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.
METHODS: Warfarin relies on regular monitoring of International Normalized Ratio which is a standardized test to measure prothrombin time and appropriate dose adjustment. Pharmacometabonomics is a novel scientific field which deals with identification and quantification of the metabolites present in the metabolome using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR). Pharmacometabonomics helps to indicate perturbation in the levels of metabolites in the cells and tissues due to drug or ingestion of any substance. NMR is one of the most widely-used spectroscopic techniques in metabolomics because of its reproducibility and speed.
RESULTS: There are many factors that influence the metabolism of warfarin, making changes in drug dosage common, and clinical factors like drug-drug interactions, dietary interactions and age explain for the most part the variability in warfarin dosing. Some studies have showed that pharmacogenetic testing for warfarin dosing does not improve health outcomes, and around 26% of the variation in warfarin dose requirements remains unexplained yet.
CONCLUSION: Many recent pharmacometabonomics studies have been conducted to identify novel biomarkers of drug therapies such as paracetamol, aspirin and simvastatin. Thus, a technique such as NMR based pharmacometabonomics to find novel biomarkers in plasma and urine might be useful to predict warfarin outcome.
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