Phrenic Nerve Palsy Research Articles

Comparison of the acute outcome of two cryoballoon technologies for pulmonary vein isolation: An updated systematic review and meta-analysis

Initial experience suggests that the POLARx cryoballoon system (Boston Scientific) has a similar procedural efficacy and safety as Arctic Front Advance Pro (AFA-Pro, Medtronic). We performed an updated systematic review and meta-analysis comparing POLARx and AFA-Pro. Embase, MEDLINE, Web of Science, Cochrane, and Google Scholar databases were searched until 12/01/2022 for studies comparing POLARx versus AFA-Pro in patients undergoing pulmonary vein (PV) isolation for AF. A total of 8 studies, involving 1146 patients from 11 European centers were included (POLARx n = 317; AFA-Pro n = 819). There were no differences in acute PV isolation, procedure time, fluoroscopy time, ablation time, minimal esophageal temperature, and risk of phrenic nerve palsy or thromboembolic events. Balloon nadir temperatures were lower for POLARx in all PVs. Compared with AFA-Pro, POLARx had a higher rate of first freeze isolation in the left inferior PV (LIPV) (odds ratio [OR]: 2.60; 95 % confidence interval [CI]: 1.06 to 6.43; P = 0.04), higher likelihood of time-to-isolation (TTI) recording in LIPV (OR: 2.91; 95 % CI: 1.54 to 5.49; P = 0.001) and right inferior PV (OR: 3.23; 95 % CI: 1.35 to 7.74; P = 0.008). In contrast, the TTI in LIPV was longer with POLARx in comparison to AFA-Pro (mean difference: 7.61 sec; 95 % CI 2.43 to 12.8 sec; P = 0.004). In conclusion, POLARx and AFA-Pro have a similar acute outcome. Interestingly, there was a higher rate of TTI recording in the inferior PVs with POLARx. This updated meta-analysis provides new safety data on esophageal temperature and thromboembolic events.

Dexmedetomidine for sedation during epicardial ablation for ventricular tachycardia: a single-center experience.

Epicardial approach to ventricular tachycardia (VT) ablation is mainly performed under general anesthesia (GA). Although catheter manipulation and ablation in the epicardial space could be painful, GA lowers blood pressure and may interfere with arrhythmia induction and mapping, and the use of muscle relaxants precludes identification of the phrenic nerve (PN). Moreover, an anesthesiologist's presence is required during GA for the whole procedure, which may not always be possible. Therefore, we evaluated the feasibility and safety of epicardial VT ablations performed under conscious sedation using dexmedetomidine in our center. Between January 2018 and January 2022, all patients who underwent epicardial VT ablation under continuous dexmedetomidine infusion were prospectively included in the study. All patients received premedication 30min before the epicardial puncture with paracetamol (acetaminophen 10mg/ml) 1000mg and ketorolac 30mg. Sedation protocol included an intravenous bolus of midazolam hydrochloride (0.03-0.05mg/kg) followed by continuous infusion of dexmedetomidine (0.2-0.7 mcg/kg/h). In addition, an intravenous fentanyl citrate bolus (0.7-1.4 mcg/kg) was given for short-term analgesia, followed by a second dose repeated after 30 to 45min. Sedation-related complications were defined in case of respiratory failure, severe hypotension, and bradycardia requiring treatment. Sixty-nine patients underwent epicardial or endo-epi VT ablation under conscious sedation and were included in the analysis. The mean age was 65.4 ± 12.1years; forty-six patients were males (66.6%). All patients had drug-refractory recurrent VT. Forty-seven patients (68.1%) had non-ischemic cardiomyopathy (NICM), 13 patients (18.9%) had ischemic-cardiomyopathy (ICM), and 9 patients (13%) had myocarditis. Standard percutaneous sub-xiphoid access was attempted in all patients. Non-inducibility of any VT was achieved in 82.6% (9/9 myocarditis, 10/13 ICM, 38/47 NICM, n = 57/69 patients), inducibility of non-clinical VT in 13% (3/13 ICM, 6/38 NICM, n = 9/69 patients), and failure in 4.3% (3/38 NICM, n = 3/69 patients). Although we observed procedural-related complications in five patients (7.2%), one transient PN palsy, two pericarditis, and two vascular complications, those were not related to the conscious sedation protocol. No respiratory failure, severe hypotension, or bradycardia requiring treatment has been observed among the patients. Prompt availability of anesthesiology support remains crucial for complex procedures such as epicardial VT ablation. Continuous infusion of dexmedetomidine and administration of midazolam and fentanyl seem to be a safe and effective sedation protocol in patients undergoing epicardial VT ablation.

