Objective: To identify differences in the incidences of myocardial infarction in women and men with chest pain.
Design: Prospective multicenter cohort study.
Setting: Emergency rooms of three university and four community hospitals.
Patients: 7,734 emergency room patients with acute chest pain.
Measurements and main results: Myocardial infarction was diagnosed in 10% of the 3,896 women, compared with 19% of the 3,838 men, yielding an age-adjusted relative risk of myocardial infarction for women of 0.54 (95% confidence interval 0.48, 0.60). Physicians were equally adept at admitting women and men with myocardial infarctions, but men without myocardial infarction or unstable angina were significantly more likely to be admitted than were women without these diagnoses. Most clinical and electrocardiographic features indicating a risk of myocardial infarction were present in both women and men, but several high-risk features were less commonly present in women. After adjusting for the other factors that correlate with each patient's probability of having acute myocardial infarction, the relative risk of myocardial infarction was the same in women as men when the emergency department electrocardiogram showed the classic changes associated with acute myocardial infarction, but the risk was 40% lower in women when such electrocardiographic changes were not present.
Conclusions: Clinical features that predict myocardial infarction in men predict myocardial infarction in women to a similar extent. However, female gender is associated with about a 40% lower rate of myocardial infarction except when classic electrocardiographic evidence is present on the emergency department electrocardiogram.