Objective: To assess the practical application, safety and long-term outcome of pre-hospital thrombolytic intervention with either alteplase or streptokinase in patients with extensive myocardial infarction.
Design: Prospective study.
Subjects: Patients with chest pain of more than 30 min duration, presenting within 6 h of symptom onset and with electrocardiographic evidence of extensive evolving myocardial infarction.
Methods: Eligibility of patients was established by the general practitioner or the ambulance nurse using a standardized questionnaire with (contra-) indications for thrombolytic therapy. Computerized ECG was recorded by ambulance nurses. In the presence of extensive ST segment elevation (sum ST deviation of at least 1.0 mV), eligible patients received either 100 mg alteplase (n = 246) or 50 mg alteplase in the ambulance followed by 0.75 x 10(6) IE streptokinase in hospital (n = 90), or 1.5 x 10(6) IE streptokinase intravenously (n = 193).
Main outcome measurements: Death and life-threatening complications (ventricular fibrillation, cardiac arrest) and side effects (hypotension, allergic reactions) during transportation to hospital and in the first 24 h following hospitalization, and survival up to 5 years follow-up.
Results: From 1988-1993, 529 patients received thrombolytic treatment initiated pre-hospital. The time gained by pre-hospital administration of thrombolysis amounted to 50 min. The rate of complications during transportation and during the first 24 h after hospitalization was low. Hospital mortality was 2% and 1-year mortality 3%. Cumulative survival at 5 years was 92%. This was superior to the 84% 5-year survival observed in a matched group of 239 patients with similar baseline characteristics treated with alteplase in hospital.
Conclusions: Pre-hospital administration of either alteplase or streptokinase is feasible and safe and results in significant time gain. The long-term prognosis is excellent in spite of extensive evolving myocardial infarction upon admission.