Low-dose GPIIb/IIIa blockade reduces thrombus formation in patients with COVID-19. Characteristics of control participants (ctrl) (n = 9), in vitro–heparinized control samples (n = 8), and patients with COVID-19 (n = 10) are displayed. Thrombus and fibrin formation on collagen/TF spots were assessed under arterial shear (1000 s−1) in recalcified whole blood after preincubation with eptifibatide (A-E) or tirofiban (F-J). Platelets are displayed in magenta and fibrin(ogen) in cyan. SAC (%) of platelets (B and G), platelet fluorescence intensity in AUs (C and H), morphological score depicted by 2 blinded investigators (D and I), and fibrin(ogen) SAC (E and J) are displayed. Representative images from 1 focal plane are depicted in panels A and F; scale bars indicate 50 μm. All graphs show mean ± standard error of the mean. Differences were analyzed using the Kruskal-Wallis test. ∗P < .05, ∗∗P < .01, ∗∗∗P < .001, ∗∗∗∗P < .0001.
