Ablation Strategies for Repeat Procedures in Atrial Fibrillation Recurrences Despite Durable Pulmonary Vein Isolation: The Prospective Randomized ASTRO AF Multicenter Trial.

BACKGROUND: Ablation strategies for patients with symptomatic atrial fibrillation and isolated pulmonary veins vary and their effects on arrhythmia recurrence remain unclear. A prospective randomized German multicenter trial sought to compare 2 ablation strategies in this patient cohort. METHODS: Patients with atrial fibrillation despite durable pulmonary vein isolation were randomly assigned at 7 centers to undergo low-voltage area ablation using 3-dimensional mapping and irrigated radiofrequency current ablation (group A) or empirical left atrial appendage isolation (LAAI) using the cryoballoon followed by staged interventional left atrial appendage closure (group B). The primary end point was freedom from atrial tachyarrhythmias between 91 and 365 days after index ablation. The study was powered for superiority of LAAI compared with low-voltage area. RESULTS: Patients (40% women; mean age, 68.8±8 years) with paroxysmal (32%) or persistent atrial fibrillation (68%) were randomized to undergo low-voltage area ablation (n=79) or cryoballoon-guided LAAI (n=82). After a planned interim analysis, enrollment was halted for futility on January 10, 2023. In the LAAI group, 77 of 82 left atrial appendages were successfully isolated with subsequent left atrial appendage closure in 57 patients. Procedure-related complications occurred in 4 (5%) and 11 (13.5%) patients in group A and B, respectively (P=0.10). The median follow-up was 367 days (interquartile range, 359-378). The Kaplan-Meier point estimate for freedom from atrial tachyarrhythmias was 51.7% (CI, 40.9%-65.4%) for group A and 55.5% (CI, 44.4%-69.2%; P=0.8069) for group B. CONCLUSIONS: The current study did not detect superiority of cryoballoon-guided LAAI over low-voltage area ablation in patients with atrial fibrillation despite durable PVI. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04056390.

Ventricular tachycardia due to left ventricular metastasis: A case report.

We present the case of a 60-year-old male patient who was admitted to our hospital after experiencing a syncopal episode. First ECGs showed sinus rhythm with polymorphic premature ventricular complexes and later ventricular tachycardia with a left bundle branch block morphology were recorded. Imaging with TEE and MRI revealed a space-occupying lesion in the left ventricle, which was ultimately identified as a rare cardiac metastasis of renal cell carcinoma. Treatment was initiated with monoclonal antibodies resulting in lesion regression. This case highlights the importance of comprehensive diagnostic in patients with history of malignancy.

A worldwide survey on incidence, management, and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: the POTTER-AF study.

AIMS: Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management, and outcome are sparse. METHODS AND RESULTS: This international multicentre registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553 729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed, at 214 centres in 35 countries. In 78 centres 138 patients [0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (P < 0.0001)] were diagnosed with an oesophageal fistula. Peri-procedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8% and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) [odds ratio 7.463 (2.414, 23.072) P < 0.001]. CONCLUSION: Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

Early recurrences predict late therapy failure after pulsed field ablation of atrial fibrillation.

INTRODUCTION: Pulsed field ablation (PFA) is a new ablation technology for atrial fibrillation (AF). Data regarding early recurrences of atrial tachyarrhythmia (ERAT) after PFA-pulmonary vein isolation (PVI) are sparse. METHODS: Consecutive patients with symptomatic AF were enrolled to undergo PFA-PVI. A dedicated catheter delivering bipolar energy (1.9-2.0 kV) was used. Late recurrence (LR) was defined as documented AF/atrial tachycardia (AT) lasting more than 30 s after a 90-day blanking period. RESULTS: Two hundred and thirty-one patients (42% female, age 69 ± 12, 55% paroxysmal AF [PAF]) were included in this analysis. Median follow-up time was 367 days (interquartile range: 253-400). Forty-six patients (21%) experienced ERAT after a median of 23 days (46% in PAF and 54% in persistent AF [persAF]). Kaplan-Meier estimated freedom of AF/AT was 74.2% at 1 year, 81.8% for PAF, and 64.8% for persAF (p = .0079). Of patients experiencing ERAT, an LR was observed in 54%. There was no significant difference of LR between those who presented with very early ERAT (0-45 days) and those with ERAT (46-90 days) (p = .57). In multivariate analysis, ERAT (hazard ratio [HR]: 3.370; 95% confidence interval [95% CI]: 1.851-6.136; p < .001) and female sex (HR: 2.048; 95% CI: 1.114-3.768; p = .021) were the only independent predictors for LR. CONCLUSIONS: ERAT could be recorded in 21% of patients after PFA-PVI and was an independent predictor for LR. We found no difference in the rate of LRs among patients experiencing ERAT before or after 45 days.

