Analysis of risk factors of ST-segment elevation myocardial infarction in young patients

BACKGROUND Acute myocardial infarction (AMI) is often present in old populations and rare in young people. Its incidence significantly increased recent years. The mechanism and disease course of AMI in young people are probably different from that in old population. The aim of this study was to analyze clinical risk factors of STEMI in young patients. METHODS Data was collected from consecutive patients ≤ 44 years of age (young; n = 86) and 60-74 years of age (old; n = 65) diagnosed with STEMI, and 79 young age-matched patients without coronary artery disease (CAD), hospitalized between January 2009 and June 2013. RESULTS The young STEMI group had a significantly higher proportion of males (88.37 vs. 53.16%; P < 0.01), smokers (82.56 vs. 49.37%; P < 0.01) and patients with a family history of early CAD (54.65 vs. 32.91%; P < 0.05) than age-matched controls. Young STEMI patients also had significantly higher levels of fasting blood sugar (6.39 vs. 5.25 mmol/L; P < 0.001), glycated hemoglobin (HbA1c) (6.26 vs. 5.45%; P < 0.05), total cholesterol (5.14 vs. 4.65 mmol/L, P < 0.05), and fibrinogen (Fib) (3.39 vs. 2.87; P < 0.01). Compared with the old STEMI group, young STEMI patients had significantly higher proportions of males (88.37 vs. 63.08%; P < 0.01) smokers (82.56 vs. 41.54%; P < 0.01), and those with a family history of early CAD (54.65 vs. 18.46%; P < 0.01). Young STEMI patients also lower Fib (3.39 vs. 3.88 g/L; P < 0.01), less frequent occurrence of angina pectoris before STEMI (13.95 vs. 29.23%; P < 0.05) compared with the old STEMI group. Logistic regression analysis indicated that male sex (OR = 5.891), smoking (OR = 3.500), family history of early CAD (OR = 3.194), Fib (OR = 2.414) and HbA1c (OR = 1.515) are associated with STEMI in young patients. CONCLUSION In addition to previously recognized risk factors (male sex, smoking and family history of early CAD), Fib and HbA1c are associated with STEMI in individuals ≤ 44 years of age without antecedent angina pectoris.