Efficacy and safety of cryoballoon pulmonary vein isolation for paroxysmal and persistent atrial fibrillation: A comparison with radiofrequency ablation

BackgroundCryoballoon ablation was established as an effective and safe modality to achieve pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF). However, its role in persistent atrial fibrillation (PersAF) remains unclear.ObjectiveThis study aimed to evaluate the efficacy and safety of cryoballoon PVI in PAF and PersAF comparing conventional radiofrequency catheter ablation (RFCA).MethodsTwo hundred patients undergoing cryoballoon ablation for symptomatic AF were consecutively enrolled in this retrospective study. For comparison, 210 patients undergoing RFCA in the same period were included. The primary outcome was a recurrence of any atrial tachyarrhythmias (ATas) after the index ablation. 12-lead ECG and 24-hour Holter monitoring were obtained at 1,3,6 and 9–12 months.ResultsPVI by cryoablation alone was achieved in 197 patients (98.5%). ATas-free survival at 12 months post-ablation was 72.7% in the cryoablation and 80.6% in the RFCA group (P = 0.123), respectively. The cryoablation showed comparable efficacy maintaining sinus rhythm compared with RFCA in PAF (P = 0.539), whereas in PersAF, ATas-free survival was significantly lower in cryoablation (P = 0.039). PV reconnection was observed in the majority of patients (14/16, 87.5%) who receive redo RFCA. Complications were encountered in 10 patients, including femoral arteriovenous fistula (n = 1), transient phrenic nerve palsy (n = 8), and minimal amount pericardial effusion (n = 1).ConclusionThe efficacy of cryoballoon PVI is comparable with conventional RFCA in PAF, whereas PVI alone using cryoballoon may not be insufficient to maintaining sinus rhythm in PersAF. The safety of cryoballlon PVI is tolerable.

Safety and long-term efficacy of cryoballoon ablation for atrial fibrillation in octogenarians: a multicenter experience

Cryoballoon technology (CB-A) has become a cornerstone of atrial fibrillation (AF) ablation in terms of safety and efficacy. Data regarding CB-A in octogenarians are still scarce and limited to single center experiences. The present study sought to analyze the performances of index CB-A in patients older than 80years-old referring to 3 high-volume European centers. We retrospectively enrolled 95 patients with a median age of 81 [80, 83] years. 62 (65.3%) patients presented with paroxysmal AF and 33 (33.7%) with persistent AF. Mean procedure and fluoroscopy times were 73.8 ± 25.2 and 15.3 ± 7.5min, respectively. At 12months and 24months of follow-up, the overall freedom from AF was 81.1% and 66.6%, respectively. When divided for AF type, freedom from AF was higher in patients with paroxysmal AF (p = 0.007). Cryoballoon ablation was able to significantly improve AF-related symptoms as proven by the significant decrease in EHRA score during the follow-up (p < 0.0001). Phrenic nerve palsy occurred in 8 (8.5%) patients and always resolved during the procedure without affecting procedural outcome. Two major complications occurred (2.1%); one patient experienced pneumonia, successfully treated with antibiotics and non-invasive mechanical ventilation, the latter one experienced acute kidney failure secondary to urosepsis successfully treated by renal replacement therapy. The present study showed that CB-A is a feasible and effective procedure among octogenarians with a low complication rate. Contemporarily, CB-A can help to alleviate arrhythmia-related symptoms also among this group of subjects.

Use of Ultrasound-Guided Interfascial Plane Blocks in Anterior and Lateral Thoracic Wall Region as Safe Method for Patient Anesthesia and Analgesia: Review of Techniques and Approaches during COVID-19 Pandemic.

Ultrasound-guided interfascial plane blocks performed on the anterior and lateral thoracic wall have become an important adjuvant method to general anesthesia and an independent method of local anesthesia and pain management. These procedures diminish the harmful effects of anesthesia on respiratory function and reduce the risk of phrenic nerve paralysis or iatrogenic pneumothorax. In postoperative pain management, interfascial plane blocks decrease the dosage of intravenous drugs, including opioids. They can also eliminate the complications associated with general anesthesia when used as the sole method of anesthesia for surgical procedures. The following procedures are classified as interfascial plane blocks of the anterior and lateral thoracic wall: pectoral nerve plane block (PECS), serratus anterior plane block (SAP), transversus thoracic muscle plane block (TTP), pectoral interfascial plane block (PIF), and intercostal nerve block (ICNB). These blocks are widely used in emergency medicine, oncologic surgery, general surgery, thoracic surgery, cardiac surgery, orthopedics, cardiology, nephrology, oncology, palliative medicine, and pain medicine. Regional blocks are effective for analgesic treatment, both as an anesthesia procedure for surgery on the anterior and lateral thoracic wall and as an analgesic therapy after trauma or other conditions that induce pain in this area. In the era of the COVID-19 pandemic, ultrasound-guided interfascial plane blocks are safe alternatives for anesthesia in patients with symptoms of respiratory distress related to SARS-CoV-2 and appear to reduce the risk of COVID-19 infection among medical personnel.

