Abstract 11940: Plasma Platelet Derived Microparticle May be a Feasible Parameter to Detect Left Atrial Appendage Dysfunction in Patients with Acute Ischemic Stroke
Left atrial appendage (LAA) thrombus is a major embolic source in stroke patients with atrial fibrillation (AF). Several large randomized clinical trials repeatedly have demonstrated the efficacy of anticoagulation treatment with warfarin to reduce the annual rate of stroke in patients with ischemic stroke. Some patients with AF suffer from the cardioembolic stroke despite appropriate anticoagulation therapy. We investigated the impact of platelet activation on the LAA thrombus formation in ischemic stroke patients. In 138 consecutive patients with acute ischemic stroke (90 males, mean age 70 ± 13 years), we performed transesophageal echocardiography within 7 days after the onset, and measured platelet-derived microparticles (PDMP) level as a marker of platelet activation. PDMP level was significantly higher in patients with LAA thrombus compared with those without thrombus independent of anti-platelet therapy (178 vs. 99 U/ml, P<0.0001). Serum levels of fibrinogen and D-dimer were significantly higher in patients with LAA thrombus (n=28) than in those without thrombus (481 vs. 400 mg/dl, P=0.0149; 2.1 vs. 1.0 μg/ml, P=0.0036, respectively). Eleven patients with LAA thrombus (39%) had the appropriate treatment with warfarin. Serum levels of fibrinogen and D-dimer were suppressed by anticoagulant therapy even in patients with LAA thrombus (550 vs. 374 mg/dl, P=0.0261; 7.0 vs. 0.8 μg/ml, P=0.0267, respectively). However, PDMP level was significantly higher in patients with LAA thrombus than in those without thrombus independent of anticoagulant therapy (218 vs. 129 U/ml, P=0.0374). PDMP level was significantly higher in patients with cardioembolic stroke than in those with atherothrombotic stroke and lacunar stroke (164 vs. 88, and 56 U/ml, P<0.01). Further, PDMP increased with advancing CHADS2 score. Multivariate logistic regression analysis revealed that elevated PDMP level was an independent predictor for LAA thrombus independent of anticoagulant therapy (odds ratio 1.892 (per 1SD increase), p<0.05). In conclusion, PDMP may be a valuable marker for LAA dysfunction in patients with acute ischemic stroke.
- © 2011 by American Heart Association, Inc.