ABSTRACT
Background: Concerns emerged for the management of intramuscular (IM) injections for COVID-19 vaccines in patients with therapeutic anticoagulation. Aim(s): The aim of the study was to evaluate the risk of bleeding events following IM vaccination in patients under therapeutic anticoagulation Methods: We first performed a French multicentre prospective study including patient treated by anticoagulant therapy for venous thromboembolism between May 2021 and September 2021. Consecutive patients were asked to report bleeding events at the site of COVID-19 vaccine injection during follow-up. We next performed a request in the French national pharmacovigilance database to identify cases of bleeding events at the site of injections following COVID-19 vaccine in patients under therapeutic anticoagulation between December, 27th, 2020 and June, 30th, 2021. Result(s): Between May and September 2021, a total of 348 patients with anticoagulant therapy received 561 IM injections of COVD-19 vaccines. Median age of patients was 68.4 years and 65.2% were males. Almost all patients were treated with direct oral anticoagulant (DOAC 96.6%), 11 (3.2%) patients with vitamin K antagonist and one (0.2%) with tinzaparin. Among them, 17.9% had pressure at the injection site after the injection and 4.2% had anticoagulant dose skipping before vaccination. After IM injections, a total of 3 (0.6%) bleeding events were observed, 2 (0.4%) minor and one (0.2%) clinically relevant non-major bleeding. We next observed in the French national pharmacovigilance database a total of 13 bleeding events (all minor bleeding) at the site of injection in patients on therapeutic anticoagulation between December, 27th, 2020 and June, 30th, 2021. In France, 69,089,410 doses of COVID-19 vaccine were administered during this period. These bleeding events correspond to a spontaneous notification rate of 0.19 cases (95% CI 0.09-0.29) reported per million of doses administered. Conclusion(s): IM vaccination appears safe in patients under therapeutic anticoagulation in particular with DOAC, and may not require skipping doses.
ABSTRACT
Background : High rates of venous thromboembolic events associated to LMWH/heparin therapy lead to numerous heparin-induced thrombocytopenia (HIT) suspicion during COVID-19 outbreak. Aims : We aim to describe HIT-suspected patient's characteristics and prevalence between March 15 and April 15 of 2020. Methods : This is a multi-centric retrospective cohort study of HITsuspected patients referred to our center. 4T score has been realized by experienced hematologist and/or pharmacologist and allowed us to trigger specific HIT assays if score was >3 (IgG anti-PF4/H and 14C-serotonine release assay, SRA). We included all consecutive HIT-suspected patients during COVID-19 outbreak compared to the same period in 2019. Results : During 2019 and 2020-study periods we identified, respectively, 17 and 41 consecutive HIT-suspected patients. Among the 2020-group, 23 were COVID-19 and 18 were non-COVID-19 patients. Clinical and biological characteristics were not significantly different between the 2019, 2020 non-COVID-19 and COVID-19 HIT-suspected patients. During 2019-period study, 11 (64.7%) patients had a 4T score >3, 4 (36.3%) of them had positive anti-PF4/H antibodies and only one had a positive SRA assay. During 2020-period study, 8 (44.4%) non-COVID-19 and 10 (43.5%) COVID-19 patients had a 4T score >3. Among them, respectively, 3 (37.5%) and 3 (30.%) had positive anti-PF4/H antibodies. SRA assay was positive in 3 non-COVID-19 patients tested and in the only one COVID-19 tested patient. The 4T score was able to exclude HIT in 67% of COVID-19 patients suspected. In 2020-study period, when comparing COVID-19 and non-COVID-19 patients, the only significantly difference in term of HIT suspicion criteria was the mean duration of heparin exposition before suspicion: 9.9 days ±6.3 for non-COVID-19 patients versus 15.2 days ±8.8 for COVID-19 patients, P = 0.043). Conclusions : HIT suspicion in COVID-19 occurs after longer anticoagulation time than non-COVID-19. We did not observe more confirmed HIT in COVID-19 in contrast our two non-COVID-19 control groups.