Cardiac resynchronization using fusion pacing during exercise.

INTRODUCTION: Fusion pacing requires correct timing of left ventricular pacing to right ventricular activation, although it is unclear whether this is maintained when atrioventricular (AV) conduction changes during exercise. We used cardiopulmonary exercise testing (CPET) to compare cardiac resynchronization therapy (CRT) using fusion pacing or fixed AV delays (AVD). METHODS: Patients 6 months post-CRT implant with PR intervals < 250 ms performed two CPET tests, using either the SyncAV™ algorithm or fixed AVD of 120 ms in a double-blinded, randomized, crossover study. All other programming was optimized to produce the narrowest QRS duration (QRSd) possible. RESULTS: Twenty patients (11 male, age 71 [65-77] years) were recruited. Fixed AVD and fusion programming resulted in similar narrowing of QRSd from intrinsic rhythm at rest (p = .85). Overall, there was no difference in peak oxygen consumption (V̇O2 PEAK , p = .19), oxygen consumption at anaerobic threshold (VT1, p = .42), or in the time to reach either V̇O2 PEAK (p = .81) or VT1 (p = .39). The BORG rating of perceived exertion was similar between groups. CPET performance was also analyzed comparing whichever programming gave the narrowest QRSd at rest (119 [96-136] vs. 134 [119-142] ms, p < .01). QRSd during exercise (p = .03), peak O2 pulse (mL/beat, a surrogate of stroke volume, p = .03), and cardiac efficiency (watts/mL/kg/min, p = .04) were significantly improved. CONCLUSION: Fusion pacing is maintained during exercise without impairing exercise capacity compared with fixed AVD. However, using whichever algorithm gives the narrowest QRSd at rest is associated with a narrower QRSd during exercise, higher peak stroke volume, and improved cardiac efficiency.

In Silico TRials guide optimal stratification of ATrIal FIbrillation patients to Catheter Ablation and pharmacological medicaTION: the i-STRATIFICATION study.

AIMS: Patients with persistent atrial fibrillation (AF) experience 50% recurrence despite pulmonary vein isolation (PVI), and no consensus is established for secondary treatments. The aim of our i-STRATIFICATION study is to provide evidence for stratifying patients with AF recurrence after PVI to optimal pharmacological and ablation therapies, through in silico trials. METHODS AND RESULTS: A cohort of 800 virtual patients, with variability in atrial anatomy, electrophysiology, and tissue structure (low-voltage areas, LVAs), was developed and validated against clinical data from ionic currents to electrocardiogram. Virtual patients presenting AF post-PVI underwent 12 secondary treatments. Sustained AF developed in 522 virtual patients after PVI. Second ablation procedures involving left atrial ablation alone showed 55% efficacy, only succeeding in the small right atria (<60 mL). When additional cavo-tricuspid isthmus ablation was considered, Marshall-PLAN sufficed (66% efficacy) for the small left atria (<90 mL). For the bigger left atria, a more aggressive ablation approach was required, such as anterior mitral line (75% efficacy) or posterior wall isolation plus mitral isthmus ablation (77% efficacy). Virtual patients with LVAs greatly benefited from LVA ablation in the left and right atria (100% efficacy). Conversely, in the absence of LVAs, synergistic ablation and pharmacotherapy could terminate AF. In the absence of ablation, the patient's ionic current substrate modulated the response to antiarrhythmic drugs, being the inward currents critical for optimal stratification to amiodarone or vernakalant. CONCLUSION: In silico trials identify optimal strategies for AF treatment based on virtual patient characteristics, evidencing the power of human modelling and simulation as a clinical assisting tool.

Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in Transvenous and Subcutaneous Implantable Defibrillators: Analysis of All Appropriate Therapy in the PRAETORIAN Trial.

