Journal of thrombosis and thrombolysis
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J. Thromb. Thrombolysis · Apr 2013
ReviewReversal of novel oral anticoagulants in patients with major bleeding.
Novel oral anticoagulants (NOACs) that directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban, edoxaban) are effective therapies for the prevention and treatment of thromboembolism with reduced bleeding complications compared with warfarin for some indications. However, specific antidotes to reverse the anticoagulant activity of NOACs in the event of major bleeding are not available. Evidence supporting non-specific prohemostatic therapies (prothrombin complex concentrate [PCC], activated prothrombin complex concentrate [aPCC], recombinant factor VIIa) in this setting is limited to healthy human volunteers, animal models, and in vitro studies. ⋯ Administration of PCC or aPCC may be considered in addition to supportive measures for patients with severe or life-threatening bleeding. Clinical studies are needed to establish the efficacy and safety of these treatments. Target-specific antidotes are in development and hold promise for NOAC reversal, but require further investigation.
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J. Thromb. Thrombolysis · Feb 2013
Measurement of dabigatran and rivaroxaban in primary prevention of venous thromboembolism in 106 patients, who have undergone major orthopedic surgery: an observational study.
No routine coagulation laboratory test is recommended during rivaroxaban or dabigatran treatment. However measuring drug concentration and/or anticoagulant activity can be desirable in some special clinical settings, such as bleeding, thrombosis recurrence or emergency surgery. The effects of dabigatran etexilate and rivaroxaban on various coagulation assays have been previously studied in normal plasma spiked with increasing concentrations of the drug. ⋯ Rivaroxaban--mean Cmax 140 ng/mL (extremes 0-412) induces a greater increase of PT than dabigatran. aPTT is sensitive to dabigatran. Rivaroxaban concentrations were in good agreement with two other studies while unexplained lower than expected concentrations were found in dabigatran patients receiving 220 mg once a day [mean Cmax 60 ng/mL (extremes 0-320)]. An interference by pantoprazole, a drug which reduces dabigatran absorption, could explain the observed lower than expected results.
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J. Thromb. Thrombolysis · Jan 2013
Clinical TrialUsing fibrin degradation products level to facilitate diagnostic evaluation of potential acute aortic dissection.
This study evaluated whether degradation products of plasma fibrin and fibrinogen (FDP) level can be used to differentiate acute aortic dissection (AAD) from acute myocardial infarction (AMI), angina pectoris, acute cerebral infarction, or transient cerebral ischemic attack (TIA). Ninety-six consecutive patients with definitive diagnosis of AAD by contrast-enhanced computed tomography scan underwent measurement of FDP on admission. Of these patients, 45 had a patent false lumen (patent-type), and 51 had complete thrombosis of the false lumen (thrombosed-type). ⋯ A simple liner regression, calculated using FDP and D-dimer values from a total of 71 patients, yielded a correlation coefficient (R2) of 0.95, indicating a strong correlation. In symptomatic patients with suspected AAD, a diagnosis of patent-type AAD should be considered if FDP ≥ 12.6 μg/mL. Patients with FDP ≥ 5.6 μg/mL have the possibility of thrombosed-type AAD.
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J. Thromb. Thrombolysis · Jan 2013
Clinical TrialBleeding risk assessment using multiple electrode aggregometry in patients following coronary artery bypass surgery.
Individual variability in the response to antiplatelet therapy (APT), frequently administered preoperatively, has been established by various platelet function assays and could reflect bleeding tendency after coronary artery bypass surgery (CABG). Our hypothesis is that multiple electrode whole-blood aggregometry (MEA) can identify patients at risk for excessive bleeding. We enrolled 211 patients (155 male and 56 female) undergoing isolated CABG in a prospective observational study. ⋯ The proportion of patients transfused with PRBC did not significantly differ among the groups in regard to preoperative APT (p = 0.636). Comparison of the ASPI test values between patients with respect to PRBC administration revealed lower values in the ASPI test in a group of patients transfused with PRBC (mean, 27.88 vs. 40.32 AUC, p = 0.002). Our study showed that MEA is a useful method of predicting CABG patients with excessive postoperative bleeding.
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J. Thromb. Thrombolysis · Jan 2013
Clinical TrialThree-month cumulative incidence of thromboembolism and bleeding after periprocedural anticoagulation management of arterial vascular bypass patients.
The objective of this study was to determine 3-month cumulative incidence of peri-procedural thromboembolism (TE) including graft occlusion, and peri-procedural bleeding for chronically anticoagulated vascular bypass graft (BG) patients requiring temporary warfarin interruption for an invasive procedure. Appropriate peri-procedural management of patients receiving chronic warfarin therapy to preserve lower extremity arterial BG patency is unknown. In a protocol driven, cohort study design, all BG patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation (1997-2007) were followed forward in time to estimate the 3-month cumulative incidence of TE and bleeding. ⋯ TE and bleeding did not differ by bridging status. The 3-month cumulative incidence of TE among BG patients in whom warfarin is temporarily interrupted for an invasive procedure may be higher than in other "bridging" populations (atrial fibrillation, prosthetic heart valve, venous thromboembolism). This finding underscores the often tenuous nature of distal bypass grafts necessitating an aggressive approach to peri-procedural anticoagulation management.