Impact of delay in door-to-needle time on mortality in patients with ST-segment elevation myocardial infarction

Abstract

Fibrinolytic therapy is the most common reperfusion strategy for patients with ST-segment elevation myocardial infarction (STEMI), particularly in smaller centers. Previous studies evaluated the relation between time to treatment and outcomes when few patients were treated within 30 minutes of hospital arrival and many did not receive modern adjunctive medications. To quantify the impact of a delay in door-to-needle time on mortality in a recent and representative cohort of patients with STEMI, a cohort of 62,470 patients with STEMI treated using fibrinolytic therapy at 973 hospitals that participated in the National Registry of Myocardial Infarction from 1999 to 2002 was analyzed. Hierarchical models were used to evaluate the independent effect of door-to-needle time on in-hospital mortality. In-hospital mortality was lower with shorter door-to-needle times (2.9% for < or =30 minutes, 4.1% for 31 to 45 minutes, and 6.2% for >45 minutes; p <0.001 for trend). Compared with those experiencing door-to-needle times < or =30 minutes, adjusted odd ratios (ORs) of dying were 1.17 (95% confidence interval [CI] 1.04 to 1.31) and 1.37 (95% CI 1.23 to 1.52; p for trend <0.001) for patients with door-to-needle times of 31 to 45 and >45 minutes, respectively. This relation was particularly pronounced in those presenting within 1 hour of symptom onset to presentation time (OR 1.25, 95% CI 1.01 to 1.54; OR 1.54, 95% CI 1.27 to 1.87, respectively; p for trend <0.001). In conclusion, timely administration of fibrinolytic therapy continues to significantly impact on mortality in the modern era, particularly in patients presenting early after symptom onset.

Figure 1

Frequency distribution of door-to-needle times for the entire cohort.

Figure 2

Door-to-needle time and in-hospital mortality for the entire cohort, p <0.001 for trend.

Figure 3

In-hospital mortality in subgroups based on door-to-needle time (x-axis across the page) and on symptom onset-to-presentation time (y-axis going into the page). For trend across door-to-needle times, p values all <0.001. For trend across symptom onset-to-presentation times, p <0.001 for door-to-needle time ≤30 minutes, p = 0.031 for door-to-needle time 31–45 minutes, and p = 0.758 for door-to-needle time >45 minutes.

Figure 4

With DTN <30 minutes as the reference, adjusted odds ratios of inhospital mortality from delay in reperfusion therapy by symptom onset-to-presentation time. For symptom onset-to-presentation time <1 hour, p <0.001; for symptom onset-to-presentation time 1–2 hours, p <0.03; for symptom onset-to-presentation time >2 hours, p <0.02. DTN = door-to-needle time