Safety and delay time in prehospital thrombolysis of acute myocardial infarction in urban and rural areas in Sweden.
Sixteen hospitals in Sweden, including those in urban and more sparsely populated areas, and the associated ambulance organizations were enrolled in a prospective evaluation of the feasibility of treating patients with a ST-elevation infarction with a thrombolytic agent (reteplase) before hospital admission. A physician staffed the ambulances in 1% of cases, a nurse in 67%, and a staff nurse in 32% of cases. In all, 64 patients in urban areas and 90 patients in rural areas were included. The occurrence of complications before hospital admission was low and similar in the 2 groups. The median interval between the onset of symptoms and the start of thrombolysis was 1 hour 44 minutes in urban areas versus 2 hours 14 minutes in rural areas (P = 0.03). The median arrival time (interval between onset of symptoms and arrival of the ambulance) tended to be shorter in urban areas (1 hr 10 min vs 1 hr 33 min; not significant) and the median interval between the arrival of the ambulance and the start of thrombolysis was shorter in urban areas (27 min vs 36 min; P < 0.0001). When comparing urban areas with the least-populated rural areas, differences in various delay times became even more marked. Patients in urban areas had a higher ejection fraction and fewer symptoms of heart failure after 30 days and a lower 1-year mortality.