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The Cochrane Database of Systematic... Apr 2010Patients who have undergone total hip or knee replacement (THR, TKR) have a high risk of developing venous thromboembolism (VTE) following surgery, despite appropriate... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Patients who have undergone total hip or knee replacement (THR, TKR) have a high risk of developing venous thromboembolism (VTE) following surgery, despite appropriate anticoagulation with warfarin or low molecular weight heparin (LMWH). New anticoagulants are under investigation.
OBJECTIVES
To examine the efficacy and safety of prophylactic anticoagulation with direct thrombin inhibitors (DTIs) versus LMWH or vitamin K antagonists in the prevention of VTE in patients undergoing THR or TKR.
SEARCH STRATEGY
The Cochrane Peripheral Vascular Disease Group searched their Specialized Register (last searched 12 March 2010) and CENTRAL (last searched 2010, Issue 2).
SELECTION CRITERIA
Randomised controlled trials.
DATA COLLECTION AND ANALYSIS
Three reviewers independently assessed methodological quality and extracted data in pre-designed tables. The reported follow-up events were included
MAIN RESULTS
We included 14 studies included involving 21,642 patients evaluated for efficacy and 27,360 for safety. No difference was observed in major VTE in DTIs compared with LMWH in both types of operations (odds ratio (OR) 0.91; 95% confidence interval (CI) 0.69 to 1.19), with high heterogeneity (I(2) 71%). No difference was observed with warfarin (OR 0.85; 95% CI 0.63 to 1.15) in TKR, with no heterogeneity (I(2) 0%).More total bleeding events were observed in the DTI group (in ximelagatran and dabigatran but not in desirudin) in patients subjected to THR (OR 1.40; 95% CI 1.06, 1.85; I(2) 41%) compared with LMWH. No difference was observed with warfarin in TKR (OR 1.76; 95% CI 0.91 to 3.38; I(2) 0%). All-cause mortality was higher in the DTI group when the reported follow-up events were included (OR 2.06; 95% CI 1.10 to 3.87).Studies that initiated anticoagulation before surgery showed less VTE events; those that began anticoagulation after surgery showed more VTE events in comparison with LMWH. Therefore, the effect of the DTIs compared with LMWH appears to be influenced by the time of initiation of coagulation more than the effect of the drug itself.The results obtained from sensitivity analysis, did not differ from the analysed results; this strengthens the value of the results.
AUTHORS' CONCLUSIONS
Direct thrombin inhibitors are as effective in the prevention of major venous thromboembolism in THR or TKR as LMWH and vitamin K antagonists. However, they show higher mortality and cause more bleeding than LMWH. No severe hepatic complications were reported in the analysed studies. Use of ximelagatran is not recommended for VTE prevention in patients who have undergone orthopedic surgery. More studies are necessary regarding dabigatran.
Topics: Anticoagulants; Antifibrinolytic Agents; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Azetidines; Benzimidazoles; Benzylamines; Contraindications; Dabigatran; Heparin, Low-Molecular-Weight; Humans; Pyridines; Randomized Controlled Trials as Topic; Thrombin; Venous Thromboembolism; Vitamin K; Warfarin
PubMed: 20393944
DOI: 10.1002/14651858.CD005981.pub2 -
The American Journal of Medicine Jun 2019Vitamin K antagonists (VKA) are the most widely used anticoagulants, and bridging is commonly administered during periprocedural VKA interruption. Given the unclear...
BACKGROUND
Vitamin K antagonists (VKA) are the most widely used anticoagulants, and bridging is commonly administered during periprocedural VKA interruption. Given the unclear benefits and risks of periprocedural bridging in patients with previous venous thromboembolism, we aimed to assess recurrent venous thromboembolism and bleeding outcomes with and without bridging in this population.
METHODS
We performed a systematic review searching the PubMed and Embase databases from inception to December 7, 2017 for randomized and nonrandomized studies that included adults with previous venous thromboembolism requiring VKA interruption to undergo an elective procedure, and that reported venous thromboembolism or bleeding outcomes. Quality of evidence was graded by consensus.
