Higher prehospital priority level of stroke improves thrombolysis frequency and time to stroke unit: the Hyper Acute STroke Alarm (HASTA) study.

Early initiated treatment of stroke increases the chances of a good recovery. This randomized controlled study evaluates how an increased priority level for patients with stroke, from level 2 to 1, from the Emergency Medical Communication Center influences thrombolysis frequency, time to stroke unit, and whether other medical emergencies reported negative consequences. Patients aged 18 to 85 years in Stockholm, Sweden, with symptoms of stroke within 6 hours were randomized from the Emergency Medical Communication Center or emergency medical services to an intervention group, priority level 1, immediate call of an ambulance, or to a control group with standard priority level, that is, priority level 2 (within 30 minutes). Before study start, an educational program on identification of stroke and importance of early initiated treatment was directed to all medical dispatchers and ambulance and emergency department personnel. During 2008, 942 patients were randomized of which 53% (n=496) had a final stroke/transient ischemic attack diagnosis. Patients in the Emergency Medical Communication Center randomized intervention group reached the stroke unit 26 minutes earlier than the control group (P<0.001) after the emergency call. Thrombolysis was given to 24% of the patients in the intervention group compared with 10% of the control subjects (P<0.001). The higher priority level showed no negative effect on other critical ill patients requiring priority level 1 prehospital attention. This randomized study shows negligible harm to other medical emergencies, a significant increase in thrombolysis frequency, and a shorter time to the stroke unit for patients with stroke upgraded to priority level 1 from the Emergency Medical Communication Center and through the acute chain of stroke care.