The influence of pre-hospital medication administration in ST-elevation myocardial infarction patients on left ventricular ejection fraction and intra-hospital death

Introduction
Currently, invasive cardiology techniques are the preferred method of treatment for patients with ST-elevation myocardial infarction (STEMI). Improving the care of patients with STEMI is possible by minimizing the time that elapses from the onset of pain to the start of treatment. As studies indicate, early pharmacotherapy, especially with antiplatelet and anticoagulant medications, allows for their early effectiveness. Aim: To assess the influence of early administration of antiplatelet (clopidogrel) and anticoagulant medications in the pre-hospital period in patients with ST-elevated myocardial infarction on the frequency of in-hospital deaths and on the left ventricular ejection fraction evaluated at hospital discharge.

Material and methods
In this study, a retrospective analysis of 573 patients hospitalized due to ST-segment elevation myocardial infarction in one of Krakow’s hospitals from January 2011 to December 2015 (excluding the whole of 2013) was used as a research method.

Results
As many as 97% of patients received pre-hospital pharmacotherapy, but only 46.0% of respondents received unfractionated heparin, and 19.2% received clopidogrel. The in-hospital mortality rate was 6.7%, but among patients prehospitally treated with clopidogrel and unfractionated heparin, the in-hospital mortality rate was 1.1%. Prehospital administration of clopidogrel significantly decreased the possibility of reduced left ventricular ejection fraction (OR = 0.27; 95% CI: 0.09–0.90).

Conclusions
Among pre-hospital procedures, only administration of a second antiplatelet drug (clopidogrel) significantly decreased the risk of reduced left ventricular ejection fraction, and administration of clopidogrel or heparin, or a combination of both, significantly decreased the risk of in-hospital death in patients with STEMI.