BACKGROUND: The PRAETORIAN trial (A Prospective, Randomized Comparison of Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Therapy) showed noninferiority of subcutaneous implantable cardioverter defibrillator (S-ICD) compared with transvenous implantable cardioverter defibrillator (TV-ICD) with regard to inappropriate shocks and complications. In contrast to TV-ICD, S-ICD cannot provide antitachycardia pacing for monomorphic ventricular tachycardia. This prespecified secondary analysis evaluates appropriate therapy and whether antitachycardia pacing reduces the number of appropriate shocks. METHODS: The PRAETORIAN trial was an international, investigator-initiated randomized trial that included patients with an indication for implantable cardioverter defibrillator (ICD) therapy. Patients with previous ventricular tachycardia <170 bpm or refractory recurrent monomorphic ventricular tachycardia were excluded. In 39 centers, 849 patients were randomized to receive an S-ICD (n=426) or TV-ICD (n=423) and were followed for a median of 49.1 months. ICD programming was mandated by protocol. Appropriate ICD therapy was defined as therapy for ventricular arrhythmias. Arrhythmias were classified as discrete episodes and storm episodes (≥3 episodes within 24 hours). Analyses were performed in the modified intention-to-treat population. RESULTS: In the S-ICD group, 86 of 426 patients received appropriate therapy, versus 78 of 423 patients in the TV-ICD group, during a median follow-up of 52 months (48-month Kaplan-Meier estimates 19.4% and 17.5%; P=0.45). In the S-ICD group, 83 patients received at least 1 shock, versus 57 patients in the TV-ICD group (48-month Kaplan-Meier estimates 19.2% and 11.5%; P=0.02). Patients in the S-ICD group had a total of 254 shocks, compared with 228 shocks in the TV-ICD group (P=0.68). First shock efficacy was 93.8% in the S-ICD group and 91.6% in the TV-ICD group (P=0.40). The first antitachycardia pacing attempt successfully terminated 46% of all monomorphic ventricular tachycardias, but accelerated the arrhythmia in 9.4%. Ten patients with S-ICD experienced 13 electrical storms, versus 18 patients with TV-ICD with 19 electrical storms. Patients with appropriate therapy had an almost 2-fold increased relative risk of electrical storms in the TV-ICD group compared with the S-ICD group (P=0.05). CONCLUSIONS: In this trial, no difference was observed in shock efficacy of S-ICD compared with TV-ICD. Although patients in the S-ICD group were more likely to receive an ICD shock, the total number of appropriate shocks was not different between the 2 groups. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01296022.

Baseline left atrial low-voltage area predicts recurrence after pulmonary vein isolation: WAVE-MAP AF results.

AIMS: Electro-anatomical mapping may be critical to identify atrial fibrillation (AF) subjects who require substrate modification beyond pulmonary vein isolation (PVI). The objective was to determine correlations between pre-ablation mapping characteristics and 12-month outcomes after a single PVI-only catheter ablation of AF. METHODS AND RESULTS: This study enrolled paroxysmal AF (PAF), early persistent AF (PsAF; 7 days-3 months), and non-early PsAF (>3-12 months) subjects undergoing de novo PVI-only radiofrequency catheter ablation. Sinus rhythm (SR) and AF voltage maps were created with the Advisor HD Grid™ Mapping Catheter, Sensor Enabled™ for each subject, and the presence of low-voltage area (LVA) (low-voltage cutoffs: 0.1-1.5 mV) was investigated. Follow-up visits were at 3, 6, and 12 months, with a 24-h Holter monitor at 12 months. A Cox proportional hazards model identified associations between mapping data and 12-month recurrence after a single PVI procedure. The study enrolled 300 subjects (113 PAF, 86 early PsAF, and 101 non-early PsAF) at 18 centres. At 12 months, 75.5% of subjects were free from AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence. Univariate analysis found that arrhythmia recurrence did not correlate with AF diagnosis, but LVA was significantly correlated. Low-voltage area (<0.5 mV) >28% of the left atrium in SR [hazard ratio (HR): 4.82, 95% confidence interval (CI): 2.08-11.18; P = 0.0003] and >72% in AF (HR: 5.66, 95% CI: 2.34-13.69; P = 0.0001) was associated with a higher risk of AF/AFL/AT recurrence at 12 months. CONCLUSION: Larger extension of LVA was associated with an increased risk of arrhythmia recurrence. These subjects may benefit from substrate modification beyond PVI.

Treatment of pathophysiologic propagation outside of the pulmonary veins in retreatment of atrial fibrillation patients: RECOVER AF study.

