Pulmonary vein isolation using pulsed field ablation vs. high-power short-duration radiofrequency ablation in paroxysmal atrial fibrillation: efficacy, safety, and long-term follow-up (PRIORI study).

AIMS: Pulsed field ablation (PFA) is a novel, non-thermal, cardiac tissue-selective ablation modality. To date, radiofrequency (RF)-guided high-power short-duration (HPSD) ablation represents the gold standard besides cryo-ablation for pulmonary vein isolation (PVI). This single-centre, retrospective study investigated the efficacy of PFA-PVI vs. HPSD-RF PVI in terms of single-procedure arrhythmia-free outcome and safety in a real-world setting. METHODS AND RESULTS: Consecutive, paroxysmal atrial fibrillation (AF) patients who underwent PVI using PFA or HPSD-RF were enrolled. In group PFA, PVI was performed using a pentaspline PFA catheter. The ablation procedure in group HPSD-RF was performed with RF energy (45 W, ablation index). A total of 410 patients (group PFA, 201; group HPSD-RF, 209) were included. There was no difference between both groups regarding age, gender, and CHA2DS2-VASc score. The procedure time was significantly shorter in group PFA [61 (44-103) vs. 125 (105-143) min; P < 0.001]; fluoroscopy time and dose area product were significantly higher in group PFA [16 (13-20) vs. 4 (2-5) min; P < 0.01 and 412 (270-739) vs. 129 (58-265) µGym2; P < 0.01]. The overall complication rates were 2.9% in group PFA and 6.2% in group HPSD (P = 0.158). There was one fatal stroke in the PFA group. The 1-year Kaplan-Meier estimated freedom from any atrial tachyarrhythmia was 85% with PFA and 79% with HPSD-RF (log-rank P = 0.160). In 56 repeat ablation procedures, the PV reconnection rate was 30% after PFA and 38% after HPSD-RF (P = 0.372). CONCLUSION: Both PFA and HPSD-RF were highly efficient and effective in achieving PVI in paroxysmal AF patients. The arrhythmia-free survival is comparable. The PV reconnection rate was not different.

Bronchial Safety After Pulsed Field Ablation for Paroxysmal Atrial Fibrillation.

BACKGROUND: Thermal left atrial ablation can cause bronchial damage. Pulsed field ablation (PFA) is a novel, nonthermal ablation modality for paroxysmal atrial fibrillation. We report on bronchial effects after pulmonary vein isolation using PFA for paroxysmal atrial fibrillation. METHODS: A computed tomography scan showing the respiratory tract adjacent to the left atrial was obtained. Oral anticoagulation was interrupted on procedure day. Peri-procedurally, patients received heparin with an activated clotting time goal of >350 seconds. All pulmonary veins were individually isolated with a 13F steerable sheath and a pentaspline PFA catheter using either a straight-tip or J-tip guide wire. The J-tip guide wire patients were added to test the hypothesis that the straight-tip guidewire was associated with bleeding complications. One day afterward, bronchoscopy was performed. Serial hemoglobin levels were measured during 30-day follow-up. RESULTS: In 2 series of 30 patients, PFA was performed, with all pulmonary veins acutely isolated. Clinical course was uneventful, no patient had chest discomfort, coughing, or hemoptysis. All patients underwent uncomplicated bronchoscopy, without thermal lesions or ulcers. In 12 out of 30 (40%) straight-tip guide wire patients, small amounts of old blood without active bleeding were seen in multiple segments. All hemoglobin levels remained clinically stable. At 30-day follow-up, all patients were asymptomatic. CONCLUSIONS: Pulmonary vein isolation using PFA for paroxysmal atrial fibrillation does not cause thermal lesions in the bronchial system. Use of a straight-tip, extrastiff guide wire for the over-the-wire PFA catheter can lead to asymptomatic bleeding in the bronchial system without clinical relevance at 30-day follow-up, opposite to use of a J-tip guide wire.

Influence of pressure release rate and protein concentration on the formation of pressure-induced casein structures.

The formation of pressure-induced casein structures (600 MPa for 30 min at 30 degrees C) was investigated for different pressure release rates (20 to 600 MPa min-1) and casein contents (1 to 15 g/100 ml). Structures from liquid (sol) to solid (gel) were observed. The higher the protein content and the pressure release rate, the higher was the dynamic viscosity. A firm gel was built up at a casein content of 7 g/100 ml for a pressure release rate of 600 MPa min-1, while lower release rates resulted in less firm gels (200 MPa min-1) or liquid structures (20 MPa min-1). In a 5 g/100 ml casein solution and at a pressure release rate of 600 MPa min-1, casein aggregates were generated which were built from smaller casein particles with a larger hydrodynamic diameter and higher voluminosity than in the untreated solution. After a slow release rate casein micelles had a smaller hydrodynamic diameter and a lower voluminosity, but were similar in shape and diameter as compared with the micelles in solution before high pressure treatment.