An approach to help differentiate postinfarct scar from borderzone tissue using Ripple Mapping during ventricular tachycardia ablation.

BACKGROUND: Ventricular scar is traditionally highlighted on a bipolar voltage (BiVolt) map in areas of myocardium <0.50 mV. We describe an alternative approach using Ripple Mapping (RM) superimposed onto a BiVolt map to differentiate postinfarct scar from conducting borderzone (BZ) during ventricular tachycardia (VT) ablation. METHODS: Fifteen consecutive patients (left ventricular ejection fraction 30 ± 7%) underwent endocardial left ventricle pentaray mapping (median 5148 points) and ablation targeting areas of late Ripple activation. BiVolt maps were studied offline at initial voltage of 0.50-0.50 mV to binarize the color display (red and purple). RMs were superimposed, and the BiVolt limits were sequentially reduced until only areas devoid of Ripple bars appeared red, defined as RM-scar. The surrounding area supporting conducting Ripple wavefronts in tissue <0.50 mV defined the RM-BZ. RESULTS: RM-scar was significantly smaller than the traditional 0.50 mV cutoff (median 4% vs. 12% shell area, p < .001). 65 ± 16% of tissue <0.50 mV supported Ripple activation within the RM-BZ. The mean BiVolt threshold that differentiated RM-scar from BZ tissue was 0.22 ± 0.07 mV, though this ranged widely (from 0.12 to 0.35 mV). In this study, septal infarcts (7/15) were associated with more rapid VTs (282 vs. 347 ms, p = .001), and had a greater proportion of RM-BZ to RM-scar (median ratio 3.2 vs. 1.2, p = .013) with faster RM-BZ conduction speed (0.72 vs. 0.34 m/s, p = .001). Conversely, scars that supported hemodynamically stable sustained VT (6/15) were slower (367 ± 38 ms), had a smaller proportion of RM-BZ to RM-scar (median ratio 1.2 vs. 3.2, p = .059), and slower RM-BZ conduction speed (0.36 vs. 0.63 m/s, p = .036). RM guided ablation collocated within 66 ± 20% of RM-BZ, most concentrated around the RM-scar perimeter, with significant VT reduction (median 4.0 episodes preablation vs. 0 post, p < .001) at 11 ± 6 months follow-up. CONCLUSION: Postinfarct scars appear significantly smaller than traditional 0.50 mV cut-offs suggest, with voltage thresholds unique to each patient.

Relationship between sodium channel function and clinical phenotype in SCN5A variants associated with Brugada syndrome.

The identification of a pathogenic SCN5A variant confers an increased risk of conduction defects and ventricular arrhythmias (VA) in Brugada syndrome (BrS). However, specific aspects of sodium channel function that influence clinical phenotype have not been defined. A systematic literature search identified SCN5A variants associated with BrS. Sodium current (INa ) functional parameters (peak current, decay, steady-state activation and inactivation, and recovery from inactivation) and clinical features (conduction abnormalities [CA], spontaneous VA or family history of sudden cardiac death [SCD], and spontaneous BrS electrocardiogram [ECG]) were extracted. A total of 561 SCN5A variants associated with BrS were identified, for which data on channel function and clinical phenotype were available in 142. In the primary analysis, no relationship was found between any aspect of channel function and CA, VA/SCD, or spontaneous BrS ECG pattern. Sensitivity analyses including only variants graded pathogenic or likely pathogenic suggested that reduction in peak current and positive shift in steady-state activation were weakly associated with CA and VA/SCD, although sensitivity and specificity remained low. The relationship between in vitro assessment of channel function and BrS clinical phenotype is weak. The assessment of channel function does not enhance risk stratification. Caution is needed when extrapolating functional testing to the likelihood of variant pathogenicity.

Systematic re-evaluation of SCN5A variants associated with Brugada syndrome.

