Background: In April 2004, Aurora St. Luke’s Medical Center implemented an in-house 24x7 interventional cardiology program to improve door-to-balloon time (D2BT) in ST-segment elevation myocardial infarction (STEMI). Previously published data showed a significant reduction in median D2BT, from 98 minutes (January 1, 2002-March 31, 2004) to 55 minutes (April 1, 2004-June 30, 2008), along with a reduction in major adverse cardiovascular events (MACE) and mortality after implementation of the program. Hypothesis: We hypothesized that the continued experience with the 24x7 program would demonstrate further gain in STEMI outcomes in regard to D2BT. Aims: The primary objective was to evaluate the overall median D2BT over a 15-year period. The secondary objectives were to evaluate median D2BT stratified by weekdays and weekends, on- and off-hours, the proportion of D2BT <90 minutes, and the proportion of D2BT <60 minutes over time. Methods: We collected data on all non-transfer adult patients with STEMI from April 1, 2004, to March 31, 2019, at our center. On-hours were from 7:30 a.m. to 5 p.m. and off-hours from 5 p.m. to 7:30 a.m. Results: A total of 1889 patients with STEMI (median age [IQR] 61 [54-71] years, 31% female) were evaluated. Over 15 years, median D2BT decreased from 69 minutes to 46 minutes (P < .001; Fig 1A). The decreasing trend was seen on weekdays and weekends (Fig 1B) and on-hours and off-hours. The percentage of cases with a median D2BT <90 minutes increased from 77% to 97% over 15 years, and those with a median D2BT <60 minutes increased from 36% to 76% (Fig 1B). Conclusion: We show sustained improvement in our median D2BT and remarkable improvement in the proportion of D2BT <60 minutes. This paves the way for redefining the contemporary D2BT from <90 to <60 minutes.