Background: Atrial thrombus formation in patients with atrial flutter raises concerns of
stroke risk. We investigated patients with isthmus-dependent atrial flutter for coagulation
abnormalities before and after cardioversion to sinus rhythm by catheter ablation, and evaluated
the relationship of the abnormalities to the echocardiographic risk markers of stroke.
Methods and results: Plasma samples were drawn prior to insertion of catheters, immediately
after the procedure, and 24 hours afterwards. At baseline, coagulation abnormalities
were found in 22 out of 25 patients (88%). von Willebrand factor antigen (vWF-Ag) and factor
VIII:C were elevated in 17 patients (68%) and 15 patients (60%), respectively. At baseline,
mean plasma levels of vWF-Ag (250.1 ± 144.4%) and factor VIII:C (215.0 ± 77.1%) were
increased. Key markers of thrombin generation, thrombin-antithrombin III complex (TAT;
47.8 ± 30.9 μg/L vs 14.5 ± 13.8 μg/L; p < 0.05) and prothrombin fragments 1.2 (F1.2;
2.5 ± 0.5 nmoL/L vs 1.2 ± 1.0 nmoL/L) were significantly elevated in the presence of
spontaneous echo contrast. Further, both markers of thrombin generation inversely correlated
with left atrial appendage emptying velocity (r = -0.42 and -0.63, p < 0.05). Levels of TAT
and F1.2 increased after conversion and ablation.
Conclusions: Endothelial-dependent coagulation factors were enhanced in most patients
with atrial flutter. Spontaneous echo contrast and decreased atrial contractility were associated
with increased thrombin generation. After conversion and ablation, an increase in thrombin
generation and fibrinolysis suggest a transient pro-thrombotic state. (Cardiol J 2010; 17, 4: 390-396