Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19
RCT (n=2219) found therapeutic-dose anticoagulation with heparin increased probability (98.6%; OR 1.27; 95% CI, 1.03-1.58) of survival to hospital discharge vs. usual-care thromboprophylaxis, with reduced use of CV or respiratory organ support
Source:
New England Journal of Medicine
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SPS commentary:
This is one of two RCTs reported in the journal that examine the potential benefits and risks of therapeutic-dose heparin or LMWH compared to standard thromboprophylaxis.
The other study found that therapeutic-dose heparin or LMWH did not improve the primary outcome of days without organ support in critically ill patients and was associated with more major bleeding complications than usual-care prophylaxis (3.8% vs. 2.3%).
An editorial discusses how to reconcile these different outcomes in different populations, It suggests that one factor may be that in critically ill patients, the underlying thrombotic and inflammatory damage may have been too advanced to have been influenced by higher doses of heparins compared to noncritically ill patients. It adds that other causes for the different findings may relate to the differences in populations. Although the vast majority of critically ill patients were recruited in centres that were running the REMAP-CAP trial in the UK, the patients with moderate disease were recruited mostly from the ATTACC and ACTIV-4a trials in the US and Brazil. These populations differ not only geographically but also ethnically. With these caveats in mind, it concludes that the available evidence does not support use of therapeutic-dose heparin or LMWH for thrombosis prevention in critically ill patients and whether intermediate or therapeutic doses of thromboprophylactic drugs are effective and safe in moderately ill patients with Covid-19 remains an important question.