Comparing One-Year Survival in Anterior Versus Inferior ST-Elevation Myocardial Infarction Patients: Results of a Cohort Study in Western Iran

Abstract

Background: The site of acute myocardial infarction (MI) plays a pivotal role in determining the prognosis and risk assessment for patients experiencing their first ST-segment elevation MI (STEMI). Objectives: This study aims to compare one-year survival rates in patients with anterior versus inferior ST-elevation myocardial infarction. Methods: This registry-based cohort study was conducted from July 2018 to December 2019, examining data from STEMI patients. A total of 643 patients diagnosed with STEMI who met the inclusion criteria were enrolled. Patients were categorized based on the location of their myocardial infarction (MI) into two groups: Those with anterior MI and those with inferior MI. Their progress was meticulously followed over the course of one year. For data analysis, Cox proportional hazards models were used to calculate two sets of hazard ratio estimates: The initial unadjusted (crude) hazard ratios and the fully adjusted hazard ratios, which accounted for potential confounding factors. Along with these hazard ratio estimates, their corresponding 95% confidence intervals (HR, 95% CI) were obtained. All statistical analyses were performed using R software version 4.2.1. Results: Throughout the follow-up period, totaling 598 patients and 4,109 person-days, only 7 patients (1.09%) were lost to follow-up. The analysis revealed no significant difference in one-year mortality rates between the inferior and anterior STEMI groups, with rates of 37 (8.39%) versus 15 (7.69%), respectively, yielding a P-value of 0.767. However, it is noteworthy that the mortality risk trended higher in the inferior MI group, with a hazard ratio of 1.093 (95% CI: 0.60 - 1.99). Conclusions: In conclusion, our study highlights the heightened mortality risk associated with inferior wall MI. These results underscore the prognostic value of MI location, shedding light on its potential role in predicting the severity and extent of infarction, thereby guiding clinical decision-making and risk management strategies in STEMI patients.