Isolation of the superior vena cava by ultra-low temperature cryoablation.

A patient with shocks from his ICD related to AF underwent redo ablation. The only identifiable target was the superior vena cava. This was isolated using ultra-low cryotherapy, eliminating episodes of AF.

Optimizing transseptal puncture guided by three-dimensional mapping: the role of a unipolar electrogram in a needle tip.

AIMS: A three-dimensional electroanatomic mapping system-guided transseptal puncture (3D-TSP), without fluoroscopy or echocardiography, has been only minimally reported. Indications for 3D-TSP remain unclear. Against this background, this study aims to establish a precise technique and create a workflow for validating and selecting eligible patients for fluoroless 3D-TSP. METHODS AND RESULTS: We developed a new methodology for 3D-TSP based on a unipolar electrogram derived from a transseptal needle tip (UEGM tip) in 102 patients (the derivation cohort) with intracardiac echocardiography (ICE) from March 2018 to February 2019. The apparent current of injury (COI) was recorded at the muscular limbus of the foramen ovalis (FO) on the UEGM tip (sinus rhythm: 2.57 ± 0.95 mV, atrial fibrillation: 1.92 ± 0.77 mV), which then disappeared or significantly reduced at the central FO. Changes in the COI, serving as a major criterion to establish a 3D-TSP workflow, proved to be the most valuable indicator for identifying the FO in 99% (101/102) of patients compared with three previous techniques (three minor criteria) of reduction in atrial unipolar or bipolar potential and FO protrusion. A total of 99.9% (1042/1043) patients in the validation cohort underwent successful 3D-TSP through the workflow from March 2019 to July 2023. Intracardiac echocardiography guidance was required for 6.6% (69/1042) of patients. All four criteria were met in 740 patients, resulting in a 100% pure fluoroless 3D-TSP success rate. CONCLUSION: In most patients, fluoroless 3D-TSP was successfully achieved using changes in the COI on the UEGM tip. Patients who met all four criteria were considered suitable for 3D-TSP, while those who met none required ICE guidance.

Multi-catheter cryotherapy for the treatment of resistant accessory pathways.

OBJECTIVE: To investigate the utility of simultaneous multi-catheter cryotherapy for the treatment of APs that were previously resistant to standard radiofrequency (RF) catheter ablation. BACKGROUND: Catheter ablation is established in the treatment of accessory pathways (AP), with high rates of permanent procedural success with a single attempt. However, there are still instances of acute procedural failure and AP recurrences with standard RF and cryotherapy methods. METHODS: Seven consecutive cases of pre-excitation syndromes with prior failed RF catheter ablation had the novel treatment. Cryotherapy was delivered using two 8 mm tip focal cryoablation catheters (Freezor® Max, Medtronic, Minneapolis, Minnesota, USA). RESULTS: Accessory pathway localisation was septal in 5 cases, left posterolateral in 1, right lateral in 1. In all cases, ablation of the AP was acutely successful with no procedural complications. Median procedure and fluoroscopy durations were 199 and 35 min, sequentially. Median Procedure duration fell significantly in the second half of series (174 min) compared to the first half (233 min, P = 0.05). One patient had evidence of a recurring AP conduction with pre-excitation at 5-week follow up. After a median follow up of 66.8+-6.5 months, 6 out of 7 patients remained asymptomatic and free of pre-excitation. CONCLUSION: Simultaneous multi-catheter cryotherapy is feasible, safe and can provide definitive cure of accessory pathways that were previously resistant to standard radiofrequency ablation. Further study is required in the assessment of this novel form of advanced cryotherapy to treat complex and resistant arrhythmias.

Transvenous lead extraction: Experience of the Tandem approach.