AIMS: RECOVER AF evaluated the performance of whole-chamber non-contact charge-density mapping to guide the ablation of non-pulmonary vein (PV) targets in persistent atrial fibrillation (AF) patients following either a first or second failed procedure. METHODS AND RESULTS: RECOVER AF was a prospective, non-randomized trial that enrolled patients scheduled for a first or second ablation retreatment for recurrent AF. The PVs were assessed and re-isolated if necessary. The AF maps were used to guide the ablation of non-PV targets through elimination of pathologic conduction patterns (PCPs). Primary endpoint was freedom from AF on or off antiarrhythmic drugs (AADs) at 12 months. Patients undergoing retreatment with the AcQMap System (n = 103) were 76% AF-free at 12 months [67% after single procedure (SP)] on or off AADs (80% free from AF on AADs). Patients who had only received a pulmonary vein isolation (PVI) prior to study treatment of non-PV targets with the AcQMap System were 91% AF-free at 12 months (83% SP). No major adverse events were reported. CONCLUSION: Non-contact mapping can be used to target and guide the ablation of PCPs beyond the PVs in persistent AF patients returning for a first or second retreatment with 76% freedom from AF at 12 months. The AF freedom was particularly high, 91% (43/47), for patients enrolled having only a prior de novo PVI, and freedom from all atrial arrhythmias for this cohort was 74% (35/47). These early results are encouraging and suggest that guiding individualized targeted ablation of PCPs may therefore be advantageous to target at the earliest opportunity in patients with persistent AF.

Device-related complications in subcutaneous versus transvenous ICD: a secondary analysis of the PRAETORIAN trial.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is developed to overcome lead-related complications and systemic infections, inherent to transvenous ICD (TV-ICD) therapy. The PRAETORIAN trial demonstrated that the S-ICD is non-inferior to the TV-ICD with regard to the combined primary endpoint of inappropriate shocks and complications. This prespecified secondary analysis evaluates all complications in the PRAETORIAN trial. METHODS AND RESULTS: The PRAETORIAN trial is an international, multicentre, randomized trial in which 849 patients with an indication for ICD therapy were randomized to receive an S- ICD (N = 426) or TV-ICD (N = 423) and followed for a median of 49 months. Endpoints were device-related complications, lead-related complications, systemic infections, and the need for invasive interventions. Thirty-six device-related complications occurred in 31 patients in the S-ICD group of which bleedings were the most frequent. In the TV-ICD group, 49 complications occurred in 44 patients of which lead dysfunction was most frequent (HR: 0.69; P = 0.11). In both groups, half of all complications were within 30 days after implantation. Lead-related complications and systemic infections occurred significantly less in the S-ICD group compared with the TV-ICD group (P < 0.001, P = 0.03, respectively). Significantly more complications required invasive interventions in the TV-ICD group compared with the S-ICD group (8.3% vs. 4.3%, HR: 0.59; P = 0.047). CONCLUSION: This secondary analysis shows that lead-related complications and systemic infections are more prevalent in the TV-ICD group compared with the S-ICD group. In addition, complications in the TV-ICD group were more severe as they required significantly more invasive interventions. This data contributes to shared decision-making in clinical practice.

Clinical utility of non-contact charge density 'SuperMap' algorithm for the mapping and ablation of organized atrial arrhythmias.

AIMS: SuperMap is a novel non-contact algorithm for the mapping of organized atrial arrhythmias. We prospectively evaluated SuperMap during mapping and ablation of atrial tachycardias (ATs) and paced rhythms and compared to conventional high-density contact mapping. METHODS AND RESULTS: Consecutive patients undergoing SuperMap guided ablation of pre-existing ATs or AT developed during atrial fibrillation ablation procedures were included together with maps obtained during pacing to assess block in linear lesions. The time taken to obtain diagnostic maps was measured together with the number of electrogram (EGM) points and accuracy compared to the arrhythmia diagnosis confirmed using a combination of map findings, entrainment, and response to ablation. In a subgroup of patients, concurrent contact mapping was performed with contact and SuperMap analysed by separate operators blinded to the other technique. The time taken to generate a diagnostic map, EGM number, and map accuracy was compared. Thirty-one patients (62 maps) were included with contact mapping performed in 19 [39 maps (33 for AT)]. SuperMap acquisition time was 314 s [interquartile range (IQR) 239-436]. The median number of EGM points used per map was 5399 (IQR 3279-8677). SuperMap was faster than contact mapping [394 ± 219 s vs. 611 ± 331 s; difference 217 s, 95% confidence interval (CI) 116-318, P < 0.0005]. The number of EGM points used per map was higher for SuperMap (7351 ± 5054 vs. 3620 ± 3211; difference 3731, 95% CI 2073-5388, P < 0.0005). SuperMap and contact mapping were accurate in 92% and 85% of maps, respectively, P = 0.4805. CONCLUSION: SuperMap non-contact charge density mapping is a rapid and reliable approach to guide the ablation of complex atrial arrhythmias.

Efficacy and safety of same-day discharge after atrial fibrillation ablation compared with post-procedural overnight stay: a systematic review and meta-analysis.

