Sticky Platelet Syndrome: An important consideration for otherwise unexplained thrombotic events in young stroke patients

INTRODUCTION: This case highlights the importance of considering platelet function and aggregability in patients with recurrent ischemic stroke and deep vein thrombosis. RESULTS: We present a case of a 47-year-old man with history of hypertension, hyperlipidemia, and multiple thrombotic events but no family history of clotting events. Over a period of eight years, he was diagnosed with deep vein thrombosis, pulmonary embolism, and occipital lobe, cerebellar, and parietal lobe infarcts. After presenting with new embolic strokes, platelet aggregometry demonstrated hyperactivity to three agonists, including adenosine-diphosphate (ADP)- indicative of Sticky Platelet Syndrome. Repeat platelet aggregometry demonstrated poor response to clopidogrel, so the patient was discharged on triple therapy with aspirin, clopidogrel, and enoxaparin to warfarin bridge. Two years later, the patient was diagnosed with right eye central retinal artery occlusion two months after an outpatient provider discontinued the clopidogrel and switched warfarin to apixaban. He was discharged back on triple therapy with re-initiation of clopidogrel and apixaban switched to warfarin. CONCLUSION: Thrombosis in unusual sites and despite anticoagulant use, coupled with platelet hyperactivity to ADP, were suggestive of Sticky Platelet Syndrome. Due to lack of testing standardization, diagnosis of a persistent, hyperreactive platelet phenotype remains challenging. However, improvements in diagnostic approaches for Sticky Platelet Syndrome can be highly beneficial in enabling faster treatment with an appropriate antithrombotic regimen, reducing the risk of subsequent thrombotic events.