Surpoint algorithm for improved guidance of ablation for ventricular tachycardia (SURFIRE-VT): A pilot study.

INTRODUCTION: The utility of ablation index (AI) to guide ventricular tachycardia (VT) ablation in patients with structural heart disease is unknown. The aim of this study was to assess procedural characteristics and clinical outcomes achieved using AI-guided strategy (target value 550) or conventional non-AI-guided parameters in patients undergoing scar-related VT ablation. METHODS: Consecutive patients (n = 103) undergoing initial VT ablation at a single center from 2017 to 2022 were evaluated. Patient groups were 1:1 propensity-matched for baseline characteristics. Single lesion characteristics for all 4707 lesions in the matched cohort (n = 74) were analyzed. The impact of ablation characteristics was assessed by linear regression and clinical outcomes were evaluated by Cox proportional hazard model. RESULTS: After propensity-matching, baseline characteristics were well-balanced between AI (n = 37) and non-AI (n = 37) groups. Lesion sets were similar (scar homogenization [41% vs. 27%; p = .34], scar dechanneling [19% vs. 8%; p = .18], core isolation [5% vs. 11%; p = .4], linear and elimination late potentials/local abnormal ventricular activities [35% vs. 44%; p = .48], epicardial mapping/ablation [11% vs. 14%; p = .73]). AI-guided strategy had 21% lower procedure duration (-47.27 min, 95% confidence interval [CI] [-81.613, -12.928]; p = .008), 49% lower radiofrequency time per lesion (-13.707 s, 95% CI [-17.86, -9.555]; p < .001), 21% lower volume of fluid administered (1664 cc [1127, 2209] vs. 2126 cc [1750, 2593]; p = .005). Total radiofrequency duration (-339 s [-24%], 95%CI [-776, 62]; p = .09) and steam pops (-155.6%, 95% CI [19.8%, -330.9%]; p = .08) were nonsignificantly lower in the AI group. Acute procedural success (95% vs. 89%; p = .7) and VT recurrence (0.97, 95% CI [0.42-2.2]; p = .93) were similar for both groups. Lesion analysis (n = 4707) demonstrated a plateau in the magnitude of impedance drops once reaching an AI of 550-600. CONCLUSION: In this pilot study, an AI-guided ablation strategy for scar-related VT resulted in shorter procedure time and average radiofrequency time per lesion with similar acute procedural and intermediate-term clinical outcomes to a non-AI-guided approach utilizing traditional ablation parameters.

Comparison of radiofrequency ablation from the coronary cusps and endocardial left ventricular outflow tract for left ventricular summit ventricular arrhythmias in a porcine and infrared thermal model.

INTRODUCTION: The coronary cusps (CCs) are utilized as an alternative vantage point for radiofrequency catheter ablation (RFCA) of left ventricular summit ventricular arrhythmias but are sometimes a challenge despite favorable activation timing and pace mapping. METHODS: Ex vivo experiments were performed in 12 intact porcine hearts submerged in a 37°C saline bath. Radiofrequency (RF) applications were delivered with an irrigated contact force sensing catheter oriented 45° to the endocardial left ventricular outflow tract (LVOT) surface and nadir of the CCs using different dosing parameters. Sections were stained in 2% triphenyltetrazolium chloride and lesion dimensions were measured. Thermal infrared imaging analysis was used to compare time-to-lethal tissue temperature and depth/area of lethal isotherms. RESULTS: A total of 60 RF applications were performed under different dosing parameters for (1) 30, 40, and 50 Watts (W) × 30 s and (2) 40 W × 30, 45, and 60 s. Lesion depth was greater with RFCA from LVOT than from the CCs (maximum depth 6.11 vs. 2.68 mm). Longer RF duration led to larger lesion volume in the CC group (40 W × 30 s: 8.1 ± 0.4 vs. 40 W × 60 s: 10.1 ± 0.96 mm; p = .002). One steam pop occurred in both the LVOT (50 W × 30 s) and CC groups (40 W × 60 s). Time-to-reach lethal temperature of 58°C was longer in the CC group than in the LVOT group (4.7 vs. 11.3 s; p = .02) CONCLUSIONS: RFCA from the CC led comparatively to shallower lesion depth than from the LVOT. Longer RF duration led to an increase in lesion volume during ablation from CCs.

