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Prehospital unfractionated heparin prior to primary PCI

02 September 2020
Volume 10 · Issue 3



Unfractionated heparin is an anticoagulant used by some, but not all, ambulance services in the treatment of patients who will undergo primary percutaneous coronary intervention (PPCI) due to ST-elevation myocardial infarction (STEMI).


The purpose of this study is to review the effectiveness and safety of prehospital unfractionated heparin administration to STEMI patients prior to PPCI, and to consider whether this drug should be more widely used for these purposes across international ambulance services.


A literature search was conducted to identify articles relevant to prehospital unfractionated heparin (UFH) administration prior to PPCI. Eighteen journal articles and ten clinical practice guideline compendiums from international ambulance services were selected for this review.


The reviewed literature unequivocally demonstrates that early anticoagulant administration is safe, effective and highly appropriate for STEMI patients who subsequently undergo PPCI. There are disagreements, however, about whether UFH is the more optimal anticoagulant when compared with enoxaparin.


This study finds that anticoagulants—such as unfractionated heparin or, in some jurisdictions, enoxaparin—should be strongly considered as a standard feature of prehospital treatment regimens for STEMI patients who will subsequently undergo PPCI.

Unfractionated heparin (UFH) is an anticoagulant agent used by a variety of ambulance services to treat patients suffering ST-elevation myocardial infarction (STEMI). The primary treatment objective for patients with STEMI is early coronary reperfusion, which is the restoration of blood flow to an occluded coronary artery (Barron et al, 1998: 1150). Coronary reperfusion may be achieved by primary percutaneous coronary intervention (PPCI), or by fibrinolysis through the administration of a tissue plasminogen activator (tPA). In many jurisdictions, PPCI is the preferred method of treatment for patients suffering STEMI (Giralt et al, 2015: 70). Therefore, this paper will chiefly focus on the prehospital administration of UFH prior to PPCI.

Percutaneous coronary intervention (PCI) is a mechanical procedure that treats the narrowing or obstruction of coronary arteries by combining coronary angioplasty with stenting (Heart and Stroke Foundation, 2018). Coronary angioplasty is the temporary expansion of blood vessels by inflating a surgical balloon in the affected artery to increase vessel size and improve blood flow. The insertion of a wire-meshed stent is then used to stabilise the expanded blood vessel permanently (National Heart, Lung and Blood Institute, n.d). UFH has traditionally been considered the ‘gold standard’ drug of choice to be administered prior to PPCI (van Gameren et al, 2018: 1443).

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