Delay in presentation and reperfusion therapy in ST-elevation myocardial infarction.

BACKGROUND: We studied the relationship between longer delays from symptom onset to hospital presentation and the use of any reperfusion therapy, door-to-balloon time, and door-to-drug time.
METHODS: Cohort study of patients with ST-elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction from January 1, 1995 to December 31, 2004. Delay in hospital presentation was categorized into 1-hour intervals as < or =1 hour, >1-2 hours, >2-3 hours, etc, up to >11-12 hours. The study analyzed 3 groups: 440,398 patients for the association between delay and use of any reperfusion therapy; 67,207 patients for the association between delay and door-to-balloon time; 183,441 patients for the association between delay and door-to-drug time.
RESULTS: In adjusted analyses, patients with longer delays between symptom onset and hospital presentation were less likely to receive any reperfusion therapy, had longer door-to-balloon times, and had longer door-to-needle times (all P <.0001 for linear trend). For patients presenting < or =1 hour, >1-2 hours, >2-3 hours, >9-10 hours, >10-11 hours, and >11-12 hours after symptom onset, the use of any reperfusion therapy were 77%, 77%, 73%, 53%, 50%, and 46%, respectively. Door-to-balloon times were 99, 101, 106, 123, 125, and 123 minutes, respectively, and door-to-drug times were 33, 34, 36, 46, 44, and 47 minutes, respectively.
CONCLUSIONS: Longer delays from symptom onset to hospital presentation were associated with reduced likelihood of receiving primary reperfusion therapy, and even among those treated, late presenters had significantly longer door-to-balloon and door-to-drug times.