Mortality benefit of catheter ablation versus medical therapy in atrial fibrillation: An RCT only meta-analysis.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF) in comparison to medical therapy alone is known to improve freedom from arrhythmia and quality of life, but the benefit regarding mortality is unclear. The publication of several recent large randomized controlled trials (RCT) comparing ablation with medical therapy has warranted an updated meta-analysis. METHODS: We sought to compare the effectiveness of catheter ablation versus medical therapy only in patients with AF. MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched from inception until 04/30/2021. Relevant RCTs comparing catheter ablation versus medical therapy in patients with AF were selected. RESULTS: A total of 24 RCTs involving 5730 adult patients were included (2992 in catheter ablation and 2738 in medical therapy). There was a reduction in all-cause mortality with catheter ablation compared with medical therapy only (risk ratio (RR) 0.70 [95% confidence interval (CI) 0.55-0.89]; p = .003). Catheter ablation also demonstrated a reduction in hospitalizations (RR 0.50 [95% CI 0.36-0.70]; p < .001), improvement in left ventricular ejection fraction (LVEF) (mean difference [MD] + 5.94% [95% CI 0.40-11.48] p = .04), greater freedom from atrial arrhythmia (RR 2.23 [95% CI 1.79-2.76]; p < .001), and AF (RR 1.95 [95% CI 1.44-2.66]; p < .001). In subgroup analysis, catheter ablation demonstrated a significant reduction in mortality and hospitalizations among patients with reduced LVEF, and when ablation was compared with antiarrhythmic drug use. CONCLUSIONS: In comparison to medical therapy only, catheter ablation for atrial fibrillation reduces mortality, hospitalizations, and increases freedom from arrhythmia.

Comparison of ablation index versus time-guided radiofrequency energy dosing using normal and half-normal saline irrigation in a porcine left ventricular model.

BACKGROUND: Ablation Index (AI) is a multiparametric quality marker to assess the durability of radiofrequency (RF) lesions. The comparative effectiveness and safety of AI versus time-based energy dosing for ablation of ventricular arrhythmias are unknown. OBJECTIVE: We compared AI and time-based RF dosing strategies in the left ventricles (LVs) of freshly harvested porcine hearts. METHODS: Ablation was performed in vitro with an open-irrigated ablation catheter (Thermocool ST/SF), 40 W, contact force 10-15 g. Tissue samples were stained in triphenyltetrazolium chloride for the measurement of lesion dimensions. RESULTS: A total of 560 lesions were performed (AI-group: [n = 360]; time-group: [n = 200]). Using normal saline (NS) (n = 280), growth in lesion depth slowed after 30 s and AI > 550 in comparison to width, volume, and magnitude of impedance drops which continued to increase with longer RF duration. Risk of steam pop (SP) was higher for RF > 30 s (RF < 30 s:1 SP [2.5%] vs. RF > 30 s: 15 SP [25%]; p = .002) or AI targets >550 (AI: 350-550: 2 SP [2%] vs. AI 600-750: 15 SP [19%]; p = .001). Using half-normal saline (HNS) (n = 280), lesion dimension and impedance drops were larger and growth in lesion depth slowed earlier (AI: 500). Risk of SPs was higher above AI 550 (AI: 350-550: 7 [7%] SPs vs. AI 600-750: 28 [35%] SPs; p < .00001). While codependent variables, correlation between AI and time was modest-to-strong but decreased with longer RF duration. CONCLUSION: In this ex vivo study, AI was a better predictor of lesion dimensions than ablation time and magnitude of impedance drop in the LV using NS and HNS irrigation. AI targets above 550 led to a higher risk of SPs. Future trials are required to verify these findings.

Feasibility and safety of laser balloon pulmonary vein isolation in patients with prior left atrial appendage occlusion device implantation.

INTRODUCTION: With the increasing adoption of left atrial appendage occlusion (LAAO) procedures and the eligibility of patients for pulmonary vein isolation (PVI) post device placement, we examined the feasibility and safety of laser balloon (LB) for PVI in patients with prior LAAO. METHODS: We retrospectively examined consecutive patients with paroxysmal or persistent, drug-resistant atrial fibrillation (AF) who underwent LB PVI, after Watchman FLX device implantation at Rush University Medical Center between January 2020 and December 2021. RESULTS: Seven patients (four persistent and three paroxysmal) with a mean age of 64 ± 11 years, predominantly male sex (86%), were included in the study. Two (29%) patients had prior cryoablation PVI with recurrence of AF. The mean CHA2 DS2 VASc is 2.6 ± 0.5 and the mean HAS-BLED score is 3.4 ± 0.8. The mean follow-up duration was 10 ± 7 months. The mean duration between Watchman FLX device implantation and LB PVI was 592 days. Acute first pass left pulmonary vein (PV) isolation was achieved in 100% of the procedures. There were no periprocedural complications such as death, pericardial tamponade or effusion, phrenic nerve injury, PV stenosis, device perforation or embolization, or worsening peri-device leak in any of the patients. None of the patients had AF recurrence after the blanking period. CONCLUSION: LB PVI was safe and effective with 100% acute isolation of left-sided veins in patients with prior LAAO device.

