Periprocedural Intravascular Hemolysis During Atrial Fibrillation Ablation: A Comparison of Pulsed Field With Radiofrequency Ablation.

BACKGROUND: Hemolysis-related renal failure has been described after pulmonary vein isolation (PVI) with pulsed-field ablation (PFA). OBJECTIVES: This study sought to compare the potential for hemolysis during PVI with PFA vs radiofrequency ablation (RFA). METHODS: In consecutive patients, PVI was performed with PFA or RFA. Blood samples were drawn at baseline, immediately postablation, and 24 hours postablation. Using flow cytometry, the concentration of red blood cell microparticles (RBCµ) (fragments of damaged erythrocytes) in blood was assessed. Lactate dehydrogenase (LDH), haptoglobin, and indirect bilirubin were measured at baseline and 24 hours. RESULTS: Seventy patients (age: 64.7 ± 10.2 years; 47% women; 36 [51.4%] paroxysmal atrial fibrillation) were enrolled: 47 patients were in the PFA group (22 PVI-only and 36.4 ± 5.5 PFA applications; 25 PVI-plus, 67.3 ± 12.4 pulsed field energy applications), and 23 patients underwent RFA. Compared to baseline, the RBCµ concentration increased ∼12-fold postablation and returned to baseline by 24 hours in the PFA group (median: 70.8 [Q1-Q3: 51.8-102.5] vs 846.6 [Q1-Q3: 639.2-1,215.5] vs 59.3 [Q1-Q3: 42.9-86.5] RBCµ/µL, respectively; P < 0.001); this increase was greater with PVI-plus compared to PVI-only (P = 0.007). There was also a significant, albeit substantially smaller, periprocedural increase in RBCµ with RFA (77.7 [Q1-Q3: 39.2-92.0] vs 149.6 [Q1-Q3: 106.6-180.8] vs 89.0 [Q1-Q3: 61.2-123.4] RBCµ/µL, respectively; P < 0.001). At 24 hours with PFA, the concentration of LDH and indirect bilirubin increased, whereas haptoglobin decreased significantly (all P < 0.001). In contrast, with RFA, there were only smaller changes in LDH and haptoglobin concentrations (P = 0.03) and no change in bilirubin. CONCLUSIONS: PFA was associated with significant periprocedural hemolysis. With a number of 70 PFA lesions, the likelihood of significant renal injury is uncommon.

Catheter ablation for non-paroxysmal atrial fibrillation. A review.

Atrial fibrillation (AF), the most common cardiac arrhythmia is associated with increased morbidity and mortality. The higher mortality is due to the risk of heart failure and cardioembolic events. This in-depth review focuses on the strategies and efficacy of catheter ablation for non-paroxysmal atrial fibrillation. The main medical databases were searched for contemporary studies on catheter ablation for non-paroxysmal AF. Catheter ablation is currently proven to be the most effective treatment for AF and consists of pulmonary vein isolation as the cornerstone plus additional ablations. In terms of SR maintenance, it is less effective in non-paroxysmal AF than in paroxysmal patients. but the clinical benefit in non-paroxysmal patients is substantially higher. Since pulmonary vein isolation is ineffective, a variety of techniques have been developed, e.g. linear ablations, ablation of complex atrial fractionated electrograms, etc. Another paradox consists in the technique of catheter ablation. Despite promising results in early observation studies, further randomized studies have not confirmed the initial enthusiasm. Recently, a new approach, pulsed-field ablation, appears promising. This is an in-depth summary of current technologies and techniques for the ablation of non-paroxysmal AF. We discuss the benefits, risks and implications in the treatment of patients with non-paroxysmal AF.

Myocardial Damage, Inflammation, Coagulation, and Platelet Activity During Catheter Ablation Using Radiofrequency and Pulsed-Field Energy.

