Antithrombotic Therapy for Cerebrovascular Disorders: Valvular Heart Disease

Antithrombotic Therapy for Cerebrovascular Disorders: Valvular Heart DiseaseValvular Heart Disease
Overall, about 20% of patients with mitral stenosis experienced clinical embolism. Embolism usually complicates mitral stenosis or mixed stenosis-regurgi-tation. The most important contributing factor to mitral stenosis in terms of risk is coexistent AF. Coexistent mitral stenosis and AF increase the risk of embolism from 3 to 7 times that of mitral stenosis alone. The Framingham study reported an 18-fold increase in stroke in patients with mitral stenosis and AF. In one study 16% of 622 patients with mitral stenosis and AF had left atrial thrombi by echocardiography, whereas only 1% of 192 patients with mitral stenosis without AF had atrial thrombi. The sensitivity of echocardiography for left atrial body and left atrial appendage thrombi was 78% and 35%, respectively, when compared with the presence of thrombi at surgery. This observation confirms the limited value of echocardiography in the identification of left atrial appendage thrombi. Patients with atrial thrombi had significantly greater left atrial size than those without thrombi. Advanced age has been correlated with embolic tendency in these patients. Prophylactic anticoagulation is indicated in selected patients with mitral stenosis, especially those with AF.
In patients with valvular heart disease who suffer an initial embolus, recurrent embolism occurs in 3075% of patients, at a rate of almost 10% annually. In patients who have experienced embolism, anticoagulation should be permanently administered. read more
Prosthetic Valves
Embolic stroke in patients with prosthetic valves accounts for about 10% of all cardiogenic brain emboli. A series of level V reports suggest that a greater than expected number of patients with prosthetic valves who are receiving warfarin at the onset of embolic stroke had hemorrhagic infarction on initial CT, despite none having received excessive anticoagulation. Proper anticoagulant management in this setting is uncertain. Because of the risk of early recurrent embolism, continuation of anticoagulation in these patients should be considered, providing the CT does not show hemorrhage, the infarction is small to moderate in size, and acute hypertension is absent. Repeat CT after 48 h to detect early hemorrhagic transformation may be prudent in these high-risk patients.