Selective C5 nerve root block versus combined interscalene block for clavicle surgery

Objectives: The pain sensation of the clavicle is innervated by two separate plexuses. Regional anesthesia techniques for this area are challenging and complicated. Interscalene block, superficial cervical block, or a combination of these two is commonly used for regional anesthesia in clavicle surgery. The aim of this study was to investigate the efficacy of C5 nerve root block for clavicle surgery. Methods: Patients were divided into two groups: Group C5B (patients who received C5 nerve root block + superficial cervical plexus block) and Group ISB (patients who received interscalene block + superficial cervical plexus block). Motor block was assessed by the Medical Research Council Scale for Muscle Strength, while the sensory block of the areas corresponding to the nerve trace was assessed using the pinprick and cold testing. Furthermore, ultrasound was employed to evaluate phrenic nerve paralysis. Results: There was no difference between the groups in terms of mean age. The mean age of Group ISB was higher; however, the comparison of comorbidities revealed no significant difference between the groups. This statistically significant difference was clinically insignificant. Group C5B had lower 6-hour pain at rest, lower 0, 2, 4-hour pain on movement, and less postoperative analgesic consumption. Moreover, the time to first analgesic requirement was significantly longer in Group C5B. The motor examination of the peripheral nerves showed a significant difference in Group C5B. Conclusions: We are of the opinion that C5 nerve root block can be used instead of interscalene block since it does not produce a motor block in hand movements and preserves diaphragmatic functions. C5 nerve root block may therefore be considered an alternative to conventional interscalene block for clavicle surgery.

Local Infiltration Analgesia Versus Interscalene Block for Pain Management Following Shoulder Arthroplasty: A Prospective Randomized Clinical Trial.

While providing effective analgesia following shoulder arthroplasty, an interscalene block has known complications. Local infiltration analgesia (LIA) using ropivacaine has been successfully employed in other joint arthroplasties, but its efficacy in shoulder arthroplasty has not been studied extensively. The purpose of this study was to compare pain and opioid consumption between LIA and an interscalene block following shoulder arthroplasty. Patients undergoing primary shoulder arthroplasty were prospectively randomized into 2 groups: the block group received an interscalene block using liposomal bupivacaine, and the injection group received an LIA injection intraoperatively. The LIA injection included ropivacaine, epinephrine, ketorolac, and normal saline solution. Postoperative visual analog scale pain scores, opioid consumption in morphine milligram equivalents, and complications were compared between the groups. The mean pain scores during the first 24 hours postoperatively were used to test noninferiority of LIA compared with an interscalene block. The study included 74 patients (52 men and 22 women with a mean age of 69 years; 37 were in the injection group and 37 in the block group). There was no significant difference between the groups with respect to pain scores at any postoperative time points (p > 0.05), except for the 8-hour time point, when the injection group had a significantly higher pain score than the block group (p = 0.01). There was no significant difference in opioid consumption between the groups at any time points postoperatively (p > 0.05). The amount of intraoperative opioid consumption was significantly higher in the injection group (p < 0.001). In noninferiority testing for the mean pain scores during the first 24 hours, the injection group was found to be noninferior to the block group. One patient in the block group developed transient phrenic nerve palsy. One patient in the injection group developed dislocation after reverse arthroplasty related to noncompliance. The mean procedure hospital charge was $1,718 for an interscalene block and $157 for LIA. LIA and an interscalene block provided similar analgesia during the first 24 hours after primary shoulder arthroplasty. LIA was associated with worse pain at 8 hours postoperatively and more intraoperative opioid consumption but was also substantially less costly. Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Left subclavian artery coverage during endovascular repair of thoracic aorta injury in trauma and non-trauma patients.

In thoracic endovascular aortic repair (TEVAR), the left subclavian artery (LSA) is often occluded. Although most patients tolerate this, some develop ischemic symptoms to the brain or left upper extremity (LUE). A revascularization procedure may be associated with significant complications. The purpose of this review was to assess the incidence of LSA occlusion, resulting ischemic symptoms, and complications related to revascularization operations in trauma patients compared to non-trauma patients. Studies from 2010 to 2020 were fully reviewed if they discussed incidence of LSA coverage, LUE ischemia, carotid-subclavian bypass, or complications associated with carotid-subclavian bypass. Seventeen articles were included in this analysis. A total of 167 patients were identified as trauma cases. Incidence of LSA occlusion in trauma was 91/167 (54%) compared to 281/1446 (19%) in the population exclusive of trauma (p < 0.001). Following LSA occlusion, the rate of LUE claudication/ischemia was 21/56 (38%) for trauma, compared to 12/193 (6%) in non-trauma cases (p < 0.001). The overall complication rate after carotid-subclavian rescue bypass was 29.2% (33/112), with phrenic nerve palsy (24%), recurrent laryngeal nerve palsy (5%), and pseudoaneurysm (1.7%) being the most common. LSA coverage following TEVAR is common and associated with significant complications, often requiring operative management. The incidence of ischemic complications after occlusion of the LSA is significantly higher in the trauma population. Revascularization procedures to correct the occlusion have a high rate of complications.

Characterization of Phrenic Nerve Response to Pulsed Field Ablation.

Background:Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may reduce the risk of phrenic nerve injury but has not been well characterized.Methods:Accelerometers and continuous pacing were used during PFA deliveries in a porcine model. Acute dose response was established in a first experimental phase with ascending PFA intensity delivered to the phrenic nerve (n=12). In a second phase, nerves were targeted with a single ablation level to observe the effect of repetitive ablations on nerve function (n=4). A third chronic phase characterized assessed histopathology of nerves adjacent to ablated cardiac tissue (n=6).Results:Acutely, we observed a dose-dependent response in phrenic nerve function including reversible stunning (R2=0.965, P<0.001). Furthermore, acute results demonstrated that phrenic nerve function responded to varying levels of PFA and catheter proximity placements, resulting in either: no effect, effect, or stunning. In the chronic study phase, successful isolation of superior vena cava at a dose not predicted to cause phrenic nerve dysfunction was associated with normal phrenic nerve function and normal phrenic nerve histopathology at 4 weeks.Conclusions:Proximity of the catheter to the phrenic nerve and the PFA dose level were critical for phrenic nerve response. Gross and histopathologic evaluation of phrenic nerves and diaphragms at a chronic time point yielded no injury. These results provide a basis for understanding the susceptibility and recovery of phrenic nerves in response to PFA and a need for appropriate caution in moving beyond animal models.

