Relationship between endothelial dysfunction and prosthetic heart valve thrombosis: a preliminary investigation

The etiopathogenesis of prosthetic heart valve thrombosis (PHVT) is multifactorial. Since the relationship between PHVT and endothelial function is never studied, we aimed to analyze the role of endothelial function in patients with PHVT.

Twenty-two patients with PHVT (14 female, 31.8% with atrial fibrillation, mean age 46.0±12.2) and 22 controls with prosthetic heart valves (17 female, 36.4% with atrial fibrillation, mean age 45.7±11.5) were prospectively evaluated. Two groups had similar demographic and echocardiographic characteristics. Endothelial function was evaluated in all patients by the non-invasive measurement of flow mediated dilatation (FMD) of brachial artery. High-resolution ultrasound was used to measure brachial artery diameter at rest, during reactive hyperemia (endothelium-dependent, FMD), and following sublingual administration of nitroglycerin (endothelium-independent, nitroglycerin-mediated vasodilatation, NMD).

Functional capacity at presentation determined as mean NYHA functional capacity class was worse in patients with PHVT than in control group (2.1±0.6 vs. 1.3±0.6; p < 0.0001). FMD was significantly reduced in patients with PHVT compared with control group (4.01±1.52 vs. 8.48±3.37; p < 0.0001). NMD did not differ between two groups (11.77±2.30 vs. 13.38±3.50; p = 0.08). FMD level of < 5.65 predicted prosthetic valve thrombosis with an 82% sensitivity and 77% specificity (area under the curve = 0.888, p < 0.0001).

This study demonstrated the endothelial dysfunction in patients with PHVT compared with well-matched control group. In this study, we found that patients with PHVT have endothelial dysfunction which might contribute to the development of thrombosis.