Non ST-elevation myocardial infarction (NSTEMI) patients with total coronary artery occlusion: More than meets the eye

We fully agree that there is a need for a paradigm shift in the management of non-ST elevation myocardial infarction (NSTEMI) patients as ST-elevation alone on the electrocardiogram (ECG) is a poor surrogate for total coronary occlusion. Although defined criteria exist for the accurate diagnosis and timely referral of ST-elevation (STEMI) patients for revascularization, [ [1] Ibanez B. James S. Agewall S. ESC Scientific Document Group et al. 2017 ESC guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation: the task force for the management of acute myocardial infarction in patients presenting with ST-segment elevation of the European Society of Cardiology (ESC). Eur. Heart J. 2018; 39: 119-177 Crossref PubMed Scopus (4609) Google Scholar ] these criteria fail to identify NSTEMI patients in whom total coronary occlusion is the underlying cause for myocardial infarction. As a result, patients who do not present with these typical ECG changes despite having an acutely occluded coronary artery are more likely to undergo delayed revascularization [ [2] Asatryan B. Vaisnora L. Manavifar N. Electrocardiographic diagnosis of life-threatening STEMI equivalents when every minute counts. J. Am. Coll. Cardiol. Case Rep. 2019; 1: 666-668 Google Scholar ]. Although we listed many of the ECG findings in NSTEMI patients with acute coronary occlusion in our manuscript [ [3] Tziakas D. Chalikias G. Al-Lamee R. Kaski J.C. Total coronary occlusion in non ST elevation myocardial infarction: time to change our practice?. Int. J. Cardiol. 2021 Jan 4; S0167-5273 (10.1016/j.ijcard.2020.12.082, Online ahead of print): 34330-34338 Google Scholar ], our list inadvertently omitted some important ECG patterns described by other authors previously [ [3] Tziakas D. Chalikias G. Al-Lamee R. Kaski J.C. Total coronary occlusion in non ST elevation myocardial infarction: time to change our practice?. Int. J. Cardiol. 2021 Jan 4; S0167-5273 (10.1016/j.ijcard.2020.12.082, Online ahead of print): 34330-34338 Google Scholar ] and which might help to identify total coronary artery occlusion in such patients, i.e. the 3-variable [ [4] Smith S.W. Khalil A. Henry T.D. et al. Electrocardiographic differentiation of early repolarization from subtle anterior ST-segment elevation myocardial infarction. Ann. Emerg. Med. 2012; 60 (e2): 45-56 Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar ] and 4-variable algorithms [ [5] Driver B.E. Khalil A. Henry T. et al. A new 4-variable formula to differentiate normal variant ST segment elevation in V2-V4 (early repolarization) from subtle left anterior descending coronary occlusion: adding QRS amplitude of V2 improves the model. J. Electrocardiol. 2017; 50: 561-569 Crossref PubMed Scopus (23) Google Scholar ]. Despite their importance, and to the best of our knowledge, these diagnostic algorithms do not include patient demographics, clinical data or imaging variables [ [6] Miranda D. Walsh B.M. Lobo A. Sandoval Y. Smith S.W. New insights into the use of the 12-lead electrocardiogram for diagnosing acute myocardial infarction in the emergency department. Can. J. Cardiol. 2018; 34: 132-145 Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar ] that could improve diagnostic accuracy. This, precisely, was one of the major points in our manuscript [ [3] Tziakas D. Chalikias G. Al-Lamee R. Kaski J.C. Total coronary occlusion in non ST elevation myocardial infarction: time to change our practice?. Int. J. Cardiol. 2021 Jan 4; S0167-5273 (10.1016/j.ijcard.2020.12.082, Online ahead of print): 34330-34338 Google Scholar ], as we suggested the use of a novel risk score, which in addition to ECG variables, incorporates relevant clinical, laboratory and imaging data in an attempt to identify NSTEMI patients with acute total coronary occlusions, as it is likely that such an approach could improve prognosis.