BACKGROUND: The purpose of this study is to perform a meta-analysis to compare outcomes of venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) vs other anticoagulants in patients who received total knee (TKA) or total hip arthroplasty (THA).
METHODS: MEDLINE, Cochrane, EMBASE, and Google Scholar databases were searched until June 30, 2017 for eligible randomized controlled studies.
RESULTS: Thirty-two randomized controlled studies were included. LMWH provided better protection against VTE than placebo. In both TKA and THA patients, the rates of VTE were lower with factor Xa inhibitors than LMWH. In THA patients, the rate of deep vein thrombosis (DVT) was lower with factor Xa inhibitors than LMWH. In TKA patients, the rates of VTE and DVT were similar between LMWH and direct thrombin inhibitors. In THA patients, the rate of VTE was lower with direct thrombin inhibitors than with LMWH, while the DVT rates were similar. The pulmonary embolism rates were similar between all 3 classes of drugs in TKA and THR patients, as were the major bleeding rates. Nonmajor and minor bleeding rates were also similar between the 3 drug classes.
CONCLUSION: LMWH is associated with a higher rate of VTE than factor Xa inhibitors in TKA and THA patients. Direct thrombin inhibitors are associated with a lower rate of VTE in THA patients, but their effectiveness with respect to DVT and pulmonary embolism prophylaxis is similar to that of LMWH in TKA and THA patients.
BACKGROUND: Patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) are at risk of venous thromboembolism (VTE). Australian orthopaedic guidelines recommend aspirin and low-molecular-weight heparin (e.g. enoxaparin) for VTE prophylaxis; however, there is debate in the international literature around the use of aspirin as VTE prophylaxis. This review assesses the risks and benefits of aspirin compared to enoxaparin as VTE prophylaxis for patients undergoing THA or TKA.
METHODS: A systematic review was conducted to identify relevant randomized controlled trials. Studies comparing enoxaparin, aspirin and/or placebo for VTE prophylaxis in THA or TKA patients were included. Network meta-analysis (NMA) was performed to calculate risk ratios (RRs) and confidence intervals (CIs). Quality appraisal was conducted by assessing risk of bias and the strength of the evidence.
RESULTS: Nine randomized controlled trials were eligible for inclusion. The NMA found no statistically significant differences for the investigated outcomes: total DVT rates (RR = 1.21, 95% CI 0.86, 1.72), symptomatic pulmonary embolism (PE) rates (RR = 1.02, 95% CI 0.02, 50.86), major haemorrhage (RR = 0.97, 95% CI 0.02, 50.99) and wound complication (RR = 0.73, 95% CI 0.17, 3.20). The occurrence of PE was rare. Due to limited data, sub-group analysis was not possible. The overall quality of evidence in the NMA is considered to be very low.
CONCLUSION: This review did not find statistically significant differences between aspirin and enoxaparin. Future studies should identify more evidence, particularly for rare outcomes such as PE, as this might help decision-makers to get consensus on the use of aspirin as VTE prophylaxis.
OBJECTIVES: To assess the efficacy and safety of venous thromboembolism prophylaxis in people undergoing elective total hip replacement.
METHODS: Systematic review and Bayesian network meta-analyses of randomized controlled trials were conducted for 3 outcomes: deep vein thrombosis (DVT), pulmonary embolism (PE), and major bleeding (MB). MEDLINE, EMBASE, and Cochrane Library (CENTRAL) databases were searched. Study quality was assessed using the Cochrane risk-of-bias checklist. Fixed- and random-effects models were fitted and compared. The median relative risk (RR) and odds ratio (OR) compared with no prophylaxis, with their 95% credible intervals (CrIs), rank, and probability of being the best, were calculated.
RESULTS: Forty-two (n = 24 374, 26 interventions), 30 (n = 28 842, 23 interventions), and 24 (n = 31 792, 15 interventions) randomized controlled trials were included in the DVT, PE, and MB networks, respectively. Rivaroxaban had the highest probability of being the most effective intervention for DVT (RR 0.06 [95% CrI 0.01-0.29]). Strategy of low-molecular-weight heparin followed by aspirin had the highest probability of reducing the risk of PE and MB (RR 0.0011 [95% CrI 0.00-0.096] and OR 0.37 [95% CrI 0.00-26.96], respectively). The ranking of efficacy estimates across the 3 networks, particularly PE and MB, had very wide CrIs, indicating high degree of uncertainty.
CONCLUSIONS: A strategy of low-molecular-weight heparin given for 10 days followed by aspirin for 28 days had the best benefit-risk balance, with the highest probability of being the best on the basis of the results of the PE and MB network meta-analyses. Nevertheless, there is considerable uncertainty around the median ranks of the interventions.