RESULTS
We included 28 cohort studies (20 being single-arm cohorts) with, overall, 6915 procedures for analysis. In 27 studies reporting perioperative venous thromboembolism outcomes, the pooled incidence of recurrent venous thromboembolism with bridging was 0.7% (95% confidence interval [CI], 0.4%-1.2%) and 0.5% (95% CI, 0.3%-0.8%) without bridging. Eighteen studies reported major or nonmajor bleeding outcomes. The pooled incidence of any bleeding was 3.9% (95% CI, 2.0%-7.4%) with bridging and 0.4% (95% CI, 0.1%-1.7%) without bridging. In bridged patients at high thromboembolic risk, the pooled incidence for venous thromboembolism was 0.8% (95% CI, 0.3%-2.5%) and 7.5% (95% CI, 3.1%-17.4%) for any bleeding. Quality of available evidence was very low, primarily due to a high risk of bias of included studies.
CONCLUSIONS
Periprocedural bridging increases the risk of bleeding compared with VKA interruption without bridging, without a significant difference in periprocedural venous thromboembolism rates.
Topics: Anticoagulants; Hemorrhage; Humans; Venous Thromboembolism; Vitamin K
PubMed: 30659809
DOI: 10.1016/j.amjmed.2019.01.004 -
PloS One 2018Vitamin K antagonist (VKA) therapy is safer and more effective when patients have a high time within the therapeutic range and low international normalised ratio... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamin K antagonist (VKA) therapy is safer and more effective when patients have a high time within the therapeutic range and low international normalised ratio variability. The SAMe-TT2R2 score aims to identify those at risk for poor VKA control.
OBJECTIVES
To evaluate the predictive value and clinical usefulness of the SAMe-TT2R2 score to identify those at risk for poor VKA control.
METHODS
We performed a systematic review in MEDLINE and Embase for original research papers assessing the SAMe-TT2R2's relation to poor TTR. We performed a meta-analysis where scores ≥ 2 and ≥ 3 predicting TTR < 70%. When studies evaluated other cutoffs for TTR or SAMe-TT2R2, they were harmonised by multiple simulations with patient characteristics from the individual studies, if the data were available.
RESULTS
16 studies were identified and used in the meta-analysis: 4 and 2 times directly, 8 and 8 times harmonised for scores ≥ 2 and ≥ 3, respectively (not all studies provided information about both cutoffs). The sensitivities and specificities were too heterogeneous to pool. The positive likelihood ratios were 1.25 (1.14-1.38) for a score ≥ 2, and 1.24 (1.09-1.40) for a score ≥ 3; the negative ones were 0.87 (0.82-0.93) and 0.96 (0.91-1.02), respectively. This shows that the post-test probabilities hardly differ from the prior probability (prevalence).
CONCLUSION
The SAMe-TT2R2 score does predict low TTR, but the effect is small. Its effect on individual patients is too limited to be clinically useful.
Topics: Anticoagulants; Atrial Fibrillation; Blood Coagulation; Humans; International Normalized Ratio; Likelihood Functions; Risk; Venous Thromboembolism; Vitamin K
PubMed: 29534092
DOI: 10.1371/journal.pone.0194208 -
Thrombosis Research Feb 2021Chronic kidney disease (CKD) increases the risk of venous thromboembolism (VTE) among affected patients. Vitamin K antagonists (VKA) and warfarin remains the main stay... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Chronic kidney disease (CKD) increases the risk of venous thromboembolism (VTE) among affected patients. Vitamin K antagonists (VKA) and warfarin remains the main stay of its treatment. Due to novelty and unclear risk-to-benefit ratio of direct oral anti-coagulants (DOAC), they remain underutilized in preventing VTE among CKD patients. We aim to assess the efficacy and safety of DOACs and other oral anticoagulants in preventing recurrent VTE among high-risk population.
MATERIAL METHODS
We conducted a literature search using PubMed, Embase, Cochrane, Web of Science and Clinicaltrials.gov for randomized controlled trials (RCTs) comparing anti-coagulants like DOAC, LMWH or VKA or any oral anti-coagulant (OAC) (This includes VKAs and DOACs) with either placebo or another anti-coagulant. Two independent reviewers screened the retrieved articles and extracted data using a piloted data extraction sheet. The primary outcome of interest was number of recurrent VTE and other side effects among CKD patients receiving respective treatment. Secondary outcomes were risk of major, non-major and intra-cranial bleed.