BACKGROUND: A large number of SCN5A variants have been reported to underlie Brugada syndrome (BrS). However, the evidence supporting individual variants is highly heterogeneous. OBJECTIVE: We systematically re-evaluated all SCN5A variants reported in BrS using the 2015 American college of medical genetics and genomics and the association for molecular pathology (ACMG-AMP) guidelines. METHODS: A PubMed/Embase search was performed to identify all reported SCN5A variants in BrS. Standardized bioinformatic re-analysis (SIFT, PolyPhen, Mutation Taster, Mutation assessor, FATHMM, GERP, PhyloP, and SiPhy) and re-evaluation of frequency in the gnomAD database were performed. Fourteen ACMG-AMP rules were deemed applicable for SCN5A variant analysis. RESULTS: Four hundred and eighty unique SCN5A variants were identified, the majority of which 425 (88%) were coding variants. One hundred and fifty-six of 425 (37%) variants were classified as pathogenic/likely pathogenic. Two hundred and fifty-eight (60%) were classified as variants of uncertain significance, while a further 11 (3%) were classified as benign/likely benign. When considering the subset of variants that were considered "null" variants separately, 95% fulfilled criteria for pathogenicity/likely pathogenicity. In contrast, only 17% of missense variants fulfilled criteria for pathogenicity/likely pathogenicity. Importantly, however, only 25% of missense variants had available functional data, which was a major score driver for pathogenic classification. CONCLUSION: Based on contemporary ACMG-AMP guidelines, only a minority of SCN5A variants implicated in BrS fulfill the criteria for pathogenicity or likely pathogenicity.

Early experience of thoracoscopic vs. catheter ablation for atrial fibrillation.

AIMS: Video-assisted thoracoscopic surgery (VATS) ablation has been advocated as a treatment option for non-paroxysmal atrial fibrillation (AF) in recent guidelines. Real-life data on its safety and efficacy during a centre's early experience are sparse. METHODS AND RESULTS: Thirty patients (28 persistent/longstanding persistent AF) underwent standalone VATS ablation for AF by an experienced thoracoscopic surgeon, with the first 20 cases proctored by external surgeons. Procedural and follow-up outcomes were collected prospectively, and compared with 90 propensity-matched patients undergoing contemporaneous catheter ablation (CA). Six (20.0%) patients undergoing VATS ablation experienced ≥1 major complication (death n = 1, stroke n = 2, conversion to sternotomy n = 3, and phrenic nerve injury n = 2). This was significantly higher than the 1.1% major complication rate (tamponade requiring drainage n = 1) seen with CA (P < 0.001). Twelve-month single procedure arrhythmia-free survival rates without antiarrhythmic drugs were 56% in the VATS and 57% in the CA cohorts (P = 0.22), and 78% and 80%, respectively given an additional CA and antiarrhythmic drugs (P = 0.32). CONCLUSION: During a centre's early experience, VATS ablation may have similar success rates to those from an established CA service, but carry a greater risk of major complications. Those embarking on a programme of VATS AF ablation should be aware that complication and success rates may differ from those reported by selected high-volume centres.

Same-day discharge in selected patients undergoing atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) ablation is a complex procedure, generally requiring at least one overnight hospital stay. We investigated the safety and feasibility of early mobilization and same-day discharge following streamlined peri-ablation management for AF. METHODS: From 2014, we offered same-day discharge to selected patients who underwent uncomplicated AF ablation on the morning lists, with ultrasound-guided femoral access, uninterrupted warfarin or minimal interruption in novel oral anticoagulants, and reversal of intraprocedural heparin with protamine. Patients were discharged 6-8 h postprocedure and offered access to a dedicated nurse helpline. RESULTS: Of 1599 AF ablation cases performed from April 2014 to March 2017, 811 (50.7%) were performed on the morning lists and 169/811 (20.8%) were discharged on the same day. Excluding 26 research cases, 1/143 (0.7%) had transient right phrenic nerve palsy and five (3.5%) cases experienced minor problems that did not preclude same-day discharge; three (2.1%) needed rehospitalization postdischarge: one for pericarditic chest pain and two for nausea/vomiting. Compared to 642 overnight cases, day-case procedures were shorter, more likely to be redos, to be performed under sedation rather than general anesthesia, and less likely to involve linear lesions and electrical cardioversion. There were no significant differences in patient age, gender, body mass index, CHA2 DS2 -VASc, in preprocedural anticoagulation regimen (warfarin vs novel anticoagulants vs no anticoagulation) and in choice of ablation method (cryoballoon vs radiofrequency). CONCLUSIONS: Selective same-day discharge after AF ablation is safe and feasible using a streamlined peri-procedural care protocol. Wider adoption can potentially reduce health-care costs while improving patient experience.

