Improvement of endothelial function early after thrombolytic therapy in patients with prosthetic heart valve thrombosis

OBJECTIVE
Prosthetic valve thrombosis (PVT) is a serious complication among patients with prosthetic heart valves. Thrombolytic therapy (TT) is now widely used as first-line treatment for PVT. Endothelial dysfunction has previously been reported in patients with PVT. The aim of this study was to investigate the changes in endothelial function soon after TT in PVT patients.

METHODS
The study group included 85 patients with PVT [female: 53 (62.3%); age: 48.7±13.9 years] who were evaluated prospectively before and shortly after TT. All of the patients were evaluated using transthoracic and transesophageal echocardiography. TT was administered in all cases with a low-dose, ultra-slow infusion regimen. Endothelial function was evaluated using a noninvasive measurement of flow-mediated dilatation (FMD) of the brachial artery during reactive hyperemia.

RESULTS
The study population included 38 (44.7%) obstructive and 47 (55.3%) non-obstructive PVT patients. The obstructive PVT patients had lower baseline FMD values than the non-obstructive PVT group (5.31±0.76% vs. 5.87±0.84%; p=0.003). TT was successful in 79 patients (92.9%). FMD was significantly increased in the successfully thrombolyzed patients after TT (5.65±0.86% vs. 7.13±1.26%; p<0.001). There was no significant difference in the FMD values after TT in patients who were unresponsive to TT (5.07±0.61% vs. 5.38±0.95%; p=0.371). There was a significant increase in FMD values after TT in patients with obstructive PVT (5.31±0.76% vs. 8.22±1.15%; p<0.001). However, this difference was not statistically significant for patients with non-obstructive PVT (5.87±0.84% vs. 6.11±0.95%; p=0.276).

CONCLUSION
This study demonstrated that successful TT may contribute to improvement of impaired endothelial function in patients with obstructive PVT.