AIMS: Transvenous lead extraction (TLE) is important in the management of cardiac implantable electronic devices but carries risk. It is most commonly completed from the superior access, often with 'bail-out' support via the femoral approach. Superior and inferior access may be used in tandem, which has been proposed as an advance in safety and efficacy. The aim of this study is to evaluate the safety and efficacy of the Tandem approach. METHOD: The 'Tandem' procedure entailed grasping of the targeted lead in the right atrium to provide countertraction as a rotational dissecting sheath was advanced over the lead from the subclavian access. Consecutive 'Tandem' procedures performed by a single operator between December 2020 and March 2023 in a single large-volume TLE centre were included and compared with the conventional superior approach (control) using 1:1 propensity score matching; patients were statistically matched for demographics. RESULTS: The Tandem in comparison with the conventional approach extracted leads of much greater dwell time (148.9 ± 79 vs. 108.6 ± 77 months, P < 0.01) in a shorter procedure duration (96 ± 36 vs. 127 ± 67 min, P < 0.01) but requiring more fluoroscopy (16.4 ± 10.9 vs. 10.8 ± 14.9 min, P < 0.01). The Tandem and control groups had similar clinical (100% vs. 94.7%, P = 0.07) and complete (94.8% vs. 92.8%, P = 0.42) success, with comparable minor (4% vs. 6.7%, P = 0.72) and major (0% vs. 4%, P = 0.25) complications; procedural (0% vs. 1.3%, P = 1) and 30-day (1.3% vs. 4%, P = 0.62) mortality were also similar. CONCLUSION: The Tandem procedure is as safe and effective as the conventional TLE. It can be applied to leads of a long dwell time with a potentially shorter procedure duration.

Progress in Cardiac Resynchronisation Therapy and Optimisation.

Cardiac resynchronisation therapy (CRT) has become the cornerstone of heart failure (HF) treatment. Despite the obvious benefit from this therapy, an estimated 30% of CRT patients do not respond ("non-responders"). The cause of "non-response" is multi-factorial and includes suboptimal device settings. To optimise CRT settings, echocardiography has been considered the gold standard but has limitations: it is user dependent and consumes time and resources. CRT proprietary algorithms have been developed to perform device optimisation efficiently and with limited resources. In this review, we discuss CRT optimisation including the various adopted proprietary algorithms and conduction system pacing.

Comparison of non-laser and laser transvenous lead extraction: a systematic review and meta-analysis.

AIMS: Transvenous lead extraction (TLE) is performed using non-laser and laser techniques with overall high efficacy and safety. Variation in outcomes between the two approaches does exist with limited comparative evidence in the literature. We sought to compare non-laser and laser TLE in a meta-analysis. METHODS AND RESULTS: We searched Medline, Embase, Scopus, ClinicalTrials.gov, and CENTRAL databases for TLE studies published between 1991 and 2021. From the included 68 studies, safety and efficacy data were carefully evaluated and extracted. Aggregated cases of outcomes were used to calculate odds ratio (OR), and pooled rates were synthesized from eligible studies to compare non-laser and laser techniques. Subgroup comparison of rotational tool and laser extraction was also performed. Non-laser in comparison with laser had lower procedural mortality (pooled rate 0% vs. 0.1%, P < 0.01), major complications (pooled rate 0.7% vs. 1.7%, P < 0.01), and superior vena cava (SVC) injury (pooled rate 0% vs. 0.5%, P < 0.001), with higher complete success (pooled rate 96.5% vs. 93.8%, P < 0.01). Non-laser comparatively to laser was more likely to achieve clinical [OR 2.16 (1.77-2.63), P < 0.01] and complete [OR 1.87 (1.69-2.08), P < 0.01] success, with a lower procedural mortality risk [OR 1.6 (1.02-2.5), P < 0.05]. In the subgroup analysis, rotational tool compared with laser achieved greater complete success (pooled rate 97.4% vs. 95%, P < 0.01) with lower SVC injury (pooled rate 0% vs. 0.7%, P < 0.01). CONCLUSION: Non-laser TLE is associated with a better safety and efficacy profile when compared with laser methods. There is a greater risk of SVC injury associated with laser sheath extraction.

Transvenous Lead Extraction: Work in Progress.

Cardiac implantable electronic devices are the cornerstone of cardiac rhythm management, with a significant number of implantations annually. A rising prevalence of cardiac implantable electronic devices coupled with widening indications for device removal has fuelled a demand for transvenous lead extraction (TLE). With advancement of tools and techniques, the safety and efficacy profile of TLE has significantly improved since its inception. Despite these advances, TLE continues to carry risk of significant complications, including a superior vena cava injury and mortality. However, innovative approaches to lead extraction, including the use of the jugular and femoral accesses, offers potential for further gains in safety and efficacy. In this review, the indications and risks of TLE are discussed while examining the evolution of this procedure from simple traction to advanced methodologies, which have contributed to a significant improvement in safety and efficacy.

Effect of esophageal cooling on ablation lesion formation in the left atrium: Insights from Ablation Index data in the IMPACT trial and clinical outcomes.

