Abstract W P224: Higher Pre-Hospital Blood Pressure Prolongs Door to Needle Thrombolysis Times

Abstract

Background: Per American Heart Association guidelines, blood pressure (BP) should be < 185/110 to be eligible for intravenous tissue plasminogen activator (tPA). It is shown that door to needle (DTN) time is prolonged in patients who require anti-hypertensive medications prior to thrombolysis in the emergency department (ED). To our knowledge, no studies have focused on pre-hospital BP and its impact on DTN times. We hypothesize that DTN times are longer for patients with higher pre-hospital BP. Methods: We conducted a retrospective review of acute ischemic stroke patients who presented between 1/2010 and 12/2010 to our ED through Emergency Medical Services (EMS) within 3-hrs of symptom onset. Patients were identified from our registry and categorized into two groups: Pre-hospital BP ≥ 185/110 (Pre-hsp HBP) and < 185/110 (Pre-hsp LBP). BP records were abstracted from EMS sheets. Two groups were compared using two-sample t-test or Wilcoxon rank sum test for continuous variables and Chi-square test or Fisher’s exact test for categorical variables. Results: A total of 107 consecutive patients were identified. Out of these, 75 patients (70%) were treated with tPA. Among the patients who received thrombolysis, 35% had pre-hospital BP ≥ 185/110 (n= 26/75). Greater number of patients required anti-hypertensive medications in ED in high BP group compared to low BP group (Pre-hsp HBP n= 14/26, 54%; Pre-hsp LBP n= 13/49, 27%, p < 0.02). Mean door to needle times were significantly higher in Pre-hsp HBP group. (mean ± SD 87.5± 34.2 Vs. 59.7±18.3, p<0.0001). Analysis of patients only within the Pre-hsp HBP group (n= 26) revealed that DTN times were shorter if patients received pre-hsp BP medications compared to patients in the same group who did not receive pre-hsp BP medication (n= 10 vs 16; mean ± SD 76.5 ± 25.7 Vs. 94.3 ± 37.7, p = 0.20) Conclusion: Higher pre-hospital BP is associated with prolonged DTN times and it stays prolonged if pre-hospital high BP remains untreated. Although the later finding was not statistical significant due to small sample size, pre-hospital blood pressure control could be a potential area for improvement to reduce door to needle times in acute ischemic stroke.