Likelihood and Predictors of ST-Elevation in Patients Hospitalized for Myocardial Infarction

IMPORTANCE: Emergency treatment options in myocardial infarction are guided by presence or absence of ST-elevations in electrocardiography. Occurrence and factors associated with ST-presentation in different population groups are however inadequately known. OBJECTIVE: To determine likelihood and patient features associated with ST-elevations in myocardial infarction. DESIGN: Nationwide registry study including 22 hospitals with angiolaboratory during an eight year period in Finland. SETTING: Hospitalized care. PARTICIPANTS: 68,162 consecutive patients aged ≥30 with myocardial infarction. MEASURES: Likelihood and patient features associated with presence of ST-elevations. RESULTS: Myocardial infarction presented with ST-elevation in 37.5% (CI 37.0–37.9%) and without in 62.5% (CI 61.9–63.1%) of patients, p<0.0001. Majority of patients aged 30–59 years with myocardial infarction had ST-elevation, but among octogenarians ST-elevations were present in only 24.7%. Presence of ST-elevations decreased with age by estimated 15.6% (CI 15.0–16.2%) per 10 year increase (p<0.0001). Men aged 40–79 years had significantly higher rate for ST-elevation myocardial infarction compared to women. Sex-based difference in presentation of myocardial infarction declined with increasing age. Overall, men had a 13% (CI 11–15%, p<0.0001) higher relative risk for ST-elevations compared to women when adjusted for age and co-morbidities. Diabetes, atrial fibrillation, peripheral or cerebral artery disease, chronic pulmonary disease, malignancy, and renal insufficiency were associated with absence of ST-elevations in myocardial infarction in multivariate analysis. CONCLUSIONS AND RELEVANCE: Myocardial infarction presents with ST-elevations more commonly in men. Presence of ST-elevations decreases with increasing age. Diabetes, atrial fibrillation, peripheral or cerebral artery disease, chronic pulmonary disease, malignancy, and renal insufficiency are associated with absence of ST-elevations in myocardial infarction. These findings may help to predict likelihood of ST-elevations in a patient with myocardial infarction.