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Introduction: Valoctocogene roxaparvovec uses an adeno‐associated virus serotype 5 (AAV5) vector to transfer a factor VIII (FVIII) coding sequence to individuals with severe haemophilia A, providing bleeding protection. Aim: To assess safety and efficacy of valoctocogene roxaparvovec 5‒6 years post‐treatment. Methods: In a phase 1/2 trial, adult male participants with severe haemophilia A (FVIII ≤1 IU/dL) without FVIII inhibitors or anti‐AAV5 antibodies received valoctocogene roxaparvovec and were followed for 6 (6 × 1013 vg/kg; n = 7) and 5 (4 × 1013 vg/kg; n = 6) years. Safety, including investigation of potential associations between a malignancy and gene therapy, and efficacy are reported. Results: No new treatment‐related safety signals emerged. During year 6, a participant in the 6 × 1013 vg/kg cohort was diagnosed with grade 2 parotid gland acinar cell carcinoma; definitive treatment was uncomplicated parotidectomy with lymph node dissection. Target enrichment sequencing of tumour and adjacent healthy tissue revealed low vector integration (8.25 × 10−5 per diploid cell). Integrations were not elevated in tumour samples, no insertions appeared to drive tumorigenesis, and no clonal expansion of integration‐containing cells occurred. During all follow‐ups, >90% decreases from baseline in annualised treated bleeds and FVIII infusion rates were maintained. At the end of years 6 and 5, mean FVIII activity (chromogenic assay) was 9.8 IU/dL (median, 5.6 IU/dL) and 7.6 IU/dL (median, 7.1 IU/dL) for the 6 × 1013 and 4 × 1013 vg/kg cohorts, respectively, representing proportionally smaller year‐over‐year declines than earlier timepoints. Conclusions: Valoctocogene roxaparvovec safety and efficacy profiles remain largely unchanged; genomic investigations showed no association with a parotid tumour. [ABSTRACT FROM AUTHOR]

COVID-19 causes significant thrombosis and coagulopathy, with elevated D-dimer a predictor of adverse outcome. The precise mechanism of this coagulopathy remains unclear; one hypothesis is that loss of angiotensin-converting enzyme 2 activity during viral endocytosis leads to pro-inflammatory angiotensin-II accumulation, loss of angiotensin-1-7 and subsequent vascular endothelial activation. We undertook a double-blind randomized, placebo-controlled experimental medicine study to assess the effect of TRV027, a synthetic angiotensin-1-7 analogue on D-dimer in 30 patients admitted to hospital with COVID-19. The study showed a similar rate of adverse events in TRV027 and control groups. There was a numerical decrease in D-dimer in the TRV027 group and increase in D-dimer in the placebo group; however, this did not reach statistical significance (P = .15). A Bayesian analysis demonstrated that there was a 92% probability that this change represented a true drug effect. [ABSTRACT FROM AUTHOR]

Introduction: The "problem joint" (PJ) concept was developed to address patient‐centric needs for a more holistic assessment of joint morbidity for people with haemophilia (PwH). Aim: To quantify the humanistic burden of PJs in PwH to further support validation of the PJ outcome measure. Methods: Multivariable regression models evaluated the relationship between PJs and health‐related quality of life (HRQoL, EQ‐5D‐5L) and overall work productivity loss (WPL) using data from the 'Cost of HaEmophilia: a Socioeconomic Survey' population studies (adults: CHESS II, CHESS US+; children/adolescents: CHESS‐Paeds). Covariates included were haemophilia severity, age, comorbidities and education. Results: The CHESS II sample included 292 and 134 PwH for HRQoL and WPL analyses, mean age 38.6 years (39% ≥1 PJ, 61% none). CHESS US+ included 345 and 239 PwH for HRQoL and WPL, mean age 35 years (43% ≥1 PJ, 57% none). CHESS‐Paeds included 198 PwH aged 4–17 (HRQoL only), mean age 11.5 years (19% ≥1 PJ, 81% none). In CHESS II and CHESS US+, presence of PJs was associated with worse HRQoL (Both p <.001). Few CHESS‐Paeds participants had PJs, with no significant correlation with HRQoL. In CHESS II, upper body PJs were significantly correlated to WPL (p <.05). In CHESS US+, having ≥1 PJ or upper and lower body PJs were significantly correlated to WPL (vs. none; both p <.05). Conclusion: This study has shown a meaningful burden of PJs on PwH, which should be considered in clinical and health policy assessments of joint health. [ABSTRACT FROM AUTHOR]

