Krzysztof Bartus1, Radoslaw Litwinowicz2, Joanna Natorska3, Michal Zabczyk3, Anetta Undas3, Boguslaw Kapelak1, Dhanunjaya Lakkireddy4, Randall J Lee5. 1. Department of Cardiovascular Surgery and Transplantology, Jagiellonian University Medical College, John Paul II Hospital, Krakow, Poland. 2. Department of Cardiovascular Surgery and Transplantology, Jagiellonian University Medical College, John Paul II Hospital, Krakow, Poland. Electronic address: md.litwinowicz@gmail.com. 3. Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland. 4. The Kansas City Heart Rhythm Institute & Research Foundation, Overland Park, KS, USA. 5. Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA.
Abstract
INTRODUCTION: Atrial fibrillation (AF), a risk factor for stroke and systemic thromboembolism, is associated with unfavorable fibrin clot properties and increased thrombus formation in peripheral blood. The left atrial appendage (LAA) is known to be the primary site of thrombus formation. AIM: We investigated 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. METHODS: Sixteen patients with nonvalvular AF who stopped oral anticoagulant therapy at least 2 days before a LARIAT procedure participated in a single-center prospective study. 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. RESULTS: LAA clot porosity was reduced by 16.2% compared to peripheral blood (p = 0.026), 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 clots prepared from blood samples obtained from the LAA compared to those prepared from peripheral blood, but no differences between the RA, RV, LA and LV (all p > 0.05) were found. There were no significant differences in other parameters, including ETP, between heart chambers. CONCLUSIONS: Patients with AF are characterised by a local prothrombotic state as reflected by formation of compact fibrin clots in the LAA compared to peripheral blood, which may contribute to LAA thrombus formation and device-related thrombi.
INTRODUCTION:Atrial fibrillation (AF), a risk factor for stroke and systemic thromboembolism, is associated with unfavorable fibrin clot properties and increased thrombus formation in peripheral blood. The left atrial appendage (LAA) is known to be the primary site of thrombus formation. AIM: We investigated 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. METHODS: Sixteen patients with nonvalvular AF who stopped oral anticoagulant therapy at least 2 days before a LARIAT procedure participated in a single-center prospective study. 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. RESULTS: LAA clot porosity was reduced by 16.2% compared to peripheral blood (p = 0.026), 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 clots prepared from blood samples obtained from the LAA compared to those prepared from peripheral blood, but no differences between the RA, RV, LA and LV (all p > 0.05) were found. There were no significant differences in other parameters, including ETP, between heart chambers. CONCLUSIONS:Patients with AF are characterised by a local prothrombotic state as reflected by formation of compact fibrin clots in the LAA compared to peripheral blood, which may contribute to LAA thrombus formation and device-related thrombi.
Authors: Matthew J Lawrence; Vanessa Evans; Janet Whitley; Suresh Pillai; Phylip R Williams; James Coulson; Manju Krishnan; Peter Slade; Kieron Power; Roger H K Morris; Phillip A Evans Journal: Pharmacol Res Perspect Date: 2022-04