Demonstration of pulmonary vein exit block following pulmonary vein isolation: A novel use for adenosine.

INTRODUCTION: Demonstration of exit block after pulmonary vein isolation (PVI) is the cornerstone of ablation for atrial fibrillation (AF). It requires the demonstration of local pulmonary vein (PV) capture and absence of conduction to the atrium but is often challenging due to the inability to see local paced PV-evoked potentials. We retrospectively examined the ability of adenosine to augment this technique during CARTO-based radiofrequency ablation procedures. METHODS: Retrospective analysis of evoked PV potentials during adenosine administration while testing for PV exit block at a single UK center. RESULTS: One hundred and twenty-nine PVs in 33 patients were isolated using radiofrequency energy to demonstrate entry block. Of those, the pacing of 24 veins under baseline conditions did not clearly demonstrate local PV-evoked potentials sufficient to be sure that the local vein was truly captured and dissociated from the atrium. Adenosine was administered in 19 of these, with 10 of 19 (52.6%) veins then demonstrating clear local PV-evoked potentials transiently during adenosine administration, sufficient to allow assessment of definite exit block. CONCLUSION: Adenosine administered during PV pacing allows transient visualization of local PV-evoked potentials after PVI facilitating the clearer demonstration of PV exit block in over 50% veins.

Ablation index, a novel marker of ablation lesion quality: prediction of pulmonary vein reconnection at repeat electrophysiology study and regional differences in target values.

AIMS: Force-Time Integral (FTI) is commonly used as a marker of ablation lesion quality during pulmonary vein isolation (PVI), but does not incorporate power. Ablation Index (AI) is a novel lesion quality marker that utilizes contact force, time, and power in a weighted formula. Furthermore, only a single FTI target value has been suggested despite regional variation in left atrial wall thickness. We aimed to study AI's and FTI's relationships with PV reconnection at repeat electrophysiology study, and regional threshold values that predicted no reconnection. METHODS AND RESULTS: Forty paroxysmal atrial fibrillation patients underwent contact force-guided PVI, and the minimum and mean AI and FTI values for each segment were identified according to a 12-segment model. All patients underwent repeat electrophysiology study at 2 months, regardless of symptoms, to identify sites of PV reconnection. Late PV reconnection was seen in 53 (11%) segments in 25 (62%) patients. Reconnected segments had significantly lower minimum AI [308 (252-336) vs. 373 (323-423), P < 0.0001] and FTI [137 (92-182) vs. 228 (157-334), P < 0.0001] compared with non-reconnected segments. Minimum AI and FTI were both independently predictive, but AI had a smaller P value. Higher minimum AI and FTI values were required to avoid reconnection in anterior/roof segments than for posterior/inferior segments (P < 0.0001). No reconnection was seen where the minimum AI value was ≥370 for posterior/inferior segments and ≥480 for anterior/roof segments. CONCLUSION: The minimum AI value in a PVI segment is independently predictive of reconnection of that segment at repeat electrophysiology study. Higher AI and FTI values are required for anterior/roof segments than for posterior/inferior segments to prevent reconnection.