Use of infrared thermography to delineate temperature gradients and critical isotherms during catheter ablation with normal and half normal saline: Implications for safety and efficacy.

BACKGROUND: Radiofrequency (RF) ablation with half-normal saline (HNS) has shown promise as a bail-out strategy following failed ventricular tachycardia ablation using standard approaches. OBJECTIVE: To use a novel infrared thermal imaging (ITI) model to evaluate biophysical and lesion characteristics during RF ablation using normal saline (NS) and HNS irrigation. METHODS: Left ventricular strips of myocardium were excised from fresh porcine hearts. RF ablation was performed using an open-irrigated ablation catheter (Thermocool ST/SF) with NS (n = 75) and HNS (n = 75) irrigation using different power settings (40/50 W), RF durations (30/60 s), contact force of 10-15 g, and flow rate of 15 ml/min. RF lesions were recorded using an infrared thermal camera and border zone, lethal, 100° isotherms were matched with necrotic borders after 2% triphenyltetrazolium chloride staining. Lesion dimensions and isotherms (mm2 ) were measured. RESULTS: In total, 150 lesions were delivered. HNS lesions were deeper (6.4 ± 1.1 vs. 5.7 ±0.8 mm; p = .03), and larger in volume (633 ± 153 vs. 468 ± 107 mm3 ; p = .007) than NS lesions. Steam pops (SPs) occurred during 19/75 lesions (25%) in the NS group and 32/75 lesions (43%) in the HNS group (p = .34). Lethal (57.8 ± 6.5 vs. 36.0 ± 3.9 mm2 ; p = .001) and 100°C isotherm areas (16.9 ± 6.9 vs. 3.8 ± 4.2 mm2 ; p = .003) areas were larger and were reached earlier in the HNS group. CONCLUSIONS: RFA using HNS created larger lesions than NS irrigation but led to more frequent SPs. The presence of earlier lethal isotherms and temperature rises above 100°C on ITI suggest a potentially narrower therapeutic-safety window with HNS.

High-power short duration vs. conventional radiofrequency ablation of atrial fibrillation: a systematic review and meta-analysis.

AIMS: We sought to compare the effectiveness and safety of high-power short-duration (HPSD) radiofrequency ablation (RFA) with conventional RFA in patients with atrial fibrillation (AF). METHODS AND RESULTS: MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 15 May 2020 for relevant studies comparing HPSD vs. conventional RFA in patients undergoing initial catheter ablation for AF. A total of 15 studies involving 3718 adult patients were included in our meta-analysis (2357 in HPSD RFA and 1361 in conventional RFA). Freedom from atrial arrhythmia was higher in HPSD RFA when compared with conventional RFA [odds ratio (OR) 1.44, 95% confidence interval (CI) 1.10-1.90; P = 0.009]. Acute PV reconnection was lower (OR 0.56, P = 0.005) and first-pass isolation was higher (OR 3.58, P < 0.001) with HPSD RFA. There was no difference in total complications between the two groups (P = 0.19). Total procedure duration [mean difference (MD) -37.35 min, P < 0.001], fluoroscopy duration (MD -5.23 min, P = 0.001), and RF ablation time (MD -16.26 min, P < 0.001) were all significantly lower in HPSD RFA. High-power short-duration RFA also demonstrated higher freedom from atrial arrhythmia in the subgroup analysis of patients with paroxysmal AF (OR 1.80, 95% CI 1.29-2.50; P < 0.001), studies with ≥50 W protocol in the HPSD RFA group (OR 1.53, 95% CI 1.08-2.18; P = 0.02] and studies with contact force sensing catheter use (OR 1.65, 95% CI 1.21-2.25; P = 0.002). CONCLUSION: High-power short-duration RFA was associated with better procedural effectiveness when compared with conventional RFA with comparable safety and shorter procedural duration.

His bundle pacing: Tips and tricks.

His bundle (HB) pacing is an established modality for achieving physiological pacing with a low risk of long-term lead-related complications. The development of specially designed lead and delivery tools has improved the feasibility and safety of HB pacing (HBP). Knowledge of the anatomy of HB region and the variations is essential for successful implantation. Newer delivery systems have further improved procedural outcomes. Challenging implant cases can be successfully performed by reshaping the current sheaths, using "sheath in sheath" technique or "two-lead implantation technique." Special attention to the lead parameters at implant, programming, and follow-up is necessary for successful long-term outcomes with HBP. Widespread use of HBP by electrophysiologists and further advances in dedicated delivery systems and leads are essential to further improve the effectiveness of the implantation.