INTRODUCTION: The IMPACT study established the role of controlled esophageal cooling in preventing esophageal thermal injury during radiofrequency (RF) ablation for atrial fibrillation (AF). The effect of esophageal cooling on ablation lesion delivery and procedural and patient outcomes had not been previously studied. The objective was to determine the effect of esophageal cooling on the formation of RF lesions, the ability to achieve procedural endpoints, and clinical outcomes. METHODS: Participants in the IMPACT trial underwent AF ablation guided by Ablation Index (30 W at 350-400 AI posteriorly, 40 W at ≥450 AI anteriorly). A blinded 1:1 randomization assigned patients to the use of the ensoETM® device to keep esophageal temperature at 4°C during ablation or standard practice using a single-sensor temperature probe. Ablation parameters and clinical outcomes were analyzed. RESULTS: Procedural data from 188 patients were analyzed. Procedure and fluoroscopy times were similar, and all pulmonary veins were isolated. First-pass pulmonary vein isolation and reconnection at the end of the waiting period were similar in both randomized groups (51/64 vs. 51/68; p = 0.54 and 5/64 vs. 7/68; p = 0.76, respectively). Posterior wall isolation was also similar: 24/33 versus 27/38; p = 0.88. Ablation effect on tissue, measured in impedance drop, was no different between the two randomized groups: 8.6Ω (IQR: 6-11.8) versus 8.76Ω (IQR: 6-12.2; p = 0.25). Arrhythmia recurrence was similar after 12 months (21.1% vs. 24.1%; 95% CI: 0.38-1.84; HR: 0.83; p = 0.66). CONCLUSIONS: Esophageal cooling has been shown to be effective in reducing ablation-related thermal injury during RF ablation. This protection does not compromise standard procedural endpoints or clinical success at 12 months.

Protecting Against Collateral Damage to Non-cardiac Structures During Endocardial Ablation for Persistent Atrial Fibrillation.

Injury to structures adjacent to the heart, particularly oesophageal injury, accounts for a large proportion of fatal and life-altering complications of ablation for persistent AF. Avoiding these complications dictates many aspects of the way ablation is performed. Because avoidance involves limiting energy delivery in areas of interest, fear of extracardiac injury can impede the ability of the operator to perform an effective procedure. New techniques are becoming available that may permit the operator to circumvent this dilemma and deliver effective ablation with less risk to adjacent structures. The authors review all methods available to avoid injury to extracardiac structures to put these developments in context.

Economic Evaluation of Catheter Ablation Versus Medical Therapy for the Treatment of Atrial Fibrillation from the Perspective of the UK.

Randomised evidence supports an early rhythm control strategy as treatment for AF, and catheter ablation outperforms medical therapy in terms of effectiveness when studied as first- and second-line treatment. Despite evidence consistently showing that catheter ablation treatment is superior to medical therapy in most AF patients, only a small proportion receive ablation, in some cases after a prolonged trial of ineffective medical therapy. Health economics research in electrophysiology remains limited but is recognised as being important in influencing positive change to ensure early access to ablation services for all eligible patients. Such information has informed the updated recommendations from the recently published National Institute for Health and Care Excellence clinical guideline on the diagnosis and management of AF, but increased awareness is needed to drive real-world adoption and to ensure patients are quickly referred to specialists. In this article, economic evaluations of catheter ablation versus medical therapy are reviewed.

New approaches to achieving hemostasis after venous access in cardiovascular patients.

Recent decades have seen a series of advances in percutaneous transvenous procedures for cardiac arrhythmias, including the implantation of leadless pacemakers. Many of these procedures require the insertion of large caliber sheaths in large veins, usually the femoral vein. Securing hemostasis efficiently and reliably at the access site is a key step to improving a procedure's safety profile. Traditionally, hemostasis was achieved by manual compression of venous access sites, but the trend toward larger sheaths and the increased use of uninterrupted anticoagulation has pushed the limits of this method. Achieving hemostasis by compression alone in these circumstances requires more attention and longer duration, leading to greater patient discomfort and prolonged immobility. In turn, manual compression may be more time-consuming for medical professionals and increase the number of occupied hospital beds. New approaches have been developed to facilitate early ambulation, decrease patient discomfort, and address the risk of access site complications. These approaches include vascular closure devices and subcutaneous suture techniques including figureof- eight and purse-string sutures. This article reviews the new approaches applied to achieve venous access site hemostasis in patients undergoing transvenous procedures for cardiac arrhythmias.