Prevention and treatment of pericardial tamponade in the electrophysiology laboratory: a European Heart Rhythm Association survey.

AIMS: Pericardial tamponade (PT) is the most frequent severe complication during electrophysiology (EP) procedures and requires immediate, co-ordinated, and effective treatment. However, multiple aspects of PT treatment are either not standardized or are under ongoing debate. METHODS AND RESULTS: An online questionnaire consisting of 26 multiple-choice questions was sent out to the European Heart Rhythm (EHRA) Research Network and also distributed via social media outputs. The EHRA survey was conducted between May and June 2023. A total of 213 replies were received from European (87%) and non-European countries. Ninety per cent of all participants perform interventions in dedicated EP labs equipped with different ablation platforms. In case of PT, most participants use X-ray as the main imaging modality guiding pericardial puncture, predominantly aiming for an anterior puncture site. Sheaths of different sizes are introduced into the pericardial space (84.3%), followed by a pigtail catheter. Application of protamine is an established but variable step in the majority (84.6%). Novel oral anticoagulants (NOAC) antidotes are not used by 73.3% of participants, while 15.2% routinely apply them. Re-transfusion of aspirated blood is performed by 72.1% [before protamine administration (18.2%), after protamine administration (13.5%), if pericardial effusion cannot be controlled (40.4%)]. A total of 72.4% re-transfuse without blood filter systems. A decision for surgical intervention is mostly taken if bleeding continues despite all interventional measures. CONCLUSION: The current survey demonstrates that the management of PT is heterogeneous among centres. The findings of this survey may help to guide operators in their treatment and decisions in the setting of PT.

Findings from repeat ablation using high-density mapping after pulmonary vein isolation with pulsed field ablation.

AIMS: Pulsed-field ablation (PFA) can offer a novel perspective for atrial fibrillation (AF) ablation. We aimed to characterize the incidence of pulmonary vein (PV) reconnection, types of recurrent atrial tachyarrhythmia (ATa) and lesion quality after PFA-guided PV isolation (PVI). METHODS AND RESULTS: Patients undergoing second ablation for recurrent ATa following the initial PVI using the pentaspline PFA catheter were investigated. The rate of PV reconnection, the features of recurrent ATa, and the amount of isolated posterior wall (PW) surface area (ISAPW%) (ratio of the isolated- to total surface area on PW) were analyzed. RESULTS: Among 360 patients treated with PFA, 25 patients (paroxysmal AF, n = 19) with 99 PVs underwent a second procedure 6.1 ± 4.0 months after the initial procedure. The rate of PV reconnection was 9.1% (9 PVs). Patients presented with atrial tachycardia (AT) (n = 16), AF (n = 8) and typical atrial flutter (n = 1). The mechanism of all but one AT was macro-reentry. The critical isthmus was found to be linked to the initial lesion set at the left atrial (LA) PW in eight patients and linked to pre-existing substrate at the LA anterior wall in four patients. One AT had a focal origin at the septum. In three patients, AT were unmappable. Mean ISAPW% was 72.7 ± 19.0%. CONCLUSION: We revealed a remarkable low reconnection rate with a large antral lesion at the PW after pentaspline PFA catheter-guided PVI. However, macro-reentrant AT with a critical isthmus at the LAPW linked to the PVI lesion set was commonly observed.