Reablated Sites of Acute Reconnection After Pulmonary Vein Isolation Do Not Predict Sites of Late Reconnection at Repeat Electrophysiology Study.

INTRODUCTION: Acute reconnection of pulmonary veins (PVs) is frequently seen in the waiting period following pulmonary vein isolation (PVI). There are concerns that reablation at these sites may not be durably effective due to tissue edema caused by the initial ablation. We aimed to prospectively study the relationship between acute and late reconnection. METHODS AND RESULTS: Wide-area circumferential PVI was performed in 40 paroxysmal AF patients. Spontaneous reconnection was assessed after a minimum 20-minute waiting period, with adenosine administered to unmask dormant reconnection. All sites of acute reconnection were ablated to reisolate the PV. All 40 patients then underwent repeat electrophysiology study after 2 months, regardless of symptoms, to identify late reconnection. Sites of acute and late reconnection were compared according to a 12-segment PVI model. Acute reconnection was seen in 28 (6%) PVI segments in 20 (50%) patients, affecting 24/160 (15%) PVs. All were successfully reisolated. At repeat electrophysiology study, 51 (11%) PVI segments were reconnected in 25 (62%) patients, affecting 41 (25%) PVs. The proportion of PVI segments with and without acute reconnection exhibiting late reconnection at repeat study was no different (14% vs. 10%, P = 0.524). There was also no difference in late reconnection between PVI circles or patients with and without acute reconnection. CONCLUSION: Most PVI segments that undergo further ablation for acute reconnection show persistent isolation at repeat electrophysiology study, and the rate of late reconnection for these segments is no different to that for segments that did not acutely reconnect. This implies that effective reablation is delivered at these sites.

Radiofrequency ablation of the interventricular septum to treat outflow tract gradients in hypertrophic obstructive cardiomyopathy: a novel use of CARTOSound® technology to guide ablation.

AIMS: Septal reduction is needed for hypertrophic obstructive cardiomyopathy (HOCM) patients with severe left ventricular outflow tract (LVOT) gradients and symptoms despite medication. Myectomy cannot be performed in all. Alcohol septal ablation cannot be performed in 5-15% due to technical difficulties. A method of delivering percutaneous tissue damage to the septum that is not reliant on coronary anatomy is desirable. To directly ablate the interventricular septum at the mitral valve (MV) systolic anterior motion (SAM)-septal contact point using radiofrequency (RF) energy guided by CARTOSound. METHODS AND RESULTS: Five patients underwent RF ablation (RFA); we describe follow-up at 6 months in four patients. Intracardiac echocardiography (ICE) images are merged with CARTO to create a shell of the cardiac chambers. The SAM-septal contact area is marked from ICE images and mapped on to the CARTO shell; this becomes the target for RF delivery. Conduction tissue is mapped and avoided where possible. Twenty-eight to 42 min of RF energy was delivered to the target area using retrograde aortic access and SmartTouch catheters. Resting LVOT gradient improved from 64.2 (±50.6) to 12.3 (±2.5) mmHg. Valsalva/exercise-induced gradient reduced from 93.5 (±30.9) to 23.3 (±8.3) mmHg. Three patients improved New York Heart Association status from III to II, one patient improved from class III to I. Exercise time on bicycle ergometer increased from 612 to 730 s. Cardiac magnetic resonance shows late gadolinium enhancement up to 8 mm depth at LV target myocardium. One patient died following a significant retroperitoneal haemorrhage. CONCLUSION: Radiofrequency ablation using CARTOSound(®) guidance is accurate and effective in treating LVOT gradients in HOCM in this preliminary group of patients.

A novel marker to predict early recurrence after atrial fibrillation ablation: the ablation effectiveness quotient.

