Real-World Data of Radiofrequency Catheter Ablation in Paroxysmal Atrial Fibrillation: Short- and Long-term Clinical Outcomes from the Prospective Multicenter REAL-AF Registry.

BACKGROUND: The safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. OBJECTIVE: We aim to assess the contemporary real-world practice approach and long-term outcomes of RF-CA for PAF through a prospective multicenter registry. METHODS: Using the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; NCT04088071) registry, patients undergoing RF-CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380-420 for posterior and 500-550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. RESULTS: A total of 2,470 patients undergoing CA of registry from January 2018 to December 2022 were included. The mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedure and total RF times of 95.4±41.7 and 22.1±11.8 min, respectively. At one-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing PVI vs. PVI+ ablation approaches. The complication rate was 1.9%. CONCLUSIONS: Refinement of RF-CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows, resulted in excellent short and long-term clinical outcomes.

High-Frequency Low-Tidal Volume Ventilation Improves Long-Term Outcomes in AF Ablation: A Multicenter Prospective Study.

BACKGROUND: High-frequency, low-tidal-volume (HFLTV) ventilation is a safe and simple strategy to improve catheter stability and first-pass isolation during pulmonary vein (PV) isolation. However, the impact of this technique on long-term clinical outcomes has not been determined. OBJECTIVES: This study sought to assess acute and long-term outcomes of HFLTV ventilation compared with standard ventilation (SV) during radiofrequency (RF) ablation of paroxysmal atrial fibrillation (PAF). METHODS: In this prospective multicenter registry (REAL-AF), patients undergoing PAF ablation using either HFLTV or SV were included. The primary outcome was freedom from all-atrial arrhythmia at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and hospitalizations at 12 months. RESULTS: A total of 661 patients were included. Compared with those in the SV group, patients in the HFLTV group had shorter procedural (66 [IQR: 51-88] minutes vs 80 [IQR: 61-110] minutes; P < 0.001), total RF (13.5 [IQR: 10-19] minutes vs 19.9 [IQR: 14.7-26.9] minutes; P < 0.001), and PV RF (11.1 [IQR: 8.8-14] minutes vs 15.3 [IQR: 12.4-20.4] minutes; P < 0.001) times. First-pass PV isolation was higher in the HFLTV group (66.6% vs 63.8%; P = 0.036). At 12 months, 185 of 216 (85.6%) in the HFLTV group were free from all-atrial arrhythmia, compared with 353 of 445 (79.3%) patients in the SV group (P = 0.041). HLTV was associated with a 6.3% absolute reduction in all-atrial arrhythmia recurrence, lower rate of AF-related symptoms (12.5% vs 18.9%; P = 0.046), and hospitalizations (1.4% vs 4.7%; P = 0.043). There was no significant difference in the rate of complications. CONCLUSIONS: HFLTV ventilation during catheter ablation of PAF improved freedom from all-atrial arrhythmia recurrence, AF-related symptoms, and AF-related hospitalizations with shorter procedural times.

Steerable sheath visualizable under 3D electroanatomical mapping facilitates paroxysmal atrial fibrillation ablation with minimal fluoroscopy.

BACKGROUND: Advances in technology and workflows have facilitated substantial reductions in fluoroscopy utilization and procedure times for atrial fibrillation (AF) ablations. A recently available steerable sheath, visualizable on a 3D electroanatomical map (EAM), may further simplify low/zero fluoroscopy ablation workflows by facilitating understanding of the relative positions of the catheter and sheath. The objective of this study was to demonstrate feasibility, safety, procedural efficiency, and clinical effectiveness of incorporating the new visualizable sheath into a low-fluoroscopy workflow. METHODS: Consecutive de novo paroxysmal AF procedures were performed with a porous tip contact force catheter at a high-volume site between January 2018 and May 2019. Procedures performed with and without the VIZIGO™ EAM-visualizable sheath (Vizigo) were compared. All ablations employed the same standardized low-fluoroscopy workflow. Statistical analyses employed stabilized inverse probability of treatment weights (IPTW) to balance cohorts by operator and key patient characteristics. RESULTS: Cohorts of 142 Vizigo and 173 non-Vizigo patients were similar at baseline. Use of the Vizigo sheath was associated with approximately 10% improvement in catheter stability (p = 0.0005), 16% reduction in radiofrequency time (p < 0.0001), and 7% fewer ablations that used fluoroscopy (p = 0.0030). There was one cardiac tamponade in each cohort and no deaths, atrioesophageal fistulas, or strokes. Single-procedure freedom from atrial arrhythmia recurrence through 12 months was similar between cohorts (p = 0.9556). CONCLUSIONS: Use of a 3D EAM-visualizable sheath resulted in improved catheter stability, reduced radiofrequency time, and more procedures performed without fluoroscopy, without compromise to safety or effectiveness.

