Low left atrial appendage flow velocity (<40 cm/s) in nonvalvular AF was associated with higher rates of LA spontaneous echo contrast or thrombus compared to high velocity (58% vs 0%, p<0.001).
Observational (n=45)
Is low left atrial appendage flow velocity associated with increased hemostatic abnormalities and thrombus formation in patients with nonvalvular atrial fibrillation?
Decreased left atrial appendage flow velocity in nonvalvular AF is associated with increased intravascular coagulation-fibrinolysis activity, platelet activation, and thrombus formation.
Absolute Event Rate: 58% vs 0%
p-value: p=< 0.001
To investigate the relationship between left atrial (LA) flow dynamics and hemostatic markers in nonvalvular atrial fibrillation (AF), 45 patients with nonvalvular AF who had not received anticoagulants were evaluated by transesophageal echocardiography. We determined the LA appendage flow and the presence of LA spontaneous echo contrast (SEC) or thrombus. We measured plasma levels of thrombin-antithrombin III complex (TAT), fibrinopeptide A, D-dimer, beta-thromboglobulin, and platelet factor 4 in peripheral blood as hemostatic markers. The patients were divided into a low-velocity group (n = 19; sum of peak emptying and filling LA appendage flow velocities or = 40 cm/s). The maximum LA diameter was significantly greater and the LA expansion fraction was significantly smaller in the low-velocity group than in the high-velocity group. LA SEC or thrombus was observed in 11 patients (58%) in the low-velocity group, but not in any patients in the high-velocity group (p < 0.001). The plasma levels of TAT, fibrinopeptide A, D-dimer, beta-thromboglobulin, and platelet factor 4 were significantly higher in the low-velocity group than in the high-velocity group. The plasma levels of TAT, fibrinopeptide A, beta-thromboglobulin, and platelet factor 4 were significantly higher in 8 patients without LA SEC or thrombus in the low-velocity group than in 26 patients in the high-velocity group. Patients with nonvalvular AF accompanied by an enlarged and dysfunctioning LA and a decreased LA appendage flow velocity had increased intravascular coagulation-fibrinolysis activity and platelet activation. These abnormalities may be closely related to the thrombogenetic state in patients with nonvalvular AF.
Shinohara et al. (Thu,) conducted a observational in nonvalvular atrial fibrillation (n=45). Low-velocity LA appendage flow (< 40 cm/s) vs. High-velocity LA appendage flow (≥ 40 cm/s) was evaluated on Presence of LA spontaneous echo contrast (SEC) or thrombus (p=< 0.001). Low left atrial appendage flow velocity (<40 cm/s) in nonvalvular AF was associated with higher rates of LA spontaneous echo contrast or thrombus compared to high velocity (58% vs 0%, p<0.001).