Single-sweep pulmonary vein isolation using the new third-generation laser balloon-Evolution in ablation style using endoscopic ablation system.

BACKGROUND: The endoscopic ablation system (EAS) is an established ablation device for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). The novel X3 EAS is now equipped with a contiguous circumferential ablation mode (RAPID mode). AIM: To determine the feasibility of single-shot fashioned ablation using X3. METHODS: Consecutive patients who underwent AF ablation using X3 were enrolled. We assessed the acute procedural data focusing on "Single-sweep PVI" defined as successful PVI with a single RAPID mode energy application, and on "first-pass isolation" defined as successful PVI after initial circular lesion set. RESULTS: One hundred AF patients (56% male, age: 68 ± 10 years, 66% paroxysmal AF) were analyzed. A total of 379 of 383 PVs (99%) were isolated with X3. Single-sweep PVI and first-pass-isolation were achieved in 214 PVs (56%) and in 362 PVs (95%), respectively. Single-sweep PVI rates varied across PVs with higher rates at the superior PVs (61.2% vs. inferior PVs: 49.5%, p = .0239) and at PVs with maximal ostial diameter <24 mm (57.6% vs. >24 mm: 36.8%, p = .0151). The mean total procedure and fluoroscopy times were 43.0 ± 10 and 4.0 ± 2 min, respectively. In none of the patients an acute thromboembolic event (stroke or transient ischemic attack) or a pericardial effusion/tamponade occurred. A single transient phrenic nerve palsy was observed. CONCLUSION: The new X3 EAS allows for single-shot fashioned ablation in terms of single-sweep PVI in half or more of PVs. The new RAPID ablation mode leads to an improved rate of first-pass isolation associated with very short procedure times without compromising safety.

Ablation Index-guided high-power (50 W) short-duration for left atrial anterior and roofline ablation: Feasibility, procedural data, and lesion analysis (AI High-Power Linear Ablation).

OBJECTIVES: To evaluate the feasibility, procedural data, and lesion characteristics of the anterior line (AL) and roofline (RL) ablation by using ablation index (AI)-guided high power (50 W) among patients with recurrent atrial fibrillation (AF) or atrial tachycardia (AT) after pulmonary vein isolation (PVI). METHODS: Data from 35 consecutive patients with macro-reentrant left atrial tachycardia or substrate at the left atrium anterior wall or roof after previous PVI were collected. Ablation power was set to 50 W, targeting AI 500 for AL and 400 for RL. The first-pass conduction block (FPB) was evaluated. The AL was arbitrarily divided into three (caudal, middle, and cranial) segments to analyze the location of conduction gaps in non-FPB patients. RESULTS: A total of 32 AL and 17 RL were deployed and FPB was achieved in 24 (75%) and 14 (82%) of them, respectively. In the non-FPB group, the most frequent gap location along the AL was the middle third. The final block of AL was achieved in 97%, and the block of RL was achieved in 100%. The radiofrequency (RF) ablation time was short (2.9 ± 0.8 min for AL and 46.2 ± 15.6 s for RL). For AL, the female gender was significantly more frequent in FPB than in non-FPB patients (p = .028); patients with non-FPB were associated with significantly longer RF time as compared to patients with FPB (204 ± 47 s vs. 161 ± 41 s; p = .02). No procedural complications occurred. CONCLUSION: AI-guided high-power (50 W) ablation appears to be a feasible, effective, and fast technique for AL and RL ablation.

Catheter ablation of atrial fibrillation using ablation index-guided high-power technique: Frankfurt AI high-power 15-month follow-up.

