Branka Kresic

Background: Thromboembolic events, though infrequent, remain a significant complication of atrial fibrillation (AF) ablation, largely related to endothelial damage. Cryoballoon (CB) and radiofrequency ablation can induce pro-coagulant responses, whereas pulsed-field ablation (PFA), a novel non-thermal electroporation-based technique, has shown tissue selectivity with potential endothelial-sparing effects. Methods: We aimed to compare PFA and second-generation CB ablation regarding endothelial injury in patients with paroxysmal AF. In this single-center prospective observational study, 25 patients with paroxysmal drug-refractory AF underwent pulmonary vein isolation using either a pentaspline PFA catheter (n = 14) or a second-generation CB catheter (n = 11). Circulating von Willebrand factor antigen (vWF) levels were assessed before and after ablation as a biomarker of endothelial damage, alongside routine laboratory and echocardiographic parameters. Procedural characteristics were also analyzed. Results: Baseline demographic, clinical, and echocardiographic data were comparable between groups. PFA was associated with significantly shorter skin-to-skin procedure time (59 vs. 94 min, p = 0.005) and left atrial dwell time (44 vs. 79 min, p < 0.001) compared with CB ablation. Importantly, vWF levels decreased significantly after PFA (−7.6%, p = 0.007), while CB ablation showed a non-significant increase (+9.5%, p = 0.155). The between-group difference in percent change of vWF was statistically significant (−5.6% vs. +8.3%, p = 0.006). Conclusions: PFA was associated with reduced endothelial injury and shorter procedural times compared with CB ablation, suggesting a potential advantage in lowering thromboembolic risk. These findings support the concept of PFA as an “endothelial sparing” ablation modality. However, the PFA procedure was associated with a significantly greater extent of myocardial injury, as reflected in circulating high-sensitivity cardiac troponin T values, compared to CB ablation (p = 0.007). Larger, randomized studies are warranted to confirm these results and evaluate long-term clinical outcomes.

Thromboembolic events, though infrequent, remain a significant complication of atrial fibrillation (AF) ablation, largely related to endothelial damage. Cryoballoon (CB) and radiofrequency ablation can induce pro-coagulant responses, whereas pulsed-field ablation (PFA), a novel non-thermal electroporation-based technique, has shown tissue selectivity with potential endothelial-sparing effects. We aimed to compare PFA and second-generation CB ablation regarding endothelial injury in patients with paroxysmal AF. In this single-center prospective observational study, 25 patients with paroxysmal drug-refractory AF underwent pulmonary vein isolation using either a pentaspline PFA catheter (n=14) or a second-generation CB catheter (n=11). Circulating von Willebrand factor antigen (vWF) levels were assessed before and after ablation as a biomarker of endothelial damage, alongside routine laboratory and echocardiographic parameters. Procedural characteristics were also analyzed. Baseline demographic, clinical, and echocardiographic data were comparable between groups. PFA was associated with significantly shorter skin-to-skin procedure time (59 vs. 94 min, p=0.005) and left atrial dwell time (44 vs. 79 min, p<0.001) compared with CB ablation. Importantly, vWF levels decreased significantly after PFA (−7.6%, p=0.007), while CB ablation showed a non-significant increase (+9.5%, p=0.155). The between-group difference in percent change of vWF was statistically significant (−5.6% vs. +8.3%, p=0.006). PFA was associated with reduced endothelial injury and shorter procedural times compared with CB ablation, suggesting a potential advantage in lowering thromboembolic risk. These findings support the concept of PFA as an “endothelial-sparing” ablation modality. Larger, randomized studies are warranted to confirm these results and evaluate long-term clinical outcomes.

Background and Objectives: Anticoagulants are a well-known risk factor for gastrointestinal bleeding (GIB). In recent years, direct oral anticoagulants (DOACs) have taken a leading role in the treatment and prevention of thromboembolic incidents. The aim of this study was to investigate the prevalence of DOAC-treated patients with GIB whose plasma drug concentrations exceeded the cut-off values reported in the literature and to evaluate their clinical characteristics. Materials and Methods: Patients who were admitted to the Intensive Care Unit in the period 2/2020–3/2022 due to GIB were prospectively included in the study and classified into three groups according to the prescribed type of DOAC (apixaban, rivaroxaban, and dabigatran). For all participants, it was determined if the measured plasma drug levels exceeded the maximum serum concentration (C_max) or trough serum concentration (C_trough) obtained from the available data. A comparison of clinical parameters between the patients with and without excess drug values was performed. Results: There were 90 patients (54.4% men) included in the study, of whom 27 were treated with dabigatran, 24 with apixaban, and 39 with rivaroxaban. According to C_max, there were 34 (37.8%), and according to C_trough, there were 28 (31.1%) patients with excess plasma drug values. A statistically significant difference regarding excess plasma drug values was demonstrated between DOACs according to both C_max (p = 0.048) and C_trough (p < 0.001), with the highest rate in the group treated with dabigatran (55.6% for C_max and 59.3% for C_trough). Multivariate logistic regression showed that age (OR 1.177, p = 0.049) is a significant positive and glomerular filtration rate (OR 0.909, p = 0.016) is a negative predictive factor for excess plasma drug values. A total of six (6.7%) patients had fatal outcomes. Conclusions: Plasma drug concentrations exceed cut-off values reported in the literature in more than one-third of patients with GIB taking DOAC, with the highest rate in the dabigatran group. Clinicians should be more judicious when prescribing dabigatran to the elderly and patients with renal failure. In these patients, dose adjustment, plasma drug monitoring, or substitution with other, more appropriate DOACs should be considered.