Cor Vasa 2014, 56(5):e388-e395 | DOI: 10.1016/j.crvasa.2013.12.003

Prasugrel loading dose in diabetic patients with acute STEMI - Always sufficiently effective? Observation in two cases and review of current knowledge

Matej Samoš^a,*, Marián Fedor^b, František Kovář^a, Lukáš Duraj^b, Jana Fedorová^c, Peter Galajda^a, Ján Staško^b, Tomáš Bolek^a, Peter Kubisz^b, Marián Mokáň^a

^a I. interná klinika, Jesseniova lekárska fakulta v Martine, Univerzita Komenského v Bratislave, Martin, Slovenská republika

^b Národné centrum hemostázy a trombózy, Klinika hematológie a transfuziológie, Jesseniova lekárska fakulta v Martine, Univerzita Komenského v Bratislave, Martin, Slovenská republika

^c HemoMedica - Centrum trombózy a hemostázy, Martin, Slovenská republika

The activation and subsequent platelet aggregation plays a key role in the formation of arterial thrombosis and therefore is the key therapeutic target in the treatment of acute coronary syndromes. Dual antiplatelet therapy containing aspirin and P2Y12 ADP receptor antagonist forms currently the basis in acute ST-elevation myocardial infarction (STEMI) pharmacological treatment. Nevertheless, there is a wide variability in pharmacodynamic response to administration of clopidogrel, the most frequently used P2Y12 ADP receptor antagonist. High platelet reactivity after clopidogrel administration is associated with increased risk of stent thrombosis and points to the suitability of laboratory monitoring of antiplatelet therapy efficacy in clinical practice. Laboratory monitoring of antiplatelet therapy by ex vivo platelet function tests may help to identify individuals with poor antiplatelet response. Recently, there is a growing number of data reporting a failure in antiplatelet response following clopidogrel administration, which is specifically associated with insulin resistance and diabetes mellitus. Prasugrel, a new, potent P2Y12 ADP receptor antagonist, provides faster and more consistent inhibition of platelet function compared with clopidogrel. Prasugrel therapy was repeatedly described as an effective method to overcome clopidogrel resistance and prasugrel resistance has not yet been reliably described. We report two cases of patients with diabetes mellitus type 2 at the stage of organ complications, in whom a prasugrel loading dose of 60 mg did not reach adequate antiplatelet response in 60 minutes after prasugrel administration. The antiplatelet response was measured by light transmission aggregometry and by VASP protein phosphorylation assessment.

Keywords: Acute macrovascular complications; Antiplatelet therapy; Clopidogrel resistance; Prasugrel resistance

Received: October 23, 2013; Revised: November 27, 2013; Accepted: December 1, 2013; Published: October 1, 2014  Show citation