Introduction and objectives: Clinical trials and meta-analyses have shown that out-of-hospital thrombolysis is effective. Our objectives were to investigate out-of-hospital emergency management of acute myocardial infarction by paramedical teams and to identify factors associated with out-of-hospital use of fibrinolytic therapy.
Patients and method: The study made use of a registry of all patients with ST-segment elevation acute coronary syndrome who were diagnosed and treated out of hospital by emergency paramedical teams in Andalusia, Spain in the 2-year period: 2001-2002. Follow-up was carried out during hospital admission and after one month.
Results: The study included 981 patients, mean age 65 [13] years, 777 male (79.2%). In total, 152 (15.5%) received out-of-hospital thrombolysis; 18% within the first hour, and 68% within the first 2 hours following symptom onset. No hemorrhagic stroke was observed following thrombolysis. During hospitalization, 206 (21%) patients died, eight (0.8%) of whom had received out-of-hospital thrombolysis. Factors associated with the administration of out-of-hospital thrombolysis included: age under 55 years (P<.0001), normal systolic blood pressure (odds ratio = 6.825; 95% confidence interval, 2.442-19.069), and an in-hospital diagnosis of anterior acute myocardial infarction (P<.022).
Conclusions: The administration of out-of-hospital thrombolysis by emergency paramedical teams enables treatment to be administered within the optimum time interval. Mortality during hospital admission is lower in this subgroup of patients than in those who did not receive out-of-hospital thrombolysis. Moreover, the low complication rate observed indicates that the procedure is safe. However, the patients who received out-of-hospital thrombolysis appeared to be those at a lower risk.