Aims Very high-power short-duration (vHPSD) via temperature-controlled ablation (TCA) is a new modality to perform radiofrequency pulmonary vein isolation (PVI), conceivably at the cost of a narrower safety margin towards the oesophagus. In this two-centre trial, we aimed to determine the safety of vHPSD-based PVI with specific emphasis on silent oesophageal injury. Methods and results Ninety consecutive patients with atrial fibrillation (AF) underwent vHPSD-PVI (90 W, 3–4 s, TCA) using the QDOT MICRO catheter, in conjunction with the nGEN (Bad Neustadt, n = 45) or nMARQ generator (Bruges, n = 45). All patients underwent post-ablation oesophageal endoscopy. Procedural parameters and complications were recorded. A subgroup of 21 patients from Bad Neustadt underwent cerebral magnetic resonance imaging (cMRI) to detect silent cerebral events (SCEs). Mean age was 67 ± 9 years, 59% patients were male, and 66% patients had paroxysmal AF. Pulmonary vein isolation was obtained in all cases after 96 ± 29 min. No steam pop, cardiac tamponade, stroke, or fistula was reported. None of the 90 patients demonstrated oesophageal ulceration (0%). Charring was not observed in the nMARQ cohort (0% vs. 11% in the nGEN group). In 5 out of 21 patients (24%), cMRI demonstrated SCE (exclusively nGEN cohort). Conclusion Temperature-controlled vHPSD catheter ablation allows straightforward PVI without evidence of oesophageal ulcerations or symptomatic complications. Catheter tip charring and silent cerebral lesions when using the nGEN generator have led to further modification.

Introduction: High power short duration (HPSD) ablation proved to be an effective and safe ablation technique for atrial fibrillation (AF). In former case series, a significant amount of postablation coagulation at the catheter tip as well as silent cerebral lesions (SCL) in postprocedural cerebral magnetic resonance (cMRI) have been identified in patients undergoing de-novo AF ablations with very high power 90 W short duration (vHPvSD) ablations using the QDot ablation catheter in combination with a novel RF generator (nGEN, Biosense Webster). Therefore, the RF generator software has been recently modified. Methods and Results: Consecutive patients undergoing a first AF ablation including pulmonary vein isolation (PVI) with vHPvSD (90 W, with a predefined ablation time of 3 s at posterior left atrium (LA) wall sites and 4 s at other ablation sites) using the QDOT Micro ablation catheter (Biosense Webster) in conjunction with the technically modified nGEN RF generator (software V1c; Biosense Webster) were included. Procedural characteristics including first-pass isolation per pulmonary vein (PV) pair and early reconnection location within the 30-min waiting period were recorded. In all patients postablation endoscopy to document any thermal esophageal injury (EDEL) and in eligible patients a cMRI to detect silent cerebral events (SCEs)/lesions were performed. All acute procedure-related complications were recorded during the time until hospital discharge. Furthermore, short-term and midterm success after 3 and 6-12 months of follow-up was investigated. In total, 34 consecutive patients (67 ± 9 years; 62% male; 68% paroxysmal AF) were included. First-pass isolation of all PVs was achieved in 6/34 (18%) patients.First-pass isolation was seen in 37/68 (54%) of PV pairs. Early reconnection occurred in 11 (32%) patients (including reconnections at posterior LA wall sites n = 6 and at nonposterior sites n = 5). No patient had an EDEL (0%). In 6/23 (26%) patients undergoing postablation cerebral MRI SCEs were identified. In six patients,

Background: Endoscopically detected thermal esophageal lesions (EDEL) after ablation of atrial fibrillation may be precursors of atrioesophageal fistula and esophageal luminal temperature monitoring has previously failed to decrease thermal damage. Methods: Sixty-three patients undergoing their first pulmonary vein isolation using radiofrequency point-by-point catheter ablation were prospectively included in the HEAT-AF study (High-Resolution Esophageal Assessment of Esophageal Temperature During Atrial Fibrillation Ablation) and esophageal temperatures were continuously monitored using a novel infrared thermography system (IRTS). Peak esophageal temperature (Tpeak) was correlated to postablation endoscopy results characterizing patients as EDEL positive or negative. Results: Twelve patients had EDEL (19%). Comparing EDEL positive to negative patients, Tpeak was significantly higher (56.3±4.6°C versus 45.7±5.5°C, P <0.0001). Logistic regression analysis demonstrated Tpeak was a statistically significant predictor ( P =0.0008) of EDEL and yielded an odds ratio of 1.52; 95% CI, (1.24–2.05). Receiver operator curve analysis demonstrated Tpeak as a highly accurate binary classifier with an area under the curve of 93%. Conclusions: For the first time esophageal temperature monitoring using a high resolution, high-fidelity IRTS allowed accurate prediction of postablation EDEL suggesting that Tpeak alone is an excellent binary classifier of patients at risk of EDEL. The logistic regression model and associated receiver operator curve will aid in the selection of optimal temperature thresholds in future prospective studies.

