208 | www.critpathcardio.com Critical Pathways in Cardiology • Volume 17, Number 4, December 2018 ORIGINAL ARTICLE Abstract: Despite its clinical benefits, aspirin has been considered one of the predictors of worse outcomes in patients with unstable angina/non–ST- segment-elevation myocardial infarction. Nevertheless, such association has not been demonstrated in patients with ST-elevation myocardial infarction (STEMI). Five hundred eighty-six STEMI patients undergoing primary percutaneous coronary intervention were evaluated including 116 prior aspirin users. Angiographic characteristics and 1-year major adverse cardiac events (MACE) were then compared between the 2 groups. Adjusted analysis showed that the prior aspirin users had a significantly higher rate of totally occluded infarct-related artery before primary percutaneous coronary intervention (odds ratio: 1.859; P = 0.019). Postprocedural Thrombolysis in Myocardial Infarction flow grade 3 was less often demonstrated in the prior aspirin users (odds ratio: 1.512; P = 0.059). Aspirin consumption was associated with increased long-term mortality and MACE. Prior aspirin users had higher rate of MACE and worse pre- and postprocedural angiographic features. We suppose that patients who develop STEMI despite long- term aspirin intake probably reflect more vulnerable pre-existing coronary plaques with more thrombogenicity, which could negatively affect long-term cardiovascular outcomes. Key Words: aspirin, major cardiac adverse event, primary percutaneous coronary intervention, ST-elevation myocardial infarction (Crit Pathways in Cardiol 2018;17: 208–211) P revious studies have shown that patients on long-term aspirin who present with acute coronary syndrome (ACS) are less likely to develop ST-elevation myocardial infarction (STEMI) and have fewer procedural complications and lower in-hospital mortality rates than those not taking aspirin. 1–3 It is also stated that antiplatelet therapy with aspirin alters the nature of the coronary artery disease. Its clinical benefits notwithstanding, aspirin therapy may be deemed one of the predictors of worse outcomes in patients with unstable angina/non–ST-segment-elevation myo- cardial infarction (UA/NSTEMI)—previously suggested in the Thrombolysis in Myocardial Infarction (TIMI) risk score for NSTE-ACS study—along with other risk factors such as old age and elevated cardiac markers. 4 These patients continue to develop composite cardiovascular adverse events—including myocardial infarction (MI), death, and urgent revascularization—while tak- ing long-term aspirin, which probably reflects the progression of the atherosclerosis. 5 Such association has not been revealed in patients with STEMI, however. Indeed, in the TIMI risk score for ST-elevation myocardial infarction study, aspirin consumption was not considered a potential risk factor for these patients in the final risk-stratification model. 6 We hypothesized that although aspirin might prevent worse outcomes through its antiplatelet properties, the occurrence of STEMI in spite of chronic aspirin intake might reflect the more severe clinical condition of the patients and would be associated with adverse cardiovascular events likely due to more resistant thrombo- sis. Meanwhile, these patients often have more comorbidities, which can definitely affect the outcomes. 1 It is, therefore, advisable that they be categorized as high-risk patients for close monitoring. Considering the importance of risk assessment in clinical deci- sion making, we sought to investigate the effects of chronic aspirin intake on angiographic features and long-term cardiovascular events in STEMI patients undergoing primary percutaneous coronary inter- vention (PCI). METHODS In the present retrospective cohort study, we evaluated STEMI patients who were admitted for primary PCI to a high-volume tertiary cardiac center between March 2015 and March 2016. Patients who had history of coronary artery bypass graft surgery or stent throm- bosis were excluded from the final analyses. The study protocol was approved by the local review board of the hospital. According to the inclusion and exclusion criteria, 586 patients met the study requirements. The patients’ baseline demographic char- acteristics, cardiovascular risk factors, drug history, habitual habits, preprocedural information, angiographic features, and in-hospital survival status were retrieved from electronic medical records. Based on the history of chronic aspirin consumption (taking aspirin due to cardiac or noncardiac reasons at least 3 months before the procedure), the patients were divided into aspirin+ (n = 116) and aspirin- (n = 470) groups. The patients’ coronary angiograms were then evaluated with respect to the preprocedural TIMI flow grade, postprocedural TIMI flow grade, thrombus burden grade, and TIMI frame count (TFC) by a cardiovascular interventionist, who was blinded to the aspirin consumption status. The TIMI flow grade was classified according to what has been previously described. 7 The thrombus burden grade was defined as “high” if the modified TIMI thrombus grade was 4, and a thrombus grade ≤3 was classified as “low.” 2 The TFC was finally corrected (defined as the CTFC) by dividing the initial mea- sure by 1.7 in the patients whose culprit lesion was in the left anterior descending artery. 7 According to the policy of our center, patients who undergo PCI are routinely followed up after the procedure by referral to the hospi- tal’s follow-up clinics. Through these visits, the patients are followed up for their general conditions, symptom exacerbations, medical treat- ments, need for invasive or noninvasive tests, and occurrence of any major adverse cardiac events (MACE). Consequently, we retrieved the Are Prior Aspirin Users With ST-Elevation Myocardial Infarction at Increased Risk of Adverse Events and Worse Angiographic Features? Babak Geraiely, MD,* Hamidreza Poorhosseini, MD,* Saeed Sadeghian, MD,* Roya Sattarzadeh Badkoubeh, MD,† and Seyedeh Hamideh Mortazavi, MD* Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 1003-0117/18/1704-0208 DOI: 10.1097/HPC.0000000000000159 Received for publication May 5, 2018; accepted June 24, 2018. From the *Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran; and †Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran. Supported by Tehran Heart Center, Tehran University of Medical Sciences. The authors have no conflicts of interest to disclose. Reprints: Seyedeh Hamideh Mortazavi, MD, Tehran Heart Center, Tehran University of Medical Sciences, North Kargar Street, Tehran, Iran. E-mail: h-mortazavi@student.tums.ac.ir.