Hyperresponsive Platelets and a Reduced Platelet Granule Release Capacity Are Associated with Severity and Mortality in COVID-19 Patients.

Background:  Coronavirus disease 2019 (COVID-19) is often associated with mild thrombocytopenia and increased platelet reactivity.

Objective:  The aim of the current study was to investigate the adenosine triphosphate (ATP) release kinetics of platelets in hospitalized SARS-CoV-2-infected patients.

Methods:  We studied time-dependent platelet activation in whole blood by monitoring the ATP release kinetics upon stimulation with a PAR1 receptor agonist in 41 hospitalized critically ill COVID-19 patients, 47 hospitalized noncritically ill COVID-19 patients, and 30 healthy controls.