Feature Articles in Cardiovascular Pathophysiology

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. Full article

Myocarditis is still a major global health issue that frequently manifests due to oxidative stress, immune-mediated myocardial damage, and unpredictable clinical progression. Experiments with autoimmune myocarditis (EAM) models have shown different ways that T-cell subsets, proinflammatory cytokines, macrophage polarization, and mitochondrial dysfunction are all connected and play a part in both acute inflammation and chronic remodeling of the heart. As a possible multimodal intervention that could affect several of these disease-causing pathways, hyperbaric oxygen therapy (HBOT) has become popular. This therapy delivers 100% oxygen to different tissues at higher atmospheric pressures. Early research shows that HBOT improves the delivery of oxygen to the inflamed myocardium, suppress the activation of NF-κB and NLRP3 inflammasomes, lowers oxidative stress, protects mitochondrial function, and boosts immune-regulatory T-cell responses. Despite these potentially promising findings, there are still a number of important translational obstacles to overcome, such as inconsistent protocols, a lack of long-term outcome data, insufficient mechanistic profiling, and doubts about the best protocol length and patient selection. To assess safety and effectiveness in human myocarditis, future studies should aim to integrate multi-omics analyses, HBOT regimens that are already standardized, sophisticated imaging, and carefully planned early-phase clinical trials. Overall, the currently available evidence supports HBOT as a biologically plausible and potentially valuable adjunct therapy for autoimmune myocarditis, expressing the need for further mechanistic and clinical investigation. Full article