SAFETY of PROTHROMBIN COMPLEX CONCENTRATES IN PATIENTS REQUIRING RAPID REVERSAL of ANTICOAGULANT TREATMENT with the VITAMIN K ANTAGONISTS: a Systematic Review and a Meta-Analysis of the Literature.
Authors: Dentali Francesco , Marchesi Chiara , Pierfranceschi Matteo Giorgi , Crowther Mark A. , Garcia David , Hylek Elaine M. , Witt Dan , Clark Nathan , Squizzato Alessandro , Imberti Davide , Ageno Walter 
Published: October 2019

Abstract
Abstract 1113

Background:
Prothrombin complex concentrates (PCCs) are currently recommended by several international guidelines as the treatment of choice in warfarin-related coagulopathy. However, while the efficacy of PCCs is well established, their safety in terms of risk of thromboembolic complications, some of which may be severe or even life-threatening, is still not clear.
Thus, we performed a systematic review of the literature with the aim of evaluating the rate of thromboembolic complications in patients on Vitamin K antagonists (VKAs) treated with PCCs for a bleeding event or before an urgent invasive procedure.

Methods:
MEDLINE and EMBASE databases were searched up to June 2010. Two reviewers performed study selection independently. Studies providing data on incidence thromboembolic complications in patients on VKAs were potentially eligible for the study. Two reviewers independently extracted data on study and population characteristics, type, dose of PCC treatment. Weighted mean proportion of the rate of thromboembolic complications and the mortality rate were calculated.

Results:
28 studies for a total of 1104 patients were included in our systematic review. Seven studies used 3-factor PCCs, 21 studies used 4-factor PCCs. Concomitant vitamin K was administered in 21 studies, while fresh frozen plasma in 6.
Seventeen patients had a thromboembolic complication after PCCs administration (weighted mean 1.9%; 95% CI 1.1–2.9 %). Of the thromboembolic events, 4 were fatal (23%). The incidence of thromboembolic events was 1.9%; (95% CI 1.0–3.1 %) in patients treated for bleeding and 0.8% (95% CI 0.1–2.0 %) in patients treated before urgent surgery or invasive procedures. For 5 of the reported events we were unable to define the subgroup.
The incidence of thromboembolic events was 2.3% (95% CI 1.2–3.8) in patients treated with 4-factor PCCs, and 0.7% (95% CI 0.0–2.4) in patients treated with 3-factor PCCs.
One hundred and seven patients died for a mean mortality rate of 11.1% (95% CI 6.4–17.0 %).
Only 7 studies for a total 257 patients provided data on the incidence of viral transmission after PCCs administration. In this subgroup of patients there were 4 episode of positivity for parvovirus B19 for a mean incidence of 1.9% (95% CI 0.3–4.9%).

Conclusions:
The results of our systematic review of the literature show that the treatment with PCCs in patients on VKAs therapy is associated with a low risk of thromboembolic complications providing important information on the safety of this approach. Moreover, also the risk of viral transmission, although evaluated in few studies only, appears to be negligible. The findings of a low thromboembolic risk have been further confirmed by the results of the subgroup analyses separately evaluating treatment with 3 or 4-factors PCCs and different indications for PCCs therapy.

Disclosures:
Crowther: Pfizer: Consultancy; Leo Pharma: Research Funding; Boehringer Ingelheim: Research Funding.