Persistent phrenic nerve palsy after atrial fibrillation ablation: follow-up data from the Netherlands Heart Registration

Abstract Funding Acknowledgements Type of funding sources: None. Background Persistent phrenic nerve palsy (PNP) is an established complication of atrial fibrillation (AF) ablation, especially during cryoballoon and thoracoscopic ablation. Data on persistent PNP reversibility is limited because most patients recover &amp;lt;24hours. Purpose This study aims to investigate persistent PNP recovery, freedom of PNP-related symptoms after AF ablation and identify baseline variables associated with the occurrence and early PNP recovery in a large nationwide registry study. Methods In this study, we used data from the Netherlands Heart Registration, comprising data from 9,549 catheter and thoracoscopic AF ablations performed in 2016 and 2017. PNP data was available of 7,433 procedures, and additional follow-up data were collected for patients who developed persistent PNP. Results Overall, mean age was 62±10 years, and 67.7% were male. Fifty-four (0.7%) patients developed persistent PNP and follow-up was available in 44 (81.5%) patients. PNP incidence was 0.07%, 0.29%, 1.41%, and 1.25% for patients treated with conventional-RF, phased-RF, cryoballoon, and thoracoscopic ablation respectively. Seventy-one percent of the patients fully recovered, and 86% were free of PNP-related symptoms after a median follow-up of 203[113 – 351] and 184[82 – 359] days, respectively (Figure 1A/C). In addition, in 20/28 (71.4%) patients recovery was confirmed with imaging (Figure 1B). Female sex, cryoballoon, and thoracoscopic ablation were associated with a higher risk to develop PNP, with corresponding adjusted OR of 2.32 95% CI 1.07 – 5.06, OR 21.12 95% CI 6.49 – 129.75, and 18.93 95% CI 4.86 – 124.41, respectively. Patients with PNP recovering ≤180 days had a larger left atrium volume index than those with late or no recovery. Conclusion After AF ablation, persistent PNP recovers in the majority of patients, and most are free of symptoms. Female patients and patients treated with cryoballoon or thoracoscopic ablation are more prone to develop PNP.

Biophysical parameters and time to isolation of pulmonary veins with a novel cryoballoon: results of POLAR ICE study

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Boston Scientific Introduction Low nadir temperatures and long thaw times with cryoballoon ablation are associated with successful pulmonary vein isolation (PVI). Recently, a system that maintains uniform pressure and size has been introduced to improve catheter stability during cryoballoon ablation. The present results examine the relationship between cryoballoon time to isolation (TTI) and other biophysical parameters; time to -40ºC (TT-40), nadir temperature, time to thaw (TT0), and first pass isolation success in patients with paroxysmal AF (PAF). Methods POLAR ICE, a prospective, non-randomized, multicenter (international) registry (NCT04250714), enrolled 400 patients across 19 centers, between Aug 2020 and May 2021. This study included any patients indicated for treatment of PAF with the POLARx cryoablation system. Cryodosing regimen was left to the operator and not specified by study protocol. Procedural characteristics, such as time to isolation (TTI), cryoablations per pulmonary vein, nadir temperature, and occlusion grade were recorded. PVI was confirmed via entrance block. Biophysical parameters for ablations longer than 120s were evaluated. Results Data on 389 PVI procedures (n=2303 ablations) were collected. Of those ablations, 1914 (83%) had a duration of at least 120s and were included in this analysis. Isolation was attempted using the CB alone. TTI was reported in 1335 ablations with the majority (64%) occurring within 60s. Biophysical parameters and single shot success rates were examined based on TTI. Ablations with TTI&amp;lt;60s had significantly faster TT-40 (30.6±7.4s), lower nadir temperatures (-58.3±5.8ºC), longer thaw times (21.1±6.7s), and a greater proportion of grade 4 occlusions (88%) than longer TTIs or ablation with no TTI reported (Table 1). In TTIs&amp;lt;60s single shot success was 95%, significantly greater than TT≥60s, or No TTI. Procedure-related complications included: phrenic nerve palsy (0.5%), tamponade (0.5%), AV block (0.3%), stroke (0.3%), and transient ischemic attack (0.3%). Conclusions These data suggest a correlation between cryoballoon biophysical parameters and single shot success. Good occlusion likely drives faster freeze and lower nadir temperatures, resulting in longer thaw times with this novel cryoballoon. Future research should examine the relationship between these parameters to drive optimization of cryoablation techniques and provide guidance toward improved workflow.