INTRODUCTION: Inability to predict clinical outcome despite acutely successful pulmonary vein isolation (PVI) remains the Achilles' heel of atrial fibrillation ablation (AFA). Arrhythmia recurrence is frequently due to recovery of radiofrequency (RF) ablation lesions believed to be complete at the original procedure. OBJECTIVES: We hypothesized that a high ratio between post-AFA levels of serum high sensitivity cardiac troponin T (HScTnT), a highly specific marker of acute myocardial injury, and duration of RF application (the ablation effectiveness quotient, AEQ) would indicate effective ablation and correlate with early clinical success. METHODS: We prospectively measured HScTnT levels in 60 patients (42 [70%] male, 22 [37%] with paroxysmal AF [PAF], mean age 62.5 ± 10.6 years) 12-18 hours after AFA and calculated the AEQ for each. Patients were followed-up with ECGs and Holter monitors for recurrence of atrial tachyarrhythmia (AT). RESULTS: Early recurrence of AT within 6 months occurred in 22 (37%). AT recurrence was not significantly related to left atrial size or comorbidities, nor to RF time or HScTnT level. Mean AEQ was significantly lower in those with recurrence than those without (0.35 ± 0.14 ng/L/s vs. 0.45 ± 0.18 ng/L/s), P = 0.02. Subgroup analysis showed this finding was due to patients with PAF in whom early significance was maintained to one year, with an AEQ >0.4 ng/L/s having 75% sensitivity and 90% specificity in predicting freedom from AT. CONCLUSION: A high AEQ correlates well with freedom from AT in patients with PAF in both the short and medium term. If confirmed in further studies, AEQ may become a useful marker of risk of AT post-AFA.

Improving safety in catheter ablation for atrial fibrillation: a prospective study of the use of ultrasound to guide vascular access.

INTRODUCTION: The most frequent complications of AF ablation (AFA) are related to vascular access, but there is little evidence as to how these can be minimized. METHODS: Consecutive patients undergoing AFA at a high-volume center received either standard care (Group S) or routine ultrasound-guided vascular access (Group U). Vascular complications were assessed before hospital discharge and by means of postal questionnaire 1 month later. Outcome measures were BARC 2+ bleeding complications, postprocedural pain, and prolonged bruising. RESULTS: Patients in Group S (n = 146) and U (n = 163) were well matched at baseline. Follow-up questionnaires were received from 92.6%. Patients in Group U were significantly less likely to have a BARC 2+ bleed, 10.4% versus 19.9% P = 0.02, were less likely to suffer groin pain after discharge (27.1% vs. 42.8%; P = 0.006) and were less likely to experience prolonged local bruising (21.5% vs. 40.4%; P = 0.001). Multivariable logistic regression analysis revealed a significant association of vascular complications with nonultrasound guided access (OR 3.12 95%CI 1.54-5.34; P = 0.003) and increasing age (OR 1.05 95%CI 1.01-1.09; P = 0.02). CONCLUSION: Routine use of ultrasound-guided vascular access for AFA is associated with a significant reduction in bleeding complications, postprocedural pain, and prolonged bruising when compared to standard care.

UltraSOUND-based characterization of ventricular tachycardia SCAR and arrhythmogenic substrate: The SOUNDSCAR study.