Background: Von Willebrand Disease (VWD) is a common inherited bleeding disorder. Patients with VWD suffering from severe bleeding may benefit from the use of secondary long‐term prophylaxis. Aim: Systematically summarize the evidence on the clinical outcomes of secondary long‐term prophylaxis in patients with VWD and severe recurrent bleedings. Methods: We searched Medline and EMBASE through October 2019 for relevant randomized clinical trials (RCTs) and comparative observational studies (OS) assessing the effects of secondary long‐term prophylaxis in patients with VWD. We used Cochrane Risk of Bias (RoB) tool and the RoB for Non‐Randomized Studies of interventions (ROBINS‐I) tool to assess the quality of the included studies. We conducted random‐effects meta‐analyses and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Results: We included 12 studies. Evidence from one placebo controlled RCT suggested that VWD prophylaxis as compared to no prophylaxis reduced the rate of bleeding episodes (Rate ratio [RR],.24; 95% confidence interval [CI],.17–.35; low certainty evidence), and of epistaxis (RR,.38; 95%CI,.21–.67; moderate certainty evidence), and may increase serious adverse events RR 2.73 (95%CI.12–59.57; low certainty). Evidence from four before‐and‐after studies in which researchers reported comparative data suggested that VWD prophylaxis reduced the rate of bleeding (RR.34; 95%CI,.25–.46; very low certainty evidence). Conclusion: VWD prophylaxis treatment seems to reduce the risk of spontaneous bleeding, epistaxis, and hospitalizations. More RCTs should be conducted to increase the certainty in these benefits. [ABSTRACT FROM AUTHOR]

Introduction: Valoctocogene roxaparvovec is an investigational AAV5‐based factor VIII (FVIII) gene therapy that has demonstrated sustained clinical benefit in people with severe haemophilia A. Aim: To report safety, tolerability, efficacy, and quality of life (QOL) among participants who received valoctocogene roxaparvovec in a phase 1/2 clinical study (NCT02576795). Methods: Men ≥18 years of age with severe haemophilia A (FVIII ≤1 IU/dl) without history of FVIII inhibitors or anti‐AAV5 antibodies received a single infusion of valoctocogene roxaparvovec and were followed for 5 years (6 × 1013 vg/kg dose, n = 7) and 4 years (4 × 1013 vg/kg dose, n = 6). Results: Over the past 2 years, few adverse events and no FVIII inhibitors were reported. Per chromogenic substrate (CSA) assay at years 5 and 4, four of seven and three of six participants in the 6 × 1013 and 4 × 1013 vg/kg cohorts, respectively, maintained median FVIII levels >5 IU/dl, corresponding to mild haemophilia. By regression analysis, rate of change in FVIII activity was ‐0.14 (95% confidence interval [CI]: ‐.32 to.03) IU/dl/wk in the 6 × 1013 vg/kg cohort in year 5 and ‐.06 (95% CI: ‐.14 to.01) IU/dl/wk in the 4 × 1013 vg/kg cohort in year 4. No participants resumed FVIII prophylaxis, and eight of 13 participants reported zero bleeds in the past 2 years. Improved QOL from baseline persisted in the 6 × 1013 vg/kg cohort; all six Haemo‐QOL‐A domain scores increased. For the 4 × 1013 vg/kg cohort, high baseline Haemo‐QOL‐A scores persisted. Conclusion: These results demonstrate transgene expression and haemostatic response for up to 5 years in individuals with haemophilia A. [ABSTRACT FROM AUTHOR]

von Willebrand disease (VWD) is the most common inherited bleeding disorder. VWD is caused by deficiencies in von Willebrand factor (VWF), a critical adhesive haemostatic protein. This review provides an overview of VWD diagnosis and treatment, special considerations in treating women with VWD, and current genomic approaches to VWD. For diagnosis and treatment in VWD, an accurate diagnosis is critical to providing effective treatments, determining appropriate laboratory monitoring and for counselling the patient and family. Diagnosis of VWD begins with the clinical assessment for the bleeding phenotype, which is usually characterized by mucocutaneous and provoked bleeding. The diagnosis of VWD is then made by laboratory investigation. Multiple assays are used to assess VWF levels and functions. The mainstays of VWD treatment are tailored by VWD type and symptoms, and can include antifibrinolytic treatment, desmopressin and VWF replacement treatment. Women with VWD are also at risk for excessive uterine bleeding, such as with menses and childbirth. In addition to standard VWD treatments, heavy menstrual bleeding can be treated with hormones. Interdisciplinary management of childbirth and prophylaxis in the postpartum period are needed to reduce the risk of postpartum haemorrhage. Genomic approaches to VWD can inform VWD diagnosis, treatment, test assay selection, reproductive planning and family counselling. Most VWD patients have an identifiable VWF gene DNA variant. Next‐generation sequencing is rapidly being adopted to provide more comprehensive VWF sequence information for patients with known or suspected VWD. [ABSTRACT FROM AUTHOR]