Acute safety and efficacy outcome of pulmonary vein isolation using pulsed field ablation technology

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Pulsed field ablation (PFA) is a new technology for electrical isolation of pulmonary veins (PVI) using electroporation for irreversible cell death. First data imply a very low complication rate in terms of esophageal lesion, phrenic nerve palsy and pulmonary vein stenosis. We present our datas of our first patients concerning acute safety and efficacy. Method 38 patients with paroxysmal and persistent atrial fibrillation (AF) consecutively underwent PFA ablation including complete PVI of all pulmonary veins in all cases (including 14 redo cases ), mean age 68,3 year, and a mean ejection fraction of 56 %, mean CHADSVASC Score 3. 19 patients had paroxysmal AF, in 21 patients additional posterior wall isolation was performed. Additional anatomical and voltage characterization with CARTO was performed before and after ablation. Post ablation, all patients underwent endoscopic evaluation of the esophagus and all eligible patients were screened for silent cerebral lesions (SCL) using cerebral magnetic resonance imaging (MRI). All acute procedure data and complications were documented. Results In all 38 patients effective PVI using only PFA catheter was achieved (100 %) within a mean procedure time of 81±15 min and a mean fluoroscopy time of 18± 5 min. In 2 patients left atrial macroreentrant tachycardia was effectively terminated with PFA pulses in the PV-mitral-annular isthmus region. In no patient an esophageal lesion could be detected (0%). Cerebral MRI was performed in 18 cases and revealed SCLs (47 %) in 5 patients (3 patients with multiple lesions, 2 patiens with 3 lesions, max size of 8 mm). No symptomatic complications including pericardial effusion or access site complications were noted. Conclusion PFA is a highly effective method for acute PVI. No relevant symptomatic complications were noted. Of note, no patient had esophageal injury related to the ablation but 40% of patients undergoing post-ablation MRI had documented SCE. Further data have to be collected to discuss these findings properly.

Six-month follow-up of first real-world experience with pulmonary vein isolation using pulsed field ablation for paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation for AF using thermal energy can cause collateral damage. Pulsed field ablation (PFA) is a novel nonthermal energy source. Only a few small clinical studies have been published. Objective We report on the first “real-world” experience with 6-month follow-up with PVI with PFA for paroxysmal AF. Methods Pre and post ablation, phrenic nerve function was assessed. A high-density LA bipolar voltage map was created. All PVs were individually isolated using a steerable sheath and a pentaspline over-the-wire PFA catheter. After ablation, mapping was repeated to assess lesion formation. Patients had a scheduled follow-up visit at days 30, 90 and 180 after ablation. Results In 30 patients (age 63 years, 47% male), uncomplicated PFA was performed, with all PVs acutely isolated. Skin-to-skin procedure time was 120±21 min. Total LA dwell time was 109±22 min. LA dwell time of the PFA catheter was 31±12 min. Fluoroscopy time was 23±7 min. Dose-area product was 4,96±3,54 Gy.cm2. Number of applications per patient until complete PVI was 32±1. In 1 patient with roof dependent flutter, a roof line was intentionally created with 8 additional applications. In 2 patients, unintentional bidirectional mitral isthmus block was created. In 10 patients, temporary pacing due to vagal bradycardia after LSPV ablation was needed. There was no phrenic nerve palsy. In 1 patient who had repeated, di!cult CS-catheter placement, 6 hours after the procedure a cardiac tamponade with uncomplicated pericardial drainage of 250 ml blood occurred. Further in-hospital stay was uneventful, on day 2 all patients were discharged in SR. On day 30, all patients were free of complaints and there were no groin complaints. 29 Patients were in SR, 1 patient had a cardioversion because of asymptomatic AT with 4:1 conduction. On day 90, 27 (90%) patients were in SR, 3 patients had AF/AT recurrence. During redo LA procedure, 2 patients with isolated PVs had inducable LA macro-reentrant tachycardia (1 roof and 1 mitral isthmus dependent) and 1 patient had LIPV reconduction. All 3 patients had uncomplicated RF ablation. On day 180, all 30 patients were o" anti-arrhythmic drugs and in SR. Conclusion PVI using PFA for paroxysmal AF in a “real-world” setting is safe and feasible. Post-ablation clinical course and 6-month follow-up are favorable.

Acute procedural characteristics, efficacy, and safety of a novel cryoballoon for the treatment of paroxysmal atrial fibrillation: Results from the POLAR-ICE study

