Emergency Medical Services
Background: Patients with ST-elevation myocardial infarction (STEMI) benefit from emergent reperfusion. Percutaneous coronary intervention (PCI) is recommended within 90-minutes of first-medical-contact (FMC). However, rural North Carolina (NC) emergency medical services (EMS) agencies have difficulty consistently achieving this goal. The EMS agency in Wilkes County, NC protocolized the administration of the thrombolytic tenecteplase (TNK) in 2001. The objectives of this study were to describe the TNK patient cohort and determine the percent of patients who would have likely failed to meet the 90-minute PCI goal.
Methods: We performed a retrospective review of prehospital records over an 18-year period (1/2001-12/2018). Patients who received TNK and were transported directly by ground EMS to a PCI facility were included. Scene time, transport time, and time from EMS FMC-to-TNK administration were abstracted. Estimated FMC-to-PCI time was calculated by adding scene time and transport time to the median national hospital door-to-device time of 64.5 minutes. The percent estimate of patients who would have received PCI within the 90-minute goal was determined. Additionally, the time difference between FMC-to-TNK administration and estimated FMC-to-PCI time was calculated to find the estimated time difference in receiving a reperfusion therapy. Descriptive and parametric univariate analysis was performed.
Results: Fifty-two cases were identified. Mean age was 60.2 years (95%CI 57.2-63.1). Males accounted for 75.0% (n=39/52) of the sample. Cardiac arrest occurred in 7.7% of patients (n=4/52), with 75% (n=3/4) successfully resuscitated. Mean scene time was 25.4 minutes (95%CI 22.5-28.3), transport time was 45.2 minutes (95%CI 42.3-48.2), and FMC-to-TNK time was 30.2 minutes (95%CI 26.9-33.4). Mean estimated FMC-to-PCI time was 134.3 minutes (95%CI 129.6-139.1), with 100% of cases being greater than 90-minutes. Mean time to reperfusion therapy difference by using TNK instead of PCI was 103.9 minutes (95%CI 99.1-108.7).
Conclusion: Prehospital thrombolytic therapy drastically reduces time to reperfusion therapy. Rural EMS systems should consider using thrombolytics when they are unable to consistently achieve the 90-minute STEMI PCI goal. Research is needed to determine the safety and efficacy of prehospital thrombolytic therapy compared to PCI.