TICAGRELOR IN UNSTABLE CAROTID STENOSIS - A CASE REPORT/TIKAGRELOR U NESTABILNOJ KAROTIDNOJ STENOZI - PRIKAZ SLUCAJA

Introduction. Ticagrelor is an oral, reversible, direct-acting inhibitor of adenosine diphosphate receptor P2Y12, which has a faster onset of action and stronger inhibition of platelet aggregation than Clopidogrel. Case Report. This case report describes a 54-year-old male patient with repeated, transient ischemic attacks due to ipsilateral, significant carotid stenosis registered by carotid duplex ultrasound. In addition to aspirin, clopidogrel and rosuvastatin were added to the therapy. Despite optimal treatment, the patient was continuously unstable with frequent but transient neurological symptoms. A magnetic resonance imaging of the brain showed acute, cortical-subcortical ischemic lesions in the left frontal and parietal lobes, while the computed tomography angiography of the endocranium showed progression of findings and occlusion of the left common carotid artery. Subsequently, laboratory platelet aggregation analysis confirmed aspirin resistance and poor response to clopidogrel. Episodes of transient ischemic attacks were stabilized after the exclusion of dual antiplatelet therapy and introduction of ticagrelor. After that, the patient's symptoms did not recur and he remained stable. Conclusion. The incidence of resistance to antiplatelet therapy in patients with stroke or transient ischemic attack varies greatly and ranges from 3% to 85% for aspirin, and 28% to 44% for clopidogrel. Our case showed that platelet aggregation analysis is reasonable if patients with transient ischemic attack or minor acute ischemic stroke are neurologically unstable, despite optimal medical treatment and when other therapeutic options, such as carotid revascularization, are not indicated. In such situations, ticagrelor may be a suitable alternative to dual antiplatelet therapy. Key words: Ischemic Attack, Transient; Ischemic Stroke; Carotid Stenosis; Ticagrelor; Clopidogrel; Platelet Aggregation Inhibitors; Aspirin; Secondary Prevention Uvod. Tikagrelor je oralni, reverzibilni, direktni inhibitor adenozin-difosfatnog receptora P2Y12, koji ima brzi pocetak dejstva i snazniju inhibiciju agregacije trombocita nego klopidogrel. Prikaz slucaja. Prikazan je slucaj muske osobe, starosti 54 godine, sa ponovljenim, tranzitornim ishemijskim atacima nastalim usled ipsilateralne, signifikantne karotidne stenoze, registrovane neurosono-loskom obradom. Pored aspirina, klopidogrel i rosuvastatin su bili ukljuceni u terapiju. Uprkos optimalnom tretmanu, pacijent je bio kontinuirano