RESULTS
We retrieved 7244 titles on initial search, reviewed full text of 818 articles, and selected 10 phase III RCTS for quantitative meta-analysis. Out of 36,326 patients in these trials, only 10,840 (29.8%) were evaluable. We stratified patients into four categories based on severity of renal impairment using serum creatinine clearance (SCr) as the marker e.g. mild (>50 - <80) moderate (>30 - ≤50) severe (<30) and any level (from <30 to <80). There was no difference between DOACs vs VKA in decreasing the risk of recurrent VTE among patients with mild (RR:0.86, 95% CI:0.61-1.22, I = 25%) moderate/severe (RR:0.72, 95% CI:0.44-1.17, I = 0%) or any level of renal impairment (RR:0.83, 95% CI:0.60-1.14, I = 34%). No difference in efficacy between LMWH vs VKA among patients with moderate (RR:2.40, 95% CI:0.44-12.96, I = 76%) and any level (RR:2.59, 95% CI:0.66-10.16, I = 71%) of renal impairment respectively. Similarly, no difference in efficacy between LMWH vs any OAC (This includes VKAs and edoxaban) among patients with (RR:2.16, 95% CI:0.66-7.-06, I = 51%) and any level (RR:1.48, 95% CI:0.79-2.78, I = 78%) of renal impairment. DOACs compared to VKAs had significantly lower risk of combined major and non-major bleeding (RR: 0.74, 95% CI:0.65-0.84, I = 26%), major bleeding (RR: 0.51, 95% CI:0.38-0.69, I = 7%) and non-major clinically relevant bleeding (RR: 0.73, 95% CI:0.57-0.94, I = 45%) respectively. Risk of intracranial bleeding was comparable (RR: 0.68, 95% CI:0.19-2.44, I = 0%). There was no difference in the risk of major bleeding between LMWH vs any OAC (RR: 0.83, 95% CI:0.46-1.51, I = 0%).
CONCLUSION
DOACS and other anticoagulants (VKA and LMWH) showed no statistical difference in preventing recurrent VTEs among CKD patients but DOACs had significantly lower risk of major and non-major clinically relevant bleeding irrespective of the level of renal impairment compared to VKAs. There was no difference in risk of intra-cranial bleeding between DOACs and VKAs.
Topics: Anticoagulants; Hemorrhage; Humans; Renal Insufficiency, Chronic; Venous Thromboembolism; Vitamin K
PubMed: 33310644
DOI: 10.1016/j.thromres.2020.11.036 -
PloS One 2021Although several meta-analyses have compared efficacies of vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) for treatment of left ventricular thrombus... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Although several meta-analyses have compared efficacies of vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) for treatment of left ventricular thrombus (LVT), those meta-analyses included no single-arm studies.
METHODS AND RESULTS
PubMed, Scopus, and the Cochrane Library databases were searched for articles investigating thrombus resolution, stroke, any thromboembolism, major bleeding, any bleeding, or all-cause death in LVT treated with VKAs or DOACs, and single-class meta-analyses were also included (PROSPERO database, CRD42021230849). Event rates were pooled using a random effects model. Meta-regression analysis was performed to explore factors that may influence outcomes. 2,612 patients from 23 articles were included (VKAs: 2,004, DOACs: 608). There were no significant differences between VKAs and DOACs in the frequency of thrombus resolution (VKAs: 0.75 [95% confidence interval; 0.67 to 0.81], DOACs: 0.75 [0.67 to 0.82]), stroke (VKAs: 0.06 [0.04 to 0.10], DOACs: 0.02 [0.01 to 0.01]), any thromboembolism (VKAs: 0.08 [0.05 to 0.13], DOACs: 0.03 [0.01 to 0.10]), major bleeding (VKAs: 0.06 [0.04 to 0.09], DOACs: 0.03 [0.01 to 0.06]), any bleeding (VKAs: 0.08 [0.05 to 0.12], DOACs: 0.08 [0.06 to 0.10]), and all-cause death (VKAs: 0.07 [0.04 to 0.13], DOACs: 0.09 [0.05 to 0.16]). Meta-regression analysis revealed that increased duration of follow-up was associated with lower-rates of stroke (estimate: -0.040, p = 0.0495) with VKAs, but not with DOACs. There was significant publication bias for thrombus resolution, stroke, any thromboembolism, any bleeding, and all-cause death.
CONCLUSIONS
Efficacy and adverse outcomes of therapy with DOACs and VKAs do not differ. Randomized controlled trials are needed to determine the optimal anticoagulant strategy.