BACKGROUND: Currently there is significant variation in the management of venous thromboembolism prophylaxis following total knee arthroplasty (TKA). Excessive wound ooze and bleeding is thought to increase a patient's risk of haematoma formation and possible infection. We evaluated the rate of unexpected reoperation in the perioperative period in patients who received aspirin, rivaroxaban or enoxaparin following primary TKA.
METHOD: A systematic literature search was conducted in MEDLINE, CENTRAL and Embase to identify patients who underwent primary TKA. Two researchers independently reviewed the references identified in the literature search. The final 11 studies included for review were published between 1996 and 2016.
RESULTS: There was a higher rate of reoperation in patients treated with aspirin following TKA when compared to enoxaparin and rivaroxaban in the perioperative period. Of the 5141 patients treated with enoxaparin, 11 (0.21%) required reoperation; of the 2764 patients treated with rivaroxaban, 12 (0.43%) required reoperation; and of the 228 patients treated with aspirin, seven (3.07%) required reoperation. The average time to follow-up in the 11 studies was 55 days, ranging from 30 to 180 days post-operatively.
CONCLUSION: There was a higher rate of reoperation in patients treated with aspirin following TKA when compared to enoxaparin and rivaroxaban in the perioperative period. While there is extensive data on the safety and efficacy of these medications following joint arthroplasty, improved reporting of surgically relevant outcomes are needed to assist both the surgeon and patient in clinical decision-making.
Background: Patients who undergo knee or hip arthroplasty are at a significant risk of venous thromboembolism (VTE) development (pulmonary embolism and/or deep-vein thrombosis). Many different thromboprophylactic strategies have been used for the prevention of VTE in these patients with different outcomes. Therefore, our aim was to evaluate the efficacy and safety of aspirin prophylaxis when compared with placebo or anticoagulants in this population of patients. Methods: A comprehensive electronic database search was conducted for all randomized controlled trials (RCTs) comparing the clinical outcomes of aspirin versus placebo or anticoagulants for the prevention of VTE after knee or hip arthroplasty. The primary outcome was VTE incidence. Secondary outcomes included any bleeding, major bleeding and mortality. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) using a random-effects model at the longest possible follow-up period. Results: We included 13 RCTs with a total of 20,115 patients with a mean age of 67.15 ± 9.54 and 24.39% males. Aspirin was found to be associated with a non-significantly reduced VTE events compared with other thromboprophylactic methods (RR 0.87; 95% CI: 0.61–1.23; P = 0.43). Compared with placebo, aspirin was associated with significant reduction of VTE (RR 0.65; 95% CI: 0.47–0.89; P = 0.008). There were no significant differences in the clinical outcomes between all groups with regard to mortality (RR 0.98; 95% CI: 0.86–1.11; P = 0.72), major bleeding events (RR 0.96; 95% CI: 0.50–1.84; P = 0.91), and any bleeding events (RR: 1.09; 95% CI: 0.82–1.44; P = 0.56). Conclusion: Among patients who underwent knee or hip arthroplasty, aspirin prophylaxis was found to be associated with similar efficacy and safety outcomes when compared with anticoagulants. When compared with placebo, aspirin prophylaxis was associated with significantly reduced VTE and a comparable safety profile.
BACKGROUND: Hospitalised patients are at increased risk of developing deep vein thrombosis (DVT) in the lower limb and pelvic veins, on a background of prolonged immobilisation associated with their medical or surgical illness. Patients with DVT are at increased risk of developing a pulmonary embolism (PE). The use of graduated compression stockings (GCS) in hospitalised patients has been proposed to decrease the risk of DVT. This is an update of a Cochrane Review first published in 2000, and last updated in 2014.
OBJECTIVES: To evaluate the effectiveness and safety of graduated compression stockings in preventing deep vein thrombosis in various groups of hospitalised patients.
SEARCH METHODS: For this review the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), and trials registries on 21 March 2017; and the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE Ovid, Embase Ovid, CINAHL Ebsco, AMED Ovid , and trials registries on 12 June 2018.
SELECTION CRITERIA: Randomised controlled trials (RCTs) involving GCS alone, or GCS used on a background of any other DVT prophylactic method. We combined results from both of these groups of trials.
DATA COLLECTION AND ANALYSIS: Two review authors (AS, MD) assessed potentially eligible trials for inclusion. One review author (AS) extracted the data, which a second review author (MD) cross-checked and authenticated. Two review authors (AS, MD) assessed the methodological quality of trials with the Cochrane 'Risk of bias' tool. Any disagreements were resolved by discussion with the senior review author (TL). For dichotomous outcomes, we calculated the Peto odds ratio and corresponding 95% confidence interval. We pooled data using a fixed-effect model. We used the GRADE system to evaluate the overall quality of the evidence supporting the outcomes assessed in this review.