Summary: Chronic venous disease (CVD) represents a significant healthcare burden. Thrombophilia is proposed as a risk factor, particularly for post‐thrombotic CVD. A systematic review was performed to determine the relationship between thrombophilia and non‐thrombotic CVD. MEDLINE® and Embase® databases were searched from 1946 up to March 2018. Case‐control studies, cohort studies or randomised clinical trials reporting on thrombophilias in non‐thrombotic lower limb CVD in adult patients were included. Non‐English and post‐thrombotic syndrome studies were excluded. Study selection and data extraction were performed by two reviewers. Fifteen studies were included, reporting on 916 cases and 1261 controls. Studies largely focused on venous ulceration and investigated multiple haemostatic factors. An association between thrombophilia and non‐thrombotic CVD was identified, with greater prevalence and factor concentration alteration reported in patients compared to controls. Concomitant thrombophilia presence was associated with earlier CVD onset. Relationship strength varied, with commoner aetiologies showing clearer correlation than rarer ones. Thrombophilia is associated with non‐thrombotic CVD but the mechanism is unclear and causation cannot be determined. Future research should focus on prospective studies with larger populations and identify adjunct therapies targeting thrombophilia. [ABSTRACT FROM AUTHOR]

The article features the nonprofit James Lind Alliance (JLA) top 10 research priorities in bleeding disorders in Great Britain in 2019. Topics discussed include the role and effectiveness of blood clotting tests, the risk and benefit balancing of antithrombotic treatment for cardiovascular disease, and the best management of severe haemorrhage after delivery. Also noted is the participation of patients and carers in the development of the list.

Heritable dysfibrinogenaemia ( HD) is a rare qualitative disorder of fibrinogen ( FGN). To better describe the clinical, laboratory and genotypic spectrum of HD, we evaluated 35 subjects identified at two UK centres using laboratory criteria. 12/35(34%) subjects with HD experienced bleeding (bleeding score >1 at any site), 3/35(9%) thrombosis and 20/35(57%) were asymptomatic. Amongst subjects with bleeding, symptoms were typically mild, at one anatomical site and seldom occurred after invasive procedures. All subject showed dry clot weight within or above laboratory reference interval (median 3·2 g/l; range 1·9-5·1), reduced Clauss fibrinogen (median 0·52 g/l; range 0·21-1·3), and prolonged thrombin (median 30·7 s; range 21·3-45·7) and reptilase (median 42·0 s; range 20·0-68·0) times. In all subjects, the prothrombin time ratio ( PTR), determined by Sysmex CA-1500 coagulometer and Innovin activator, was abnormal (median 1·42; range 1·22-1·61). The activated partial thromboplastin time ratio and PTR with other coagulometers and activators were comparatively insensitive to HD. All subjects with HD harboured heterozygous candidate nucleotide variations within known hotspots in the FGN genes. The HD variants identified in this cross-sectional study seldom have significant clinical manifestations and show similar laboratory features irrespective of genotype. Selection of coagulometer and PT activator may markedly affect the detection of new HD cases using coagulation screening tests. [ABSTRACT FROM AUTHOR]

