessment and intervention reduces mortality following myocardial injury after non-cardiac surgery (MINS),” Journal of Thoracic Disease, vol. 8, no. 5, p. 920-924, May 2016. [Online]. Available: https://doi.org/10.21037/jtd.2016.03.55.