BACKGROUND: Pulsed-field ablation (PFA) represents a new, nonthermal ablation energy for the ablation of atrial fibrillation (AF). Ablation energies producing thermal injury are associated with an inflammatory response, platelet activation, and coagulation activation. OBJECTIVES: This study aimed to compare the systemic response in patients undergoing pulmonary vein isolation (PVI) using pulsed-field and radiofrequency (RF) energy. METHODS: Patients with AF indicated for PVI were enrolled and randomly assigned to undergo PVI using RF (CARTO Smart Touch, Biosense Webster) or pulsed-field (Farapulse, Boston-Scientific) energy. Markers of myocardial damage (troponin I), inflammation (interleukin-6), coagulation (D-dimers, fibrin monomers, von Willebrand antigen and factor activity), and platelet activation (P-selectin, activated GpIIb/IIIa antigen) were measured before the procedure (T1), after trans-septal puncture (T2), after completing the ablation in the left atrium (T3), and 1 day after the procedure (T4). RESULTS: A total of 65 patients were enrolled in the pulsed-field ablation (n = 33) and RF ablation (n = 32) groups. Both groups were similar in baseline characteristics (age 60.5 ± 12.7 years vs 64.0 ± 10.7 years; paroxysmal AF: 60.6% vs 62.5% patients). Procedural and left atrial dwelling times were substantially shorter in the PFA group (55:09 ± 11:57 min vs 151:19 ± 41:25 min; P < 0.001; 36:00 ± 8:05 min vs 115:58 ± 36:49 min; P < 0.001). Peak troponin release was substantially higher in the PFA group (10,102 ng/L [IQR: 8,272-14,207 ng/L] vs 1,006 ng/L [IQR: 603-1,433ng/L]). Both procedures were associated with similar extents (>50%) of platelet and coagulation activation. The proinflammatory response 24 h after the procedure was slightly but nonsignificantly higher in the RF group. CONCLUSIONS: Despite 10 times more myocardial damage, pulsed-field ablation was associated with a similar degree of platelet/coagulation activation, and slightly lower inflammatory response. (The Effect of Pulsed-Field and Radiofrequency Ablation on Platelet, Coagulation and Inflammation; NCT05603637).

Prediction of post-operative atrial fibrillation in patients after cardiac surgery using heart rate variability.

PURPOSE: Post-operative atrial fibrillation (PoAF) occurs in ~ 30% of patients after cardiac surgery. The etiology of PoAF is complex, but a disbalance in autonomic systems plays an important role. The goal of this study was to assess whether pre-operative heart rate variability analysis can predict the risk of PoAF. METHODS: Patients without a history of AF with an indication for cardiac surgery were included. Two-hour ECG recordings one day before surgery was used for the HRV analysis. Univariate and multivariate logistic regression, including all HRV parameters, their combination, and clinical variables, were calculated to find the best predictive model for post-operative AF. RESULTS: One hundred and thirty-seven patients (33 women) were enrolled in the study. PoAF occurred in 48 patients (35%, AF group); the remaining 89 patients were in the NoAF group. AF patients were significantly older (69.1 ± 8.6 vs. 63.4 ± 10.5 yrs., p = 0.002), and had higher CHA2DS2-VASc score (3 ± 1.4 vs. 2.5 ± 1.3, p = 0.01). In the multivariate regression model, parameters independently associated with higher risk of AF were pNN50, TINN, absolute power VLF, LF and HF, total power, SD2, and the Porta index. A combination of clinical variables with HRV parameters in the ROC analysis achieved an AUC of 0.86, a sensitivity of 0.95, and a specificity of 0.57 and was more effective in PoAF prediction than a combination of clinical variables alone. CONCLUSION: A combination of several HRV parameters is helpful in predicting the risk of PoAF. Attenuation of heart rate variability increases the risk for PoAF.

Previous antithrombotic therapy does not have an impact on the in-hospital mortality of patients with upper gastrointestinal bleeding.

The association between antithrombotics (ATs) and the risk of gastrointestinal bleeding is well known; however, data regarding the influence of ATs on outcomes are scarce. The goals of this study are: (i) to assess the impact of prior AT therapy on in-hospital and 6-month outcomes and (ii) to determine the re-initiation rate of the ATs after a bleeding event. All patients with upper gastrointestinal bleeding (UGB) who underwent urgent gastroscopy in three centres from 1 January 2019 to 31 December 2019 were retrospectively analysed. Propensity score matching (PSM) was used. Among 333 patients [60% males, mean age 69.2 (±17.3) years], 44% were receiving ATs. In multivariate logistic regression, no association between AT treatment and worse in-hospital outcomes was observed. Development of haemorrhagic shock led to worse survival [odds ratio (OR) 4.4, 95% confidence interval (CI) 1.9-10.2, P < 0.001; after PSM: OR 5.3, 95% CI 1.8-15.7, P = 0.003]. During 6-months follow-up, higher age (OR 1.0, 95% CI 1.0-1.1, P = 0.002), higher comorbidity (OR 1.4, 95% CI 1.2-1.7, P < 0.001), a history of cancer (OR 3.6, 95% CI 1.6-8.1, P < 0.001) and a history of liver cirrhosis (OR 2.2, 95% CI 1.0-4.4, P = 0.029) were associated with higher mortality. After a bleeding episode, ATs were adequately re-initiated in 73.8%. Previous AT therapy does not worsen in-hospital outcomes in after UGB. Development of haemorrhagic shock predicted poor prognosis. Higher 6-month mortality was observed in older patients, patients with more comorbidities, with liver cirrhosis and cancer.