The anticoagulant effect of unfractionated heparin (UFH) is monitored using the activated partial thromboplastin time (APTT). An APTT of 1·5–2·5 times the control is usually taken as the therapeutic range and assumed to reflect an anti-activated factor X (anti-Xa) level of 0·35–0·7 u/ml. However, in some cases, despite administration of sufficient heparin to achieve a therapeutic anti-Xa assay level, the APTT remains sub-therapeutic. This ‘apparent heparin resistance’ is commonly due to high levels of factor VIII (FVIII). In these situations, the anti-Xa is usually preferred for monitoring in order to avoid, what might be, dangerously high levels of heparin. We hypothesized that at high FVIII levels, the heparin resistance encountered may be genuine rather than apparent and that higher doses of heparin may indeed be needed for an equivalent anticoagulant effect. The relationship between heparin level, APTT and anticoagulant effect at different FVIII concentrations was determined using thrombelastography and the thrombin generation assay. Thromboelastographic and thrombin generation parameters concurred with APTT, demonstrating a genuine heparin resistance in the presence of high FVIII levels. This suggests that APTT may be a more accurate measure of anticoagulant effect in vivo than anti-Xa. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the role of markers of bone remodelling, and osteoclast activation/function in patients with monoclonal gammopathy of undetermined significance (MGUS). We have measured serum levels of soluble RANKL (sRANKL), osteoprotegerin (OPG), macrophage inflammatory protein-1alpha (MIP-1 α), markers of bone resorption [N-telopeptide of collagen type-I (NTX), and tartrate-resistant acid phosphatase isoform-5b (TRACP-5b)] and bone formation [bone-alkaline phosphatase (bALP)] in 40 MGUS patients. These parameters were compared with those of 42 newly diagnosed myeloma patients, and 45 healthy, gender- and age-matched controls. MGUS patients had elevated levels of NTX, sRANKL, and sRANKL/OPG ratio compared with controls ( P < 0·0001). Furthermore, TRACP-5b, MIP-1 α and NTX were decreased in patients with MGUS compared with myeloma patients ( P < 0·001), while OPG and bALP were increased ( P < 0·001). Serum levels of MIP-1 α, as well as TRACP-5b, and sRANKL/OPG ratio were reduced, while bALP was increased in MGUS patients, even when compared with myeloma patients who had stage I/II disease. These results demonstrate that increased osteoclastogenesis leading to increased bone resorption is present in MGUS but seems to be compensated for by normal bone formation, which is absent in MM. Furthermore MIP-1 α, bALP, and sRANKL/OPG may be useful tools for distinguishing between cases of MGUS and early myeloma. [ABSTRACT FROM AUTHOR]

We have characterized the molecular defect in two families with severe factor VII (FVII) deficiency. In family I, the proband was found to be homozygous for a novel 18 bp deletion in exon 8 (g.10896–10913del) resulting in the in-frame deletion of six amino acids in the serine protease domain. Molecular modelling suggests the deletion is likely to disrupt folding of the FVII molecule. The reduced FVII antigen (21 U/dl) and negligible activity (0·4 U/dl) in the patient's plasma indicated that the deletion affected both the secretion/ stability and function of the mutant protein. In family II, the proband was found to be a compound heterozygote for a novel missense mutation (g.7884G>A; FVII G117R) in exon 5 encoding the EGF2 domain of FVII and a nonsense mutation (g.8960C>T; FVII R152X) in exon 6. Extensive sequence comparison in a wide evolutionary context suggested that the Gly117 residue is critical for structure of FVII. The grossly reduced FVII antigen (1·1 U/dl) and activity (0·4 U/dl) plasma values indicate the mutation primarily affected the folding/secretion or stability of the protein. [ABSTRACT FROM AUTHOR]

Background: Recombinant FVIIa (rFVIIa/NovoSeven) is a novel hemostatic agent originally developed to treat patients with hemophilia who had developed inhibitors. Several case reports have suggested that rFVIIa may be effective in treating patients without a pre-existing bleeding disorder who have uncontrolled bleeding.Study Design and Methods: Data on the efficacy and safety of rFVIIa in the treatment of massive hemorrhage were obtained retrospectively from the NovoSeven extended-use data collection system.Results: A total of 40 patients received rFVIIa for uncontrolled bleeding, and in these patients, bleeding stopped or decreased in 32 (80%). Blood product usage was significantly decreased after rFVIIa administration. Thromboembolic events occurred in three patients with additional risk factors for thrombosis. Of 40 patients, 23 (57.5%) died. Bleeding was the direct cause of death in seven cases (all within 24 hr of administration of rFVIIa). The remaining 16 deaths were the result of sepsis, multi-organ failure, or the underlying disease.Conclusions: In this retrospective study of data voluntarily submitted to a web-based drug surveillance program, we present preliminary results on the use of rFVIIa in nonhemophilia patients with bleeding. Although some efficacy is suggested, there was a high mortality rate from nonhemorrhagic causes. Randomized controlled trials are needed to properly assess the role of rFVIIa in the management of hemorrhage. [ABSTRACT FROM AUTHOR]

