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Bioprosthetic valve thrombosis is an unexpected complication which has no guidelines for its management. A 70-year-old female presented 10 days after a stroke, three years after having undergone mitral bioprosthetic valve implantation. Both, transthoracic echocardiography and transesophageal echocardiography (TEE) revealed a large mobile, non-obstructive mass attached to the atrial side of the sewing ring of the bioprosthesis. The administration of low-molecular-weight heparin and aspirin resulted only in a reduction of thrombus size, whereas a slow streptokinase infusion resulted in complete disappearance of the thrombus after 16 h. A review of the literature shows that late non-obstructive bioprosthetic valve thrombosis, as diagnosed with TEE, is a rare condition that can be successfully treated either by anticoagulant or thrombolytic therapy. Late bioprosthetic valve thrombosis should be considered as a cause of prosthetic valve dysfunction, and long-term preventive anticoagulant treatment of high-risk patients is warranted. Slow thrombolytic therapy is safe and successful, even for large non-obstructive bioprosthetic thrombi, if there are no contraindications.

Prosthetic valve thrombosis (PVT) is a life-threatening disease, for which treatment strategies have been controversial. Herein, existing data on management options are reviewed, and conclusions drawn as to the choice and use of treatment strategies for PVT. The use of transesophageal echocardiography (TEE) allows distinction to be made between obstructive and non-obstructive PVT by the presence or absence of occluder motion limitation. The differentiation of PVT from pannus and vegetation is, however, still limited by TEE. The incidence of PVT has been underestimated by not taking into account a large percentage of non-obstructive PVT. Although the standard treatment for PVT has been surgery, thrombolysis has lower mortality rates, particularly in patients in NYHA functional classes III-IV. The lowest complication rates with thrombolysis have been achieved in patients with non-obstructive PVT. Pregnancy, left atrial appendage thrombi and large PVT are not contraindications to thrombolysis. The third therapeutic option is anticoagulant therapy. The detrimental effect of anticoagulant treatment in obstructive PVT was shown in a prospective study. Non-obstructive thrombi of > 5 mm length have been treated with higher success rates and lower complication rates by thrombolysis than by anticoagulant treatment. In conclusion, all patients with suspected PVT should undergo multiplane TEE. Thrombolysis is the first-line treatment for obstructive PVT, independent of NYHA class and thrombus size if there are no contraindications. Serial TEE studies must be conducted during thrombolysis. Surgery should be reserved for those patients in whom thrombolysis is contraindicated, or has failed. Initial anticoagulant therapy is recommended only for small, non-obstructive PVT if anticoagulation had been subtherapeutic; otherwise, thrombolysis is the treatment of choice if there are no contraindications.

Prosthetic valve thrombosis (PVT) is a life-threatening disease, the treatment strategies for which remain controversial. Transesophageal echocardiography (TEE) is the diagnostic technique of choice. Prosthetic valve obstruction is defined as limited leaflet motion; obstructive and non-obstructive PVT are separated by abnormal or normal leaflet motion. TEE is limited in differentiating thrombus from pannus ('tissue ingrowth'), and sterile thrombi from infected vegetations. Clinical aspects are helpful. The estimated incidence of PVT is 2-4% per year based on autopsy and surgical findings. The true incidence should be higher, as TEE reveals almost as many obstructive as non-obstructive PVT, of which 50% are asymptomatic. The prevalence of asymptomatic non-obstructive PVT in the early postoperative period may reach 10%. Three therapeutic approaches are available for PVT. Surgical mortality may reach 69%, depending on NYHA class and need for emergency surgery. Thrombolysis represents an alternative to surgery, with 84% success and low complication rates (stroke 9%, mortality 5%). In non-obstructive PVT patients in NYHA class I or II, thrombolysis success was higher (92%), without severe complications. No other clinical predictor of success could be confirmed. Besides classical contraindications there are no absolute contraindications (large thrombi, pregnancy, early postoperative period) for thrombolysis. Long-term streptokinase protocols have been used with regular TEE monitoring. Heparin may be an initial treatment for non-obstructive PVT, but thrombolysis is superior in this subset. If thrombi are > 5 mm in size, heparin therapy is unsuccessful and unsafe. TEE monitoring is mandatory during heparin treatment, as thrombi may increase in size and become obstructive. Thrombolysis is recommended as first-line treatment if there are no contraindications. Heparin may be used initially for small non-obstructive thrombi, particularly if thrombolysis is contraindicated. Surgery should be reserved for patients in whom thrombolysis is either contraindicated or has been ineffective, independent of NYHA class.