Reduced plasma level of basic fibroblast growth factor is associated with incomplete device endothelialization at six months following left atrial appendage closure.

Objectives: To investigate whether inflammatory and growth factors (IGFs) were associated with incomplete device endothelialization (IDE) at 6 months after successful left atrial appendage closure (LAAC).

Background: IDE after LAAC is correlated with device-related thrombus (DRT) formation and subsequent thromboembolic events. However, biomarkers for early detection of IDE remain lacking.

Methods: Plasma levels of IGFs including basic fibroblast growth factor (bFGF), platelet derived growth factor (PDGF), stromal cell derived factor (SDF)-1a, transforming growth factor (TGF)-β, vascular growth factor receptor-1 (VEGF-R) and von Willebrand factor (vWF) were determined using ELISA kits in 55 consecutive patients with atrial fibrillation (AF) at 6 months after LAAC with Watchman devices. The status of device endothelialization was assessed by transesophageal echocardiography and cardiac CT.

Results: IDE and complete device endothelialization(CDE)were detected in 38 and 17 patients, respectively. Among the six IGFs, only plasma level of bFGF was significantly lower in patients with IDE compared to those with CDE (303.49 ± 246.84 vs. 556.31 ± 197.84 pg/ml, p < 0.001). C-statistics of plasma bFGF for discriminating patients with IDE from those with CDE was 0.785 (95 % CI: 0.663-0.907, p < 0.001), with a cut-off value of 440.52pg/ml (sensitivity 0.765; specificity 0.789). Multivariate logistic regression model showed that lower bFGF was an independent factor for IDE (OR: 11.752, 95 % CI: 2.869-48.144, P = 0.001). bFGF improved the classification of patients (NRI: 0.677,95 % CI: 0.320-1.033, p = 0.004).

Conclusions: Reduced plasma bFGF level confers an increased risk for IDE after LAAC. Further prospective studies are warranted to examine if bFGF could serve as a biomarker for IDE post LAAC.