[Acute myocardial infarction patients without COVID-19 manifestations in the pandemic may have high thrombus burden].

Objective: The objective of the study is to identify clinical and angiographic characteristics of patients with ST-segment elevation myocardial infarction (STEMI) but without clinical manifestations of COVID-19 infection during the pandemic, compared with patients 1 year before the pandemic. Methods: Observational study that included 138 consecutive patients hospitalized with STEMI who underwent primary percutaneous coronary intervention (PCI) without COVID-19 infection during the 2020 pandemic. A group of 175 STEMI patients treated with PCI in the year before the pandemic served as the control group. Results: During the periods analyzed, compared with the control group, patients admitted during the pandemic without clinical manifestations of COVID-19 did not have significant differences in demographic characteristics, comorbidities, or delayed time and location of the acute myocardial infarction. Furthermore, there were no differences between the two groups concerning levels of CK-MB and NT-proBNP, or in inflammation markers and left ventricular ejection fraction. In patients without COVID-19 during the pandemic compared with control, we found a higher intracoronary thrombus burden (thrombus grade 5; 78.3% vs. 62.9%, respectively. p = 0.002). Accordingly, the use of glycoprotein IIB/IIIa inhibitors (37.7% vs. 26.3%, p = 0.03) was higher in these patients. Conclusions: This study demonstrates an increased thrombus burden in STEMI patients without clinical manifestation of COVID-19 during the pandemic compared with the same time period in the previous year.