The pathologic and clinical features of coronavirus disease 19 (COVID-19) may be mechanistically linked to an increased risk for disseminated intravascular coagulation (DIC) and propensity for diffuse alveolar hemorrhage (DAH), according to an article published in Circulation.

The COVID-19 pandemic has raised serious safety concerns related to dual antiplatelet therapy (DAPT) on life-threatening bleeding complications among patients with acute respiratory syndrome coronavirus-2 (SARS-CoV-2), especially the risk for DAH. At the same time, the pandemic has created a unique opportunity to study critical questions regarding the preventive, therapeutic or even aggravating effects of antiplatelet therapy on viral pneumonia based on non-randomized real-world data.

Both DIC and DAH are commonly observed in patients with COVID-19. The risk for DAH is increased early after infection with COVID-19, which leads to alveolar endothelial dysfunction, platelet activation, generation of neutrophil-platelet aggregates, neutrophil migration, and fibrin/micro-thrombus formation. If untreated, these modifications may activate secondary fibrinolysis, coagulation factors depletion, and DIC and DAH. Recent studies support a putative role of platelets in host defense against infections, which complicates the evaluation of the role of antiplatelet therapy in viral pneumonia. Three issues which should be taken into account when interpreting the impact of antiplatelet therapy on progression of COVID-19:

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  1. Timing of administration: in early infection, platelet inhibition may lessen intravascular fibrin and thrombus formation, thus preventing the ensuing consequences. In addition, pre-hospital aspirin use, but not postadmission use, was linked to reduced risk for developing severe acute respiratory distress syndrome (ARDS) and mortality in patients with community-acquired pneumonia.
  2. Choice of oral P2Y12 inhibitors: ticagrelor confers potent anti-inflammatory properties via dual inhibition of platelet P2Y12 receptor and equilibrative nucleoside transporter 1. Several trials have shown a clinical benefit of ticagrelor in the management of pneumonia by averting the complications of sepsis and minimizing lung injury.
  3. Circulating platelet counts: both primary and secondary thrombocytopenia are linked with higher risk for infection (including pneumonia) and deteriorated clinical outcomes associated with acute respiratory distress syndrome. Proactive measures or even discontinuation of all antiplatelet therapy are recommended in expert consensus for patients with a platelet count < 100,000/µL and < 50,000/µL, respectively.

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”[C]linicians need to be cognizant of the pros and cons of antiplatelet therapy in patients complicated by COVID-19.” concluded the article’s authors.


Zhou X, Li Y, Yang Q. Antiplatelet therapy following percutaneous coronary intervention in patients complicated by COVID-19: Implications from clinical features to pathological findings (published online April 16, 2020). Circulation. 10.1161/CIRCULATIONAHA.120.046988