Mortality and morbidity in patients with atrial fibrillation and liver cirrhosis.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice. However, the outcomes associated with AF in hospitalized patients with liver cirrhosis are unknown. AIM: To determine the outcomes of hospitalized patients with liver cirrhosis and AF. METHODS: In this study, we examined morbidity and mortality of patients with concomitant AF and liver cirrhosis from the National Inpatient Sample database, the largest publicly available inpatient healthcare database in the United States. RESULTS: A total of 696937 patients with liver cirrhosis were included, 45745 of whom had concomitant AF (6.6%). Liver cirrhosis patients with AF had higher rates of in-hospital mortality (12.6% vs 10.3%, P < 0.001), clinical stroke (1.6% vs 1.1%, P < 0.001), and acute kidney injury (28.2% vs 25.1%, P < 0.001), and less gastrointestinal bleeding (4.4% vs 5.1%, P < 0.001) and blood transfusion (22.5% vs 23.8%, P < 0.001) compared with those who did not have the arrhythmia. In addition, they had a longer length of stay (8 ± 10 d vs 7 ± 8 d, P < 0.001) and higher hospitalization costs (20720 ± 33210 $ vs 16272 ± 24166 $, P < 0.001). CONCLUSION: In subjects with liver cirrhosis, AF is associated with higher rates of inpatient mortality, stroke, and acute kidney injury compared to those who do not have the cardiac arrhythmia.

Single incision technique for implantation of subcutaneous implantable cardioverter defibrillators.

BACKGROUND: Subcutaneous implantable cardioverter defibrillators (S-ICDs) have gained increasing popularity because of certain advantages over transvenous ICDs. However, while conventional ICDs require a single surgical incision to implant, S-ICDS need two or three incisions, making them less appealing. OBJECTIVE: This study sought out to investigate the feasibility of using a single-incision technique to implant S-ICDs. METHODS: Patients qualifying for S-ICDs were considered for a single incision. A single incision is performed by making a left inframammary incision and then the subcutaneous tissue is dissected medially toward the lower sternum. Two sutures are placed in the fascia in the xiphoid area to anchor the lead and a tunneling tool is used to dissect the tissue to place the lead parallel to the sternum. Then subcutaneous tissues are dissected down the lateral chest wall over the muscle fascia to create the pulse generator pocket in the vicinity of the fifth and sixth intercostal spaces and near the mid-axillary line. RESULTS: Eleven patients (six males and five females) successfully underwent S-ICD implantation with a single incision without acute complications (64% for primary prevention). The mean age is 47.4 ± 15.8 years. There were no lead dislodgements, inappropriate shocks, or any other issues during a median follow-up of 10 months (interquartile range 5-17). One patient had a successful appropriate shock for ventricular fibrillation about one year after device implant. CONCLUSIONS: A single incision for subcutaneous ICDs is feasible and safe in our early experience.

When a Pseudo-Infarct Electrocardiogram (ECG) Pattern in a Posterior Accessory (Wolff-Parkinson-White) Pathway Masks a True Inferior Infarct.

