Research Article Acute Occlusion of the Infarct-Related Artery as a Predictor of Very Long-Term Mortality in Patients with Acute Myocardial Infarction Nikola Kos , 1 Ivan Zeljkovi´ c , 1 Tomislav Krˇ cmar , 2,3 Karlo Golubi´ c , 1 Fran ˇ Saler, 4 Marijan Erceg , 5 Diana Deli´ c-Brkljaˇ ci´ c , 1,6 and Nikola Bulj 1,6 1 Department of Cardiovascular Diseases, University Hospital Centre Sestre Milosrdnice, Zagreb, Croatia 2 Department of Cardiovascular Diseases, University Hospital Centre Zagreb, Zagreb, Croatia 3 Department of Cardiovascular Diseases, University Hospital Centre Rijeka, Rijeka, Croatia 4 Department of Cardiovascular Diseases, University Hospital Dubrava, Zagreb, Croatia 5 Croatian Institute of Public Health, Zagreb, Croatia 6 School of Medicine, University of Zagreb, Zagreb, Croatia Correspondence should be addressed to Nikola Kos; nikolakos89@gmail.com Received 16 October 2020; Revised 18 July 2021; Accepted 22 October 2021; Published 24 November 2021 Academic Editor: Domenico Della Rocca Copyright © 2021 Nikola Kos et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Aim. e survey’s aim was to examine the significance of infarct-related artery (IRA) occlusion (verified angiographically) on very long-term outcomes of patients with acute myocardial infarction, within the STEMI and NSTEMI diagnosis. Methods. A single- center, nonrandomized, registry-based study on patients treated for acute coronary syndrome with percutaneous coronary intervention between June 2011 and December 2016 was conducted. Patients with angiographically proven IRA occlusion (100% stenosis with TIMI flow 0 distal to occlusion) were categorized as occlusive myocardial infarction (OMI) and patients with patent IRA (50–99% stenosis with TIMI 1–3 flow) were categorized as nonocclusive myocardial infarction (NOMI) and very long-term outcomes were analyzed. Data were collected prospectively from the hospital’s PCI registry and the database of the Croatian Institute of Public Health. Results. A total of 2450 patients were included in the study. 796 (32.5%) patients had NOMI and 1654 patients (67.5%) had OMI. According to ECG changes, 1534 patients presented with STEMI (62,6%) and 916 with NSTEMI (37,8%). 88% of STEMI patients presented with OMI and 12% with NOMI, while patients with NSTEMI in 33,8% presented with OMI and in 66,81% with NOMI. A median follow-up was 4.7 years. ere was no significant difference in cardiovascular mortality between the groups (14.8% vs 13.1%; OMI vs NOMI, respectively; p � 0.374) neither in all-cause mortality (19% vs 21.5%; OMI vs NOMI, respectively; p � 0.374). Patients with NSTEMI had a significantly higher very long-term mortality (21.6% vs 18.1%; NSTEMI vs STEMI, respectively; p � 0.029). Conclusion. e main findings of the study are as follows: (1) total IRA occlusion was not associated with higher long-term mortality; (2) NSTEMI was associated with a higher mortality rate compared with STEMI, independent of angiographic presentation (OMI/NOMI); (3) IRA occlusion was not associated with significantly higher mortality rates in patients with STEMI and NSTEMI, respectively. 1. Introduction e pathophysiology of acute myocardial infarction with ST elevation (STEMI) and without ST elevation (NSTEMI) differs significantly. Namely, STEMI is usually caused by a complete occlusion of the infarct-related artery (IRA), which is not the case with NSTEMI which is mostly caused by transient or incomplete IRA occlusion [1, 2]. Patients with STEMI have a worse short-term (30 days) prognosis, but if they overcome the acute phase, they tend to have a better long-term survival in comparison to NSTEMI patients [3, 4]. Although there are many theories explaining why NSTEMI patients have a higher long-term mortality rate, there are few dedicated studies evaluating the impact of the pathophysi- ological basis of infarction on outcome [5–7]. Additionally, electrocardiogram (ECG) is insufficient in detecting artery occlusion and therefore dividing patients according to IRA patency would give more precise information about patient Hindawi Cardiology Research and Practice Volume 2021, Article ID 6647626, 6 pages https://doi.org/10.1155/2021/6647626