Since 2008, the direct-acting oral anticoagulants (DOACs) have expanded the therapeutic options of cardiovascular diseases with recognized clinical and epidemiological impact, such as non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE), and also in the preventive setting of orthopedic surgical patients. The large body of evidence, not only from pivotal clinical trials but also from ‘real-world’ postmarketing observational findings (e.g. analytical epidemiological studies and registry data) gathered to date allow for a first attempt at verifying a posteriori whether or not the pharmacological advantages of the DOACs actually translate into therapeutic innovation, with relevant implications for clinicians, regulators and patients. This review aims to synthesize the risk–benefit profile of DOACs in the aforementioned consolidated indications through an ‘evidence summary’ approach gathering the existent evidence-based data, particularly systematic reviews with meta-analyses of randomized controlled trials, as well as observational studies, comparing DOACs with vitamin K antagonists. Clinical evidence will be discussed and compared with major international guidelines to identify whether an update is needed. Controversial clinically relevant safety issues will be also examined in order to highlight current challenges and unsettled questions (e.g. actual bleeding risk in susceptible populations). It is anticipated that the large number of publications on NVAF or VTE (44 systematic reviews with meta-analyses and 12 observational studies retained in our analysis) suggests the potential existence of overlapping studies and calls for common criteria to qualitatively and quantitatively assess discordances, thus guiding future research.
Objectives To critically appraise published network meta-analyses (NMAs) evaluating the efficacy or safety of the new oral anticogulants (NOACs) dabigatran, rivaroxaban, and apixaban for the prevention of stroke in patients with nonvalvular atrial fibrillation (AF). Methods A systematic literature review was performed to identify the relevant NMAs using MEDLINE, EMBASE, Cochrane Library, Database of Abstracts of Reviews of Effects, and Health Technology Assessment. The synthesis studies were evaluated using the "Questionnaire to assess the relevance and credibility of the NMA." Results Eleven NMAs evaluating NOACs among adults with nonvalvular AF were identified. Most NMAs included three large phase III randomized controlled trials, comparing NOACs to adjusted-dose warfarin (Randomized Evaluation of Long-Term Anticoagulation Therapy [RE-LY], Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation [ROCKET-AF], and Apixaban for Reduction of Stroke and Other Thromboembolic Events in Atrial Fibrillation [ARISTOTLE]). The main differences identified related to potential treatment effect modifiers regarding the mean time spent in therapeutic range (TTR) in the warfarin arm, the risk of stroke or systemic embolism across the trials (mean CHADS2 score: C = congestive heart failure, H = hypertension, A = older than age 75 years, D = diabetes mellitus, S2 = prior stroke or history of transient ischemic attack) or primary versus secondary prevention, and type of populations used in the analysis. Kansal et al. [Kansal AR, Sharma M, Bradley-Kennedy C, et al. Dabigatran versus rivaroxaban for the prevention of stroke and systemic embolism in atrial fibrillation in Canada: comparative efficacy and cost-effectiveness. Thromb Haemost 2012;108:672-82] appropriately adjusted the ROCKET-AF TTR to match the RE-LY population on the basis of individual patient data. Meta-regressions are not expected to minimize confounding bias given limited data, whereas subgroup analyses had some impact on the point estimates for the treatment comparisons. Conclusions Results of the synthesis studies were generally comparable and suggested that the NOACs had similar efficacy, although some differences were identified depending on the outcome. The extent to which differences in the distribution of TTR, CHADS2 score, or primary versus secondary prevention biased the results remains unclear.
Idiopathic thromboembolic disease presents a high risk of recurrence. There is controversy about the effects of aspirin in reducing this risk after the completion of anticoagulant treatment. Searching in Epistemonikos database, which screens 30 databases, we identified four systematic reviews that together include two randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded that aspirin administered after having completed anticoagulation reduces the risk of recurrence, probably without importantly increasing the risk of hemorrhage.
For most atrial fibrillation patients oral anticoagulation constitutes the standard treatment to prevent stroke. However, they carry a risk of bleeding, which is why alternative treatments have been put into practice, such as percutaneous closure of the left atrial appendage. It is not clear whether this is as effective as the conventional treatment with anticoagulants. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified three systematic reviews including only one pertinent randomized controlled trial. We combined the evidence and generated a summary of findings following the GRADE approach. We concluded that percutaneous left atrial appendage occlusion may decrease stroke and mortality, but the certainty of the evidence is low. The effect on other outcomes is not clear because the certainty of the evidence is very low.
BACKGROUND AND OBJECTIVES: Venous thromboembolism (VTE) is commonly encountered in the daily clinical practice. Cancer is an important VTE risk factor. Proper thromboprophylaxis is key to prevent VTE in patients with cancer, and proper treatment is essential to reduce VTE complications and adverse events associated with the therapy.
DESIGN AND SETTINGS: As a result of an initiative of the Ministry of Health of Saudi Arabia, an expert panel led by the Saudi Association for Venous Thrombo-Embolism (a subsidiary of the Saudi Thoracic Society) and the Saudi Scientific Hematology Society with the methodological support of the McMaster University working group produced this clinical practice guideline to assist health care providers in evidence-based clinical decision-making for VTE prophylaxis and treatment in patients with cancer.
METHODS: Six questions related to thromboprophylaxis and antithrombotic therapy were identified and the corresponding recommendations were made following the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach.
RESULTS: Question 1. Should heparin versus no heparin be used in outpatients with cancer who have no other therapeutic or prophylactic indication for anticoagulation?
RECOMMENDATION: For outpatients with cancer, the Saudi Expert Panel suggests against routine thromboprophylaxis with heparin (weak recommendation; moderate quality evidence).Question 2. Should oral anticoagulation versus no oral anticoagulation be used in outpatients with cancer who have no other therapeutic or prophylactic indication for anticoagulation?