Topics: Administration, Oral; Anticoagulants; Heart Ventricles; Hemorrhage; Humans; International Normalized Ratio; Stroke; Thromboembolism; Thrombosis; Vitamin K
PubMed: 34310654
DOI: 10.1371/journal.pone.0255280 -
The New Phytologist Mar 2021Understanding plant thermal tolerance is fundamental to predicting impacts of extreme temperature events that are increasing in frequency and intensity across the globe....
Understanding plant thermal tolerance is fundamental to predicting impacts of extreme temperature events that are increasing in frequency and intensity across the globe. Extremes, not averages, drive species evolution, determine survival and increase crop performance. To better prioritize agricultural and natural systems research, it is crucial to evaluate how researchers are assessing the capacity of plants to tolerate extreme events. We conducted a systematic review to determine how plant thermal tolerance research is distributed across wild and domesticated plants, growth forms and biomes, and to identify crucial knowledge gaps. Our review shows that most thermal tolerance research examines cold tolerance of cultivated species; c. 5% of articles consider both heat and cold tolerance. Plants of extreme environments are understudied, and techniques widely applied in cultivated systems are largely unused in natural systems. Lastly, we find that lack of standardized methods and metrics compromises the potential for mechanistic insight. Our review provides an entry point for those new to the methods used in plant thermal tolerance research and bridges often disparate ecological and agricultural perspectives for the more experienced. We present a considered agenda of thermal tolerance research priorities to stimulate efficient, reliable and repeatable research across the spectrum of plant thermal tolerance.
Topics: Climate Change; Cold Temperature; Ecosystem; Hot Temperature; Photosynthesis; Temperature
PubMed: 33124040
DOI: 10.1111/nph.17052 -
The Cochrane Database of Systematic... Jul 2015Treatment with vitamin K antagonists is associated with increased morbidity and mortality. Reversal therapy with prothrombin complex concentrate (PCC) is used... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Treatment with vitamin K antagonists is associated with increased morbidity and mortality. Reversal therapy with prothrombin complex concentrate (PCC) is used increasingly and is recommended in the treatment of patients with bleeding complications undertaking surgical interventions, as well as patients at high risk of bleeding. Evidence is lacking regarding indication, dosing, efficacy and safety.
OBJECTIVES
We assessed the benefits and harms of PCC compared with fresh frozen plasma in the acute medical and surgical setting involving vitamin K antagonist-treated bleeding and non-bleeding patients. We investigated various outcomes and predefined subgroups and performed sensitivity analysis. We examined risks of bias and applied trial sequential analyses (TSA) to examine the level of evidence, and we prepared a 'Risk of bias' table to test the quality of the evidence.
SEARCH METHODS
We searched the following databases from inception to 1 May 2013: Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (Ovid SP); EMBASE (Ovid SP); International Web of Science; Latin American and Caribbean Health Sciences Literature (LILACS) (via BIREME); the Chinese Biomedical Literature Database; advanced Google and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). We applied a systematic and sensitive search strategy to identify relevant randomized clinical trials and imposed no language or date restrictions. We adapted our MEDLINE search strategy for searches in all other databases. We reran the search in October 2014 and found one potential new study of interest. We added this study to a list of 'Studies awaiting classification', and we will incorporate this study into the formal review findings at the time of the review update.
SELECTION CRITERIA
We included randomized controlled trials (RCTs), irrespective of publication status, date of publication, blinding status, outcomes published or language. We contacted investigators and study authors to request relevant data.
DATA COLLECTION AND ANALYSIS
Three review authors independently abstracted data and resolved disagreements by discussion. Our primary outcome measures were 'overall mortality longest follow-up' and 'overall 28-day mortality'. We performed subgroup analyses to assess the effects of PCC in adults in terms of various clinical and physiological outcomes. We presented pooled estimates of the effects of interventions on dichotomous outcomes as risk ratios (RRs), and on continuous outcomes as mean differences (MDs), with 95% confidence intervals (CIs). We assessed risk of bias by assessing trial methodological components and risk of random error through TSA.