AIMS: Catheter ablation for atrial fibrillation (AF) has historically required inpatient admission post-procedure, but same-day discharge (SDD) has recently been reported. We aimed to assess the efficacy and safety of SDD compared with overnight stay (OS) post-ablation. METHODS AND RESULTS: We performed a systematic search of the PubMed database. Random-effects meta-analysis was performed to assess the efficacy (successful SDD) and safety (24 h complications, 30-day complications, 30-day re-admissions, and 30-day mortality) of a SDD AF ablation strategy. Fourteen non-randomized observational studies met criteria for inclusion, encompassing 26488 patients undergoing AF ablation, of whom 9766 were SDD. The mean age of participants was 61.9 years, and 67.9% were male. Around 61.7% underwent ablation for paroxysmal AF. The pooled success rate of SDD was 83.2% [95% confidence intervals (CIs): 61.5-97.0%, I2 100%]. The risk of bias was severe for all effect estimates due to confounding, as most cohorts were retrospectively identified without appropriately matched comparators. There was no significant difference in 30-day complications [odds ratio (OR): 0.95, 95% CI: 0.65-1.40, I2 53%] or 30-day re-admission (OR 0.96, 95% CI: 0.49-1.89, I2 82%) between groups. There were insufficient data for meta-analysis of 24 h complications and 30-day mortality. Where reported, no re-admissions occurred due to 24 h complications after SDD. Two deaths (0.04%) were reported in both SDD and OS groups. CONCLUSION: Same-day discharge after AF ablation appears to be an effective and safe strategy in selected patients. However, the available evidence is of low quality, and more robust prospective studies comparing SDD to OS are needed.

Caged-in: Successful percutaneous closure of left atrial appendage with Watchman-FLX in the presence of proximal thrombus.

Percutaneous mechanical closure of the left atrial appendage (LAA) is a valuable stroke prevention strategy in patients with atrial fibrillation and contraindication to oral anticoagulation. LAA thrombus is a common finding in patients with atrial fibrillation and frequently fails to resolve despite therapeutic anticoagulation. In this scenario, LAA occlusion device implant is generally discouraged due to the high risk of thrombus dislodgement and embolization; however, alternative management options are limited. We report the first case of a successful LAA occlusion device (Watchman-FLX) implant in the presence of a proximal thrombus.

Spatial and temporal variability of rotational, focal, and irregular activity: Practical implications for mapping of atrial fibrillation.

BACKGROUND: Charge density mapping of atrial fibrillation (AF) reveals dynamic localized rotational activation (LRA), irregular activation (LIA) and focal firing (FF). Their spatial stability, conduction characteristics and the optimal duration of mapping required to reveal these phenomena and has not been explored. METHODS: Bi-atrial mapping of AF propagation was undertaken using AcQMap (Acutus Medical) and variability of activation patterns quantified up to a duration of 30 s. The frequency of each pattern was quantified at each unique point of the chamber over two separate 30-s recordings before ablation and R2 calculated to quantify spatial stability. Regions with the highest frequency were identified at increasing time durations and compared to the result over 30 s using Cohen's kappa. Properties of regions with the most stable patterns were assessed during sinus rhythm and extrastimulus pacing. RESULTS: In 21 patients, 62 paired LA and RA maps were obtained. LIA was highly spatially stable with R2 between maps of 0.83 (0.71-0.88) compared to 0.39 (0.24-0.57), and 0.64 (0.54-0.73) for LRA and FF, respectively. LIA was most temporally stable with a kappa of >0.8 reached by 12 s. LRA showed greatest variability with kappa >0.8 only after 22 s. Regions of LIA were of normal voltage amplitude (1.09 mv) but showed increased conduction heterogeneity during extrastimulus pacing (p = .0480). CONCLUSION: Irregular activation patterns characterized by changing wavefront direction are temporally and spatially stable in contrast with LRA that is transient with least spatial stability. Focal activation appears of intermediate stability. Regions of LIA show increased heterogeneity following extrastimulus pacing and may represent fixed anatomical substrate.

Incidence, predictors and outcomes of device-related thrombus after left atrial appendage closure with the WATCHMAN device-Insights from the EWOLUTION real world registry.

