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Does initiation of an ambulance pre-alert call reduce the door to needle time in acute myocardial infarct?
  1. S R Learmonth1,
  2. A Ireland1,
  3. C J Mckiernan1,
  4. P Burton2
  1. 1Accident and Emergency Department, Glasgow Royal Infirmary, Glasgow, Scotland
  2. 2Clinical Audit Department, Glasgow Royal Infirmary, Glasgow, Scotland
  1. Correspondence to:
 Sarah Learmonth
 Flat 3/3, 42 Minard Road, Glasgow, G41 2HW; sarah.learmonth{at}


Objectives: To assess the effect an ambulance pre-alert call for patients with suspected acute myocardial infarction (AMI) would have on door to needle (DTN) times.

Methods: We carried out back to back audits of DTN times following the initiation of the pre-alert calls.

Participants: All patients thrombolysed within the emergency department between July 2003 and April 2004 (inclusive).

Statistical analysis: Mean DTN times and time to ECG pre-change and post-change were compared using the Two sample t test. The Fisher’s exact test was used to compare pre-change and post-change proportions of patients seen within guideline times.

Results: In total, 73 patients were thrombolysed with 40 of these arriving by ambulance. Eighteen of these 40 were pre-change and 22 were post-change. Four patients were excluded. Fifty per cent of the pre-change group had a DTN time of <30 minutes compared with 91% of the post-change group (p = 0.005, Fisher’s exact test). The phase one mean DTN time was found to be significantly greater than that for phase two (Two sample t test, p = 0.016; 95% CI 1.6 to 14.6).

Conclusions: There was a significant reduction in DTN times after the introduction of the pre-alert call.

  • A&E, accident and emergency
  • AMI, acute myocardial infarct
  • CCU, coronary care unit
  • DTN, door to needle
  • ECG, electrocardiogram
  • acute myocardial infarct
  • thrombolysis
  • MI
  • ambulance
  • pre-alert
  • DTN

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  • Funding: none.

  • Competing interests: none declared.

  • The Corresponding Author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive licence (or non-exclusive for government employees) on a worldwide basis to the BMJ Publishing Group Ltd and its Licensees to permit this article (if accepted) to be published in EMJ and any other BMJPGL products to exploit all subsidiary rights, as set out in our licence (

    Ethical approval was not obtained for this study.