BACKGROUND: Radiofrequency (RF) high-power ablation appears to be a novel concept in treating atrial fibrillation (AF). The ablation-index (AI) has been linked with the durability of pulmonary vein isolation (PVI). To report the midterm clinical results of a new ablation strategy using AI-guided high-power (50 W) ablation (AI-HP). METHODS AND RESULTS: Symptomatic AF patients were included and underwent wide-area circumferential PVI. Contact-force catheters were used, RF power was set to 50 W targeting AI values (550/400 for anterior/posterior) and interlesion distance 6 mm. Luminal esophageal temperature (LET) was monitored during the procedure; patients with LET ≥39°C underwent post-ablation esophageal-endoscopy. Seventy-two-hour-Holter ECGs were scheduled during follow-up. Procedural PVI was achieved in all (N = 122; mean age, 68.2 years; male, 71.3%) patients, rate of first-pass PVI was 96.7% per patient. Procedural mean RF time was 11.5 min, and mean RF time during posterior wall segment was 3.1 min. Per RF-lesion, the mean contact force, RF duration, AI, and impedance-drop at anterior/posterior wall were 26 ± 14 g/23 ± 12 g, 16.2 ± 7.5 s/8.8 ± 3.6 s, 552 ± 53/438 ± 47, and 13 ± 6 Ω/9 ± 5 Ω, respectively. Mean PVI procedural-time, 55.8 min; mean procedural fluoroscopic time, 5.6 min. Three (2.5%) patients had asymptomatic endoscopic small erosion/erythema esophageal lesions, no serious adverse events were observed. During a 15-month follow-up, overall single-procedure freedom from clinical recurrence of AF/atrial tachycardia (AT) off antiarrhythmic drug after blanking period was 85.2% (89.4% for paroxysmal AF, 80.4% for persistent AF). CONCLUSION: The AI-HP (50 W) appears as an efficient ablation technique in treating AF and leads to a high single-procedure arrhythmia-free survival at 15 months.

Increased procedural safety of cryoballoon pulmonary vein isolation with a double 120 s freeze protocol.

BACKGROUND: Recently a double 120 s freeze cryoballoon (CB) pulmonary vein isolation (PVI) protocol proved to be non inferior to a double 240 s freeze protocol in terms of atrial fibrillation (AF) recurrences. We hypothesized that this approach could also result in an increased procedure safety. METHODS: Eighty consecutive patients treated with a double 120 s freeze protocol (Group CB120) were compared with 80 previous consecutive patients treated with a single 240 s freeze protocol (Group CB240). Procedures were performed with a temperature probe to monitor the luminal esophageal temperature (LET), using a cut off for cryoenergy interruption of 15°C. During ablation at the septal pulmonary veins (PVs), the phrenic nerve (PN) function was monitored by pacing. RESULTS: In CB120 and CB240 the rate of single shot isolation was similar in all PVs. Time to isolation was not different between the two groups. Mean minimal esophageal temperature was lower in LSPV and LIPV of the CB240 group. A total of 4/80 patients (5%) of the CB120 group experienced a PN injury, but no persistent form was recorded; 11/80 patients (14%) of the CB240 group experienced a PN injury, three in a persistent form (p = .10). A LET <15°C was recorded in 3/80 patients (4%) in the CB120 group and in 16/80 patients (20%) in the CB240 group (p < .01). Composite rate of energy-related safety events (LET <15°C and PN injury) was significantly lower in the CB120 (34% vs. 9%, p < .01). CONCLUSIONS: Safety of second generation CB PVI can be increased using a double 120 s freeze protocol.

Rhythm control for patients with atrial fibrillation complicated with heart failure in the contemporary era of catheter ablation: a stratified pooled analysis of randomized data.

