Abstract 14193: Elevated Plasma Von Willebrand Factor Level Predict Thrombus Formation in the Left Atrial Appendage in Patients With Acute Ischemic Stroke
It is well known that left atrial appendage (LAA) dysfunction plays an important role in the occurrence of cardioembolic stroke. As shown in the Virchow's triad, low blood flow, hypercoagulable state, and endothelial dysfunction, are important factors for thrombus formation. Although coagulation markers such as fibrin-monomer (FM) are useful to evaluate LAA hypercoagulable state, many coagulation markers except for von Willebrand factor (vWF) are suppressed by treatment with warfarin. vWF is an estabrished marker of endothelial damage and dysfunction. Increased plasma vWF level was shown to predict presence of LAA thrombus in non-valuvular atrial fibrillation. However, it remains determined whether increased plasma vWF level is associated with LAA dysfunction in patients with acute ischemic stroke. We hypothesized that increased vWF level is a sensitive predictor for LAA dysfunction and LAA thrombus formation. Transthoracic and transesophageal echocardiography were performed and plasma vWF levels were measured in 154 patients (mean age 69 ± 12 years) within 7 days after the onset of acute ischemic stroke. LAA thrombus was detected in 27 patients. LAVI, serum fibrinogen and plasma vWF were significantly higher in patients with LAA thrombus than in those without it (LAVI, 76 ± 57 vs. 43 ± 28 ml/m2, P<0.01; fibrinogen, 484 ± 216 vs. 417 ± 138 mg/dl, P<0.05; vWF, 236 ± 82 vs. 178 ± 71 %, P<0.01). Plasma vWF levels increased with advancing CHADS2 score. LAVI, serum fibrinogen and plasma vWF levels were correlated with LAA emptying flow velocity (LAA eV) (LAVI, R=−0.53, P<0.01; fibrinogen, R=0.31, P<0.01; vWF, R=0.20, P<0.05). Even if patients had normal LAA eV (LAA eV>40) (n=51), plasma vWF was significantly higher in patients with LAA thrombus than in those without it (259 ± 133 vs. 133 ± 74 %, p=0.02). Multivariate logistic regression analysis showed that elevated vWF level was an independent predictor of LAA thrombus (per 1SD increase, odds ratio 2.90; 95% confidence interval 1.47–6.15; p=0.023).In conclusion, elevated vWF may be a sensitive predictor for LAA dysfunction and LAA thrombus formation in patients with acute ischemic stroke.
- © 2010 by American Heart Association, Inc.