Aims Pulmonary vein isolation (PVI) using radiofrequency (RF) ablation is an effective treatment option for patients with atrial fibrillation (AF). This study aims to investigate the safety of high-power short duration (HPSD) with emphasis on oesophageal lesions after PVI. Methods and results Consecutive patients undergoing AF ablation with HPSD (50 W; ablation index (AI)-guided; target AI 350 for posterior wall ablation, AI 450 for anterior wall ablation) using the ThermoCool SmartTouch SF catheter were included. Patients underwent post-ablation oesophageal endoscopy to detect and categorize thermal oesophageal injury (EDEL). Occurrence and risk factors of oesophageal lesions and perforating complications were analysed. A total of 1033 patients underwent AF ablation with HPSD. Of them, 953 patients (67.6 ± 9.6 years; 58% male; 43% paroxysmal AF; 68% first PVI) underwent post-procedural oesophageal endoscopy and were included in further analyses. Median procedure time was 82.8 ± 24.4 min with ablation times of 16.1 ± 9.2 min. Thermal oesophageal injury was detected in 58 patients (6%) (n = 29 Category 1 erosion, n = 29 Category 2 ulcerous). One patient developed oesophageal perforation (redo, 4th AF ablation). No patient died. Using multivariable regression models, increased total ablation time [odds ratio (OR) 1.029, P = 0.010] and history of stroke (OR 2.619, P = 0.033) were associated with increased incidence of EDEL after AF ablation, whereas increased body mass index was protective (OR 0.980, P = 0.022). Conclusion Thermal oesophageal lesions occur in 6% of HPSD AF ablations. The risk for development of perforating complications seems to be low. Incidence of atrio-oesophageal fistula (0.1%) is comparable to other reported series about RF ablation approaches.

Introduction Ablation index (AI), a novel parameter defining energy application at single ablation lesions, calculated by integration of ablation time, energy, catheter stability, and contact force, has been documented to be associated with effective lesions and higher ablation efficacy. Using a prespecified target AI in addition to acute lesion efficacy may affect local collateral damage like esophageal thermal injury when used for guiding radiofrequency (RF) ablation at the posterior left atrial (LA) wall. Methods and Results Consecutive patients undergoing first AF ablations using AI were included. Ablation energy was reduced to 25 W when ablating at posterior LA wall. Two different individually defined AI target values were used (300 and 350 for posterior wall ablation). Esophageal endoscopy (EE) was performed 1 to 3 days after ablation procedure to document and categorize endoscopically detected esophageal thermal lesion (EDEL). Two‐hundred and eleven consecutive patients with postprocedural EE were included. Incidence of EDEL was 14% (29 of 211 patients; mild category 1 lesions in 22 of 29 patients (76%) and severe category 2 lesions (ulcers > 5 mm) in 7 of 29 patients (24% of EDEL group, 3% of total group). Ablation time at posterior LA wall (9.5 vs 9.0 minutes [P = .67]) was comparable in patients with and without EDEL. Conclusion LA posterior wall RF ablation adopting AI ≤350 was associated with 14% esophageal thermal injury including 3% of severe esophageal thermal ulcers. This incidence is comparable to historic control groups with non AI–guided AF ablation.

