Abstract
We conducted a systematic review and a meta-analysis to assess the association of
anticoagulants and their dosage with in-hospital all-cause mortality in COVID-19 patients.
Articles were retrieved until January 8, 2021, by searching in seven electronic databases.
The main outcome was all-cause mortality occurred during hospitalization. Data were
combined using the general variance-based method on the effect estimate for each study.
Separate meta-analyses according to type of COVID-19 patients (hospitalized or intensive
care unit [ICU] patients), anticoagulants (mainly heparin), and regimens (therapeutic
or prophylactic) were conducted. A total of 29 articles were selected, but 23 retrospective
studies were eligible for quantitative meta-analyses. No clinical trial was retrieved.
The majority of studies were of good quality; however, 34% did not distinguish heparin
from other anticoagulants. Meta-analysis on 25,719 hospitalized COVID-19 patients
showed that anticoagulant use was associated with 50% reduced in-hospital mortality
risk (pooled risk ratio [RR]: 0.50, 95% confidence interval [CI]: 0.40–0.62; I
2: 87%). Both anticoagulant regimens (therapeutic and prophylactic) reduced in-hospital
all-cause mortality, compared with no anticoagulation. Particularly in ICU patients,
the anticoagulant therapeutic regimen was associated with a reduced in-hospital mortality
risk (RR: 0.30, 95% CI: 0.15–0.60; I
2: 58%) compared with the prophylactic one. However, the former was also associated
with a higher risk of bleeding (RR: 2.53, 95% CI: 1.60–4.00; I
2: 65%). Anticoagulant use, mainly heparin, reduced all-cause mortality in COVID-19
patients during hospitalization. Due to the higher risk of bleeding at therapeutic
doses, the use of prophylactic dosages of anticoagulant is probably to be preferred
in noncritically ill COVID-19 patients.
Keywords
COVID-19 - coagulation - heparin - bleeding - mortality