BACKGROUND: In this analysis of the EWOLUTION registry, we evaluated the incidence, relevance and predictors of device-related thrombus in a large multi-center real-world cohort undergoing LAAc with the WATCHMAN device. METHODS AND RESULTS: We analyzed the 835 patients who underwent percutaneous LAA closure with the WATCHMAN device in the EWOLUTION registry in whom at least one TEE follow up was performed. Patients were 74 ± 9 y/o and were at high risk for stroke and bleeding (CHA2DS2-VASC-Score 4.3 ± 1.7; HAS-BLED-Score 2.3 ± 1.2). Device-related thrombus was detected in 4.1% (34/835) after a median of 54 days (IQR 42-111 days) with 91.2% (31/34) being detected within 3 months after the procedure or at the time of first TEE. Hereby DRT occurred irrespective of postprocedural anticoagulation. Patients with DRT more frequently had long-standing, non-paroxysmal atrial fibrillation (82.4 vs. 64.9%, p < .01), evidence of dense spontaneous echo contrast (26.5 vs. 11.9%, p = .03) and larger LAA diameters at the ostium (22.8 ± 3.5 vs. 21.1 ± 3.5 mm, p < .01) compared to patients without DRT. Left ventricular ejection fraction, device compression ratio and the incidence of renal dysfunction did not differ between the two groups. In a multivariate analysis, only non-paroxysmal atrial fibrillation identified as an independent predictor of developing DRT. Specific treatment of DRT was initiated in 62% (21/34) of patients whereas resolution was confirmed in 86% (18/21) of cases. Overall, no significant differences in annual rates of stroke/TIA or systemic embolism were observed in patients with or without DRT (DRT 1.7 vs. No-DRT 2.2%/year, p = .8). CONCLUSIONS: In real-world patients undergoing LAAc with the WATCHMAN device, DRT is rare. DRT was most frequently detected within the first 3 months after LAAc regardless of post-procedural regimen and was not associated with an increased risk of stroke or SE. While long-standing atrial fibrillation was the only independent factor associated with DRT, medical treatment of DRT resulted in a resolution of thrombi in most cases.

Leadless left ventricular endocardial pacing for CRT upgrades in previously failed and high-risk patients in comparison with coronary sinus CRT upgrades.

AIMS: Cardiac resynchronization therapy (CRT) upgrades may be less likely to improve following intervention. Leadless left ventricular (LV) endocardial pacing has been used for patients with previously failed CRT or high-risk upgrades. We compared procedural and long-term outcomes in patients undergoing coronary sinus (CS) CRT upgrades with high-risk and previously failed CRT upgrades undergoing LV endocardial upgrades. METHOD AND RESULTS: Prospective consecutive CS upgrades between 2015 and 2019 were compared with those undergoing WiSE-CRT implantation. Cardiac resynchronization therapy response at 6 months was defined as improvement in clinical composite score (CCS) and a reduction in LV end-systolic volume (LVESV) ≥15%. A total of 225 patients were analysed; 121 CS and 104 endocardial upgrades. Patients receiving WiSE-CRT tended to have more comorbidities and were more likely to have previous cardiac surgery (30.9% vs. 16.5%; P = 0.012), hypertension (59.2% vs. 34.7%; P < 0.001), chronic obstructive airways disease (19.4% vs. 9.9%; P = 0.046), and chronic kidney disease (46.4% vs. 21.5%; P < 0.01) but similar LV ejection fraction (30.0 ± 8.3% vs. 29.5 ± 8.6%; P = 0.678). WiSE-CRT upgrades were successful in 97.1% with procedure-related mortality in 1.9%. Coronary sinus upgrades were successful in 97.5% of cases with a 2.5% rate of CS dissection and 5.6% lead malfunction/displacement. At 6 months, 91 WiSE-CRT upgrades and 107 CS upgrades had similar improvements in CCS (76.3% vs. 68.5%; P = 0.210) and reduction in LVESV ≥15% (54.2% vs. 56.3%; P = 0.835). CONCLUSION: Despite prior failed upgrades and high-risk patients with more comorbidities, WiSE-CRT upgrades had high rates of procedural success and similar improvements in CCS and LV remodelling with CS upgrades.

Initial and long-term antithrombotic therapy after left atrial appendage closure with the WATCHMAN.