Triple access transvenous lead extraction: Pull-through of a lead from subclavian to jugular access to facilitate extraction.

A 39-years old ventricular lead of a right-sided single-chamber pacemaker required extraction for infection. Angulation at the right subclavian-superior vena cava junction coupled with calcified fibrotic encapsulating tissue prevented advancement of a rotational dissecting sheath. To straighten the lead, it was pulled from the subclavian and out of the right internal jugular vein, whilst the Needle's-Eye Snare via the femoral access provided counter-traction. A 13-french rotational dissecting sheath was successfully advanced over the lead via the jugular access to complete the lead extraction without any complication.

Anatomical variations in coronary venous drainage: Challenges and solutions in delivering cardiac resynchronization therapy.

AIMS: To investigate the abnormalities of the coronary venous system in candidates for cardiac resynchronization therapy (CRT) and describe methods for circumventing the resulting difficulties. METHODS: From four implanting institutes, data of all CRT implants between October 2008 and October 2020 were screened for abnormal cardiac venous anatomy, defined as an anatomical variation not conforming to the accepted 'normal' anatomy. Patient demographics, procedural detail, and subsequent left ventricle (LV) lead pacing indices were collected. RESULTS: From a total of 3548 CRT implants, 15 (0.42%) patients (80% male) of 72.2 ± 10.6 years in age with an LV ejection fraction of 34 ± 10.3% were identified to have had an abnormal cardiac venous anatomy over the study period. There were 13 cases of persistent left side superior vena cava (pLSVC), five of which had coronary sinus ostium atresia (CSOA) including two with an "unroofed" coronary sinus (CS); one patient had a unique anomalous origin of the CS and one patient had an isolated CSOA. In total 14 patients (60% repeat attempt) had successful percutaneous implant under general anesthesia (46.7%) via the cephalic vein (59.1%), using the femoral approach (53.3%) for levophase venography and/or pull-through, including one case of endocardial LV implant. Pacing follow-up over 37.64 ± 37.6 months demonstrated LV lead threshold between 0.62 and 2.9 volts (pulsewidth 0.4-1.5 ms) in all cases; five patients died within 2.92 ± 1.6 years of a successful implant. CONCLUSION: CRT devices can be implanted percutaneously even in the presence of substantial abnormalities of coronary venous anatomy. Alternative routes of venous access may be required.

Patient related outcomes of mechanical lead extraction techniques (PROMET) study: A comparison of two professions.

BACKGROUND: With an increasing number of cardiac implantable electronic devices (CIEDs), there has been a paralleled increase in demand for transvenous lead extraction (TLE). Cardiac surgeons (CS) and cardiologists perform TLE; however, data comparing the two groups of operators is scarce. OBJECTIVE: We compared the outcomes of TLE performed by cardiologists and CS from six European lead extraction units. METHOD: Data was collected retrospectively of 2205 patients who had 3849 leads extracted (PROMET) between 2005 and 2018. Patient demographics and procedural outcomes were compared between the CS and cardiologist groups, using propensity score matching. A multivariate regression analysis was also performed for variables associated with 30-day mortality. RESULTS: CS performed the majority of extractions (59.8%), of leads with longer dwell times (90 [57-129 interquartile range (IQR)] vs. 62 [31-102 IQR] months, CS vs. cardiologists, p < .001) and with pre-dominantly non-infectious indications (57.4% vs. 50.2%, CS vs. cardiologists, p < .001). CS achieved a higher complete success per lead than the cardiologists (98.1% vs. 95.7%, respectively, p < .01), with a higher number of minor complications (5.51% vs. 2.1%, p < .01) and similar number of major complications (0.47% vs. 1.3%, p = .12). Thirty-day mortality was similarly low in the CS and cardiologist groups (1.76% vs. 0.94%, p = .21). Unmatched data multivariate analysis revealed infection indication (OR 6.12 [1.9-20.3], p < .01), procedure duration (OR 1.01 [1.01-1.02], p < .01) and CS operator (OR 2.67, [1.12-6.37], p = .027) were associated with 30-day mortality. CONCLUSION: TLE by CS was performed with similar safety and higher efficacy compared to cardiologists in high and medium-volume lead extraction centers.