Summary. ABO blood group determines plasma von Willebrand factor (VWF) levels and ABH antigens are present on VWF. To investigate whether ABO influences the rate of VWF synthesis, we performed stable transfection of A transferase in a phenotypically group-O endothelial cell line (EAhy926). A transferase expression did not affect the rate of VWF synthesis. Although high levels of A antigen were expressed on the cell surface, no A determinants were added to VWF synthesized within these cells. Further studies demonstrated H structures were not present on EAhy926-derived VWF, despite the fact that H antigen is constitutively expressed by these cells. [ABSTRACT FROM AUTHOR]

Summary. The interdomain acidic region a1 is a unique structural feature of coagulation factor VIII (FVIII) and may mediate the proteolytic activation of FVIII and the inactivation of FVIIIa. We report an individual with a Tyr346→Cys substitution within region a1 , who presented with a one-stage FVIII activity (FVIII:C) of 0·34 iu/ml (normal range 0·5–2·0) but normal two-stage FVIII:C and FVIII antigen values. In a factor Xa (FXa)-generation assay for FVIII in which the activation time with thrombin was varied, the variant plasma showed normal FVIII:C at both short and long activation times. However, at intermediate activation times the FXa generation of the variant plasma was less than that of normal pooled plasma. In a modified one-stage FVIII:C assay in which partially purified FVIII was activated with thrombin at low concentrations, the variant FVIII showed less activation than wild-type FVIII, although this defect corrected with increasing concentrations of thrombin. When partially purified variant FVIII was activated with a large molar excess of thrombin, the subsequent rate of decay of FVIII:C was greater for variant FVIII. The complex defects in activation and inactivation displayed by FVIII Tyr346→Cys support the hypothesis that the a1 sequence is a key regulator of FVIII activity. [ABSTRACT FROM AUTHOR]

Summary. Previous reports on the effect of Secretor and Lewis blood groups on plasma factor VIII–von Willebrand factor (FVIII–VWF) levels have produced conflicting findings. To determine whether either or both loci can influence plasma FVIII–VWF complex levels, we studied the relationship between Secretor and Lewis genotypes, determined definitively using polymerase chain reaction–restriction fragment length polymorphism analysis, and plasma FVIII coagulant activity (FVIII:C) and VWF antigen (VWF:Ag) levels in 136 healthy volunteers. Overall, significantly higher VWF:Ag levels were found in those individuals homozygous for the Se allele (genotype SeSe ) than in those heterozygous for the Se allele (P < 0·001). To minimize any confounding influence of ABO genotype/phenotype, we investigated the relationship between Secretor genotype and plasma FVIII–VWF levels within individuals of the same ABO blood group genotype. In the subgroup analysis of group O 1 O 1 individuals alone, VWF:Ag levels were again significantly higher in those individuals with Secretor genotype SeSe than in those either heterozygous or homozygous for the se null allele. Among A 1 O 1 subjects, homozygous Secretor s also had significantly higher VWF:Ag levels. In contrast, we found no relationship between Lewis genotype and either VWF:Ag or FVIII:C levels. This study is the first based on genotypic rather than serological analysis, and resolves the previously confounding effects of the Lewis and Secretor loci on plasma FVIII–VWF complex levels. [ABSTRACT FROM AUTHOR]

Elevated plasma factor VIII coagulant activity (FVIII:C, > 150 IU/dl) is a risk factor for venous thromboembolism (VTE). We hypothesized that increased FVIII:C may exert a prothrombotic effect by increasing basal thrombin generation. To test this hypothesis we have measured prothrombin fragment 1 + 2 (F1 + 2) and thrombin–antithrombin complex (TAT) in three groups: (i) patients with objectively confirmed VTE and elevated FVIII:C; (ii) patients with VTE and no detectable thrombophilia; and (iii) healthy age- and sex-matched control subjets. In the group of patients with elevated FVIII:C, TAT and F1 + 2 levels were increased in 85% and 78% of individuals respectively. This frequency of coagulation activation is dramatically higher than that reported for other recognized constitutional thrombophilias. In the group of patients with VTE but no proven thrombophilia, increased thrombin generation was present in 30% of individuals. Basal thrombin generation was significantly higher in patients with elevated FVIII:C compared with individuals with VTE but no documented thrombophilia (median TAT = 8·65 µg/l versus 2·95 µg/l, median F1 + 2 = 1·5 nmol/l versus 0·87 nmol/l; P < 0·0001, P < 0·001). Overall FVIII:C levels were strongly correlated with levels of thrombin generation (r= 0·5, P < 0001). The clinical significance of such markedly increased F1 + 2 and TAT levels in patients with high FVIII:C levels remains unclear. [ABSTRACT FROM AUTHOR]