MAIN RESULTS: We included 20 RCTs involving a total of 1681 individual participants and 1172 individual legs (2853 analytic units). Of these 20 trials, 10 included patients undergoing general surgery; six included patients undergoing orthopaedic surgery; three individual trials included patients undergoing neurosurgery, cardiac surgery, and gynaecological surgery, respectively; and only one trial included medical patients. Graduated compression stockings were applied on the day before surgery or on the day of surgery and were worn up until discharge or until the participants were fully mobile. In the majority of the included studies DVT was identified by the radioactive I125 uptake test. Duration of follow-up ranged from seven to 14 days. The included studies were at an overall low risk of bias.We were able to pool the data from 20 studies reporting the incidence of DVT. In the GCS group, 134 of 1445 units developed DVT (9%) in comparison to the control group (without GCS), in which 290 of 1408 units developed DVT (21%). The Peto odds ratio (OR) was 0.35 (95% confidence interval (CI) 0.28 to 0.43; 20 studies; 2853 units; high-quality evidence), showing an overall effect favouring treatment with GCS (P < 0.001).Based on results from eight included studies, the incidence of proximal DVT was 7 of 517 (1%) units in the GCS group and 28 of 518 (5%) units in the control group. The Peto OR was 0.26 (95% CI 0.13 to 0.53; 8 studies; 1035 units; moderate-quality evidence) with an overall effect favouring treatment with GCS (P < 0.001). Combining results from five studies, all based on surgical patients, the incidence of PE was 5 of 283 (2%) participants in the GCS group and 14 of 286 (5%) in the control group. The Peto OR was 0.38 (95% CI 0.15 to 0.96; 5 studies; 569 participants; low-quality evidence) with an overall effect favouring treatment with GCS (P = 0.04). We downgraded the quality of the evidence for proximal DVT and PE due to low event rate (imprecision) and lack of routine screening for PE (inconsistency).We carried out subgroup analysis by speciality (surgical or medical patients). Combining results from 19 trials focusing on surgical patients, 134 of 1365 (9.8%) units developed DVT in the GCS group compared to 282 of 1328 (21.2%) units in the control group. The Peto OR was 0.35 (95% CI 0.28 to 0.44; high-quality evidence), with an overall effect favouring treatment with GCS (P < 0.001). Based on results from seven included studies, the incidence of proximal DVT was 7 of 437 units (1.6%) in the GCS group and 28 of 438 (6.4%) in the control group. The Peto OR was 0.26 (95% CI 0.13 to 0.53; 875 units; moderate-quality evidence) with an overall effect favouring treatment with GCS (P < 0.001). We downgraded the evidence for proximal DVT due to low event rate (imprecision).Based on the results from one trial focusing on medical patients admitted following acute myocardial infarction, 0 of 80 (0%) legs developed DVT in the GCS group and 8 of 80 (10%) legs developed DVT in the control group. The Peto OR was 0.12 (95% CI 0.03 to 0.51; low-quality evidence) with an overall effect favouring treatment with GCS (P = 0.004). None of the medical patients in either group developed a proximal DVT, and the incidence of PE was not reported.Limited data were available to accurately assess the incidence of adverse effects and complications with the use of GCS as these were not routinely quantitatively reported in the included studies.
AUTHORS' CONCLUSIONS: There is high-quality evidence that GCS are effective in reducing the risk of DVT in hospitalised patients who have undergone general and orthopaedic surgery, with or without other methods of background thromboprophylaxis, where clinically appropriate. There is moderate-quality evidence that GCS probably reduce the risk of proximal DVT, and low-quality evidence that GCS may reduce the risk of PE. However, there remains a paucity of evidence to assess the effectiveness of GCS in diminishing the risk of DVT in medical patients.
BACKGROUND: Venous thromboembolism (VTE) is an important complication following total hip replacement (THR) and total knee replacement (TKR) surgeries. Aim of this study was to comprehensively compare the clinical outcomes of low-molecular-weight heparin (LMWH) with other anticoagulants in patients who underwent TKR or THR surgery.
METHODS: Medline, Cochrane, EMBASE, and Google Scholar databases were searched for eligible randomized controlled studies (RCTs) published before June 30, 2017. Meta-analyses of odds ratios were performed along with subgroup and sensitivity analyses.