BACKGROUND: Intracardiac echocardiography (ICE) represents a valuable image integration technique, with the unique advantage of dynamic real-time scar characterization. OBJECTIVES: The goals of this study were to assess the correlation between ICE-defined and electroanatomic mapping (EAM)-defined scar in patients with ischemic cardiomyopathy and to define the outcomes of ICE-guided ventricular tachycardia (VT) ablation. METHODS: Thirty-eight patients with ischemic cardiomyopathy (SOUNDSCAR cohort) underwent full left ventricular (LV) ICE imaging and EAM. ICE-defined scar parameters (end-diastolic and end-systolic wall diameter [EDWD and ESWD], end-systolic wall thickening [percentage difference between EDWD and ESWD with respect to EDWD], slope [end-diastole to end-systole wall thickening], and American Heart Association wall motion scoring) were correlated with EAM-defined scar (voltage <1.5 mV). In a separate cohort (n = 21), outcomes of an ICE-guided VT ablation approach (EAM focused to ICE-defined scar regions) were compared with those of conventional ablation (full left ventricular mapping with EAM only; n = 21). RESULTS: In the 38 SOUNDSCAR patients (mean age 67 ± 11 years; 35 male [92%]; left ventricular ejection fraction 31% ± 10%; 2474 ICE segments; 524 ICE sectors), all ICE-defined parameters strongly predicted EAM-defined scar (area under the curve: American Heart Association score 0.873; ESWD 0.880; EDWD 0.827; slope 0.855; percentage difference between EDWD and ESWD with respect to EDWD, 0.851). All ICE-defined parameters had large effect sizes for predicting EAM-defined scar (logistic regression, P < .001). A detailed topographical comparison of ICE-defined (slope) and EAM-defined scar was possible in 25 patients and demonstrated 88% ± 10% overlap. Compared with conventional VT ablation, ICE-guided ablation was associated with shorter procedure times and comparable VT-free survival (ICE-guided vs conventional: procedure time 240 ± 20 minutes vs 298 ± 39 minutes; P < .001; VT recurrence 3 [14%] vs 7 [31%]; P = .19). CONCLUSION: ICE-defined scar demonstrates a strong correlation with EAM-defined scar. ICE-guided VT ablation is associated with enhanced procedural efficiency.

Delineating postinfarct ventricular tachycardia substrate with dynamic voltage mapping in areas of omnipolar vector disarray.

Background: Defining postinfarct ventricular arrhythmic substrate is challenging with voltage mapping alone, though it may be improved in combination with an activation map. Omnipolar technology on the EnSite X system displays activation as vectors that can be superimposed onto a voltage map. Objective: The study sought to optimize voltage map settings during ventricular tachycardia (VT) ablation, adjusting them dynamically using omnipolar vectors. Methods: Consecutive patients undergoing substrate mapping were retrospectively studied. We categorized omnipolar vectors as uniform when pointing in one direction, or in disarray when pointing in multiple directions. We superimposed vectors onto voltage maps colored purple in tissue >1.5 mV, and the voltage settings were adjusted so that uniform vectors appeared within purple voltages, a process termed dynamic voltage mapping (DVM). Vectors in disarray appeared within red-blue lower voltages. Results: A total of 17 substrate maps were studied in 14 patients (mean age 63 ± 13 years; mean left ventricular ejection fraction 35 ± 6%, median 4 [interquartile range 2-8.5] recent VT episodes). The DVM mean voltage threshold that differentiated tissue supporting uniform vectors from disarray was 0.27 mV, ranging between patients from 0.18 to 0.50 mV, with good interobserver agreement (median difference: 0.00 mV). We found that VT isthmus components, as well as sites of latest activation, isochronal crowding, and excellent pace maps colocated with tissue along the DVM border zone surrounding areas of disarray. Conclusion: DVM, guided by areas of omnipolar vector disarray, allows for individualized postinfarct ventricular substrate characterization. Tissue bordering areas of disarray may harbor greater arrhythmogenic potential.

Durability of thermal pulmonary vein isolation in persistent atrial fibrillation assessed by mandated repeat invasive study.