Haemorrhage is a frequent manifestation of amyloidosis. We performed a retrospective clinical analysis of 337 patients with systemic immunoglobulin light-chain (AL)-amyloidosis, in whom whole-body serum amyloid P component (SAP) scintigraphy and a clotting screen had been performed. Abnormal bleeding was noted in 94 cases (28%), and the coagulation screen was abnormal in 172 cases (51%). The most common abnormalities were prolongation of the thrombin time (TT; 108 cases, 32%) and the prothrombin time (PT; 82 cases, 24%). In multivariate analysis, a prolonged PT was the only coagulation abnormality associated with abnormal bleeding (P = 0·0012), but this was independent of the whole-body amyloid load. Prolongation of the TT was associated with hepatic amyloid infiltration (P < 0·00001), with proteinuria (P < 0·001) and low serum albumin (P < 0·00001). In 154 patients who were studied further, subnormal factor X activity (FX:C) was found in 22 cases (14%). In cases with subnormal FX:C, the corresponding factor X antigen (FX:Ag) measurements were consistently higher (median FX:Ag/FX:C 2·5, range 0·81–9·25, n = 16) than cases with normal FX:C (median FX:Ag/FX:C 0·96, range 0·65–1·29, n = 28, P < 0·0001). No evidence was found of an FX inhibitor. Of the 48/154 (31%) cases with a prolonged TT, the reptilase time was also prolonged in 38/48 cases (79%). These data show that haemorrhage and abnormal coagulation are common in AL-amyloidosis and are multifactorial in origin. We provide evidence suggesting that hepatic amyloid infiltration and nephrotic syndrome are determinants of the TT. In most patients, prolongation of the PT was explained by reduction in FX:C, but this was not wholly explained by a reduction in FX:Ag. [ABSTRACT FROM AUTHOR]

Summary. Beta-blockers significantly reduce elevated factor VIII (FVIII) levels in patients with venous thromboembolism (VTE). To determine whether β-adrenergic receptors are important in the aetiology of high FVIII levels, we investigated four coding polymorphisms of the β1- and β2-receptor genes in 64 patients with high FVIII and VTE and 100 healthy controls. Genotypic and allelic frequencies were not significantly different between the patient and control groups. However, a significant dosage effect of the β2 E27 allele on plasma FVIII coagulant activity levels was observed in normal group O individuals. [ABSTRACT FROM AUTHOR]

Coagulation dysfunction and thrombosis are major complications in patients with coronavirus disease 2019 (COVID-19). Patients on oral anticoagulants (OAC) prior to diagnosis of COVID-19 may therefore have better outcomes. In this multicentre observational study of 5 883 patients (≥18 years) admitted to 26 UK hospitals between 1 April 2020 and 31 July 2020, overall mortality was 29·2%. Incidences of thrombosis, major bleeding (MB) and multiorgan failure (MOF) were 5·4%, 1·7% and 3·3% respectively. The presence of thrombosis, MB, or MOF was associated with a 1·8, 4·5 or 5·9-fold increased risk of dying, respectively. Of the 5 883 patients studied, 83·6% (n = 4 920) were not on OAC and 16·4% (n = 963) were taking OAC at the time of admission. There was no difference in mortality between patients on OAC vs no OAC prior to admission when compared in an adjusted multivariate analysis [hazard ratio (HR) 1·05, 95% confidence interval (CI) 0·93-1·19; P = 0·15] or in an adjusted propensity score analysis (HR 0·92 95% CI 0·58-1·450; P = 0·18). In multivariate and adjusted propensity score analyses, the only significant association of no anticoagulation prior to diagnosis of COVID-19 was admission to the Intensive-Care Unit (ICU) (HR 1·98, 95% CI 1·37-2·85). Thrombosis, MB, and MOF were associated with higher mortality. Our results indicate that patients may have benefit from prior OAC use, especially reduced admission to ICU, without any increase in bleeding., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)