AIMS: Evidence regarding post-procedural antithrombotic regimen other than used in randomized trials assessing percutaneous left atrial appendage (LAA) closure is limited. The present work aimed to compare different antithrombotic strategies applied in the real-world EWOLUTION study. METHODS AND RESULTS: A total of 998 patients with successful WATCHMAN implantation were available for the present analysis. The composite ischaemic endpoint of stroke, transitory ischaemic attack, systemic embolism and device thrombus, and the bleeding endpoint defined as at least major bleeding were assessed during an initial period (from implant until first medication change) and long-term period (from first change up to 2 years). The antithrombotic medication chosen in the initial phase was dual antiplatelet therapy (DAPT) in 60%, oral anticoagulation (OAC) in 27%, single antiplatelet therapy (SAPT) in 7%, and no medication in 6%. In the second long-term phase, SAPT was used in 65%, DAPT in 23%, no therapy in 8%, and OAC in 4%. No significant differences were found between the groups regarding the ischaemic endpoint both in the initial period (Kaplan-Meier estimated rate 2.9% for DAPT vs. 4.3% for OAC vs. 3.9% for SAPT or no therapy) and in the second period (4.2% for SAPT vs. 1.8% for DAPT vs. 3.5% for no therapy). With respect to bleeding events, the only difference was found in the initial phase with a higher incidence in patients under SAPT or no therapy. CONCLUSIONS: Tailored antithrombotic treatment using even very reduced strategies such as SAPT or no therapy showed no significant differences regarding ischaemic complications after LAA closure.

Leadless left ventricular endocardial pacing in nonresponders to conventional cardiac resynchronization therapy.

BACKGROUND: Endocardial pacing may be beneficial in patients who fail to improve following conventional epicardial cardiac resynchronization therapy (CRT). The potential to pace anywhere inside the left ventricle thus avoiding myocardial scar and targeting the latest activating segments may be particularly important. The WiSE-CRT system (EBR systems, Sunnyvale, CA) reliably produces wireless, endocardial left ventricular (LV) pacing. The purpose of this analysis was to determine whether this system improved symptoms or led to LV remodeling in patients who were nonresponders to conventional CRT. METHOD: An international, multicenter registry of patients who were nonresponders to conventional CRT and underwent implantation with the WiSE-CRT system was collected. RESULTS: Twenty-two patients were included; 20 patients underwent successful implantation with confirmation of endocardial biventricular pacing and in 2 patients, there was a failure of electrode capture. Eighteen patients proceeded to 6-month follow-up; endocardial pacing resulted in a significant reduction in QRS duration compared with intrinsic QRS duration (26.6 ± 24.4 ms; P = .002) and improvement in left ventricular ejection fraction (LVEF) (4.7 ± 7.9%; P = .021). The mean reduction in left ventricular end-diastolic volume was 8.3 ± 42.3 cm3 (P = .458) and left ventricular end-systolic volume (LVESV) was 13.1 ± 44.3 cm3 (P = .271), which were statistically nonsignificant. Overall, 55.6% of patients had improvement in their clinical composite score and 66.7% had a reduction in LVESV ≥15% and/or absolute improvement in LVEF ≥5%. CONCLUSION: Nonresponders to conventional CRT have few remaining treatment options. We have shown in this high-risk patient group that the WiSE-CRT system results in improvement in their clinical composite scores and leads to LV remodeling.

Approaches to catheter ablation for persistent atrial fibrillation.

BACKGROUND: Catheter ablation is less successful for persistent atrial fibrillation than for paroxysmal atrial fibrillation. Guidelines suggest that adjuvant substrate modification in addition to pulmonary-vein isolation is required in persistent atrial fibrillation. METHODS: We randomly assigned 589 patients with persistent atrial fibrillation in a 1:4:4 ratio to ablation with pulmonary-vein isolation alone (67 patients), pulmonary-vein isolation plus ablation of electrograms showing complex fractionated activity (263 patients), or pulmonary-vein isolation plus additional linear ablation across the left atrial roof and mitral valve isthmus (259 patients). The duration of follow-up was 18 months. The primary end point was freedom from any documented recurrence of atrial fibrillation lasting longer than 30 seconds after a single ablation procedure. RESULTS: Procedure time was significantly shorter for pulmonary-vein isolation alone than for the other two procedures (P<0.001). After 18 months, 59% of patients assigned to pulmonary-vein isolation alone were free from recurrent atrial fibrillation, as compared with 49% of patients assigned to pulmonary-vein isolation plus complex electrogram ablation and 46% of patients assigned to pulmonary-vein isolation plus linear ablation (P=0.15). There were also no significant differences among the three groups for the secondary end points, including freedom from atrial fibrillation after two ablation procedures and freedom from any atrial arrhythmia. Complications included tamponade (three patients), stroke or transient ischemic attack (three patients), and atrioesophageal fistula (one patient). CONCLUSIONS: Among patients with persistent atrial fibrillation, we found no reduction in the rate of recurrent atrial fibrillation when either linear ablation or ablation of complex fractionated electrograms was performed in addition to pulmonary-vein isolation. (Funded by St. Jude Medical; ClinicalTrials.gov number, NCT01203748.).

