Delayed Hospital Presentation in Patients Who Have Had Acute Myocardial Infarction

BACKGROUND: In patients who have had acute myocardial infarction, the delay between the onset of symptoms and hospital presentation is a critical factor in determining the initial management strategy and outcomes of treatment. OBJECTIVE: To examine the determinants of delayed hospital presentation in patients who have had acute myocardial infarction. DESIGN: Retrospective chart review. SETTING: 37 hospitals in Minnesota. PATIENTS: 2409 persons hospitalized with acute myocardial infarction between October 1992 and July 1993. MAIN OUTCOME MEASURE: Hospital presentation delayed more than 6 hours after the onset of symptoms of acute myocardial infarction. RESULTS: Information on length of delay was available for 2404 patients. Of these patients, 969 (40%) delayed presentation to the hospital for more than 6 hours after the onset of symptoms. Factors associated with prolonged delay included advanced age and female sex. The presence of chest discomfort and a history of mechanical revascularization significantly reduced the risk for prolonged delay. Risk for delay was greatest during the evening and early morning hours (6:00 p.m. to 6:00 a.m.) Patients with a history of hypertension were more likely to delay presentation. Only 42% of all patients hospitalized with acute myocardial infarction had used emergency medical transport services. CONCLUSIONS: Patients who have had acute myocardial infarction often delay hospital presentation. Educational interventions that encourage the prompt use of emergency medical transport services and target specific patient populations, such as elderly persons, women, and persons with cardiac risk factors, may be most successful in reducing the length of delay and improving the outcomes of patients with acute myocardial infarction.