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.
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 ≤1 hour, >1 to 2 hours, >2 to 3 hours, etc., and >11 to 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.
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<0.0001 for linear trend). For patients presenting ≤1 hour, >1 to 2 hours, and >2 to 3 hours, >9 to 10 hours, >10 to 11 hours, and >11 to 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; door-to-drug times were 33, 34, 36, 46, 44, and 47 minutes respectively.
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.