Timing the First Postoperative Dose of Anticoagulants: Lessons Learned From Clinical Trials.

The non-vitamin K antagonist oral anticoagulants (NOACs), rivaroxaban, apixaban, and dabigatran, have been shown in phase 3 trials to be effective for thromboprophylaxis in patients undergoing elective hip or knee arthroplasty. Results from prior studies suggested that the safety of anticoagulants in such patients was improved if the first postoperative dose was delayed for at least 6 h after surgery. The timing of the first postoperative dose of the NOACs tested in phase 2 studies differed among the three NOACs: dabigatran was started 1 to 4 h postoperatively, whereas rivaroxaban and apixaban were started at least 6 and 12 h, postoperatively, respectively.

Transesophageal echocardiography in patients with cryptogenic ischemic stroke: a systematic review.

Background: The clinical utility of routine transesophageal echocardiography (TEE) for patients with unexplained ischemic stroke is controversial. We performed a systematic review to determine the frequency of detection of new cardiac findings in patients with cryptogenic ischemic stroke (IS) undergoing transesophageal echocardiography (TEE).

Methods: Systematic review and meta-analysis of cohort studies of consecutive patients with "cryptogenic" IS undergoing TEE after routine etiologic workup.

New oral anticoagulants for stroke prevention in atrial fibrillation: impact of study design, double counting and unexpected findings on interpretation of study results and conclusions.

Four recently introduced new oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban) have been shown to be at least as efficacious and safe as warfarin for stroke prevention in patients with atrial fibrillation in their respective trials. The first three have been approved, while edoxaban is awaiting regulatory approval. Several guidelines have endorsed the approved new oral anticoagulants over warfarin because of their favourable risk-benefit ratio, low propensity for food and drug interactions, and lack of requirement for routine coagulation monitoring.

Dabigatran attenuates thrombin generation to a lesser extent than warfarin: could this explain their differential effects on intracranial hemorrhage and myocardial infarction?

Compared with warfarin, dabigatran is associated with less intracranial hemorrhage, but an increased risk of myocardial infarction. To explore these phenomena, we compared their effects on thrombin generation. Thrombin generation in plasma from 10 patients taking therapeutic doses of warfarin (mean INR 2.

Rivaroxaban for stroke prevention in atrial fibrillation: a critical review of the ROCKET AF trial.

Oral anticoagulation is the mainstay of therapy for stroke prevention in patients with atrial fibrillation (AF). Vitamin K antagonists such as warfarin have many drawbacks that reduce their uptake, safety and effectiveness. The ROCKET AF trial compared rivaroxaban (20 mg/day; 15 mg/day in patients with creatinine clearance 30-49 ml/min) with dose-adjusted warfarin (international normalized ratio 2-3) in 14,264 patients with AF and a prior history of stroke or at least two other additional risk factors for stroke.

Subtle differences in commercial heparins can have serious consequences for cardiopulmonary bypass patients: A randomized controlled trial.

Objective: To compare the potency, reversibility, and perioperative bleeding risk of Hepalean with those of PPC heparin.

Methods: Because in vitro testing failed to detect differences in the potency or protamine reversibility of the 2 heparin preparations, we conducted a parallel group, single-center, double-blind, randomized, controlled trial to compare the anticoagulant effects of Hepalean to those of PPC heparin in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Results: From June 1, 2011, to June 30, 2011, we randomly assigned 11 patients to receive PPC heparin and 10 to receive Hepalean.

Dabigatran for stroke prevention in atrial fibrillation: the RE-LY trial.

Oral anticoagulation is the mainstay of therapy for stroke prevention in patients with atrial fibrillation. Vitamin K antagonists such as warfarin reduce the risk of cardioembolic stroke by approximately two-thirds compared with no treatment, but are limited by their unpredictable anticoagulant effect and narrow therapeutic index. Warfarin therapy requires routine coagulation monitoring, which is inconvenient for patients and costly for the healthcare system.

Effectiveness and safety of combined antiplatelet and anticoagulant therapy: a critical review of the evidence from randomized controlled trials.

Antiplatelet and anticoagulant drugs are effective for the prevention of arterial and venous thrombosis but patients continue to experience major cardiovascular events despite their use. Strategies to improve the effectiveness of antithrombotic therapies include selecting the optimal drug and dosing regimen, the use of combinations of antiplatelet and anticoagulant drugs and the development of new more effective drugs to replace existing therapies. Evidence from randomized controlled trials indicates that the combination of aspirin and an anticoagulant is more effective than aspirin alone for the prevention of recurrent cardiovascular events in patients with acute coronary syndrome and is more effective than anticoagulation alone for the prevention of thromboembolic events in patients with mechanical heart valves, but at a cost of increased bleeding.

New antithrombotic agents--insights from clinical trials.

Antithrombotic agents are the cornerstones of therapy for thrombosis. The compositions of arterial and venous clots differ, rendering antiplatelet agents more effective for arterial thrombosis and anticoagulants more effective for venous disease. Despite taking acetylsalicylic acid, some patients with arterial disease experience thrombotic events.