OBJECTIVES:

DOACs are an attractive treatment option for acute HIT due to their ease of administration and reduced need for outpatient monitoring. The 2018 American Society of Hematology (ASH) HIT treatment guidelines conditionally recommend DOAC use due to very low certainty in the evidence about effects. We conducted a systematic literature review of published studies to assess the outcomes of DOAC use in acute HIT treatment.

METHODS:

MEDLINE and Embase databases were searched through July 2022 to identify studies that assessed DOAC use in acute HIT treatment. This search resulted in 902 published records. Eight cohort studies met our inclusion criteria and were included in the final review.

RESULTS:

Zero randomized control trials (RCTs) that assessed the use of DOACs in acute HIT were identified. Out of eight studies included in our review, six were retrospective cohort studies and two were single-arm interventional studies. A moderate-to-high 4Ts score result was reported for all patients; a positive antibody immunoassay was reported for 115 patients; a positive serotonin release assay (SRA) was reported for 81 patients. Six, four, and three studies reported use of rivaroxaban, apixaban, and dabigatran, respectively. Of 241 patients, 95 received initial parenteral acute HIT treatment. Mean time to platelet recovery ranged between 4 to 13 days. Thrombosis, major bleeding, and clinically relevant non-major bleeding were reported in 12, 6, and 12 patients respectively.

CONCLUSIONS:

Preliminary results indicate that rivaroxaban, apixaban, and dabigatran may possibly be used for the treatment of acute HIT. Study design, small study size, and variability in diagnostic criteria limit data utility. More prospective observational studies with a large sample size and specific outcome measures to assess DOAC use in acute HIT are needed.