Chronic Oral Anticoagulation Research Articles

Determinants of the still-face phenomenon by 2 to 6-month-olds

Chronic oral anticoagulation frequently requires interruption for various reasons and durations. Whether or not to bridge with heparin or other anticoagulants is a common clinical dilemma. The evidence to inform decision making is limited, making current guidelines equivocal and imprecise. Moreover, indications for anticoagulation interruption may be unclear. New observational studies and a recent large randomized trial have noted significant perioperative or periprocedural bleeding rates without reduction in thromboembolism when bridging is employed. Such bleeding may also increase morbidity and mortality. In light of these findings, physician preferences for routine bridging anticoagulation during chronic anticoagulation interruptions may be too aggressive. More randomized trials, such as PERIOP2 (A Double Blind Randomized Control Trial of Post-Operative Low Molecular Weight Heparin Bridging Therapy Versus Placebo Bridging Therapy for Patients Who Are at High Risk for Arterial Thromboembolism), will help guide periprocedural management of anticoagulation for indications such as venous thromboembolism and mechanical heart valves. In the meantime, physicians should carefully consider both the need for oral anticoagulation interruption and the practice of routine bridging when anticoagulation interruption is indicated.

Amoxicillin-related postextraction bleeding in an anticoagulated patient with tranexamic acid rinses

This report describes a patient who had significant postoperative bleeding 4 days after undergoing surgery while using a tranexamic acid (4.8%) mouth rinse protocol for local control of hemostatis. Patients undergoing dentoalveolar surgery who are receiving chronic oral anticoagulants are treated with a tranexamic acid mouth rinse at our hospital. No systemic modification of their coagulation status is attempted. The postoperative bleeding problem that developed was determined to be caused by an antibiotic-induced vitamin K deficiency rather than a failure of the tranexamic acid protocol.

Should All Patients with Dilated Cardiomyopathy Receive Chronic Anticoagulation?

To review the mechanism of intracardiac thrombus formation, describe the risk of systemic thromboembolization, critically evaluate the literature regarding the use of oral anticoagulation, review the American College of Chest Physicians (ACCP) guidelines, and provide recommendations for oral anticoagulation in patients with dilated cardiomyopathy (DCM). English language clinical studies, abstracts, and review articles pertaining to oral anticoagulation and DCM. Relevant human studies examining the role of anticoagulation for preventing systemic thromboembolism in patients with DCM. Potential mechanisms and risk factors for systemic thromboembolization in patients with DCM are discussed. Studies evaluating the benefits and risks of chronic oral anticoagulation to prevent systemic thromboembolization are critiqued. Recommendations for oral anticoagulation in patients with DCM from the second and third ACCP Consensus Conferences are reviewed. Suggestions for study design of a new clinical trial are presented. The second ACCP Consensus Conference recommended chronic anticoagulation for all patients with DCM, but the third conference did not address this issue. Review of demographic data from clinical trials demonstrates reluctance to use anticoagulation in all patients with DCM because of lack of support from prospective, controlled trials. Recent data from large clinical trials suggest that the risk of systemic embolization may be lower than previously believed. We recommend the use of chronic anticoagulation with warfarin in patients for whom the risk of embolism is greater than the risk of major bleeding, such as those with atrial fibrillation or previous systemic embolization. Lack of compliance with ACCP guidelines suggests that clinicians require additional information regarding the bleeding risk and systemic embolization rate reduction of chronic anticoagulation in patients with DCM who remain in normal sinus rhythm. It is only through prospective, controlled trials that this risk/benefit ratio to prevent systemic embolism in patients with DCM can be established.

Antiphospholipid syndrome as the second cause of non-tumorous Budd-Chiari syndrome

In a prospective study of 22 patients with non-tumorous Budd-Chiari syndrome, four were found to have the antiphospholipid syndrome with no other cause of hepatic vein thrombosis. All four patients were young women. The antiphospholipid syndrome was secondary to systemic lupus in one case, to a "lupus-like disease" in another, and apparently primary in the remaining two cases. Two patients died. The other two are in good health on chronic oral anticoagulation. In our experience, the antiphospholipid syndrome is a frequent cause, after myeloproliferative disorders, of non-tumorous Budd-Chiari syndrome. In such patients, long-term anticoagulation may prevent recurrence or extension of thrombosis.