Effectiveness of therapeutic heparin versus prophylactic heparin on death, mechanical ventilation, or intensive care unit admission in moderately ill patients with covid-19 admitted to hospital: RAPID randomised clinical trial

SPS commentary:

Participants in this study could receive either unfractionated or low molecular weight heparin (LMWH); the majority (98.2% therapeutic dose and 93.7% prophylactic dose) received LMWH. Concomitant treatments (systemic corticosteroids, remdesivir, and tocilizumab) were balanced between treatment arms. The primary outcome was a composite of death, invasive mechanical ventilation, non-invasive mechanical ventilation, or admission to an intensive care unit, assessed up to 28 days.

There was no statistically significant benefit for therapeutic dose heparin for the primary composite endpoint, or for time to ICU admission, or mechanical ventilation). A benefit in favour of therapeutic heparin was however observed for the secondary endpoint of death at 28 days (1.8% v 7.6% prophylactic heparin; OR 0.22, 0.07 to 0.65; P=0.006); this emerged during the first week and continued to be apparent up to 28 days. The risk of major bleeding was low (0.9% in the therapeutic group and 1.7% in the prophylactic group), with no fatal bleeding events or cases of intracranial haemorrhage.

The authors suggest that the findings of this trial, in conjunction with those of the REMAP-CAP multiplatform trial, suggest therapeutic heparin is beneficial in moderately ill patients with covid-19 admitted to hospital wards.