Antithrombotic Therapy for Cerebrovascular Disorders: Mitral Valve Prolapse
Mitral Valve Prolapse
In young adults with unexplained stroke mitral valve prolapse (MVP) is increased 3-9 times over control subjects. It is difficult to establish convincingly a causal relationship between MVP and cerebral ischemia in an individual patient. Embolism of valvular thrombi probably accounts for most brain ischemia associated with MVP, although other potential mechanisms include embolism of left atrial thrombi related to MVP associated AF, septic embolism from MVP-associated infective endocarditis, and in situ thrombosis related to platelet hyperaggregability. The overall risk of stroke in young adults with MVP is low. Assuming that as many as one third of strokes in young adults are due to MVP (a clear overestimate), a stroke incidence of 3/ 100,000/year in young adults, and a 6% prevalence of MVP, it is calculated that the maximal risk of stroke in all young adults with MVP is only 1/6,000/year. Clearly, no prophylactic treatment is warranted in asymptomatic persons with MVP, except precautions against endocarditis. The treatment of MVP-associated brain ischemia has been largely empiric, based on level V evidence. Based on the observation of platelet-fibrin emboli and platelet activation in these patients, initial treatment with platelet-fibrin emboli and platelet activation in these patients, initial treatment with platelet-antiaggregating agents appears rational. If ischemia recurs, reevaluation for other occult causes of stroke and consideration of anticoagulation therapy appear logical. add comment
Mitral Annulus Calcification
The presence of mitral annulus calcification correlates with age, hypertension, and difluse atherosclerosis. Some degree of mitral annulus calcification is present in 10% of consecutive autopsies and 3% of elderly patients without stroke who undergo echocardiography. It is likely that mitral annulus calcification is more often a marker of other vascular disease causing stroke than the primary embolic source. In patients with mitral annulus calcification and cerebral ischemia, a causal relationship should be considered only after exclusion of cerebrovascular mechanisms and cardiac monitoring to detect AF.
Category: Antithrombotic Therapy
Tags: antithrombotic therapy, cardioembolic source, cerebrovascular disorders