Abstract 2811: Effects of EMS Routing to Stroke Centers and Participation in a Prehospital Neuroprotective Trial on Door to Needle Times for IV tPA
Introduction: IV tPA is an effective therapy for acute ischemic stroke and better outcomes occur with earlier lytic start. Prehospital initiation of neuroprotective therapies may stabilize penumbral tissue until reperfusion occurs. Prehospital neuroprotective treatments might modify start times of thrombolysis, including accelerating start by galvanizing receiving stroke teams or delaying start by requiring greater care time in the field. Door to needle (DTN) times are a target of improving stroke care nationwide with a goal of <60 minutes according to guidelines.
Hypothesis: Participating in prehospital research does not delay appropriate thrombolysis and may actually improve treatment times by focusing attention and local resources on eligible patients. We expect primary stroke centers (PSC) to have shorter DTN times.
Methods: We analyzed consecutive patients enrolled in the Field Administration of Stroke Therapy - Magnesium (FAST-MAG), phase 3, NIH-sponsored trial of magnesium sulfate started prehospital within 2h of symptom onset. Parameters examined in IV tPA treated patients included: time from ED arrival to IV tPA start (DTN), type of hospital (PSC/non PSC), enrollment before and after start of LA EMS policy routing patients directly to PSCs, and arrival in ED within 60 minutes of last known well time (LKWT).
Results: Among the first 1324 enrollments, 300 received IV tPA and 292 had complete data of LKWT’s and tPA initiation times. Mean DTN was 88.7 minutes with 290 (99%) treated in the 3h and 2 (1%) treated in the 3-4.5 hour time window. Overall, DTN <60 minutes was 17% and 55% received tPA ≤ 90 minutes from ED arrival. DTN times were faster (79 vs. 96 min, p<0.0001) and a greater proportion received treatment ≤ 90 minutes (72% vs. 46%, p<0.0001) in hospitals that were PSCs at the time of enrollment. DTN within 60 minutes in PSC vs. non PSC was 27% vs 11%, P=0.001. Overall onset to tPA initiation was reduced at PSC hospitals (147 vs. 156 min p=0.046). Trialwide, DTN times were reduced after implementation of a countywide PSC triage system in November of 2009(84 vs. 92 min, p=0.024).
Conclusions: Acute stroke patients can be enrolled in a prehospital treatment trial without delaying start of IV tPA compared with national norms. Compared with non-PSC hospitals, certified hospitals achieved shorter door to needle times and faster overall onset to needle times when administering thrombolytic stroke therapy.
- © 2012 by American Heart Association, Inc.