Intracardiac Prothrombotic State Differences in Patients with Atrial Fibrillation and Changes in the Coagulation System After Laa Closure
Radoslaw Litwinowicz1, Grzegorz Filip1, Bguslaw Kapelak1, Joanna Natorska2, Michal Zabczyk2, Krzysztof Bartus1
1Department of Cardiovascular Surgery and Transplantology, Jagiellonian University Medical College, J, Kraków, Poland, 2Jagiellonian University Medical College, J, Kraków, Poland
Background The left atrial appendage (LAA) is known to be the primary source of thrombus formation in atrial fibrillation (AF). Our aim was to investigate the relative differences in plasma fibrin clot features including plasma fibrin clot permeability (Ks) and clot lysis time (CLT) between the right atrium (RA), right ventricle (RV), left atrium (LA), left ventricle (LV), LAA, and peripheral blood. We also exanimated if LAA elimination (LAAO) from the cardiovascular system has an effect on the coagulation and prothrombotic status in AF. Methods We measured fibrinogen and plasminogen levels along with Ks, CLT, and endogenous thrombin potential (ETP) during the LARIAT procedure in blood obtained from the right femoral vein, RA, RV, LA, LV and LAA and 1 month after procedure in twenty-two patients with AF. Results LAA clot porosity was reduced by 16.2% in the LAA compared to peripheral blood (p = 0.026), and also after adjustment for fibrinogen levels (p = 0.038). Ks was similar for the RA, RV, LA, LV, and LAA (all p > 0.05). We found 14.7% prolonged CLT for blood samples obtained from the LAA compared to peripheral blood, but no differences between the RA, RV, LA and LV (all p > 0.05). 1 month after the LAAO procedure compared to baseline value, we found Ks improved by 39.3% measured in clots prepared from peripheral blood (p=0.019) and also after adjustment for fibrinogen (p=0.027). Higher Ks was associated with improved clot susceptibility to lysis (r=-0.67, p=0.013). We found shortened CLT by 10.3% (p=0.0020); a 52% lower PAI-1 antigen levels (p=0.023) along with 8.9% increased plasminogen activity (p=0.0077). Conclusions We confirm, that LAA plays a key role in thrombogenesis and is the main source of thrombus in AF. LAA elimination from the circulatory improve fibrin clot permeability and susceptibility to fibrinolysis in peripheral blood. 