Thrombolytic therapy for prosthetic valve thrombosis: short- and long-term results

Thrombolytic therapy (TT) has evolved as an alternative to surgery for prosthetic valve thrombosis (PVT), but its utility in patient management is still debated and the long-term results are not available.

From 1990 through 1999, we treated 110 consecutive patients (52 men, mean age 35.4 +/- 10.8 years) of left-sided obstructive PVT (96 mitral, 14 aortic) with TT (streptokinase in 108, urokinase in 2) according to a specified protocol of prolonged infusion. Serial echo Doppler parameters were monitored in all patients to guide the duration of TT and to quantify its efficacy. Ninety of the 102 survivors of the index episode were followed up for a mean period of 31.3 +/- 27.8 months (range 1-112 months).

Complete hemodynamic response (on cinefluoroscopy and echo Doppler criteria) was seen in 90 (81.8%) episodes, partial response in 11 (10%), and failure in 9 (8.2%). The mean duration of TT was 42.8 +/- 20.4 hours. Five of the 7 patients who were initially seen in cardiogenic shock/overt pulmonary edema died during therapy. After these patients were excluded, the rate of complete response did not differ among patients with New York Heart Association class I/II (80%), class III (86.3%), or class IV (81.5%). The response rate also did not vary with the type, position of prosthesis, duration of symptoms, or time lag since surgery. There were 21 (19.1%) embolic episodes during therapy, including 6 strokes. These were significantly more frequent in patients with atrial fibrillation (AF) (odds ratio on multivariate analysis 2.3, 95% confidence interval 1.3-3.9, P =.01). On follow-up, there were 25 recurrences of PVT, of which 20 again received TT with a complete response in 14 (70%). At 5 years the actuarial survival was 85.2% and the event-free survival was 61.5%. The presence of chronic AF was a significant predictor of recurrence of PVT (odds ratio 2.2, 95% confidence interval 1.2-3.9, P =.008).

TT is effective in the majority of patients with PVT but is associated with a high rate of embolism, especially in patients with AF. Excluding patients with cardiogenic shock/overt pulmonary edema (in whom TT is largely ineffective), the success of TT does not vary with the New York Heart Association class, duration of symptoms, or other patient variables. The recurrence rates of PVT are high after even successful TT, especially in patients with AF.