Clinical Characteristics and Outcomes of Acute ST-Segment Elevation Myocardial Infarction in Younger Korean Adults

Background and Objectives: This study aims to investigate the clinical features, angiographic findings, and outcomes of younger Korean ST-segment elevation myocardial infarction (STEMI) patients. Subjects and Methods: We analyzed major adverse cardiac events (MACE) in the Korea Acute Myocardial Infarction Registry from November 2005 to October 2010. The registered patients were divided into two groups; young age group (<65 years) and old age group (>= 65 years). Results: The young age group included 5281 patients (age, 53 +/- 7.8 years), and the old age group included 4896 patients (age, 74.3 +/- 6.5 years). Male gender, smoking, family history, dyslipidemia, and metabolic syndrome were more frequently observed in the young age group than in the old age group (89.5% vs. 59.3%, p<0.001; 77.3% vs. 47.2%, p<0.001; 11% vs. 4.6%, p<0.001; 11.2% vs. 7.7%, p<0.001; 67.6% vs. 62.9%, p<0.001). Most of the young Korean adults with STEMI complained of typical chest pain (89.8%), and they had a shorter symptom-to-door time (12 +/- 53.2 hours vs. 17.3 +/- 132 hours, p=0.010). The young age group showed a favorable prognosis, which was represented by the MACE, compared with the old age group at one month (1.8% vs. 2.80/0, p=0.028), six months (6.80/0 vs. 8.2%, p<0.001), and twelve months (10.1% vs. 11.9%, p=0.025). However, there was no significant difference in the adjusted MACE rate at one month {hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.60-1.51, p=0.828} and twelve months (HR 0.86, 95% CI 0.68-1.10, p=0.233). Conclusion: Younger Korean adults with STEMI have clinical outcomes similar to old aged patients, and therefore, they should be treated intensively like the elderly patients.