BACKGROUND Wolff-Parkinson-White (WPW) pattern is due to a pre-excitation leading to characteristic ECG changes in sinus rhythm as short PR interval, the presence of delta waves, wide QRS complexes, and potentially Q wave-T wave vector discordance (pseudo-infarct pattern). These later changes can mask the underlying ECG depolarizing solely through the His-Purkinje system. Our case highlights how the ECG of a WPW pattern with a pseudo-infarct pattern can in fact mask a true infarct on the underlying ECG without pre-excitation. CASE REPORT A 61-year-old diabetic man with a recent history of supra-ventricular tachycardia (SVT) presented with the ECG characteristic of a Wolff-Parkinson-White pattern i-e short PR interval of 0.10 s (<0.12 s) and the presence of delta waves in sinus rhythm. In addition, there was a wide significant Q wave in the inferior leads meeting the criteria for significant and pathologic Q waves, related to the pre-excitation and known as a pseudo-infarct pattern. The patient underwent successful ablation of his left inferoseptal accessory pathway. The pre-excitation pattern (short PR and delta wave) disappeared after successful ablation revealed a narrower Q wave in inferior leads, likely from unexpected true old inferior infarction, which was later confirmed by 2D echocardiogram and nuclear stress test (fixed inferior defect). CONCLUSIONS The presence of pseudo-infarct pattern due to a WPW does not always preclude the presence of underlying true infarct pattern, especially in the presence of coronary artery disease risk factors.

Single Day Observational Experience at High Volume Ablation Programs: What is the Impact to Practicing Electrophysiologists?

INTRODUCTION: Significant improvements in catheter technology, electro-anatomic (EA) mapping and techniques to reduce fluoroscopy during radiofrequency ablation (RFA) of atrial fibrillation (AF) are on-going.However, few educational opportunities are available post fellowship for Electrophysiologists (EPs) to understand and integrate them into their practice, preventing wide spread adoption. The impact of observational learning for adoption of new technologies and techniques in the field of cardiac electrophysiology has not been studied. We sought to report the impact of a visit to a high-volume center with experience in new technologies and fluoroscopy reductionto the clinical practice of EPs. METHODS: Between 8/2014 and 10/2017 a total of 150 EPs visited 3 hospitals that perform a high volume of AF RFAs. EPs observed a minimum of 4 RFAs, primarily AF. AF RFAs were performed without fluoroscopy, using Carto 3 Version 4 (Biosense Webster) and intracardiac Echocardiography. There was ample interaction and discussion between hosting and visiting EP. RESULTS: 73 EPs (48.6% of visitors) completed an electronic survey after the visit. The majority reported a significant reduction in fluoroscopy (>50%) and procedure (>20%).68% adopted a rigorous workflow and reported an increase in their confidence level with intracardiac echo (79%), continuous mapping (52%) and the Visitag module (61%). CONCLUSIONS: Observational experience can have an immense impact on the clinical practice of EPs. Further effort should be devoted to such programs and to study in a more systematic way their ultimate impact on patient care.

Colchicine for prevention of post-cardiac procedure atrial fibrillation: Meta-analysis of randomized controlled trials.

BACKGROUND: Development of atrial fibrillation after certain cardiac procedures is a common medical problem. The inflammatory process plays an important role in the pathogenesis of post-cardiac procedure atrial fibrillation (PCP-AF). Colchicine, a potent anti-inflammatory agent, has been used in several studies to reduce the risk of PCP-AF. This meta-analysis of randomized controlled trials (RCTs) was conducted to assess the efficacy of colchicine in prevention of PC-PAF. METHODS: We searched PubMed, EMBASE, Web of Science, Cochrane Library database and Google Scholar for RCTs, using terms "Atrial fibrillation, atrial, or fibrillation and colchicine". The primary end-point was the occurrence of AF post cardiac procedure, which includes cardiac surgery or pulmonary vein isolation. The safety end point was the occurrence of any side effects. Estimated odds ratios (OR) and 95% confidence intervals (CI) were evaluated. RESULTS: A total of six RCTs were included in this meta-analysis, enrolling a total of 1257 patients. Colchicine significantly reduced the odds of PCP-AF (OR 0.52; 95% CI, 0.40-0.68, P<0.001, I2=0%). However, occurrence of side effects was significantly higher with colchicine when compared to placebo (OR 2.10; 95% CI, 1.34-3.30, P<0.001, I2=0%). The number needed to treat is 7 and the number needed to harm is 11.2. The proportion of patients discontinuing treatment was 16%. CONCLUSION: This meta-analysis shows that colchicine is an effective drug for prevention of PCP-AF. Colchicine could be considered as a prophylaxis to reduce PCP-AF, with some risk of treatment discontinuation due to the poor gastrointestinal tolerance (diarrhea).

