Background: Treatment for ST-elevation myocardial infarction (STEMI) is based on early reperfusion therapy (coronary angioplasty or fibrinolysis). Such treatment requires the adoption of healthcare models that allow to perform angioplasty within 90 min of first medical contact, or when this is not the case and in absence of any contraindications, prehospital thrombolysis.
Methods: This retrospective observational study was carried out in 119 STEMI patients undergoing prehospital thrombolysis from June 2003 to December 2006. The diagnosis of STEMI was made by trained physicians of the emergency system on the basis of clinical symptoms and 12-lead ECG with the support of telecardiology. Patient selection for fibrinolytic treatment was made in accordance with international guidelines on STEMI. Thrombolysis was considered effective in the presence of an ST-segment elevation resolution > 50% at 90 min following drug administration. Patients with unchanged or poorly modified ST-segment elevation (< 30%) at 60 min underwent rescue angioplasty for failure of thrombolysis. Coronary angiography was performed in all patients, including those in whom thrombolysis was effective. All patients were followed up for 1 year.
Results: The diagnosis of STEMI on this setting did not prove difficult and the quality of tele-ECG was suitable. Total symptom-to-needle time was 78 min. Fifty-nine patients (49.6%) showed 50-100% ST-segment elevation resolution within 90 min of fibrinolytic administration. Failure of thrombolysis, symptom worsening and/or hemodynamic impairment were observed in 7 patients (5.8%) who were submitted to rescue angioplasty. Neither cardiogenic shock nor deaths or major bleeding complications developed in any patients. The survival rate was 94.1% at 1-year follow-up (112 patients).
Conclusions: This study confirms the feasibility, high effectiveness and low risk of prehospital thrombolysis provided that therapy is undertaken by trained staff according to prespecified protocols in the context of a well defined organized model.