BACKGROUND: No study has assessed the durability of pulmonary vein isolation (PVI) with radiofrequency (RF) and cryoballoon (CB) in patients with persistent atrial fibrillation. These data are especially lacking for those with significantly diseased left atria (LA). OBJECTIVES: The goals of this study were to assess PVI durability in patients with significant LA disease and to compare reconnection rates between RF and CB. METHODS: Forty-four patients (mean age 63 years; 34 (77%) male; median time since atrial fibrillation diagnosis 22.5 months; median indexed LA volume 36 mL/m2) were randomized 1:1 to RF or CB PVI. A redo procedure using ultra-high-density electroanatomic mapping was mandated at 2 months, where PV reconnections were identified and reisolated. RESULTS: Thirty-eight patients underwent both procedures (CB n = 17; RF n = 21). Index RF procedures were longer (median 158 minutes vs 97 minutes; P < .001) but required less fluoroscopy (9.5 minutes vs 23 minutes; P < .001). At the index RF procedure, a median of 47% of LA myocardium had voltage < 0.5 mV, suggesting that half of the mapped LA comprised scar. PV reconnection was observed in 73 of 152 PVs (48.0%) and was more frequent with CB (58.8%) than with RF (39.3%) (P = .022). Reconnection of at least 1 PV was detected in >75% of patients. Significantly more ablation was required during the redo procedure to reisolate PVs in the CB arm (median 10.8 minutes vs 1.2 minutes; P < .001). CONCLUSION: PVI durability may be poor in those with significant LA scarring and dilatation, even with modern thermal ablation technologies. RF resulted in significantly better PVI durability than did CB in this complex population. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT04111731.

Cost, efficiency, and outcomes of pulsed field ablation vs thermal ablation for atrial fibrillation: A real-world study.

BACKGROUND: With the exponential growth of catheter ablation for atrial fibrillation (AF), there is increasing interest in associated health care costs. Pulsed field ablation (PFA) using a single-shot pentaspline multielectrode catheter has been shown to be safe and effective for AF ablation, but its cost efficiency compared to conventional thermal ablation modalities (cryoballoon [CB] or radiofrequency [RF]) has not been evaluated. OBJECTIVE: The purpose of this study was to compare cost, efficiency, effectiveness, and safety between PFA, CB, and RF for AF ablation. METHODS: We studied 707 consecutive patients (PFA: 208 [46.0%]; CB: 325 [29.4%]; RF: 174 [24.6%]) undergoing first-time AF ablation. Individual procedural costs were calculated, including equipment, laboratory use, and hospital stay, and compared between ablation modalities, as were effectiveness and safety. RESULTS: Skin-to-skin times and catheter laboratory times were significantly shorter with PFA (68 and 102 minutes, respectively) than with CB (91 and 122 minutes) and RF (89 and 123 minutes) (P < .001). General anesthesia use differed across modalities (PFA 100%; CB 10.2%; RF 61.5%) (P < .001). Major complications occurred in 1% of cases, with no significant differences between modalities. Shorter procedural times resulted in lower staffing and laboratory costs with PFA, but these savings were offset by substantially higher equipment costs, resulting in higher overall median costs with PFA (£10,010) than with CB (£8106) and RF (£8949) (P < .001). CONCLUSION: In this contemporary real-world study of the 3 major AF ablation modalities used concurrently, PFA had shorter skin-to-skin and catheter laboratory times than did CB and RF, with similarly low rates of complications. However, PFA procedures were considerably more expensive, largely because of higher equipment cost.

Predictors of the need for atrioventricular nodal ablation following redo ablation for atrial fibrillation.

Background: Patients who have recurrent atrial fibrillation (AF) following redo catheter ablation may eventually be managed with a pace-and-ablate approach, involving pacemaker implant followed by atrioventricular nodal ablation (AVNA). We sought to determine which factors would predict subsequent AVNA in patients undergoing redo AF ablation. Methods: We analyzed patients undergoing redo AF ablations between 2013 and 2019 at our institution. Follow-up was censored on December 31, 2021. Patients with no available follow-up data were excluded. Time-to-event analysis with Cox proportional hazard regression was used to compare those who underwent AVNA to those who did not. Results: A total of 467 patients were included, of whom 39 (8.4%) underwent AVNA. After multivariable adjustment, female sex (aHR 4.68 [95% CI 2.30-9.50]; p < 0.001), ischemic heart disease (aHR 2.99 [95% CI 1.25-7.16]; p = 0.014), presence of a preexisting pacemaker (aHR 3.25 [95% CI 1.10-9.60]; p = 0.033), and persistent AF (aHR 2.22 [95% CI 1.07-4.59]; p = 0.032) were associated with increased risk of subsequent AVNA requirement. Conclusion: Female sex, ischemic heart disease, and persistent AF may be useful clinical predictors of the requirement for subsequent AVNA and may be considered as part of shared clinical decision making.