RESULTS: Twenty-one RCTs were included. In comparison with placebo, LMWH treatment was associated with a lower risk of VTE and deep vein thrombosis (DVT) (P values < 0.001) but similar risk of pulmonary embolism (PE) (P = 0.227) in THR subjects. Compared to factor Xa inhibitors, LMWH treatment was associated with higher risk of VTE in TKR subjects (P < 0.001), and higher DVT risk (P < 0.001) but similar risk of PE and major bleeding in both THR and TKR. The risk of either VTE, DVT, PE, or major bleeding was similar between LMWH and direct thrombin inhibitors in both THR and TKR, but major bleeding was lower with LMWH in patients who underwent THR (P = 0.048).
CONCLUSION: In comparison with factor Xa inhibitors, LMWH may have higher risk of VTE and DVT, whereas compared to direct thrombin inhibitors, LMWH may have lower risk of major bleeding after THR or TKR.
CONTEXTE: La thrombocytopénie induite par l'héparine (TIH) est une réaction indésirable à un médicament qui se présente comme un trouble thrombotique lié à une activation des plaquettes par un anticorps. Il s'agit d'une réaction immunitaire paradoxale mal comprise entraînant la génération de thrombine in vivo, ce qui conduit à un état d'hypercoagulabilité pouvant initier une thrombose veineuse ou artérielle. Un certain nombre de facteurs semblent influer sur l'incidence de la TIH, notamment le type et la préparation d'héparine (héparine non fractionnée (HNF) ou héparine de bas poids moléculaire (HBPM)) et la population de patients exposés à l'héparine, les patients postopératoires présentant un risque plus élevé.Bien que l'HBPM ait largement remplacé l'HNF comme traitement de première ligne, il existe des preuves de la non supériorité de l'HBPM sur l'HNF pour ce qui concerne la prévention de la thrombose veineuse profonde et de l'embolie pulmonaire après une intervention chirurgicale, et des fréquences similaires de saignements ont été décrites avec l'HBPM et l'HNF. La décision d'utiliser une de ces deux préparations d'héparine plutôt que l'autre peut donc être influencée par des effets indésirables tels que la TIH. Nous avons donc spécifiquement cherché à déterminer l'impact relatif de l'HNF et de l'HBPM sur la TIH chez les patients postopératoires recevant une prophylaxie thromboembolique.
OBJECTIFS: L'objectif de cette revue était de comparer l'incidence de la TIH et de la TIH compliquée par une thrombose chez les patients exposés à l'HNF par rapport à ceux exposés à l'HBPM, dans des essais contrôlés randomisés (ECR) sur l'héparinothérapie postopératoire.
STRATÉGIE DE RECHERCHE DOCUMENTAIRE: Le groupe Cochrane sur les maladies vasculaires périphériques a effectué des recherches dans son registre spécialisé (mars 2012) et dans CENTRAL (2012, numéro 2). En outre, les auteurs ont cherché dans LILACS (mars 2012) ainsi que dans les références bibliographiques de publications pertinentes.
CRITÈRES DE SÉLECTION: Nous étions intéressés à comparer l'incidence de la TIH survenant au cours de l'exposition à l'HNF ou à l'HBPM après une intervention chirurgicale. Nous avons donc étudié des ECR dans lesquels les participants étaient des patients postopératoires assignés à recevoir de l'HNF ou de l'HBPM, en aveugle ou de manière ouverte. Les études éligibles devaient compter parmi leurs critères de jugement le diagnostic clinique de la TIH, définie comme une réduction relative d'au moins 50 % de la numération plaquettaire par rapport au pic postopératoire (même si, à son plus bas, la numération plaquettaire est restée > 150 x 109/l) survenant dans les cinq à 14 jours suivant l'opération, avec ou sans la survenue d'un événement thrombotique dans ce laps de temps. De plus, les anticorps circulants associés au syndrome devaient avoir été étudiés au moyen d'essais de laboratoire.
RECUEIL ET ANALYSE DES DONNÉES: Deux auteurs de la revue ont extrait les données et évalué le risque de biais de façon indépendante. Les désaccords ont été résolus par consensus avec la participation d'un troisième auteur.
