Prolonged platelet hyperactivity after COVID‐19 infection

Abstract

SummaryPlatelet hyperactivity often occurs in patients with coronavirus disease 2019 (COVID‐19). However, it remains unclear how long platelet hyperactivity lasts after the acute phase, owing to a lack of follow‐up studies. To elucidate the course of platelet hyperactivity, we serially measured platelet activity in patients with COVID‐19 up to 40 days after hospital admission using an easily assessable haematology analyser that semi‐quantitates platelet clumps on a scattergram. Our results showed that platelet hyperactivity persisted for at least 40 days even after acute inflammation subsided in most patients with COVID‐19, regardless of disease severity. Persistent platelet hyperactivity may contribute to thromboembolic complications in post‐COVID‐19 patients.