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Boston Scientific Background/Introduction Pulmonary vein isolation (PVI) using a cryoballoon is well-established for the treatment of paroxysmal atrial fibrillation (PAF). Initial experience with a novel cryoballoon (CB) with a stable low balloon pressure (POLARx, Boston Scientific) has demonstrated acute procedural safety and efficacy in de novo PVI procedures in patients with paroxysmal AF. However, to date, there is limited multicenter data on real world acute outcomes and procedural characteristics with this novel cryoballoon. Purpose The purpose of POLAR ICE was to provide real-world data on the acute and chronic outcomes of cryoballoon ablation with POLARx for the treatment of PAF. Here we report on the initial acute outcomes up to 3 months including procedural efficacy, safety, and biophysical parameters. Methods POLAR ICE, a prospective, non-randomized, multicenter (international) registry (NCT04250714), enrolled 400 patients across 19 centers, between Aug 2020 and May 2021. This study included any patients indicated for treatment of PAF with the POLARx cryoablation system. The study protocol did not mandate any specific cryodosing regimen, this was left to the operator. Procedural characteristics, such as time to isolation (TTI), cryoablations per pulmonary vein, balloon nadir temperature, and occlusion grade were recorded. PVI was confirmed with entrance block testing. Results Complete PVI was achieved in 96.1% of PVs (1437/1496). Procedure and fluoroscopy times were 69.0±25.2 min and 15.8±10.0 min, respectively. Left atrial dwell time was 47.3±18.8 min. The cryoablation characteristics by vein are shown in the Table 1. An average of 4.9±1.8 ablations were performed per patient (1.3±0.7 per vein). Grade 3 or 4 occlusion was achieved in 98.1% of PVs reported. Electrical isolation was achieved with an average TTI of 50±33.8s and in 81.4% of PVs isolation required only a single cryoablation. Nadir temperatures across all pulmonary veins averaged -56.3± 6.5C. Time to -40C was 32.9±11s and Time to Thaw (0C) was 19.5±6.7s across all veins. PVI was performed on atypical anatomies (12 LCPV, 7 RMPV, &amp; 3 RCPV) in 19 pts. Serious adverse events included phrenic nerve palsy (0.5%), tamponade (0.5%), AV block (0.3%), stroke (0.3%), and transient ischemic attack (0.3%). Conclusions Real world usage data on the novel CB suggests that this device is safe and effective, with a PV isolation success rate of 96.2% and 81.4% of PVs isolated with a single cryoablation. These data are in keeping with reports on other cryoballon systems and have markedly shorter procedure times than have been previously reported on this cryoballon.

Novel cryo-balloon technology for a successful pulmonary vein isolation: acute outcome and follow-up from a large multicenter Italian clinical setting

Abstract Funding Acknowledgements Type of funding sources: None. Background Complete electrical pulmonary vein isolation (PVI) by cryo-balloon approach is a well-established ablation strategy of atrial fibrillation (AF). Recently, a new cryoablation system (POLARx) with unique features has been made available for clinical use. To date, limited data exist on acute and follow-up outcome of this system in a multicentric clinical practice. Purpose We reported the preliminary experience of this novel technology in a multicenter Italian registry. Methods Consecutive patients (pts) undergoing AF ablation from the CHARISMA registry at 6 Italian centres were included. Protocol-directed cryoablation was delivered for 180 sec or 240 sec according to operator’s preference for isolation achieved in ≤60 sec, or 240 sec if isolation occurred &amp;gt;60 sec or when time to isolation (TTI) was not available. The ablation endpoint was PV isolation as assessed by entrance and exit block. Rhythm monitoring during the follow-up examinations was performed via the clinical assessment of AF recurrence, ECG and Holter monitoring, according to the clinical practice of each center. All patients were followed-up for at least 6 months after the procedure. Arrhythmia recurrences within the first 3 months (blanking period) were classified as early recurrences and were not considered procedural failures Results Six-hundred twenty-four cryoapplications from 112 pts (439 PVs) were analyzed (n=89, 79.5% paroxysmal AF, n=23, 20.5% persistent AF, mean age 61.5±9 years, 76% male, 22% with an history of AT, mean LVEF 49±10%). PVI was achieved in all pts using only cryoablation. The mean number of freeze applications per pt was 5.6±2.1 (1.4±1.2 for LSPV, 1.5±1.1 for LIPV, 1.3±0.8 for RSPV and 1.3±0.8 for RIPV), with 318 (72.4%) PVs treated with a single cryoablation (92, 21% with 2 cryoablation; 29, 6.6% with more than 2 cryoablations). Fourty-four (39.3%) pts were treated with a single application to each of the PVs. Over a median of 296[245 to 382] days of follow-up, five (4.5%) patients experienced an early recurrence of AF/AT during the 90-day blanking period. Overall, 12 patients (10.7%) suffered an AF/AT recurrence after the 90-day blanking period (median time to recurrence 200[124 to 297] days). Specifically, 8 (7.1%) patients had AF recurrence only, 3 (2.7%) had AT recurrence only and 1 (0.9%) experienced both events. One (0.9%) patient underwent a repeated ablation procedure. The proportion of patients exhibiting AF/AT recurrences was similar between AF types (10 out 89, 11.2% for paroxysmal AF vs 2 out 23, 8.7% for persistent AF, p=1.00) with a hazard ratio of 0.9 (95%CI: 0.2 to 3.9, log-rank p=0.8894). One transient phrenic nerve palsy was observed, with full recovery in the 48-h post procedure; no major procedure-related adverse events were reported. Conclusion In this first multicentric experience, the novel cryo-balloon system proved to be safe and effective and resulted in a very low rate of AF/AT recurrence during follow-up.