The Effects of Catheter Ablation on Permanent Pacemakers and Implantable Cardiac Defibrillators.

Catheter ablation is a procedure that is frequently performed in patients with cardiac implantable electronic devices. Here, we review all of the potential interactions that can occur among patients undergoing catheter ablation while having implantable cardiac electronic devices, and discuss the precautionary measures to minimize such interactions.

Regional Lack of Consistency in the Management of Atrial Fibrillation (from the RECORD-AF Trial).

American and European society guidelines for atrial fibrillation management mostly agree on the utilization of rate and rhythm control strategies and the indications for oral anticoagulant (OAC) use. However, the level of adherence to guidelines in clinical practice may vary by region. In this study, data analysis from The Registry on Cardiac rhythm disorders assessing the control of Atrial Fibrillation (RECORD-AF) registry, an international registry in patients with newly diagnosed atrial fibrillation of <1 year, shows that differences in practice exist between 3 regions, namely Western Europe, Eastern Europe, and North America. Data analyzed included major cardiovascular outcomes at 12 months, choice of rhythm versus rate control strategy and the use of OAC according to CHADS2 score between regions, and the cost incurred according to management strategy. In conclusion, there is preference for rhythm control strategy in Europe compared to North America without a significant impact on major cardiovascular outcomes; there is significant discrepancy in the use of OAC in Eastern Europe compared to the 2 other regions; and rate control was found to be more costly in all regions.

Radiofrequency and Cryo-Ablation Effect on Transvenous Pacing and Defibrillatory Lead Integrity: An In Vitro Study.

INTORDUCTION: Medical societies and cardiac implantable electronic device (CIED) manufacturers recommend avoiding close or direct contact between the body of transvenous leads and ablation catheters used to treat cardiac arrhythmias. These recommendations are made despite the lack of clinical studies. However, the target myocardium for successful ablation can be contiguous to CIED leads. METHODS AND RESULTS: We examine in vitro the effects of direct application of radiofrequency (RF) and cryo-ablation energy on the integrity and functionality of CIED leads (excluding the pacing electrodes and defibrillation coils). A saline bath was created to mimic the body milieu. CIED leads, including all commercially available lead insulation materials, were connected to a CIED pulse generator and placed in direct contact with an ablation catheter in the tissue bath. RF and cryo-ablation energy were delivered under various conditions, including maximal ablation power, temperature, and impedance via the RF generator. CIED lead functionality, reflective of conductor integrity, was evaluated through lead impedance monitoring during ablation. CIED leads were then visually inspected, and examined with optic and electron microscopy as per protocol. A total of 42 leads were studied. All leads showed the absence of insulation damage at the site of ablation visually and with microscopy. Lead functionality was also preserved in all leads. CONCLUSION: Catheter ablation in contact with CIED leads using radiofrequency or cryo-ablation in vitro did not affect lead body integrity and function despite aggressive ablation settings. It may be reasonable to perform ablation in contact with the body of CIED leads when clinically necessary.

Interference between dental electrical devices and pacemakers or defibrillators: results from a prospective clinical study.

BACKGROUND: The authors aimed to determine whether electrical dental devices would interfere with the function of cardiac pacemakers or implantable cardioverter defibrillators (ICDs) in humans. METHODS: The authors exposed asymptomatic nonpacemaker-dependent patients to commonly used electrical dental equipment (for example, battery-operated curing lights, ultrasonic baths, ultrasonic scalers, electric pulp testers, and electric toothbrushes) in an outpatient cardiology clinic. The authors operated dental devices at various distances and programmed cardiac devices to sense and pace. The authors obtained cardiac tracings using a cardiac programming unit and a cardiac provider who noted any interference interpreted the results in real time. RESULTS: The authors enrolled 32 consecutive patients and tested 12 pacemakers and 20 ICDs. They did not observe any significant clinical interference in sensing and pacing functions in any patient; however, they noted minor interference without clinical impact in the telemetry from the cardiac programming unit during use of the ultrasonic scaler and bath. CONCLUSIONS: The findings of this prospective study suggest that electrical devices commonly used in dental practices do not interfere with the sensing and pacing of contemporary cardiac patients' pacemakers or ICDs. However, they do interfere with the telemetry from the cardiac programming unit, without any clinical impact on patient safety. These findings should help in the development of clinical guidelines regarding dental management of patients with pacemakers or ICDs. PRACTICAL IMPLICATIONS: Electrical dental devices (for example, ultrasonic baths, ultrasonic scalers) induced minor interference with programmers that interrogate cardiac devices implanted in patients; however, overall, dental devices do not appear to interfere with pacemakers' and defibrillators' pacing and sensing function.

