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).