Background: Optimizing the emergency medical care chain might shorten the time to treatment of patients with ST-elevation myocardial infarction (STEMI). The initial care by a physician, and, in particular, correct ECG interpretation, are critically important factors.
Methods: From 1999 onward, data on the care of patients with myocardial infarction have been recorded and analyzed in the Berlin Myocardial Infarction Registry. In the First Medical Contact Study, data on initial emergency medical care were obtained on 1038 patients who had been initially treated by emergency physicians in 2012. Their pre-hospital ECGs were re-evaluated in a blinded fashion according to the criteria of the European Society of Cardiology.
Results: The retrospective re-evaluation of pre-hospital ECGs revealed that 756 of the 1038 patients had sustained a STEMI. The emergency physicians had correctly diagnosed STEMI in 472 patients (62.4%), and they had correctly diagnosed ventricular fibrillation in 85 patients (11.2%); in 199 patients (26.3%), the ECG interpretation was unclear. The pre-hospital ECG interpretation was significantly associated with the site of initial hospitalization and the ensuing times to treatment. In particular, the time from hospital admission to cardiac catheterization was longer in patients with an unclear initial ECG interpretation than in those with correctly diagnosed STEMI (121 [54; 705] vs. 36 [19; 60] minutes, p <0.001). After multivariate adjustment, this corresponded to a hazard ratio* of 2.67 [2.21; 3.24].
Conclusion: Pre-hospital ECG interpretation in patients with STEMI was a trigger factor with a major influence on the time to treatment in the hospital. The considerable percentage of pre-hospital ECGs whose interpretation was unclear implies that there is much room for improvement.