Adenosine testing in atrial flutter ablation: unmasking of dormant conduction across the cavotricuspid isthmus and risk of recurrence.

BACKGROUND: Adenosine-induced hyperpolarization may identify pulmonary veins at risk of reconnection following electrical isolation for atrial fibrillation. The potential role of adenosine testing in other arrhythmic substrates, such as cavotricuspid isthmus (CTI)-dependent atrial flutter, remains unclear. We assessed whether dormant conduction across the CTI may be revealed by adenosine after ablation-induced bidirectional block, and its association with recurrent flutter. METHODS AND RESULTS: Patients undergoing catheter ablation for CTI-dependent flutter were prospectively studied. After confirming bidirectional block across the CTI by standard pacing maneuvers, adenosine (≥ 12 mg IV) was administered to assess resumption of conduction, followed by isoproterenol (ISP) bolus. Further CTI ablation was performed for persistent (but not transient) resumption of conduction. Bidirectional block across the CTI was achieved in all 81 patients (63 males), age 61.2 ± 11.0 years. The trans-CTI time increased from 71.9 ± 18.1 milliseconds preablation to 166.2 ± 26.4 milliseconds postablation. Adenosine elicited resumption of conduction across the CTI in 7 patients (8.6%), 2 of whom had transient recovery. No additional patient with dormant conduction was identified by ISP. Over a follow-up of 11.8 ± 8.0 months, atrial flutter recurred in 4 (4.9%) patients, 3/7(42.9%) with a positive adenosine challenge versus 1/74 (1.3%) with a negative response, P = 0.0016 (relative risk 31.7). CONCLUSION: Adenosine challenge following atrial flutter ablation provoked transient or persistent resumption of conduction across the CTI in almost 9% of patients and identified a subgroup at higher risk of flutter recurrence. It remains to be determined whether additional ablation guided by adenosine testing during the index procedure may further improve procedural outcomes.

Inside-out access: a new method of lead placement for patients with central venous occlusions.

BACKGROUND: Physicians will increasingly encounter patients who require rhythm management devices but have venous obstructions that prevent conventional access. Alternate access options, such as thoracotomy or transiliac approaches, exist but are associated with greater cost and morbidity. OBJECTIVE: The purpose of this study is to describe a novel method of vascular access that allows prepectoral placement of conventional pacing and defibrillation leads in patients with complex central venous occlusions. METHODS: Eight patients with central venous occlusions were referred for device implantation. Inside-out central venous access (IOCVA) was obtained via a percutaneous femoral approach. A catheter-dilator system was advanced via the right atrium to the most central point of venous occlusion. The occluded vein segment was punctured with a directionally guided needle, which was advanced along intravascular or extravascular tissue planes to the subclavian region. A solid wire needle was oriented toward the skin surface and advanced through the soft tissues until it exists from the body. The wire was used to pull rigid dilators through the occluded segment. Standard transvenous leads were implanted though the newly created channel. RESULTS: All patients with total central venous occlusions (4 superior vena cava, 4 brachiocephalic and bilateral subclavian) had successful, prepectoral device implants (4 left-sided, 1 single-chamber, 4 dual-chamber, 3 biventricular). No procedure-related complications occurred. All patients had normal device function at follow-up of 485 ± 542 days. CONCLUSION: IOCVA is an effective method of pacemaker and defibrillator implantation for patients with central venous occlusions. Further clinical evaluation of this novel method is needed.