AIMS: The optimal treatment for patients with atrial fibrillation (AF) and heart failure (HF) has been a subject of debate for years. We aimed to evaluate the efficacy and safety of rhythm control strategy in patients with AF complicated with HF regarding hard clinical endpoints. METHODS AND RESULTS: Up-to-date randomized data comparing rhythm control using antiarrhythmic drugs (AADs) vs. rate control (Subset A) or rhythm control using catheter ablation vs. medical therapy (Subset B) in AF and HF patients were pooled. The primary outcomes were all-cause mortality, re-hospitalization, stroke, and thromboembolic events. A total of 11 studies involving 3598 patients were enrolled (Subset A: 2486; Subset B: 1112). As compared with medical rate control, the AADs rhythm control was associated with similar all-cause mortality [odds ratio (OR): 0.96, P = 0.65], significantly higher rate of re-hospitalization (OR: 1.25, P = 0.01), and similar rate of stroke and thromboembolic events (OR: 0.91, P = 0.76,); however, as compared with medical therapy, catheter ablation rhythm control was associated with significantly lower all-cause mortality (OR: 0.51, P = 0.0003), reduced re-hospitalization rate (OR: 0.44, P = 0.003), similar rate of stroke events (OR: 0.59, P = 0.27), greater improvement in left ventricular ejection fraction [weighted mean difference (WMD): 6.8%, P = 0.0004], lower arrhythmia recurrence (29.6% vs. 80.1%, OR: 0.04, P < 0.00001), and greater improvement in quality of life (Minnesota Living with Heart Failure Questionnaire score) (WMD: -9.1, P = 0.007). CONCLUSION: Catheter ablation as rhythm control strategy substantially improves survival rate, reduces re-hospitalization, increases the maintenance rate of sinus rhythm, contributes to preserve cardiac function, and improves quality of life for AF patients complicated with HF.

miRNA degradation in the mammalian brain.

MicroRNAs (miRNAs) are short, noncoding RNAs that are evolutionarily conserved across many different species. miRNA regulation of gene expression, specifically in the context of the mammalian brain, has been well characterized; however, the regulation of miRNA degradation is still a focus of ongoing research. This review focuses on recent findings concerning the cellular mechanisms that govern miRNA degradation, with an emphasis on target-mediated miRNA degradation and how this phenomenon is uniquely poised to maintain homeostasis in neuronal systems.

Phrenic nerve injury in atrial fibrillation ablation using balloon catheters: Incidence, characteristics, and clinical recovery course.

AIMS: Systematic data on phrenic nerve palsy (PNP) associated with contemporary balloon ablation techniques (cryoballoon [CBA] vs laser balloon [LBA]) are sparse. We aimed to investigate the incidence, characteristics, and clinical recovery course in patients with PNP who underwent CBA or LBA. METHODS AND RESULTS: A total of 2433 consecutive patients who underwent balloon-based pulmonary vein isolation (CBA: n = 1720 and LBA: n = 713) were retrospectively identified. PNP was classified into (a) transient (recovery before discharge) or (b) persistent (within 6 months, 6-12 months, and >12 months) according to clinical recovery course. In general, PNP occurred significantly more often in CBA 71/1720 (4.2%) than LBA 11/713 (1.5%) (P = .003). The rate of transient PNP was significantly higher in CBA (3.0%, n = 45) than LBA (0.1%, n = 1, P = .004). The rate of persistent PNP did not significantly differ between two groups (CBA: 1.2% vs LBA: 1.4%, P = .89). The rate of persistent PNP which recovered within 6 months was similar (CBA: 17.4% vs LBA 18.2%, P = 1.000). However, the rates of persistent PNP which recovered within 6 to 12 months (CBA: 2.9% vs LBA 27.3%, P = .0171) and more than 12 months (CBA: 7.3% vs LBA 45.5%, P = .0034) were significantly higher in LBA. CONCLUSION: PNP occurred more often in CBA than LBA, however, the majority of PNP in CBA was transient whereas the majority of PNP in LBA was persistent. Either balloon technology is not superior in terms of long-term PNP.

Cryoballoon pulmonary vein isolation in treating atrial fibrillation using different freeze protocols: The "ICE-T 4 minutes vs 3 minutes" propensity-matched study (Frankfurt ICE-T 4 vs. 3).