MAIN RESULTS
We included four RCTs with a total of 453 participants and determined that none of these trials had overall low risk of bias. We found six ongoing trials from which we were unable to retrieve further data. Three trials provided data on mortality. Meta-analysis showed no statistical effect on overall mortality (RR 0.93, 95% CI 0.37 to 2.33; very low quality of evidence). We were unable to associate use of PCC with the number of complications probably related to the intervention (RR 0.92, 95% CI 0.78 to 1.09; very low quality of evidence). Lack of transfusion data and apparent differences in study design prevented review authors from finding a beneficial effect of PCC in reducing the volume of fresh frozen plasma (FFP) transfused to reverse the effect of vitamin K antagonist treatment. The number of new occurrences of transfusion of red blood cells (RBCs) did not seem to be associated with the use of PCC (RR 1.08, 95% CI 0.82 to 1.43; very low quality of evidence). Still, the included studies demonstrate the possibility of equally reversing vitamin K-induced coagulopathy using PCC without the need for transfusion of FFP. No effect on other predefined outcomes was observed.
AUTHORS' CONCLUSIONS
In the four included RCTs, use of prothrombin complex concentrate does not appear to reduce mortality or transfusion requirements but demonstrates the possibility of reversing vitamin K-induced coagulopathy without the need for transfusion of fresh frozen plasma. All included trials have high risk of bias and are underpowered to detect mortality, benefit or harm. Clinical and statistical heterogeneity is high, and definitions of clinically important outcomes such as adverse events are highly dissimilar between trials. Only weak observational evidence currently supports the use of PCC in vitamin K antagonist-treated bleeding and non-bleeding patients, and the current systematic review of RCTs does not support the routine use of PCC over FFP. Additional high-quality research is urgently needed.
Topics: Blood Coagulation Factors; Erythrocyte Transfusion; Hemorrhage; Humans; Plasma; Randomized Controlled Trials as Topic; Vitamin K
PubMed: 26151108
DOI: 10.1002/14651858.CD010555.pub2 -
Blood Coagulation & Fibrinolysis : An... Oct 2022Thromboprophylaxis is the cornerstone strategy for thrombotic antiphospholipid syndrome (APS). Data comparing direct oral anticoagulants (DOACs) to Vitamin K antagonists... (Meta-Analysis)
Meta-Analysis
Comparing the efficacy and safety of direct oral anticoagulants versus Vitamin K antagonists in patients with antiphospholipid syndrome: a systematic review and meta-analysis.
Thromboprophylaxis is the cornerstone strategy for thrombotic antiphospholipid syndrome (APS). Data comparing direct oral anticoagulants (DOACs) to Vitamin K antagonists (VKAs) in the secondary prevention of thrombosis in APS patients remain contentious. We aim to review and analyse literature on the efficacy and safety of DOACs compared with VKAs in treating patients with APS. A literature search was performed from inception to 31 December 2021. Subgroups were analysed based on the risk stratification of APS profiles and different DOAC types. A total of nine studies with 1131 patients were included in the meta-analysis. High-risk APS patients (triple positive APS) who used DOACs displayed an increased risk of recurrent thrombosis [risk ratio = 3.65, 95% confidence interval (95% CI): 1.49-8.93; I2 = 29%, P = 0.005] compared with those taking VKAs. Similar risk of recurrent thrombosis or major bleeding was noted in low-risk APS patients (single or double antibody-positive) upon administering DOACs or VKAs. The utilization of Rivaroxaban was associated with a high risk of recurrent thromboses (RR = 2.63; 95% CI: 1.56-4.42; I2 = 0, P = 0.0003), particularly recurrent arterial thromboses (RR = 4.52; 95% CI: 1.99-10.29; I2 = 0, P = 0.18) in overall APS patients. Comparisons of the rate of recurrent thrombosis events and major bleeding events when using dabigatran or apixaban versus VKAs yielded no statistical differences. In the absence of contraindications, this meta-analysis suggests that VKAs remain the first-choice treatment for high-risk APS patients, with DOACs a more appropriate option for low-risk APS patients. Different DOACs may exhibit different levels of efficacy and safety for thromboprophylaxis in APS patients and require further exploration.
Topics: Administration, Oral; Anticoagulants; Antiphospholipid Syndrome; Dabigatran; Fibrinolytic Agents; Hemorrhage; Humans; Rivaroxaban; Thrombosis; Venous Thromboembolism; Vitamin K
PubMed: 35867933
DOI: 10.1097/MBC.0000000000001153 -
The Cochrane Database of Systematic... Mar 2016The optimal duration of thromboprophylaxis after total hip or knee replacement, or hip fracture repair remains controversial. It is common practice to administer... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The optimal duration of thromboprophylaxis after total hip or knee replacement, or hip fracture repair remains controversial. It is common practice to administer prophylaxis using low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) until discharge from hospital, usually seven to 14 days after surgery. International guidelines recommend extending thromboprophylaxis for up to 35 days following major orthopaedic surgery but the recommendation is weak due to moderate quality evidence. In addition, recent oral anticoagulants that exert effect by direct inhibition of thrombin or activated factor X lack the need for monitoring and have few known drug interactions. Interest in this topic remains high.