Intra-procedural three-dimensional rotational angiography in cryoballoon ablation of atrial fibrillation - a randomised clinical trial

Abstract Funding Acknowledgements Type of funding sources: None. Introduction To facilitate atrial fibrillation (AF) ablation procedures there is a variety of approaches for pre-procedural imaging of pulmonary veins (PV) and left atrium (LA), including CT angiography and cardiac MRI. Intra-procedural three-dimensional rotational angiography (3DRA) is the least employed method and it can be advantageous regarding efficiency and procedural logistics. Data supporting different practices is still evolving and there is an open question whether LA imaging could improve safety and outcomes of CB ablation. Purpose The aim of this study is to evaluate possible benefits of 3DRA for procedural success, safety and long-term outcomes of CB ablation. Methods We designed a single-centre unblinded randomised clinical trial and recruited 101 patients (65.3% male, 59.3±11.5 years) with paroxysmal (92%) and early-persistent AF. Patients were randomized to no imaging or 3DRA which was performed intra-procedurally after trans-septal puncture. Angiographic images were segmented and overlaid to the fluoroscopy screen to guide the ablation procedure. All patients are followed for 1 year and data concerning procedural characteristics, safety outcomes and AF recurrence are being collected. Results Of all the patients recruited, 48 (47%) underwent 3DRA. In patients who received no imaging (non-3DRA group) one PV couldn’t be isolated while in 3DRA group isolation of one PV could not be achieved in 3 patients (OR 3.47, 95% CI 0.35-34.51). The occurrence of left common PV, an anatomical variation that could have potential to influence results, was similar in both groups (25,4% in non-3DRA and 25.0% in 3DRA group). Procedure time was significantly longer when 3DRA was performed (87.4±27.7 min compared to 69.9±23.0 in non-3DRA group, p&amp;lt;0.001). Total radiation dose (148.2±177.7 vs 387.7±203.8 mGy, p&amp;lt;0.001) and contrast administration (42.5±27.1 vs 133.8±26.8 ml, p&amp;lt;0.001) were significantly lower in the control group. Only minor complications were reported in both groups. Three patients developed large haematoma (2 in 3DRA group vs 1 in control group). In each group there was one incident of transient phrenic nerve palsy. Conclusion 3DRA is a safe and efficient intra-procedural imaging method to guide CB ablation for AF. However, it significantly increases procedure duration, total radiation dose and contrast expenditure. In our trial it did not have any impact on the acute success rate of PV isolation. One-year follow up data is still being collected and will subsequently be presented.

Initial clinical experience of pulmonary vein isolation using the ultra-low temperature cryoablation catheter for patients with atrial fibrillation.

The iCLAS ultra-low temperature cryoablation (ULTC) system has recently been brought to the market. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation in atrial fibrillation (AF) ablation. The use of an esophageal warming balloon is recommended when using the system to reduce the potential for collateral esophageal injury. To describe the initial clinical experience when using ULTC in the AF treatment without general anesthesia (GA). Consecutive patients undergoing AF ablation using ULTC under deep sedation without GA were enrolled. We assessed the procedural data focusing on "single-shot isolation" defined as successful pulmonary vein (PV) isolation after the first application. Esophagogastroduodenoscopy was systematically performed the day after ablation. A total of 27 AF patients (67% paroxysmal AF) were analyzed. Onehundredfour out of 106 PVs (98.1%) were isolated solely using ULTC. The mean procedure time was 79 ± 30 min. The mean number of applications per PV was 2.6 ± 1.0. Single-shot isolation was achieved in 57 PVs (54%) varying across PVs from left superiorto inferior PVs (40%-64%). The single procedure 6-month recurrence-free rate was 84%. No major complication (cerebrovascular event, pericardial effusion/tamponade, esophageal damage on esophagogastroduodenoscopy) occurred. A single transient phrenic nerve palsy occurred during the right superior PV ablation, which had recovered by the 3-month follow-up appointment. AF ablation using the novel ULTC system seemed feasible without GA and enabled a >50% single-shot isolation rate. The promising safety profile has to be confirmed in large-scalestudies.

Feasibility of Video-Assisted Thoracoscopic Surgery via Subxiphoid Approach in Anterior Mediastinal Surgery: A Meta-Analysis.

BackgroundAccumulating researches show potential advantages of video-assisted thoracoscopic surgery (VATS) via the subxiphoid approach, and this meta-analysis aims to investigate the efficacy and safety of the subxiphoid approach for anterior mediastinal surgery.MethodsRelevant studies were retrieved by searching Embase and PubMed databases (from the inception to October 1, 2021). Primary outcomes included postoperative pain, intraoperative blood loss, operation time, chest tube duration, and hospital length of stay. All meta-analyses were performed by using random-effects models.ResultsOverall, 14 studies with 1,279 patients were included, with 504 patients undergoing anterior mediastinal surgery via subxiphoid approach and 775 via other approaches. The pooled results indicated that the subxiphoid approach was associated with reduced postoperative pain indicated by visual analog scale [weight mean difference (WMD): 24 h: −2.27, 95% CI, −2.88 to −1.65, p < 0.001; 48–72 h: −1.87, 95% CI, −2.53 to −1.20, p < 0.001; 7 days: −0.98, 95% CI, −1.35 to −0.61, p < 0.001], shortened duration of chest tube drainage (WMD: −0.56 days, 95% CI, −0.82 to −0.29, p < 0.001), shortened hospital length of stay (WMD: −1.46 days, 95% CI, −2.28 to −0.64, p < 0.001), and reduced intraoperative blood loss (WMD: −26.44 mL, 95% CI, −40.21 to −12.66, p < 0.001) by comparison with other approaches in anterior mediastinal surgery. Besides, it has no impact on operation time and the incidence of complications of transition to thoracotomy, postoperative pleural effusion, phrenic nerve palsy, and lung infection.ConclusionsOur study suggests that the subxiphoid approach is a feasible alternative approach and even can be a better option for anterior mediastinal surgery. Further, large-scale multicenter randomized controlled trials are needed to validate this finding.