BACKGROUND: Time-to-isolation (TTI) guided second-generation cryoballoon (CB2) ablation has been shown to be effective for pulmonary vein isolation (PVI). OBJECTIVE: The objective of this paper is to compare the safety and clinical outcome of CB2 PVI using the TTI guided 4 minutes vs 3 minutes freeze protocol. METHODS: This was a propensity-matched study based on an institutional database. Symptomatic atrial fibrillation (AF) patients who underwent CB2 PVI and systematic follow-up were consecutively included. RESULTS: A total of 573 patients were identified, of them 214 (107 matched-pairs) symptomatic AF (paroxysmal AF: 61%, persistent AF: 39%) patients (age: 67.7 ± 11.2 years) were analyzed. The baseline characteristics were comparable between the two groups. Procedural time was significantly longer in the 4 minutes group compared to 3 minutes group (67.2 ± 21.8 vs 55.9 ± 16.9 minutes, P < .0001). During a mean follow-up of 2 years, the 4 minutes group was associated with a significantly higher rate of freedom from arrhythmia recurrence compared with the 3 minutes group (66.4% vs 56.1%, P = .009), which was mainly driven by patients with persistent AF. The multivariate regression showed that the 4 minutes freeze was the independent predictor of freedom from arrhythmia recurrence. During the repeat procedure, the 4 minutes group was associated with a significantly higher rate of durable PVI. There was no difference regarding procedural adverse events between the two groups. CONCLUSION: As compared with the 3 minutes freeze, the TTI guided 4 minutes freeze is associated with a significantly higher rate of arrhythmia-free and durable PVI without compromising the safety profile, patients with persistent AF may benefit from the TTI guided 4 minutes freeze more pronouncedly.

Holter ECG diagnosis of nicotine-spray induced ventricular fibrillation. An unusual case of Prinzmetal variant angina.

We report on an interesting case of resuscitated sudden cardiac death (SDC) in a 51-year-old with hypertension and positive family history for SDC. The patient was resuscitated and an emergency angiogram ruled out coronary artery disease. Cardio-MRT ruled structural disease or infection. Holter and telemetry monitoring revealed premature ventricular complexes and transient ST-changes followed by anginaepisodes in correlation with the use of the nicotine-replacement-spray. The patient was urged to quit smoking and smoking-substitutes. Medical therapy with calcium-channelblocker and a long acting nitrate was administered. One-month follow up reported no arrhythmic or angina events.

TNF-α-induced protein 3 is a key player in childhood asthma development and environment-mediated protection.

BACKGROUND: Childhood asthma prevalence is significantly greater in urban areas compared with rural/farm environments. Murine studies have shown that TNF-α-induced protein 3 (TNFAIP3; A20), an anti-inflammatory regulator of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, mediates environmentally induced asthma protection. OBJECTIVE: We aimed to determine the role of TNFAIP3 for asthma development in childhood and the immunomodulatory effects of environmental factors. METHODS: In a representative selection of 250 of 2168 children from 2 prospective birth cohorts and 2 cross-sectional studies, we analyzed blood cells of healthy and asthmatic children from urban and rural/farm environments from Europe and China. PBMCs were stimulated ex vivo with dust from "asthma-protective" farms or LPS. NF-κB signaling-related gene and protein expression was assessed in PBMCs and multiplex gene expression assays (NanoString Technologies) in isolated dendritic cells of schoolchildren and in cord blood mononuclear cells from newborns. RESULTS: Anti-inflammatory TNFAIP3 gene and protein expression was consistently decreased, whereas proinflammatory Toll-like receptor 4 expression was increased in urban asthmatic patients (P < .05), reflecting their increased inflammatory status. Ex vivo farm dust or LPS stimulation restored TNFAIP3 expression to healthy levels in asthmatic patients and shifted NF-κB signaling-associated gene expression toward an anti-inflammatory state (P < .001). Farm/rural children had lower expression, indicating tolerance induction by continuous environmental exposure. Newborns with asthma at school age had reduced TNFAIP3 expression at birth, suggesting TNFAIP3 as a possible biomarker predicting subsequent asthma. CONCLUSION: Our data indicate TNFAIP3 as a key regulator during childhood asthma development and its environmentally mediated protection. Because environmental dust exposure conferred the anti-inflammatory effects, it might represent a promising future agent for asthma prevention and treatment.

Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation.

BACKGROUND: Current guidelines recommend pulmonary-vein isolation by means of catheter ablation as treatment for drug-refractory paroxysmal atrial fibrillation. Radiofrequency ablation is the most common method, and cryoballoon ablation is the second most frequently used technology. METHODS: We conducted a multicenter, randomized trial to determine whether cryoballoon ablation was noninferior to radiofrequency ablation in symptomatic patients with drug-refractory paroxysmal atrial fibrillation. The primary efficacy end point in a time-to-event analysis was the first documented clinical failure (recurrence of atrial fibrillation, occurrence of atrial flutter or atrial tachycardia, use of antiarrhythmic drugs, or repeat ablation) following a 90-day period after the index ablation. The noninferiority margin was prespecified as a hazard ratio of 1.43. The primary safety end point was a composite of death, cerebrovascular events, or serious treatment-related adverse events. RESULTS: A total of 762 patients underwent randomization (378 assigned to cryoballoon ablation and 384 assigned to radiofrequency ablation). The mean duration of follow-up was 1.5 years. The primary efficacy end point occurred in 138 patients in the cryoballoon group and in 143 in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 34.6% and 35.9%, respectively; hazard ratio, 0.96; 95% confidence interval [CI], 0.76 to 1.22; P<0.001 for noninferiority). The primary safety end point occurred in 40 patients in the cryoballoon group and in 51 patients in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 10.2% and 12.8%, respectively; hazard ratio, 0.78; 95% CI, 0.52 to 1.18; P=0.24). CONCLUSIONS: In this randomized trial, cryoballoon ablation was noninferior to radiofrequency ablation with respect to efficacy for the treatment of patients with drug-refractory paroxysmal atrial fibrillation, and there was no significant difference between the two methods with regard to overall safety. (Funded by Medtronic; FIRE AND ICE ClinicalTrials.gov number, NCT01490814.).

Compound motor action potential guided 240 seconds plus bonus freeze for safe and durable left atrial appendage isolation in patients with recurrent persistent atrial fibrillation: How to isolate the appendage with cryoballoon (the CMAP guided ICE-B protocol).

INTRODUCTION: Pulmonary vein isolation (PVI) is the cornerstone ablation strategy for treatment of atrial fibrillation (AF). Ablation outside the PVs is sometimes needed particularly in persistent or longstanding AF. This study reported left atrial appendage isolation (LAAI) using cryoballoon (CB) focusing on technical data and short-term clinical follow-up. METHODS AND RESULTS: Patients with recurrent persistent AF after multiple AF procedures were enrolled. LAAI was performed using the second generation CB guided by compound motor action potential (CMAP) and 240 seconds plus bonus freeze (ICE-B) protocol. Ten patients were included, median age was 69.5 (56-73) years, CHA2 DS 2 -VASc score was 3 (1.8-4), LA diameter was 44 (38.8-46.5) mm. All patients had a mean of three AF procedures before the LAAI procedure. All patients were under successful CMAP guidance. During the CB LAAI procedure, the median time to LAA isolation was 100 (76-270) seconds, minimal freeze temperature was -50 (-57 to -47)°C. A "pull-down (or pull-away)" CB maneuver was performed in all patients. Median fluoroscopic time was 4.8 (3.4-6.8) minutes and acute LAAI success rate was 100%. No phrenic nerve injury or other major complications were observed. At 6-week follow-up, remapping of the LAA showed durable isolation of all PVs (100%), all patients were scheduled for LAA occlusion. Six-month follow-up showed that 80% of patients were free from AF/AT recurrence. CONCLUSION: CMAP plus ICE-B guided LAAI using cryo-technology appears feasible and safe, results in durable LAAI, and shows promising clinical results in patients with recurrent persistent AF.