OBJECTIVES
To assess the effects of extended-duration anticoagulant thromboprophylaxis for the prevention of venous thromboembolism (VTE) in people undergoing elective hip or knee replacement surgery, or hip fracture repair.
SEARCH METHODS
The Cochrane Vascular Information Specialist searched the Specialised Register (last searched May 2015) and CENTRAL (2015, Issue 4). Clinical trials databases were searched for ongoing or unpublished studies.
SELECTION CRITERIA
Randomised controlled trials assessing extended-duration thromboprophylaxis (five to seven weeks) using accepted prophylactic doses of LMWH, UFH, vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC) compared with short-duration thromboprophylaxis (seven to 14 days) followed by placebo, no treatment or similar extended-duration thromboprophylaxis with LMWH, UFH, VKA or DOACs in participants undergoing hip or knee replacement or hip fracture repair.
DATA COLLECTION AND ANALYSIS
We independently selected trials and extracted data. Disagreements were resolved by discussion. We performed fixed-effect model meta-analyses with odds ratios (ORs) and 95% confidence intervals (CIs). We used a random-effects model when there was heterogeneity.
MAIN RESULTS
We included 16 studies (24,930 participants); six compared heparin with placebo, one compared VKA with placebo, two compared DOAC with placebo, one compared VKA with heparin, five compared DOAC with heparin and one compared anticoagulants chosen at investigators' discretion with placebo. Three trials included participants undergoing knee replacement. No studies assessed hip fracture repair.Trials were generally of good methodological quality. The main reason for unclear risk of bias was insufficient reporting. The quality of evidence according to GRADE was generally moderate, as some comparisons included a single study, low number of events or heterogeneity between studies leading to wide CIs.We showed no difference between extended-duration heparin and placebo in symptomatic VTE (OR 0.59, 95% CI 0.35 to 1.01; 2329 participants; 5 studies; high quality evidence), symptomatic deep vein thrombosis (DVT) (OR 0.73, 95% CI 0.39 to 1.38; 2019 participants; 4 studies; moderate quality evidence), symptomatic pulmonary embolism (PE) (OR 0.61, 95% CI 0.16 to 2.33; 1595 participants; 3 studies; low quality evidence) and major bleeding (OR 0.59, 95% CI 0.14 to 2.46; 2500 participants; 5 studies; moderate quality evidence). Minor bleeding was increased in the heparin group (OR 2.01, 95% CI 1.43 to 2.81; 2500 participants; 5 studies; high quality evidence). Clinically relevant non-major bleeding was not reported.We showed no difference between extended-duration VKA and placebo (one study, 360 participants) for symptomatic VTE (OR 0.10, 95% CI 0.01 to 1.94; moderate quality evidence), symptomatic DVT (OR 0.13, 95% CI 0.01 to 2.62; moderate quality evidence), symptomatic PE (OR 0.32, 95% CI 0.01 to 7.84; moderate quality evidence) and major bleeding (OR 2.89, 95% CI 0.12 to 71.31; low quality evidence). Clinically relevant non-major bleeding and minor bleeding were not reported.Extended-duration DOAC showed reduced symptomatic VTE (OR 0.20, 95% CI 0.06 to 0.68; 2419 participants; 1 study; moderate quality evidence) and symptomatic DVT (OR 0.18, 95% CI 0.04 to 0.81; 2459 participants; 2 studies; high quality evidence) compared to placebo. No differences were found for symptomatic PE (OR 0.25, 95% CI 0.03 to 2.25; 1733 participants; 1 study; low quality evidence), major bleeding (OR 1.00, 95% CI 0.06 to 16.02; 2457 participants; 1 study; low quality evidence), clinically relevant non-major bleeding (OR 1.22, 95% CI 0.76 to 1.95; 2457 participants; 1 study; moderate quality evidence) and minor bleeding (OR 1.18, 95% CI 0.74 to 1.88; 2457 participants; 1 study; moderate quality evidence).We showed no difference between extended-duration anticoagulants chosen at investigators' discretion and placebo (one study, 557 participants, low quality evidence) for symptomatic VTE (OR 0.50, 95% CI 