Traditional surgical aortic valve replacement is associated with a high risk of serious complications, especially in elderly patients with other preoperative diseases and unable to undergo thoracotomy. Therefore, transcatheter aortic valve implantation (TAVI) is now the accepted standard treatment for patients with symptomatic severe aortic stenosis at elevated risk for conventional surgical valve replacement. Currently, guidelines propose the use of dual antiplatelet therapy for the prevention of thromboembolic events after TAVI in the patients without an indication for oral anticoagulation. While, this strategy is empiric and largely based on expert consensus extrapolated from the arena of percutaneous coronary intervention. Antithrombotic therapy is associated with a significant occurrence of both thrombotic and bleeding complications, thus, the balance between thrombotic and bleeding risk is critical. This review summarizes current guidelines and the evidence underpinning them and explores the rational for using antiplatelet and/or anticoagulant strategies after TAVI.
Atrial fibrillation is now the most frequent kind of adult arrhythmia in the world, with a prevalence rate at 2%-4%. In addition to the clinical symptoms of palpitation, shortness of breath, chest tightness, and decreased exercise tolerance, patients with atrial fibrillation have a 4 to 5 times higher risk of ischemic stroke than patients without atrial fibrillation, so anticoagulation therapy should be tailored to the CHA2DS2-VASc [congestive heart failure, hypertension, age≥75 years (doubled), diabetes mellitus, stroke (doubled)-vascular disease, age 65-74 years and sex category (female)] score. Oral anticoagulants not only prevent thrombosis, but also raise the risk of drug-related bleeding. This paper examines the assessment and mitigation of bleeding risk in atrial fibrillation and venous thromboembolism: A position paper from ESC/EHRA/AACA/APHRS, in order to provide readers with the most up-to-date research on anticoagulant bleeding risk management in patients with atrial fibrillation.
ObjectivesTo systematically review the efficacy and safety of new oral anticoagulants (NOACs) for cancer-associated venous thromboembolism.MethodsStudies about the efficacy and safety of NOACs versus low molecular weight heparins (LMWHs) or vitamin K antagonists (VKAs) for cancer-associated venous thromboembolism were collected by searching PubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and CBM databases from inception to August, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by RevMan 5.3 software.ResultsA total of 8 studies involving 2 448 patients were included. The results of meta-analysis showed that: there was no significant difference in the recurrent VTE rate (OR=0.74, 95%CI 0.49 to 1.11, P=0.15) or bleeding rate (OR=0.80, 95%CI 0.57 to 1.13, P=0.21) between NOACs group and VKAs group. The major bleeding rate was significantly higher in the VKAs group than in the NOACs group (OR=0.47, 95%CI 0.27 to 0.84, P=0.01). The incidences of recurrent VTE (OR=0.84, 95%CI 0.16 to 4.14, P=0.83), bleeding (OR=0.46, 95%CI 0.18 to 1.20, P=0.11), major bleeding (OR=0.45, 95%CI 0.12 to 1.60, P=0.21) were similar between NOACs group and LMWHs group.ConclusionsThe current evidence indicates that for cancer patients with VTE, NOACs are superior to warfarin and comparable to LMWHs. Due to limited quantity and quality of the included studies, more high quality studies are required to verify the above conclusion.
Objective To review the current clinical application status and research progress of different anticoagulants in the perioperative period of free flap transplantation. Methods A comprehensive review of recent relevant literature was conducted, focusing on clinical research concerning the application of anticoagulants in the perioperative period of free flaps. The administration regimens, timing, dosage selection, effectiveness, and safety of commonly used and novel anticoagulants were summarized. Results At present, the anticoagulants mainly used in the perioperative period of free flap transplantation include antivenous thrombotic drugs, antiarterial thrombotic drugs, and physical/colloidal anticoagulants, etc. Anticoagulation regimens can be classified into two major categories: single-agent anticoagulation and combined anticoagulation. Single-agent anticoagulation mainly includes unfractionated heparin, low-molecular-weight heparin, aspirin, and new anticoagulation drug regimens. Combined anticoagulation is commonly a synergistic anticoagulation regimen dominated by heparin drugs, combined with aspirin, different antiplatelet drugs, and expansion agents. Studies indicate that perioperative anticoagulant administration can effectively reduce the risk of thrombosis in free flaps and improve the overall flap survival rate. However, significant differences exist in the impact of drug types, administration routes, initiation timing, and dosage intensity on efficacy and bleeding risk. A unified, standardized application protocol has not yet been established. In addition, there has been a growing number of studies on novel anticoagulant drugs. However, their superiority and optimal application strategies in the field of free flap transplantation still necessitate more high-quality evidence. Conclusion Perioperative anticoagulation therapy is one of the key strategies to improve the survival rate of free flaps, but there is still a lack of advanced evidence-based evidence to establish a standard protocol at present. Future research should focus on the optimization of individualized anticoagulation strategies, the validation of the effectiveness of new anticoagulants, and the exploration of the advantages of different anticoagulation regimens. At the same time, attention should be paid to balancing anticoagulation and bleeding risks to promote the standardization of clinical practice and the improvement of treatment safety.