The incidence of thrombotic events with idarucizumab and andexanet alfa: A systematic review and meta-analysis.

Introduction: Direct thrombin inhibitor, dabigatran and factor Xa inhibitors, apixaban, edoxaban, and rivaroxaban (DOACs/NOACs), are currently the first-choice drugs in some indications. Life-threatening bleeding occurring during DOACs treatment may benefit from the use of reversal agents, however there are some concerns regarding potential rebound thrombotic events. In this systematic review we aimed to estimate the incidence of thrombotic events in patients treated with idarucizumab or andexanet alfa.

Methods: This systematic review included all prospective and retrospective studies, enrolling patients that received specific antidotes (idarucizumab, andexanet alfa and cirapantag) for anticoagulation reversal, published until October 2019 in CENTRAL, MEDLINE and PsycINFO. Studies in healthy individuals and those with less than 10 patients were excluded. The primary outcome was the incidence of thrombotic events and the secondary outcome was all-cause mortality. Studies screening and data extraction was performed in duplicate by reviewers. A random-effects meta-analysis was performed using the Freeman-Tukey transformation of the data. The results are expressed in percentages, with 95%-confidence intervals (CI), limited between 0 and 100% due to the data transformation.

Results: Overall 16 studies with 1774 patients were included (13 studies enrolling 1384 patients that received idarucizumab; 3 studies enrolling 390 patients that received andexanet alfa; cirapantag studies were not found). The pooled incidence rate of thrombotic events in the patients treated with specific antidote was 5.5% (95% CI 2.0-10.1%) until 30-90 days. The incidence of all-cause mortality was 13.3% (95% CI 9.6-17.5%).

Conclusions: In patients requiring idarucizumab or andexanet alfa to reach haemostasis, our data shows that there were 5.5% thrombotic events. The causality of harm associated to antidotes remains to be established due to the design of studies without a control group.