New Predictors in Determining the Need for Invasive Treatment in Non-STEMI During the COVID-19 Pandemic: A Retrospective Study

Non-ST elevation acute coronary syndrome (NSTE-ACS) is a heterogeneous disease with a wide range of treatment options from the medical follow-up to early invasive treatment due to complete occlusion of the culprit artery. Non-ST elevation myocardial infarction acute coronary syndrome (NSTEMI-ACS) is one of the subcomponents of NSTE-ACS, which has an increased mortality rate, and for which early intervention can be vital. In the European Society of Cardiology (ESC) guidelines, NSTEMI-ACS is defined as a high-risk condition that requires diagnostic angiography within 2 hours at the latest in those with very high-risk criteria and within 24 hours at the latest in those who do not have high risk. However, the non-invasive approach has come to the fore for the NSTEMI-ACS disease due to the COVID-19 pandemic conditions. In the recently published national consensus report, during the COVID-19 pandemic period, medium-high risk NSTEMI-ACS patients are recommended optimal medical therapy as an alternative treatment method, even if the diagnosis of COVID-19 was excluded, especially in areas where pandemic effects are being experienced intensely. Yet, most of these patients require invasive treatment. In fact, some of them are patients who require very early invasive treatment and have a complete occlusion in the culprit artery. Unfortunately, risk scoring systems are not sufficient enough to differentiate these patients. Therefore, the discovery of markers that can be used in the differentiation of NSTEMI-ACS patients with an increased need for invasive treatment and/or complete occlusion of the culprit's vessels, especially during pandemic periods such as the COVID-19 pandemic, has gained importance.

Inflammation is known to play an important role in the etiopathogenesis of coronary artery disease. In recent years, it has been shown that hematological parameters closely associated with inflammation in people with coronary artery disease may be useful in distinguishing those with increased severity of atherosclerotic involvement and those with high mortality risk. The main markers used in studies are Leukocyte count, neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte Ratio (PLR), systemic immune inflammation index (SII), red blood cell distribution width (RDW), and mean platelet volume (MPV). To the best of our knowledge, there is a lack of literature on the relationship between the need for invasive treatment strategy and/or complete occlusion of the culprit's vessel, and the hematological markers in patients diagnosed with NSTEMI-ACS.