Incidence of pericardial effusion after left atrial appendage closure: The impact of underlying heart rhythm-Data from the EWOLUTION study.

INTRODUCTION: Pericardial effusion/tamponade (PE/PT) is a rare but serious complication following left atrial appendage closure (LAAC). It may be speculated that LAA contraction during sinus rhythm (SR) exerts mechanical force on the device that eventually leads to PE. We sought to determine the incidence and predictors of PE following LAAC using Watchman with special emphasis on the underlying heart rhythm during implant. METHODS AND RESULTS: From 47 centers in 13 European countries 1,020 patients underwent LAAC and data on baseline rhythm were available from 1,010 patients (mean age 73 ± 9 years, 60% male, median CHA2DS2-VASc = 4). Data were collected via electronic case report forms. A Cox proportional hazard model was calculated adjusting for multiple variables: age, gender, number of recaptures, and device oversizing. During implant, 41% and 59% of patients were in SR and atrial fibrillation (AF), respectively. PE/PT rate was significantly lower in patients implanted during AF at day 30 postimplant (n = 1; 0.2% vs. n = 6; 1.5%; P = 0.02). No PE requiring intervention occurred in the AF group compared to 5 events (1.2%) in the SR group (P = 0.01). While univariate analysis identified SR and gender as predictors for PE/tamponade, multivariate analysis only showed a statistical trend for both variables. CONCLUSION: The overall incidence of PE/PT was very low after LAAC using Watchman. Although SR was not identified as an independent predictor of PE/PT, all events requiring intervention occurred in patients with SR. It may be advisable to perform an extended echocardiographic follow-up in that patient population.

Percutaneous left atrial appendage occlusion using different technologies in the United Kingdom: A multicenter registry.

OBJECTIVES: This study aimed at assessing the feasibility and long-term efficacy of left atrial appendage occlusion (LAAO) in a "real world" setting. BACKGROUND: Although LAAO has recently emerged as an alternative to oral anticoagulants in patients with atrial fibrillation for the prevention of thromboembolic stroke, "real world" data about the procedure with different devices are lacking. METHODS: Eight centers in the United Kingdom contributed to a retrospective registry for LAAO procedures undertaken between July 2009 and November 2014. RESULTS: A total of 371 patients (72.9 ± 8.3 years old, 88.9% males) were enrolled. The overall procedure success was 92.5%, with major events in 3.5% of cases. The device choice was Watchman in 63% of cases, Amplatzer Cardiac Plug in 34.7%, Lariat in 1.7%, and Coherex WaveCrest in 0.6%. A significant improvement in procedure success (from 89.2% to 95.7%; P = 0.018) and reduction of acute major complications (from 6.5% to 0.5%; P = 0.001) were observed between procedures in the first and the second half of the recruitment time. An annual 90.1% relative risk reduction (RRR) for ischemic stroke, an 87.2% thromboembolic events RRR, and a 92.9% major bleeding RRR were observed, if compared with the predicted annual risks based on CHADS2, CHA2DS2-Vasc, and HAS-BLED scores, respectively, over a follow-up period of 24.7 ± 16.07 months. CONCLUSIONS: LAAO can be performed safely in a real world setting with good implant success rates and procedural outcomes. The long-term benefits of the procedure are reassuring in terms of both ischemic events and avoidance of severe bleeding associated with anticoagulation in this patient group. © 2016 Wiley Periodicals, Inc.

Premature termination of radiofrequency delivery during pulmonary vein isolation due to oesophageal temperature alerts: impact on acute and chronic pulmonary vein reconnection.

