A Time Analysis of Cardiovascular STEMI Events in a Large Metropolitan County

Background:  Every year over one million Americans suffer acute myocardial infarctions (AMI), 375,000 die before receiving care.  One-third have ST-Segment Elevation Myocardial Infarction (STEMI), a type of AMI easily detected by 12-lead EKGs. The County of San Diego, EMS in collaboration with local hospitals operate a STEMI Receiving Center (SRC) System to care for over 11,000 9-1-1 cardiac chest pain patients transported to EDs annually.  This system allows prehospital ALS personnel to alert hospitals of possible STEMIs to expedite lifesaving interventions. Previous studies have suggested that STEMI patients who present to hospitals during off hours may have delayed treatment times and longer hospitalizations. Methods: SRC data was analyzed by mode of arrival (9-1-1 Activated, Non-Activated, Walk In), Door-To-Device-Time (DTDT), month, day, hour, and outcome to determine differences. Results: Preliminary results show most STEMI admissions occur in December, on Sundays, and at 2:00p.m.  For all time frames Activated patients had the most expedited DTDT (mean 59.2 minutes). Due to higher acuity, both Activated and Non-Activated patients had a higher percent of patients with a hospitalization > 5 days and who expired compared to Walk Ins. Further analysis will be presented. Conclusions:  Such analysis allows EMS agencies and hospitals to strategically plan staffing needs to better prepare to receive and care for STEMI patients at various times.  Also, it provides data for educating the population on benefits of seeking immediate treatment when symptoms occur. This research is very timely as the State of California is currently establishing regulations to standardize SRC systems.