RÉSULTATS PRINCIPAUX: Au total, deux études impliquant 923 participants répondaient à tous les critères d'inclusion et ont été incluses dans la revue. L'analyse groupée a montré une réduction statistiquement significative du risque de TIH avec l'HBPM par rapport à l'HNF (risque relatif (RR) 0,24 ; intervalle de confiance (IC) à 95 % 0,07 à 0,82 ; P = 0,02). Ce résultat suggère que les patients traités à l'HBPM auraient une réduction du risque relatif (RRR) de 76 % pour la probabilité de développer une TIH, par rapport aux patients traités par HNF.Une complication de thromboembolie veineuse (TEV) est survenue chez 12 des 17 patients ayant développé une TIH. L'analyse groupée a montré une réduction statistiquement significative du risque de TIH avec l'HBPM par rapport à l'HNF (risque relatif (RR) 0,20 ; intervalle de confiance (IC) à 95 % 0,04 à 0,90 ; P = 0,04). Ce résultat indique que les patients utilisant l'HBPM auraient une RRR de 80 % pour le développement d'une TIH compliquée de TEV en comparaison avec les patients utilisant l'HNF. Le seul cas de thrombose artérielle était survenu chez un patient qui avait reçu de l'HNF et aucun cas d'amputation ou de décès n'avait été rapporté.
CONCLUSIONS DES AUTEURS: Il y avait une plus faible incidence de la TIH et de la TIH compliquée de TEV chez les patients postopératoires subissant une thromboprophylaxie par HBPM en comparaison avec l'HNF. Ceci est cohérent avec l'utilisation clinique actuelle de l'HBPM plutôt que de l'HNF comme héparinothérapie de première ligne. Les conclusions sont toutefois limitées par la rareté des données de bonne qualité. Nous ne nous attendions pas à une telle rareté d'ECR incluant la TIH comme critère de jugement, étant donné que l'héparine est un des médicaments les plus couramment utilisés à travers le monde et que la TIH est une réaction indésirable potentiellement mortelle. Pour faire face à la rareté globale d'informations cliniquement pertinentes au sujet de la TIH, la TIH devrait être incluse dans les critères de jugement des futures ECR sur l'héparine, et la TIH comme réaction indésirable à un médicament devrait être prise en compte dans les recommandations cliniques concernant la surveillance de la numération plaquettaire pour la TIH.
NOTES DE TRADUCTION: Translated by: French Cochrane CentreTranslation supported by: Ministère du Travail, de l'Emploi et de la Santé Français
Background: Venous thromboembolism (VTE) is a potentially fatal complication of orthopedic surgery, and until recently, few antithrombotic compounds were available for postoperative thromboprophylaxis. The introduction of the non–vitamin K antagonists oral anticoagulants (NOAC), including apixaban, has extended the therapeutic armamentarium in this field. Therefore, estimation of NOAC net clinical benefit in comparison with the established treatment is needed to inform clinical decision making. Objectives: Systematic review to assess the efficacy and safety of apixaban 2.5 mg twice a day versus low-molecular-weight heparins (LMWH) for thromboprophylaxis in patients undergoing knee or hip replacement. Data sources: MEDLINE, Embase, and CENTRAL were searched from inception to September 2016, other systematic reviews, reference lists, and experts were consulted. Study eligibility criteria, participants, and intervention: All major orthopedic surgery randomized controlled trials comparing apixaban 2.5 mg twice daily with LMWH, reporting thrombotic and bleeding events. Data extraction: Two independent reviewers, using a predetermined form. Study appraisal and synthesis methods: The Cochrane tool to assess risk bias was used by two independent authors. RevMan software was used to estimate pooled risk ratio (RR) and 95% confidence intervals (95% CI) using random-effects meta-analysis. Trial sequential analysis (TSA) was performed in statistical significant results to evaluate whether cumulative sample size was powered for the obtained effect. Overall confidence in cumulative evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group methodology. Results: Four studies comparing apixaban 2.5 mg twice daily with LMWH were included, with a total of 11.828 patients (55% undergoing knee and 45% hip replacement). The overall risk of bias across studies was low. In comparison with LMWH (all regimens), apixaban showed a significantly lower risk of VTE events and overall mortality combined (RR: 0.63, 95% CI: 0.42-0.95, I2 = 84%, n = 8346), but not of major VTE events (RR: 0.62, 95% CI: 0.32-1.19, I2 = 63%, n = 9493), or of symptomatic VTE events and VTE-related mortality combined (RR: 1.14, 95% CI: 0.68-1.90, I2 = 0%, n = 11 879). Trial sequential analysis showed that the risk reduction obtained for VTE and mortality was based on underpowered cumulative sample size and effect dimension. Subgroup analysis according to LMWH regimens showed that apixaban reduced the risk of VTE events and overall mortality, and major VTE events, when compared with LMWH once daily, without differences between apixaban and LMWH twice daily. Conclusions: There is low to moderate evidence that in patients undergoing knee or hip replacement, apixaban seems equally effective and safe to LMWH twice a day. When compared with LMWH once a day, apixaban seems a superior thromboprophylaxis option. However, the results are underpowered which precludes definite answers regarding the true net clinical benefit of apixaban versus LMWH in this clinical context.
