Antithrombotic therapy in native heart valve disease.

In establishing the indication for anticoagulation of patients with native heart valve disease, those with thromboembolic events and/or atrial fibrillation (AF) must be distinguished from patients with sinus rhythm. Anticoagulation should be started as a matter of principle in patients with thromboembolic events and/or AF who do not undergo valve replacement. However, a more differentiated procedure is mandatory for patients with sinus rhythm. If the left atrium is enlarged, spontaneous echo contrast is detected, and/or there is no atrial contraction and/or reduced left ventricular pump function (e.g., in patients with mitral valve stenosis), then anticoagulation with a target INR of 2.5 is indicated, even in those with sinus rhythm. Whereas rheumatic mitral valve stenosis predominates in developing countries, aortic stenosis (AS) predominates in developing countries. These AS patients mainly suffer microemboli that often determine the prognosis in patients with calcification of the mitral annulus. Anticoagulation is not recommended in calcific microemboli. If there are simultaneous atherothrombotic plaques of the aortic arch > 5 mm in size owing to an often more complex cardiovascular risk profile, then warfarin treatment is indicated. Mitral valve prolapse (MVP), patient foramen ovale and atrial septal aneurysm are potential sources of embolism that may cause stroke. On their own, these congenital lesions do not entail an indication for anticoagulation. This applies in particular to patients with MVP in whom secondary prevention of stroke can be attained with 100 mg aspirin.