0.09 to 2.74), symptomatic DVT (OR 0.33, 95% CI 0.03 to 3.21), symptomatic PE (OR 1.00, 95% CI 0.06 to 16.13), and major bleeding (OR 5.05, 95% CI 0.24 to 105.76). Clinically relevant non-major bleeding and minor bleeding were not reported.We showed no difference between extended-duration VKA and heparin (one study, low quality evidence) for symptomatic VTE (OR 1.64, 95% CI 0.85 to 3.16; 1279 participants), symptomatic DVT (OR 1.36, 95% CI 0.69 to 2.68; 1279 participants), symptomatic PE (OR 9.16, 95% CI 0.49 to 170.42; 1279 participants), major bleeding (OR 3.87, 95% CI 1.91 to 7.85; 1272 participants) and minor bleeding (OR 1.33, 95% CI 0.64 to 2.76; 1279 participants). Clinically relevant non-major bleeding was not reported.We showed no difference between extended-duration DOAC and heparin for symptomatic VTE (OR 0.70, 95% CI 0.28 to 1.70; 15,977 participants; 5 studies; low quality evidence), symptomatic DVT (OR 0.60, 95% CI 0.11 to 3.27; 15,977 participants; 5 studies; low quality evidence), symptomatic PE (OR 0.91, 95% CI 0.43 to 1.94; 14,731 participants; 5 studies; moderate quality evidence), major bleeding (OR 1.11, 95% CI 0.79 to 1.54; 16,199 participants; 5 studies; high quality evidence), clinically relevant non-major bleeding (OR 1.08, 95% CI 0.90 to 1.28; 15,241 participants; 4 studies; high quality evidence) and minor bleeding (OR 0.95, 95% CI 0.82 to 1.10; 11,766 participants; 4 studies; high quality evidence).
AUTHORS' CONCLUSIONS
Moderate quality evidence suggests extended-duration anticoagulants to prevent VTE should be considered for people undergoing hip replacement surgery, although the benefit should be weighed against the increased risk of minor bleeding. Further studies are needed to better understand the association between VTE and extended-duration oral anticoagulants in relation to knee replacement and hip fracture repair, as well as outcomes such as distal and proximal DVT, reoperation, wound infection and healing.
Topics: Anticoagulants; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Hemorrhage; Heparin; Hip Fractures; Humans; Randomized Controlled Trials as Topic; Venous Thromboembolism; Vitamin K
PubMed: 27027384
DOI: 10.1002/14651858.CD004179.pub2 -
European Journal of Vascular and... Jul 2016Despite being the most common antithrombotic strategy in trials comparing venous with prosthetic grafts, the use of vitamin K antagonists (VKAs) to improve the outcome... (Review)
Review
CLINICAL VIGNETTE
Despite being the most common antithrombotic strategy in trials comparing venous with prosthetic grafts, the use of vitamin K antagonists (VKAs) to improve the outcome of venous bypass remains the subject of debate. In this systematic review, evidence supporting the use of VKAs for improving venous patency following infrainguinal venous bypass is provided.
CLINICAL QUESTION
A 67 year old man with lifestyle limiting claudication underwent a successful infrainguinal venous bypass. Can VKAs help preserve patency after venous bypass surgery?
METHODS
A systematic review of electronic databases, including MEDLINE and Embase, was conducted. Only randomized controlled studies comparing VKAs with aspirin (ASA) were included. The main outcome was bypass patency.
RESULTS
Four studies using different intensities of anticoagulation ± ASA were identified. All but one showed a benefit of VKAs over ASA with respect to primary patency. However, this benefit was also accompanied by an increased risk of bleeding. The Dutch Bypass Oral Anticoagulants, or ASA, study was the largest included and showed that VKAs (without concomitant ASA) were superior to ASA alone for the prevention of graft occlusion (hazard ratio 0.69, 95% confidence interval 0.54-0.88).
CONCLUSION
Current evidence suggests that VKAs are superior to ASA for the prevention of infrainguinal autologous venous graft thrombosis.
Topics: Anticoagulants; Graft Occlusion, Vascular; Humans; Inguinal Canal; Vascular Grafting; Vascular Patency; Vitamin K
PubMed: 27142190
DOI: 10.1016/j.ejvs.2016.03.026