Anticoagulation in valvular heart disease preoperatively and postoperatively.

We have reviewed the risks and benefits of anticoagulation for cardiac valve disease before and after valve surgery. Though the absence of standardized reporting of complications and the paucity of well-designed comparative studies mandate careful consideration of the variables of individual cases, we have made the following general recommendations: Unoperated patients with rheumatic mitral valvular disease and atrial fibrillation should be chronically treated with warfarin, regardless of the hemodynamic severity of their valvular lesion. The presence of right- or left-sided heart failure is an indication for warfarin treatment, in the absence of significant contraindications. There is emerging evidence that platelet-suppressant therapy may be of benefit in diminishing the thromboembolic risk of at least a subset of patients with rheumatic valvular disease and decreased platelet survival. Until platelet-survival studies are more readily available and larger-scale studies can be performed, however, we do not recommend routine treatment with platelet-active agents. We recommend chronic warfarin anticoagulation in all patients with mechanical prostheses in either the aortic or mitral position, regardless of cardiac rhythm or prosthesis model. We do not routinely add platelet-active agents except in the case of embolism despite adequate anticoagulation with warfarin. Patients with aortic bioprostheses generally do not require warfarin treatment for more than 3 months following valve replacement. The presence of atrial fibrillation and marked depression of postoperative ventricular function are indications for chronic anticoagulation. In the case of mitral bioprostheses, we recommend indefinite warfarin treatment for patients with atrial fibrillation, depressed ventricular function, or low cardiac output. We consider a preoperative history of embolism or an operative finding of left atrial thrombus to be an additional indication for anticoagulation, in the absence of significant contraindications. Patients on anticoagulant therapy should be followed closely--when possible in specialized anticoagulation clinics--to minimize the risks of treatment. Specific recommendations are made for management of anticoagulation during infective endocarditis, pregnancy, and noncardiac surgery.