Effect of the Use of Ambulance-Based Thrombolysis on Time to Thrombolysis in Acute Ischemic Stroke

Abstract

Stroke is a leading cause of death and disability.¹ In acute ischemic stroke, thrombolysis with intravenous tissue plasminogen activator (tPA) is the treatment of choice after exclusion of intracerebral hemorrhage by brain imaging.² Neurons die rapidly during ischemia, and randomized placebo-controlled trials have shown time-dependent benefits of tPA: early treatment is associated with better outcomes.^3-7 Within 90 minutes of symptom onset, the number needed to treat for 1 excellent outcome is 4.5; the number is 9 between 91 and 180 minutes and 14 between 181 and 270 minutes.⁵ However, only a minority of stroke patients receive tPA,⁸ and in a European stroke registry only 11% of this minority were treated within the first 90 minutes.⁹ Apart from delayed patient response, prehospital and intrahospital management (“onset-to-door” and “door-to-needle”) contribute to delays. Onset-to-door times range from 46 to 150 minutes,¹⁰ and recent data from the United States indicate that less than 30% of patients have a door-to-needle time within the recommended 60 minutes.^2,8 Recently, one study reported time saving in 12 tPA administrations performed in a special ambulance with integrated computed tomography (CT) scanner and point-of-care laboratory.¹¹ Little is known about the overall effects and risks of specialized ambulances for patients with stroke and also for patients with other diseases. After a 3-month pilot study with the Stroke Emergency Mobile (STEMO),¹² we investigated the effects of its deployment on time to treatment and safety in a larger controlled study.¹³