Introduction: Data about atrial fibrillation (AF) ablation using high-power short duration (HPSD) radiofrequency ablation in the elderly population is still scarce. The aim of our study was to investigate the efficacy and safety of HPSD ablation in patients over 75 years compared to younger patients.Methods: Consecutive patients older than 75 years with paroxysmal or persistent AF undergoing a first-time AF ablation using 50 W HPSD ablation approach were analyzed in this retrospective observational analysis and compared to a control group <75 years. Short-term endpoints included intraprocedural reconnection of at least one pulmonary vein (PV) and intrahospital and AF recurrence during 3 months blanking period, as well as a long-term endpoint of freedom from atrial arrhythmias of antiarrhythmic drugs after 12 months.Results: A total of 540 patients underwent a first AF ablation with HPSD (66 ± 10 years; 58% male; 47% paroxysmal AF). Mean age was 78 ± 2.4 and 63 ± 6.3 years (p < .001), respectively. Elderly patients were significantly more often women (p < .001). The procedure, fluoroscopy, and ablation were comparable. Elderly patients revealed significantly more often extra-PV lowvoltage areas requiring additional left atrial ablations (p < .001). Overall complication rates were low; however, elderly patients revealed higher major complication rates mainly due to unmasking sick sinus syndrome (p = .003).Freedom from arrhythmia recurrences was comparable (68% vs. 76%, log-rank p = .087). Only in the subgroup of paroxysmal AF, AF recurrences were more common after 12 months (69% vs. 82%; log-rank p = .040; hazard ratio: 1.462, p = .044) in the elderly patients. In multivariable Cox regression analysis of the whole cohort persistent AF, female gender, diabetes mellitus and presence of left atrium low-voltage areas, but not age >75 years were associated with AF recurrences.Conclusion: HPSD AF ablation of patients >75 years in experienced centers is safe and effective. Therefore, age alone should not be the reason to withhold AF ablation

Background: This study sought to evaluate the short and midterm efficacy and safety of the novel very high power very short duration (vHPvSD) 90 W approach compared to HPSD 50 W for atrial fibrillation (AF) ablation as well as reconnection patterns of 90 W ablations. Methods and Results: Consecutive patients undergoing first AF ablation with vHPvSD (90 W; predefined ablation time of 3 s for posterior wall ablation and 4 s for anterior wall ablation) were compared to patients using HPSD (50 W; ablation index-guided; AI 350 for posterior wall ablation, AI 450 for anterior wall ablation) retrospectively. A total of 84 patients (67.1 ± 9.8 years; 58% male; 47% paroxysmal AF) were included (42 with 90 W, 42 with 50 W) out of a propensity score-matched cohort. 90 W ablations revealed shorter ablation times (10.5 ± 6.7 min vs. 17.4 ± 9.9 min; p = .001). No major complication occurred. 90 W ablations revealed lower first pass PVI rates (40% vs. 62%; p = .049) and higher AF recurrences during blanking period (38% vs. 12%; p = .007). After 12 months, both ablation approaches revealed comparable midterm outcomes (62% vs. 70%; log-rank p = .452). In a multivariable Cox regression model, persistent AF (hazard ratio [HR]: 1.442, 95% confidence interval [CI]: 1.035-2.010, p = .031) and increased procedural duration (HR: 1.011, 95% CI: 1.005-1.017, p = .001) were identified as independent predictors of AF recurrence during follow-up.Conclusions: AF ablation using 90 W vHPvSD reveals a similar safety profile compared to 50 W ablation with shorter ablation times. However, vHPvSD ablation was associated with lower rates of first-pass isolations and increased AF recurrences during the blanking period. After 12 months, 90 W revealed comparable efficacy results to 50 W ablations in a nonrandomized, propensity-matched comparison.

Aims Bipolar radiofrequency ablation (B-RFA) has been reported as a bail-out strategy for the treatment of therapy refractory ventricular arrhythmias (VA). Currently, existing setups have not been standardized for B-RFA, while the impact of conventional B-RFA approaches on lesion formation remains unclear. Methods and results (i) In a multicentre observational study, patients undergoing B-RFA for previously therapy-refractory VA using a dedicated B-RFA setup were retrospectively analysed. (ii) Additionally, in an ex vivo model lesion formation during B-RFA was evaluated using porcine hearts. In a total of 26 procedures (24 patients), acute success was achieved in all 14 ventricular tachycardia (VT) procedures and 7/12 procedures with premature ventricular contractions (PVC), with major complications occurring in 1 procedure (atrioventricular block). During a median follow-up of 211 days in 21 patients, 6/11 patients (VT) and 5/10 patients (PVC) remained arrhythmia-free. Lesion formation in the ex vivo model during energy titration from 30 to 50 W led to similar lesion volumes compared with initial high-power 50 W B-RFA. Lesion size significantly increased when combining sequential unipolar and B-RFA (1429 mm3 vs. titration 501 mm3 vs. B-RFA 50 W 423 mm3, P &lt; 0.001), an approach used in overall 58% of procedures and more frequently applied in procedures without VA recurrence (92% vs. 36%, P = 0.009). Adipose tissue severely limited lesion formation during B-RFA. Conclusion Using a dedicated device for B-RFA for therapy-refractory VA appears feasible and safe. While some patients need repeat ablation, success rates were encouraging. Sequential unipolar and B-RFA may be favourable for lesion formation.