vitamin-k-semiquinone-radical and Mitral-Valve-Stenosis

To address the following question: Are vitamin K antagonists (VKA) obsolete as stroke prevention therapy for patients with atrial fibrillation (AF) and thromboembolic risk factors?. A patient-level meta-analysis of the pivotal phase III randomized trials confirmed the favorable treatment effect of direct oral anticoagulants (DOAC) over VKA in multiple key patient subgroups. Among patients with AF and rheumatic heart disease (85% of whom had mitral stenosis), a randomized trial showed that rivaroxaban was not superior to VKA for stroke prevention. Caution should be exercised when prescribing DOAC for AF-related stroke prevention for patients with elevated body mass indices or history of bariatric surgery, patients with bioprosthetic heart valves, and those who require treatment with drugs that interact with cytochrome P450 and P-glycoprotein. Drug costs associated with DOAC remain considerably higher than VKA, by up to 30-fold. Direct oral anticoagulants are preferable over VKA in the large majority of eligible patients with AF and thromboembolic risk factors. The use of DOAC should be avoided for patients with mechanical heart valves or moderate/severe rheumatic mitral stenosis. Vitamin K antagonist is a reasonable option for patients who are under-represented in randomized trials, when there are significant drug-drug interactions or when patients cannot afford DOAC agents due to their higher costs.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Humans; Mitral Valve Stenosis; Stroke; Thromboembolism; Vitamin K

Patients at thromboembolic risk with non-valvular atrial fibrillation (AF) can now be managed either with a vitamin K antagonist (VKA) or with a fixed dose of a non-VKA oral anticoagulant (NOAC), while patients with valvular AF have been restricted to VKAs on the basis of a potentially higher risk and different mechanism of thrombosis, and the lack of sufficient data on the efficacy of NOACs. The terms 'non-valvular AF' and 'valvular AF' have not been however consistently defined. 'Valvular' AF has included any valvular disorder, including valve replacement and repair. In AF with rheumatic mitral disease, observational studies strongly suggest that VKA treatment is valuable. These patients have not been included in NOAC trials, but there is also no stringent argument to have excluded them. This is at sharp variance from patients with mechanical valves, also excluded from the pivotal Phase III trial comparing warfarin with NOACs, but in whom a single Phase II trial of dabigatran etexilate against VKA treatment was stopped prematurely because of increased rates of thromboembolism as well as increased bleeding associated with dabigatran. Until more data are available, such patients should be therefore managed with VKAs. We here propose an open-label randomized trial of one of the NOACs against the best of treatment available in regions of the world in which rheumatic heart disease is still highly prevalent, aiming at showing the superiority of the NOAC used against current standard treatment.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Evidence-Based Medicine; Humans; Mitral Valve Stenosis; Randomized Controlled Trials as Topic; Thromboembolism; Treatment Outcome; Vitamin K

Rheumatic valve disease is present in 0.4 % of the word population, mainly in lowincome countries. Rheumatic mitral stenosis affects more women and between 40 to 75 % of patients may have atrial fibrillation (AF), more frequently in upper-middle income countries. This rhythm disturbance is due to increased atrial pressure, chronic inflammation, fibrosis, and left atrial enlargement. There is also an increase in the prevalence of AF with age in patients with mitral stenosis. The risk of stroke is 4 % per year. Success rates for cardioversion, Cox-Maze procedure, and catheter ablation are low. Therefore, anticoagulation with vitamin K antagonist is mandatory for Evaluated Heart valves, Rheumatic or Artificial (EHRA) classification type 1. However, this anticoagulation is used by less than 80 % of those eligible and less than 30 % have the international normalized ratio in the therapeutic range. The safety and efficacy of using rivaroxaban, a direct factor Xa inhibitor anticoagulant, were demonstrated in the RIVER trial with a sample of 1005 patients with AF and bioprosthetic mitral valve. The indication for valve replacement, that is, if severe mitral stenosis or severe mitral regurgitation, was not specified. A randomized, open-label study (DAVID-MS) is underway to compare the effectiveness and safety of dabigatran and warfarin therapy for stroke prevention in patients with AF and moderate or severe mitral stenosis. Thus, the applicability of the use of direct anticoagulants in patients with AF and mitral stenosis and also in those undergoing mitral bioprostheses surgery will be the subject of further studies. The findings may explain if specific atrial changes of mitral stenosis even after the valve replacement will influence thromboembolic events with direct anticoagulants.

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Dabigatran; Factor Xa Inhibitors; Female; Humans; Mitral Valve Stenosis; Rivaroxaban; Stroke; Vitamin K; Warfarin

Topics: Administration, Oral; Anticoagulants; Atrial Fibrillation; Humans; Mitral Valve Stenosis; Pilot Projects; Stroke; Thromboembolism; Vitamin K

Topics: Aged; Anticoagulants; Aortic Valve; Aortic Valve Stenosis; Echocardiography; Female; Heart Valve Prosthesis Implantation; Heparin; Humans; Infusions, Intravenous; International Normalized Ratio; Mitral Valve; Mitral Valve Stenosis; Rheumatic Heart Disease; Thrombosis; Vitamin K; Warfarin

Significant chronic subdural hematoma (CSDH) is usually a surgical emergency. Spontaneous resolution of CSDH has rarely been reported in the literature. We are reporting a case of spontaneous resolution of CSDH in a patient receiving anticoagulant therapy who had undergone mitral valve replacement surgery.

Topics: Adult; Anticoagulants; Antifibrinolytic Agents; Brain; Dexamethasone; Female; Glucocorticoids; Heart Valve Prosthesis Implantation; Hematoma, Subdural, Chronic; Humans; International Normalized Ratio; Mitral Valve Stenosis; Postoperative Complications; Tomography, X-Ray Computed; Treatment Outcome; Vitamin K; Withholding Treatment

A 17-year-old patient with Shone's disease had to be readmitted to the hospital 3 months after implantation of an artificial aortic valve because of extreme mitral insufficiency with consecutive pulmonary edema and hepatic dysfunction. He had been orally anticoagulated and presented with a high international normalized ratio of 6.7. Emergency replacement of the mitral valve was possible only after administration of prothrombin-complex concentrate, as vitamin K(1) and fresh frozen plasma did not correct the hemostatic defect sufficiently.

Topics: Adolescent; Anticoagulants; Aortic Valve; Aortic Valve Stenosis; Blood Coagulation Factors; Coagulation Protein Disorders; Emergencies; Heart Failure; Heart Valve Prosthesis Implantation; Humans; Liver Diseases; Male; Mitral Valve Insufficiency; Mitral Valve Stenosis; Plasma; Pulmonary Edema; Radiography; Thromboembolism; Ventricular Outflow Obstruction; Vitamin K

Topics: Anticoagulants; Atrial Fibrillation; Drug Interactions; Female; Frostbite; Humans; Mitral Valve Stenosis; Nonprescription Drugs; Vitamin K