Background: Previous studies have demonstrated the effects of single factors, such as age, sex, and race, with longer delays from symptom onset to hospital presentation in patients with ST-elevation myocardial infarction.
Methods: We studied risk factors individually and in combination to determine the cumulative effect on delay times in 482,327 patients with ST-elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction between January 1, 1995, and December 31, 2004. We analyzed patient subgroups with the following risk factors in combination: younger than 70 years vs 70 years and older, race/ethnicity, men vs women, and nondiabetic vs diabetic.
Results: The geometric mean for delay time was 114 minutes, with a decreasing trend from 123 minutes in 1995 to 113 minutes in 2004 (P < .001). Nearly half of the patients (45.5%) presented more than 2 hours and 8.7% presented more than 12 hours after the onset of symptoms. Compared with the reference group (those < 70 years, men, white, and did not have diabetes mellitus [DM]), subgroups with longer delay times (P < .01 for all) included those younger than 70 years, men, black, and had DM (+43 minutes); those younger than 70 years, women, black, and had DM (+55 minutes); those 70 years and older, men, black, and had DM (+60 minutes); and those 70 years and older, women, black, and had DM (+63 minutes).
Conclusions: Patient subgroups with a combination of factors (older age, women, Hispanic or black race, and DM) have particularly long delay times that may be 60 minutes longer than subgroups without those characteristics. Improving patient responsiveness in these subgroups represents an important opportunity to improve quality of care and minimize disparities in care.