Table 1

Previous studies with antiplatelet drugs and outcome in patients with COVID-19

StudyAim of the studyPopulation/methodsAntiplatelet agentResults
Viecca et al 3 Assess the effect of administration of antiplatelet therapy on arterial oxygenation and clinical outcomes in patients with severe COVID-195 patients received antiplatelet drugs/5 controls. Case–control study25 µg/kg/body weight tirofiban as bolus infusion, followed by a continuous infusion of 0.15 µg/kg/body weight per minute for 48 hours. Before tirofiban, patients received aspirin 250 mg infusion and oral clopidogrel 300 mg; both were continued at a dose of 75 mg daily for 30 days.Reduction in A-a O2 gradient of −32.6 mm Hg (61.9, p=0.154), –52.4 mm Hg (59.4, p=0.016) and −151.1 mm Hg (56.6, p=0.011; p=0.047 vs controls) at 24 hours, 48 hours and 7 days after treatment, respectively. PaO2/FiO2 ratio increased by 52 mm Hg (50, p=0.172), 64 mm Hg (47, p=0.040) and 112 mm Hg (51, p=0.036) after 24 hours, 48 hours and 7 days, respectively.
Liu et al 4 Assess the effect of dipyridamole effects in patients with COVID-19 to study concentrations of D-dimers, lymphocyte and platelet recovery in the circulation, and clinical outcomes14 patients received antiplatelet drugs/17 controls. Case–control group.Dipyridamole 50 mg oral three times per day for 14 consecutive daysDecreased concentrations of D-dimer (p=0.041), increased but statistically not significant lymphocyte (p=0.112) and platelet recovery (p=0.128) in the circulation, and markedly improved clinical outcomes (mechanical ventilation 14.3% vs 11.8%: discharge rate 78.6% vs 41.2%). P value not reported.
Russo et al 5 Investigate the association between preadmission antiplatelet therapy and occurrence of death and ARDS in patients with COVID-19.55 patients received antiplatelet drugs/137 controls. Case–control group.44 (22.9 %) aspirin 5 (2.6 %) P2Y12 inhibitor, 6 (3.1 %) dual antiplatelet therapy. Dose not available. No benefit in the risk of death. Unadjusted risk ratio=1.00 (95% CI 0.48 to 1.80), p=0.991. Adjusted risk ratio=0.51 (95% CI 0.21 to 1.15), p=0.110.
No benefit for the risk of ARDS. Unadjusted risk ratio=0.81 (95% CI 0.54 to 1.28), p=0.530. Adjusted risk ratio=0.58 (95% CI 0.38 to 1.14), p=0.165.
Sivaloganathan et al 6 Assess the association between preadmission antiplatelet/anticoagulant use and COVID-19 mortality.29 patients received antiplatelet drugs/58 controls. Case–control study.18 (62%) aspirin, 8 (28%) clopidogrel, 3 (10%) aspirin+clopidogrel. Dose not available.No benefit in mortality with antiplatelet drugs (p=0.516). No benefit in mortality with aspirin (p 0.62).
Pan et al 7 Assess the association between pre-hospitalisation antiplatelet medication use and COVID-19 disease severity.239 patients received antiplatelet drugs/534 controls199 (83.3%) aspirin, 9 (3.8%) clopidogrel, 1 (0.4%) ticagrelor. (12.6%) DAPT, of which 24 (80.0%) aspirin and clopidogrel, 5 (16.7%) aspirin and ticagrelor, 1 (3.3%) aspirin and prasugrel. Dose not available.No benefit in disease severity based on MOS.
Peak MOSOR95% CI
6 vs 5–21.130.70 to 1.82
6–5 vs 4–21.020.66 to 1.57
6–4 vs 3–20.980.65 to 1.46
6–3 vs 20.880.55 to 1.41
RECOVERY collaborative group8 Evaluate the outcomes in a randomised controlled study with aspirin and usual care among patients with COVID-19. 1:1 randomisation.7351 usual standard of care plus 150 mg aspirin once daily until discharge. 7541 usual standard of care alone.7351 patients 150 mg aspirin once daily.17% in aspirin group and 17% in usual care died within 28 days (rate ratio 0.96; 95% CI 0.89 to 1.04; p=0.35). Aspirin group have shorter duration of hospitalisation (median 8 vs 9 days) and a higher proportion were discharged from hospital alive within 28 days (75% vs 74%; rate ratio 1.06; 95% CI 1.02 to 1.10; p=0.0062). Aspirin group: absolute reduction in thrombotic events of 0.6% (SE 0.4%) and an absolute increase in major bleeding events of 0.6% (SE 0.2%).

  • ARDS, acute respiratory distress syndrome; DAPT, dual antiplatelet therapy; MOS, Modified Ordinal Scale.