Implementation of higher dose (HD) thromboprophylaxis has been considered in patients
infected with coronavirus disease 2019 (COVID-19). Our aim was to compare HD to standard
dose (SD) thromboprophylaxis in COVID-19 patients. The protocol is registered on PROSPERO
(CRD42021284808). We searched for randomised controlled studies (CENTRAL, Embase,
Medline and medRxviv) that compared HD to SD anticoagulation in COVID-19 and analysed
outcomes such as mortality, thrombotic events, bleedings, and disease progression.
The statistical analyses were made using the random effects model. Fourteen articles
were included (6253 patients). HD compared with SD showed no difference in mortality
(OR 0.83 [95% CI 0.54–1.28]). The use of HD was associated with a decreased risk of
thrombosis (OR 0.58 [95% CI 0.44–0.76]), although with an increased risk of major
bleeding (OR 1.64 [95% CI 1.25–2.16]). The cohort with D-dimer <1 mg/mL showed no
effect (OR 1.19 [95% CI 0.67–2.11]), but in the case of D-dimer >1 mg/mL, a tendency
of lower risk in the HD group was observed (OR 0.56 [95% CI 0.31–1.00]). The need
for intubation in moderately ill patients showed a nonsignificant lower likelihood
in the HD group (OR 0.82 [95% CI 0.63–1.08]). We cannot advocate for HD in all COVID-19
patients, although it shows some nonsignificant benefits on disease progression in
those with elevated D-dimer who do not need ICU admission.