AIMS: Oesophageal temperature monitoring is currently used during atrial fibrillation (AF) ablation to prevent atrio-oesophageal fistula. The aim of our study was to investigate if oesophageal temperature alerts, leading to early termination of radiofrequency (RF) energy and/or reduction in power during pulmonary vein isolation, can promote pulmonary vein reconnection (PVR). METHODS AND RESULTS: Patients undergone two consecutive AF ablation procedures with a three-dimensional electro-anatomical mapping system and oesophageal temperature monitoring were studied. Any lesions causing oesophageal temperature rises >39°C during the index procedure, leading to premature cessation of RF and/or reduction in power, were labelled on the left atrial geometry in a different colour from standard uninterrupted RF lesions. Acute (at the time of the index procedure) and chronic (at the time of there-do procedure) PVR and the site of subsequent re-isolation were compared with the lesion markers for temperature alerts from the index procedure. Fifty-four patients were included (36 male, mean age 68 ± 8, 59% persistent AF). Forty-six PVs (21% of the total) in 30 patients (56%) had been subject to at least one temperature alert during the index procedure. In 12 patients, 23 PVs had acute PVR requiring further ablation. At the re-do procedure, 103 PVs were found to be reconnected in 44 patients. No correlation was found between the occurrence of temperature alerts at the index procedure and acute or chronic PVR in the associated PV. CONCLUSION: Just over half of patients undergoing PV isolation will have an oesophageal temperature alert, however, precautionary oesophageal temperature monitoring does not compromise ablation efficacy.

Implant success and safety of left atrial appendage closure with the WATCHMAN device: peri-procedural outcomes from the EWOLUTION registry.

AIMS: Left atrial appendage closure is a non-pharmacological alternative for stroke prevention in high-risk patients with non-valvular atrial fibrillation. The objective of the multicentre EWOLUTION registry was to obtain clinical data on procedural success and complications, and long-term patient outcomes, including bleeding and incidence of stroke/transient ischaemic attack (TIA). Here, we report on the peri-procedural outcomes of up to 30 days. METHODS AND RESULTS: Baseline/implant data are available for 1021 subjects. Subjects in the study were at high risk of stroke (average CHADS2 score: 2.8 ± 1.3, CHA2DS2-VASc: 4.5 ± 1.6) and moderate-to-high risk of bleeding (average HAS-BLED score: 2.3 ± 1.2). Almost half of the subjects (45.4%) had a history of TIA, ischaemic stroke, or haemorrhagic stroke; 62% of patients were deemed unsuitable for novel oral anticoagulant by their physician. The device was successfully deployed in 98.5% of patients with no flow or minimal residual flow achieved in 99.3% of implanted patients. Twenty-eight subjects experienced 31 serious adverse events (SAEs) within 1 day of the procedure. The overall 30-day mortality rate was 0.7%. The most common SAE occurring within 30 days of the procedure was major bleeding requiring transfusion. Incidence of SAEs within 30 days was significantly lower for subjects deemed to be ineligible for oral anticoagulation therapy (OAT) compared with those eligible for OAT (6.5 vs. 10.2%, P = 0.042). CONCLUSION: Left atrial appendage closure with the WATCHMAN device has a high success rate in complete LAAC with low peri-procedural risk, even in a population with a higher risk of stroke and bleeding, and multiple co-morbidities. Improvement in implantation techniques has led to a reduction of peri-procedural complications previously limiting the net clinical benefit of the procedure.

Inter- and intravein differences in cardiac output with cardiac resynchronization pacing using a multipolar LV pacing lead.

BACKGROUND: Quadripolar left ventricular pacing leads permit a variety of pacing configurations from different sites within a coronary vein. There may be advantages to selecting a specific pacing vector. This study examines whether the range of cardiac outputs obtained at cardiac resynchronization therapy (CRT) implantation is greater between different poles within a vein, or greater between two different veins. METHODS AND RESULTS: The cardiac index (CI, L/min/m(2) ) was measured during CRT implantation using a noninvasive cardiac output monitor (NICOM™, Cheetah Medical Inc., Newton Center, MA, USA) and a quadripolar left ventricle (LV) lead, in 22 patients with sinus rhythm. CI was recorded during right atrial-biventricular pacing at 70/min with fixed atrioventricular and ventriculo-ventricular delay, from each LV electrode in one vein, and then from an alternate vein. Phrenic nerve stimulation (PNS) occurred in nine of 15 posterior and three of 21 anterior veins (P = 0.005). At least one electrode in each vein had no PNS. The mean (standard deviation [SD]) difference between best and worst CI within any one vein was 13.1% (±9%). The mean (SD) difference between the best CI in one vein compared to the other was 9.8% (±8%; P = 0.043). In 16 of 22 patients, the range of CI was greater between poles within one vein, rather than between two veins (best of one vein compared to best from the other). In four of 22 patients, the range was greater between veins (P = 0.0003). CONCLUSION: A greater range of CI is found within a single vein than between two different veins. This finding has implications both for the approach to implant technique and postimplant programming and optimization.