PO-695-08 PULMONARY VEIN ISOLATION (PVI) AND POSTERIOR WALL ISOLATION (PWI) FOR ATRIAL FIBRILLATION USING POINT-BY-POINT PULSED ELECTRIC FIELDS: SPACE AF ACUTE RESULTS

Pulsed electrical field (PEF) has been used for pulmonary vein isolation (PVI). The CENTAURI System enables PEF ablation via standard contact force ablation catheters. The point-by-point clinical workflow may enable treatment beyond PVI, including posterior wall isolation (PWI). SPACE AF study is evaluating feasibility and safety of PVI with PWI using PEF in patients with high burden paroxysmal and persistent AF. CENTUARI PEF System (Galaxy Medical) and a focal contact force sensing catheter (ThermoCool ST, Biosense Webster) were used for PEF ablation for wide antral PVI with PWI. Operators chose one of three doses (19A, 22A, 25A) with contact force of >5g. Primary efficacy outcome was entrance/exit block of all pulmonary veins (PVs) after a 20-minute wait. Composite safety endpoint comprised of pre-specified adverse events including microbubble formation on intracardiac echo (ICE), ST-segment changes, phrenic nerve palsy, esophageal temperature rises, NIH stroke scale (NIHSS) changes, PV stenosis, and silent cerebral lesions after PEF ablation. CT of the PVs will be done at 3 months. Cranial MRI was done at 24 hours in a subset of patients. Secondary endpoint includes recurrence of AF post-ablation at 6 and 12 months with serial Holter monitoring. SPACE AF will report on 30 patients. Thus far, 12 patients (58% Male, age 55.8±10.5 years) have been treated. Acute PVI and PWI was achieved in all 12 patients (100%). An average of 113.8±12.1 applications were delivered per patient. Energy settings were 32% at 22A and 68% at 25A. There were no ST-segment changes, microbubble formations, phrenic nerve injuries, or esophageal temperature rises during PEF ablation. There were no changes to NIHSS pre- vs. post-procedure. Three (3) patients have participated in the cranial MRI sub-study, and all had negative DWI and FLAIR post-procedure. No patients experienced procedure- or device-related AEs at 30 days. PV anatomy will be assessed at 90 days. Long-term AF recurrence outcomes will be assessed at 6-month and 12-month follow-up via 48-hour Holter. Cardiac ablation using PEF delivered through standard focal catheters is safe and acutely successful when performing PWI after PVI. Further results on additional patients and AF recurrence will be presented.

CA-536-01 PULSED-FIELD ABLATION BASED PULMONARY VEIN ISOLATION: ACUTE SAFETY AND EFFICACY IN A MULTI-CENTER REAL WORLD SCENARIO

Pulsed-field ablation (PFA) is a new energy source to perform pulmonary vein isolation (PVI) by targeted electroporation of cardiomyocytes. Integrated into a single-shot device, PFA has the potential to increase efficacy and safety of PVI compared to thermal energy sources. To assess feasibility, efficacy and safety of PFA for index PVI in a multi-center real world setting. Consecutive patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) underwent PVI using the PFA ablation catheter (Farawave®, Farapulse Inc, Menlo Park, CA, USA) at two high-volume ablation centers. The left atrium was accessed by a single transseptal puncture and PVs were located by selective PV angiographies. 3D voltage mapping of the left atrium was performed before and after PVI. A total of 110 patients (mean age 67±12 years, 62% male, 61% persistent AF) were included. PVI was achieved in all patients by deploying 3567 applications in 435 PVs (8.4±3.1 per vein). Disappearance of PV signals after the first of eight applications was demonstrated in 433/435 PVs (99%). More than eight PFA applications were applied in 23/435 PVs (0.5%) due to difficulties in positioning (3x left superior PV, 7x right superior PV, 7x right inferior PV) or due to reconnection after remapping (2x LIPV, 3x RSPV, 1x RIPV). Mean procedure time was 81±23 minutes including pre- and post PVI high-density voltage mapping. PF catheter left atrial dwell-time was 27±10 min. Left atrial dwell-time reduced from 40 to 24 min during the first 50 procedures at UHZ. Total fluoroscopy time was 16.6±9.2 minutes with a dose area product of 749±79 cGy*cm2. One pericardial tamponade occurred independent of PFA applications and two minor groin complications. No other complications occurred, especially no phrenic nerve palsy, stroke, hemoptysis, atrio-oesophageal fistula or acute symptomatic PV stenosis. In this multi-center real world setting, pulsed field ablation achieves effective pulmonary vein isolation with low complication rates.