Higher Prehospital Blood Pressure Prolongs Door to Needle Thrombolysis Times: a Target for Quality Improvement?

Background: Per the American Heart Association guidelines, blood pressure (BP) should be less than 185/110 to be eligible for stroke thrombolysis. No studies have focused on prehospital BP and its impact on door to needle (DTN) times. We hypothesized that DTN times would be longer for patients with higher prehospital BP.

Methods: We conducted a retrospective review of acute ischemic stroke patients who presented between January 2010 and December 2010 to our emergency department (ED) through emergency medical services within 3 hours of symptom onset. Patients were categorized into 2 groups: prehospital BP greater than or equal to 185/110 (group 1) and less than 185/110 (group 2). Blood pressure records were abstracted from emergency medical services run sheets. Primary outcome measure was DTN time, and secondary outcome measures were modified Rankin Score at discharge, symptomatic intracranial hemorrhage, length of stay in stroke unit, and discharge disposition.

Results: A total of 107 consecutive patients were identified. Of these, 75 patients (70%) were thrombolysed. Mean DTN times were significantly higher in group 1 (adjusted mean [95% confidence interval], 86minutes [76-97] vs 56minutes [45-68]; P<.0001). A greater number of patients required antihypertensive medications before thrombolysis in the ED in group 1 compared to group 2 (54% vs 27%; P=.02).

Conclusion: Higher prehospital BP is associated with prolonged DTN times and DTN time remains prolonged if prehospital BP greater than or equal to 185/110 is untreated before ED arrival. Prehospital BP control could be a potential area for improvement to reduce DTN times in patients with acute ischemic stroke.