Results
A total of 22 AF patients were evaluated. Patient characteristics are present in Table 1. The cohort constituted mostly males (54.5%) with CHADS2 score of 2.8±1.1 and CHA2DS2-VASc score of 4.3±1.7. Most patients (95%) presented hypertension as an additional risk factor of thromboembolism. More than 72.7% of patients had a history of previous stroke or transient ischemic attack (TIA). Patients were also at high risk of bleeding based on the clinical scale HAS-BLED (3.5±1.3).
Plasma fibrinogen level before LAAO in peripheral blood was 2.23 (1.75-2.72) g/L and increased 87% after the procedure (p=0.0051). However, after 1-month follow-up fibrinogen concentrations returned to baseline value (Table 1, p>0.05). At baseline AF patients were characterized by 19.7% reduced Ks of clots prepared from LAA obtained blood compared to peripheral blood. As expected, the LAAO procedure was associated with Ks when compared with the baseline (p=0.011; Fig. 1A). Interestingly, after 1-month follow-up we observed in patients after the LAAO Ks improved by 39.3% compared to baseline value of Ks measured in clots prepared from peripheral blood obtained from AF patients before the surgical procedure (p=0.019), also after adjustment for fibrinogen (p=0.027; Fig. 1A).
Similarly, we found shortened CLT by 10.3% in patients 1-month after the LAAO procedure compared with baseline (p=0.0020; Fig. 1B). Of note, clots prepared from blood obtained from the LAA were characterized by 16.4% prolonged CLT compared with baseline (p=0.016; Fig. 1B). The LAAO procedure was associated with 19.8% prolongation of CLT compared to baseline values (p=0.0007; Fig. 1B). After 1-month follow-up, higher Ks was associated with improved clot susceptibility to lysis (r=-0.67, p=0.013). A tendency to decreased thrombin generation, reflected by decreased ETP and peak thrombin generated, was observed 1 month after the LAAO procedure (Table 2, p=0.072 and p=0.087). Moreover, we found a 52% lower PAI-1 antigen levels (p=0.023) along with 8.9% increased plasminogen activity (p=0.0077) 1 month after the LAAO compared with baseline. No differences were found in tPA and TAFI plasma levels in AF patients before the LAA procedure and after 1-month follow-up (both p>0.05; Table 2). CLT, before the LAAO and 1 month after the procedure was associated with PAI-1 (r=0.68, p=0.0026 and r=0.073, p=0.0018, respectively) and with the plasminogen activity (r=-0.38, p=0.048 and r=-0.36, p=0.044).