Ablation index-guided 50 W ablation for pulmonary vein isolation in patients with atrial fibrillation: Procedural data, lesion analysis, and initial results from the FAFA AI High Power Study.

BACKGROUND: Radiofrequency high-power ablation appears to be a novel concept for atrial fibrillation (AF). The ablation index (AI) value has been associated with durability of pulmonary vein isolation (PVI). OBJECTIVES: This study aimed to report the procedural data and initial results of a combined ablation technique using AI-guided high-power (AI-HP; 50 W) ablation for PVI. METHODS: Symptomatic AF patients were consecutively enrolled and underwent wide-area contiguous circumferential PVI. Contact-force catheters were used, ablation power was set to 50 W targeting AI values (550 anterior and 400 posterior). Esophageal temperature was monitored during procedure, all patients underwent postablation esophageal endoscopy. RESULTS: PVI was achieved in all (n = 50, mean age: 68 ± 9 years, female: 60%) patients, rate of first-round PVI was 92%. A total of N = 2105 AI-guided ablation lesions were analyzed. Comparing left anterior wall vs left posterior wall and right anterior wall vs right posterior wall, mean ablation time (s) per lesion was 20.5 ± 8 vs 8.6 ± 3 and 12.2 ± 4 vs 9.3 ± 3; mean contact force (g): 17.1 ± 12 vs 25.4 ± 14 and 33.7 ± 13 vs 21.0 ± 11; mean AI: 547 ± 48 vs 445 ± 55 and 555 ± 56 vs 440 ± 47 (all P < .0001). Procedure and fluoroscopy time (minute) were 55.6 ± 6.6 and 6 ± 1.7, respectively. Only one (2%) patient had a minimal esophageal lesion. During In-hospital and 1-month follow-up no major complications such as death, stroke, tamponade, or atriaesophageal fistula (AE) occurred. Preliminary 6-month follow-up showed 48 of 50 (96%) patients were free from clinical AF/atrial tachycardia recurrence. CONCLUSION: AI-HP (50 W) ablation appears to be a feasible, safe, fast, and effective ablation technique for PVI.

Synergy of pulmonary vein isolation and catheter renal denervation in atrial fibrillation complicated with uncontrolled hypertension: Mapping the renal sympathetic nerve and pulmonary vein (the pulmonary vein isolation plus renal denervation strategy)?

INTRODUCTION: Disturbance of sympathetic and vagal nervous system participates in the pathogenesis of hypertension and atrial fibrillation (AF). Renal denervation (RDN) can modulate autonomic nervous activity and reduce blood pressure (BP) in hypertensive patients. We aimed to evaluate the effect of RDN combined with pulmonary vein isolation (PVI) in patients with AF and hypertension. METHODS: Clinical trials including randomized data comparing PVI plus RDN vs PVI alone were enrolled. Primary outcome was incidence of AF recurrence after procedure. RESULTS: A total of 387 patients, of them 252 were randomized and were enrolled. Mean age was 57 ± 10 years, 71% were male, and mean left ventricular ejection fraction was 57.4% ± 6.9%. Follow-up for randomized data was 12 months. Overall comparison for primary outcome showed that PVI + RDN was associated with significantly lower AF recurrence as compared with PVI alone (35.8% vs 55.4%, P < 0.0001). This advantageous effect was consistently maintained among randomized patients (37.3% vs 61.9%, odds ratio = 0.37, P = 0.0001), and among patients with implanted devices for detection of AF recurrence (38.9% vs 61.6%, P = 0.007). Post-hoc sensitivity and regression analysis demonstrated very good stability of this primary result. Pooled Kaplan-Meier analysis further showed that PVI + RDN was associated with significantly higher freedom from AF recurrence as compared with PVI alone (log-rank test, P = 0.001). Besides, RDN resulted in significant BP reduction without additionally increasing the risk of adverse events. CONCLUSIONS: RDN may provide synergetic effects with PVI to reduce the burden of AF and improve BP control in patients with AF and uncontrolled hypertension.