RECOMMENDATION: For outpatients with cancer, the Saudi Expert Panel recommends against thromboprophylaxis with oral anticoagulation (strong recommendation; moderate quality evidence).Question 3. Should parenteral anticoagulation versus no anticoagulation be used in patients with cancer and central venous catheters?
RECOMMENDATION: For outpatients with cancer and central venous catheters, the Saudi Expert Panel suggests thromboprophylaxis with parenteral anticoagulation (weak recommendation; moderate quality evidence).Question 4. Should oral anticoagulation versus no anticoagulation be used in patients with cancer and central venous catheters?
RECOMMENDATION: For outpatients with cancer and central venous catheters, the Saudi Expert Panel suggests against thromboprophylaxis with oral anticoagulation (weak recommendation; low quality evidence).Question 5. Should low-molecular-weight heparin versus unfractionated heparin be used in patients with cancer being initiated on treatment for venous thromboembolism?
RECOMMENDATION: In patients with cancer being initiated on treatment for venous thromboembolism, the Saudi Expert Panel suggests low-molecular-weight heparin over intravenous unfractionated heparin (weak; very low quality evidence).Question 6. Should heparin versus oral anticoagulation be used in patients with cancer requiring long-term treatment of VTE?
RECOMMENDATION: In patients with metastatic cancer requiring long-term treatment of VTE, the Saudi Expert Panel recommends low-molecular-weight heparin (LMWH) over vitamin K antagonists (VKAs) (strong recommendation; moderate quality evidence). In patients with non-metastatic cancer requiring long-term treatment of venous thromboembolism, the Saudi Expert Panel suggests LMWH over VKA (weak recommendation; moderate quality evidence).
INTRODUCTION: avantages et les inconvénients relatifs des anticoagulants sont nécessaires pour les décisions concernant l'anticoagulation appropriée chez les patients atteints de cancer.
OBJECTIFS: Examiner les avantages et les inconvénients des anticoagulants pour des indications d'amélioration prophylactiques, thérapeutiques et de survie chez les patients atteints de cancer.
Patients et méthodes: Vue d'ensemble de 6 recensions systématiques de l'anticoagulation dans le cancer de la suite de la Cochrane Collaboration et classement des recommandations d'évaluation, de développement et d'évaluation méthodologie.
RÉSULTATS: Central veineuse cathéters thromboprophylaxie avec de l'héparine ou la warfarine ne réduit pas significativement l'incidence de la thrombose veineuse profonde symptomatique (TVP) (risque relatif [RR] 0,43, IC 95% 0,18 à 1,06 et RR = 0,62, IC 95% de 0,30 à 1,27 respectivement) . Pour la thromboprophylaxie périopératoire, à faible poids moléculaire héparine (HBPM) et l'héparine non fractionnée (HNF) ont des effets similaires sur la mortalité (RR 0,89, IC 95% 0,61 à 1,28) et la morbidité. Pour le traitement initial de la maladie thromboembolique veineuse (MTEV), les HBPM par rapport à l'héparine non fractionnée réduit la mortalité à 3 mois (RR 0,71, IC 95% de 0,52 à 0,98). Pour le traitement à long terme de la TEV, les HBPM par rapport à des antagonistes de la vitamine K réduit la récurrence de TEV (hazard ratio [HR] 0,47, IC 95% de 0,32 à 0,71), mais pas la mortalité (HR 0,96, IC 95% 0,81 à 1,14). Comme les interventions visant à améliorer la survie, la warfarine suggère un bénéfice de survie à 6 mois dans le sous-groupe de cancer du poumon à petites cellules (SCLC) (RR = 0,69, IC 95% de 0,50 à 0,96), tandis que l'héparine suggèrent un bénéfice de survie chez les patients atteints de cancer en général (RH 0,77, IC 95% 0,65 à 0,91) et chez ceux ayant limité CPPC en particulier (HR 0,56, IC 95% 0,38 au 0,83).
CONCLUSIONS: Chez les patients atteints de cancer, les données actuelles ne supporte pas l'utilisation systématique de la thromboprophylaxie pour les cathéters veineux centraux ou un anticoagulant spécifique pour la thromboprophylaxie postopératoire. Anticoagulants peut améliorer la survie, mais davantage de données seront utiles dans le choix des sous-groupes qui bénéficient le plus.
Since 2008, the direct-acting oral anticoagulants (DOACs) have expanded the therapeutic options of cardiovascular diseases with recognized clinical and epidemiological impact, such as non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE), and also in the preventive setting of orthopedic surgical patients. The large body of evidence, not only from pivotal clinical trials but also from ‘real-world’ postmarketing observational findings (e.g. analytical epidemiological studies and registry data) gathered to date allow for a first attempt at verifying a posteriori whether or not the pharmacological advantages of the DOACs actually translate into therapeutic innovation, with relevant implications for clinicians, regulators and patients. This review aims to synthesize the risk–benefit profile of DOACs in the aforementioned consolidated indications through an ‘evidence summary’ approach gathering the existent evidence-based data, particularly systematic reviews with meta-analyses of randomized controlled trials, as well as observational studies, comparing DOACs with vitamin K antagonists. Clinical evidence will be discussed and compared with major international guidelines to identify whether an update is needed. Controversial clinically relevant safety issues will be also examined in order to highlight current challenges and unsettled questions (e.g. actual bleeding risk in susceptible populations). It is anticipated that the large number of publications on NVAF or VTE (44 systematic reviews with meta-analyses and 12 observational studies retained in our analysis) suggests the potential existence of overlapping studies and calls for common criteria to qualitatively and quantitatively assess discordances, thus guiding future research.
