Usefulness of phenprocoumon for the treatment of obstructing thrombus in bioprostheses in the aortic valve position.

Bioprosthetic valve replacement is the treatment of choice in older patients with symptomatic severe aortic valve disease. Thrombosis of bioprosthetic valves has been considered a rare complication; however, in the presence of valvular obstruction, therapeutic consequences for the individual patient may be dramatic including repeat valve replacement or thrombolysis. We therefore evaluated oral anticoagulation with phenprocoumon as an alternative treatment for obstructive thrombosis of bioprosthetic valves. Six of 470 patients who had received a single stented bioprosthetic aortic valve from January 2007 through December 2008 at our hospital presented with obstructive bioprosthetic valve thrombosis within 14 months postoperatively. All 6 patients (1% of study population) had received a porcine valve (p = 0.1 vs pericardial), were hemodynamically stable, were in sinus rhythm, and were taking acetylsalicylic acid 100 mg/day. Echocardiography showed an increase in mean pressure gradient early postoperatively from 23.3 ± 4 to 57.0 ± 10 mm Hg (p <0.001). Five patients were started on phenprocoumon and followed for 114 ± 54 days, when mean pressure gradient had returned to 23.5 ± 6 mm Hg. No adverse events were observed during that period. One patient presenting with dyspnea and fever underwent emergency repeat valve replacement for suspected endocarditis, with histology showing long-term thrombosis of the explanted valve. In conclusion, oral anticoagulation with phenprocoumon represents a safe and effective treatment in clinically stable patients with obstructive thrombosis of bioprosthetic aortic valves, thus obviating repeat valve surgery or thrombolysis.