METHODS: A systematic literature search was performed in electronic databases to identify randomized controlled trials comparing the clinical outcomes between intermediate/ therapeutic anticoagulation and prophylactic anticoagulation. Meta-analyses with random-effects models were used to estimate the pooled odds ratio (OR) for outcomes of interest at a 95% confidence interval (CI).
RESULTS: Eight randomized controlled trials were included, with a total of 5405 hospitalized patients with COVID-19. The meta-analysis revealed no statistically significant difference in the odds of mortality (pooled OR = 0.92; 95% CI 0.71-1.19) but a statistically significant reduction in the odds of development of thrombotic events (pooled OR = 0.55; 95% CI 0.42-0.72), and significantly increased odds of development of major bleeding (pooled OR = 1.81; 95% CI 1.20-2.72) with the use of intermediate/therapeutic anticoagulation, relative to prophylactic anticoagulation. Subgroup analysis in patients with a severe course of COVID-19 observed a statistically significant reduction in the odds of development of thrombotic events (pooled OR = 0.66; 95% CI 0.45-0.98) but no significant difference in the odds of development of major bleeding events (pooled OR = 1.37; 95% CI 0.74-2.56), with the use of intermediate/therapeutic anticoagulation, relative to prophylactic anticoagulation.
CONCLUSION: There could be net clinical benefits with higher-intensity dosing of anticoagulation relative to prophylactic-dosing of anticoagulation among hospitalized patients with severe COVID-19.
OBJECTIVES: The primary aim of this review was to investigate the effect of fibrinogen concentrate in postoperative blood loss in adult surgical patients.
DESIGN: Systematic review and meta-analysis.
DATA SOURCES: Databases of MEDLINE, EMBASE and CENTRAL were searched from their start date until July 2019.
ELIGIBILITY CRITERIA: All randomized clinical trials comparing intravenous fibrinogen concentrate and placebo in adult surgical patients were included, regardless of type of surgery. Observational studies, case reports, case series and non-systematic reviews were excluded.
RESULTS: Thirteen trials (n = 900) were included in this review. In comparison to placebo, fibrinogen concentrate significantly reduced the first 12-hour postoperative blood loss, with a mean difference of -134.6 ml (95% CI -181.9 to -87.4). It also significantly increased clot firmness in thromboelastometry (FIBTEM) with a mean difference of 2.5 mm (95%CI 1.1 to 3.8). No significant differences were demonstrated in the adverse events associated with fibrinogen concentrate use, namely incidence of thromboembolism, myocardial infarction and acute kidney injury.
CONCLUSIONS: In this meta-analysis of 13 randomized trials, low level of evidence and substantial heterogeneity with small sample size limit strong recommendation on the use of fibrinogen concentrate in adult surgical patients. However, its use is tolerable without any notable adverse events.
TRIAL REGISTRATION: CRD42019149164.
METHODS: This prospective, multicentre, open-label, randomised, phase 3a trial (explorer8) was conducted at 69 investigational sites in 31 countries. Eligible patients were male, aged 12 years or older, and had congenital severe haemophilia A or moderate or severe haemophilia B without inhibitors and with documented treatment with clotting factor concentrate in the 24 weeks before screening. The trial was paused because of non-fatal thromboembolic events in three patients (two from this trial [explorer8] and one from a related trial in haemophilia with inhibitors [explorer7; NCT04083781]) and restarted with mitigation measures, including a revised dosing regimen of subcutaneous concizumab at 1·0 mg/kg loading dose on day 1 and subsequent daily doses of 0·20 mg/kg from day 2, with options to decrease to 0·15 mg/kg, stay on 0·20 mg/kg, or increase to 0·25 mg/kg on the basis of concizumab plasma concentration measured after 4 weeks on concizumab. Patients recruited after treatment restart were randomly assigned 1:2 using an interactive web response system to receive no prophylaxis and continue on-demand clotting factor (group 1) or concizumab prophylaxis (group 2). The primary endpoints were the number of treated spontaneous and traumatic bleeding episodes for patients with haemophilia A and haemophilia B separately, assessed at the confirmatory analysis cutoff in randomly assigned patients. Analyses were by intention-to-treat. There were two additional groups containing non-randomly-assigned patients: group 3 contained patients who entered the trial before the trial pause and were receiving concizumab in the phase 2 trial (explorer5; NCT03196297), and group 4 contained patients who received previous clotting factor concentrate prophylaxis or on-demand treatment in the non-interventional trial (explorer6; NCT03741881), patients randomly assigned to groups 1 or 2 before the treatment pause, and patients from explorer5 enrolled after the treatment pause. The safety analysis set contained all patients who received concizumab. Superiority of concizumab over no prophylaxis was established if the two-sided 95% CI of the treatment ratio was less than 1 for haemophilia A and for haemophilia B. This trial is registered with ClinicalTrials.gov, NCT04082429, and its extension part is ongoing.
FINDINGS: Patients were recruited between Nov 13, 2019 and Nov 30, 2021; the cutoff date for the analyses presented was July 12, 2022. 173 patients were screened, of whom 148 (86%) were randomly assigned or allocated to the four groups in the study after trial restart on Sept 30, 2020 (nine with haemophilia A and 12 with haemophilia B in group 1; 18 with haemophilia A and 24 with haemophilia B in group 2; nine with haemophilia A in group 3; and 46 with haemophilia A and 30 with haemophilia B in group 4). The estimated mean annualised bleeding rate ratio for treated spontaneous and traumatic bleeding episodes during concizumab prophylaxis versus no prophylaxis was 0·14 (95% CI 0·07-0·29; p<0·0001) for patients with haemophilia A and 0·21 (0·10-0·45; p<0·0001) for patients with haemophilia B. The most frequent adverse events in patients who received concizumab were SARS-CoV-2 infection (19 [13%] of 151 patients), an increase in fibrin D-dimers (12 [8%] patients), and upper respiratory tract infection (ten [7%] patients). There was one fatal adverse event possibly related to treatment (intra-abdominal haemorrhage in a patient from group 4 with haemophilia A with a long-standing history of hypertension). No thromboembolic events were reported between the trial restart and confirmatory analysis cutoff.
INTERPRETATION: Concizumab was effective in reducing the bleeding rate compared with no prophylaxis and was considered safe in patients with haemophilia A or B without inhibitors. The results of this trial suggest that concizumab has the potential to be one of the first subcutaneous treatment options for patients with haemophilia B without inhibitors.
FUNDING: Novo Nordisk.
METHODS: The pharmacy supply database and the medical records of patients with non-valvular atrial fibrillation (NVAF) receiving warfarin, dabigatran or rivaroxaban at two tertiary hospitals were reviewed. Patients who experienced an OAC-associated major or CRB event within 12 months of follow-up, or who have received OAC therapy for at least 1 year, were identified. The BRSs were fitted separately into patient data. The discrimination and the calibration of these BRSs as well as the factors associated with bleeding events were then assessed.
RESULTS: A total of 1017 patients with at least 1-year follow-up period, or those who developed a bleeding event within 1 year of OAC use, were recruited. Of which, 23 patients experienced a first major bleeding event, whereas 76 patients, a first CRB event. Multivariate logistic regression results show that age of 75 or older, prior bleeding and male gender are associated with major bleeding events. On the other hand, prior gastrointestinal bleeding, a haematocrit value of less than 30% and renal impairment are independent predictors of CRB events. All the BRSs show a satisfactory calibration for major and CRB events. Among these BRSs, only HEMORR2 HAGES (C-statistic = 0.71, 95% CI 0.60-0.82, P