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BACKGROUND: Pulsed field ablation (PFA) is increasingly used in clinical practice for the treatment of atrial fibrillation. While the susceptibility of erythrocytes to electroporation is well established, the effect of cardiac PFA technologies on hemolysis has remained underreported. The aim of this study was to investigate the incidence, severity, and clinical impact of PFA-induced hemolysis. METHODS: We included n=145 patients undergoing atrial fibrillation catheter ablation with a pentaspline PFA catheter (biphasic, bipolar pulses of 2 kV) and n=70 patients receiving radiofrequency ablation (40--90 W) at 4 high-volume European centers. The lesion set comprised pulmonary vein isolation for paroxysmal atrial fibrillation and pulmonary vein isolation±additional lesions for persistent atrial fibrillation. Hemolysis and renal function biomarkers were analyzed in blood samples at baseline, at the end of ablation, and 24 hours after the procedure. RESULTS: Baseline characteristics were well balanced between groups (overall mean 65.7±9.4 years; 69.3% men). The ablation procedures comprised a mean of 61.6±27.4 PFA deliveries and 26.3±15.0 minutes RF duration. Hemolysis was detected in 94.3% versus 6.8% of patients after PFA versus radiofrequency ablation (P<0.001): PFA was associated with significantly lower haptoglobin levels (0.5±0.4 versus 1.0±0.4 g/L), while free plasma hemoglobin (592.8±330.6 versus 147.8±183.0 mg/L), bilirubin (21.3±11.3 versus 14.8±8.8 µmol/L), and LDH (lactate dehydrogenase, 352.7±115.7 versus 253.2±56.5 U/L) were significantly higher after PFA compared with radiofrequency ablation (all P<0.001). Hemolysis correlated with the number of PFA deliveries (r=0.62 [95% CI, 0.33--0.80]; P<0.001), with the highest severity occurring ≥54 PFA deliveries. After PFA, hemoglobinuria occurred in 36.4%, while creatinine increase was higher in patients with baseline glomerular filtration rate <50 mL/min than with baseline glomerular filtration rate >50 mL/min (Δcrea, 27.0±103.1 versus -0.2±12.1 µmol/L; P=0.010). CONCLUSIONS: Intravascular hemolysis is a frequent finding after PFA and increases with the number of PFA deliveries. Until the clinical impact of PFA-associated hemolysis is fully elucidated, a careful titration of PFA deliveries during the ablation procedure is warranted. GRAPHIC ABSTRACT: A graphic abstract is available for this article. [ABSTRACT FROM AUTHOR]

Background: For conventional ablation of paroxysmal atrial fibrillation (AF), an ablation catheter in conjunction with a circular mapping catheter (CMC) is typically used for pulmonary vein isolation (PVI).Objective: The purpose of this study was to evaluate an approach for PVI with a single contact-force (CF) ablation catheter in terms of procedural reliability, outcomes, and cost-effectiveness.Methods: One hundred consecutive patients with paroxysmal AF were included in the study. Fifty patients (study group) underwent a CF-guided single-catheter approach, whereby PVI was demonstrated when sequential pacing at 9 equidistant points within the lesion set (carina included) failed to capture the left atrium. For confirmation, PVI was verified with a CMC. In comparison, 50 patients (control group) underwent a conventional PVI ablation guided by a CMC.Results: Procedure time (101 ± 17 minutes vs 107 ± 15 minutes, P = .11), ablation time (24.2 ± 7.1 minutes vs 22.6 ± 8.8 minutes, P = .37), fluoroscopy time (5.6 ± 2.2 minutes vs 8.3 ± 3.4 minutes, P = .09), and applied CF (17.8 ± 2.6 g vs 18 ± 2.8 g, P = .72) did not reach statistical difference between the study and control groups. CF-guided single-catheter ablation achieved successful PVI in 98% of the study group and a 31% reduction in cost. At 1-year follow-up, sinus rhythm maintenance rate was similar in both groups (86% vs 84%, P = .78).Conclusion: In paroxysmal AF, a CF-guided single-catheter technique is an effective method for PVI, yielding substantial cost savings and clinical results similar to a conventional approach. [ABSTRACT FROM AUTHOR]

Background: Fifty-watt radiofrequency applications have proven to be safe and efficient for pulmonary vein isolation (PVI). However, as PV reconnection still occurs and ablation catheter instability significantly contributes to suboptimal lesion formation, a new ablation catheter capable of delivering 90 W for 4 seconds only has been developed with the aim of improving PVI outcomes. In this setting, we sought to determine whether 90 W applications create transmural lesions without collateral damage experimentally and whether they can safely improve PVI procedures clinically compared with 50 W settings.Methods: Experimentally, individual lesions were created in vivo in the right atrium of 6 swine with 90 W-4 seconds applications using the SmartTouch-SF catheter in a power-controlled mode (3 animals) or the QDOT-MICRO catheter in a temperature-controlled mode (3 animals). Clinically, PVI was performed in a homogenous population of 150 consecutive paroxysmal atrial fibrillation patients using CARTO and the QDOT-MICRO catheter in a temperature-controlled mode (75 patients 50 W-ablation index-guided and 75 patients 90 W-4 seconds).Results: Mostly, (94.9%) experimental lesions were transmural in the thin-walled right atrium of swine. However, collateral damage was observed with both catheters in 17.9% of lesions. Clinically, 90 W procedures had a lower first-pass PVI rate (49% versus 81%, P<10-4) and a higher acute PV reconnection rate (21% versus 5%, P=0.004) than 50 W procedures, whereas total procedural duration (62 versus 66 minutes, P=0.09), 1-year sinus rhythm maintenance (88% versus 90%, P=0.6) and safety (1 tamponade per group) were similar in both groups.Conclusions: Experimentally, using the QDOT-MICRO catheter, 90 W-4 seconds lesions are mostly transmural in the thin-walled right atrium of swine (median depth 1.87 mm) with a moderate lesion diameter of 6.62 mm but retain the potential for collateral damage. Clinically, 90 W-4 seconds applications are associated with a lower first-pass PVI rate and a higher acute PV reconnection rate than 50 W applications but similar safety outcomes and effectiveness at 1 year. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aims We hypothesized that left atrial appendage peak flow velocity (LAV) assessed by echocardiography was able to accurately predict successful catheter ablation as well as favorable outcome in the setting of long-standing persistent atrial fibrillation (AF). Methods This prospective pilot study enrolled 40 patients with long-standing persistent AF (age 60±11 years, persistence of AF 4.2±2 years) who underwent first catheter ablation procedure, using a standardized sequential stepwise protocol. LAV was assessed prior to catheter ablation procedure besides classical factors (age, gender, left atrial area, AF cycle length, AF duration, and left ventricular ejection fraction), and were tested using logistic regression for (i) restoration of sinus rhythm during catheter ablation as well as (ii) absence of recurrence during a one-year follow-up. Results Eighteen patients (45%) experienced AF termination during the procedure, and 18 patients (45%) did not develop any recurrence during the first 12-months. Multivariate analysis demonstrated that high LAV (>0.3 m. s-1) was the only independent predictor of AF termination (OR=5.91, 95%CI: 1.06-32.88, p=0.04) and absence of recurrence at one year (OR=4.33, 95%CI: 1.05-17.81, p=0.04). [ABSTRACT FROM AUTHOR]