Silent pulmonary veins at redo ablation for atrial fibrillation: Implications and approaches.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Despite promising success rates, redo ablation is sometimes required. At redo, PVs may be found to be isolated (silent) or reconnected. We studied patients with silent vs reconnected PVs at redo and analysed associations with adverse outcomes. METHODS: Patients undergoing redo AF ablations between 2013 and 2019 at our institution were included and stratified into silent PVs or reconnected PVs. The primary outcome was a composite of further redo ablation, non-AF ablation, atrioventricular nodal ablation, and death. Secondary outcomes included arrhythmia recurrence. RESULTS: A total of 467 patients were included with mean 4.6 ± 1.7 years follow-up, of whom 48 (10.3%) had silent PVs. The silent PV group had had more often undergone >1 prior ablation (45.8% vs 9.8%; p<0.001), had more persistent AF (62.5% vs 41.1%; p=0.005) and had more non-PV ablation performed both at prior ablation procedures and at the analysed redo ablation. The primary outcome occurred more frequently in those with silent PVs (25% vs 13.8%; p=0.053). Arrhythmia recurrence was also more common in the silent PV group (66.7% vs 50.6%; p=0.047). After multivariable adjustment, female sex (aHR 2.35 [95% CI 2.35-3.96]; p=0.001) and ischaemic heart disease (aHR 3.21 [95% CI 1.56-6.62]; p=0.002) were independently associated with the primary outcome, and left atrial enlargement (aHR 1.58 [95% CI 1.20-2.08]; p=0.001) and >1 prior ablation (aHR 1.88 [95% CI 1.30-2.72]; p<0.001) were independently associated with arrhythmia recurrence. Whilst a finding of silent PVs was not itself significant after multivariable adjustment, this provides an easily assessable parameter at clinically indicated redo ablation which informs the clinician of the likelihood of a worse future prognosis. CONCLUSIONS: Patients with silent PVs at redo AF ablation have worse clinical outcomes.

Risk of arrhythmia and sudden death in patients with asymptomatic preexcitation: a meta-analysis.

BACKGROUND: The incidence of sudden cardiac death (SCD) and the management of this risk in patients with asymptomatic preexcitation remain controversial. The purpose of this meta-analysis was to define the incidence of SCD and supraventricular tachycardia in patients with asymptomatic Wolff-Parkinson-White ECG pattern. METHODS AND RESULTS: We performed a systematic search of prospective, retrospective, randomized, or cohort English-language studies in EMBASE and Medline through February 2011. Studies reporting asymptomatic patients with preexcitation who did not undergo ablation were included. Twenty studies involving 1869 patients met our inclusion criteria. Participants were primarily male with a mean age ranging from 7 to 43 years. Ten SCDs were reported involving 11 722 person-years of follow-up. Seven studies originated from Italy and reported 9 SCDs. The risk of SCD is estimated at 1.25 per 1000 person-years (95% confidence interval [CI], 0.57-2.19). A total of 156 supraventricular tachycardias were reported involving 9884 person-years from 18 studies. The risk of supraventricular tachycardia was 16 (95% CI, 10-24) events per 1000 person-years of follow-up. Children had numerically higher SCD (1.93 [95% CI, 0.57-4.1] versus 0.86 [95% CI, 0.28-1.75]; P=0.07) and supraventricular tachycardia (20 [95% CI, 12-31] versus 14 [95% CI, 6-25]; P=0.38) event rates compared with adults. CONCLUSION: The low incidence of SCD and low risk of supraventricular tachycardia argue against routine invasive management in most asymptomatic patients with the Wolff-Parkinson-White ECG pattern.