Pre-hospital thrombolysis delivered by paramedics is associated with reduced time delay and mortality in ambulance-transported real-life patients with ST-elevation myocardial infarction

Abstract

There are sparse data on the impact of pre-hospital thrombolysis (PHT) in real-life patients. We therefore evaluated treatment delays and outcome in a large cohort of ambulance-transported real-life patients with ST-elevation myocardial infarction (STEMI) according to PHT delivered by paramedics or in-hospital thrombolysis. Prospective cohort study used data from the Swedish Register of Cardiac intensive care on patients admitted to the coronary care units of 75 Swedish hospitals in 2001-2004. Ambulance-transported thrombolytic-treated patients younger than age 80 with a diagnosis of acute myocardial infarction were included. Patients with PHT (n=1690) were younger, had a lower prevalence of co-morbid conditions, fewer complications, and a higher ejection fraction (EF) than in-hospital-treated patients (n=3685). Median time from symptom onset to treatment was 113 min for PHT and 165 min for in-hospital thrombolysis. One-year mortality was 7.2 vs. 11.8% for PHT and in-hospital thrombolysis, respectively. In a multivariable analysis, after adjusting for baseline characteristics and rescue angioplasty, PHT was associated with lower 1-year mortality (odds ratio 0.71, 0.55-0.92, P=0.008). When compared with regular in-hospital thrombolysis, pre-hospital diagnosis and thrombolysis with trained paramedics in the ambulances are associated with reduced time to thrombolysis by almost 1 h and reduced adjusted 1-year mortality by 30% in real-life STEMI patients.