A systematic review and meta-analysis comparing second-generation cryoballoon and contact force radiofrequency ablation for initial ablation of paroxysmal and persistent atrial fibrillation.

INTRODUCTION: Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the preferred modalities for catheter ablation of atrial fibrillation (AF). Technological advances have improved procedural outcomes, warranting an updated comparison. We sought to evaluate the efficacy and safety of CBA-2nd generation (CBA-2G) in comparison to RFA-contact force (RFA-CF) in patients with AF. METHODS: MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 03/01/2020 for relevant studies comparing CBA-2G versus RFA-CF in patients undergoing initial catheter ablation for AF. RESULTS: A total of 17 studies, involving 11 793 patients were included. There was no difference between the two groups in the outcomes of freedom from atrial arrhythmia (p = .67) and total procedural complications (p = .65). There was a higher incidence of phrenic nerve palsy in CBA-2G (odds ratio: 10.7; 95% confidence interval [CI]: 5.85 to 19.55; p < .001). Procedure duration was shorter (mean difference: -31.32 min; 95% CI: -40.73 to -21.92; p < .001) and fluoroscopy duration was longer (+3.21 min; 95% CI: 1.09 to 5.33; p = .003) in CBA-2G compared to RFA-CF. In the subgroup analyses of patients with persistent AF and >1 freeze lesion delivered per vein, there was no difference in freedom from atrial arrhythmia. CONCLUSIONS: In AF patients undergoing initial ablation, CBA-2G and RFA-CF were equally efficacious. The procedure duration was shorter, but with a higher incidence of phrenic nerve palsy in CBA-2G. In patients with persistent AF, there was no difference in the efficacy between CBA-2G or RFA-CF techniques.

Meta-analysis of pulmonary vein isolation ablation for atrial fibrillation conventional vs low- and zero-fluoroscopy approaches.

INTRODUCTION: Radiation exposure during catheter ablation procedures is a significant hazard for both patients and operators. Atrial fibrillation (AF) ablation procedures have been historically associated with higher fluoroscopy usage than other electrophysiology procedures. Recent efforts have been made to reduce dependence on fluoroscopy during pulmonary vein isolation (PVI) ablation procedures using alternative techniques. METHODS: We performed a meta-analysis of studies comparing zero or low fluoroscopy (LF) vs conventional fluoroscopy (CF) approaches for AF ablation. Outcomes of interest included acute and 12-month procedural efficacy, safety, procedure duration, fluoroscopy time, and dose area product. Aggregated data were analyzed with random-effects models, using a Bayesian hierarchical approach. RESULTS: A total of 2228 participants (LF, n = 1190 vs CF, n = 1038) from 15 studies were included in the meta-analysis. Risk of AF recurrence in 12 months (odds ratio [OR], 95% confidence interval [95% CI] = 1.343 [0.771-2.340]; P = .297), redo-ablation procedures (OR [95% CI] = 0.521 [0.198-1.323]; P = .186), and procedural complications (OR [95% CI] = 0.99 [0.485-2.204]; P = .979) were similar between LF- and CF-ablation groups. In comparison to CF ablation, LF ablation led to shorter procedure duration (weighted mean differences [WMDs] [95% CI] = -14.6 minutes [-22.5 to -6.8]; P < .001), fluoroscopy time (WMD [95% CI] = -8.8 minutes [-11.9 to -5.9]; P < .001), and dose area product (WMD [95% CI] = -1946 mGy/cm2 [-2685 to 1207]; P < .001). CONCLUSION: LF approaches have similar clinical efficacy and safety as CF approaches for PVI. LF approaches are associated with shorter procedure time, fluoroscopy usage, and dose area product during PVI.

Permanent His Bundle Pacing: A programming and troubleshooting guide.

Permanent His Bundle Pacing (HBP) has recently gained popularity. However, implanting physicians and those who perform the device checks must invest in additional education in order to accurately program these devices, identify changes in morphology and perform troubleshooting to help achieve the best outcomes for the patients. This paper reviews key aspects of HBP and provides the educational tools for successful HBP follow-up and troubleshooting.

Topical steroids in eosinophilic esophagitis: Systematic review and meta-analysis of placebo-controlled randomized clinical trials.

BACKGROUND AND AIMS: Eosinophilic esophagitis (EoE) is a clinicopathologic condition characterized by symptoms of esophageal dysfunction in the presence of eosinophil-predominant inflammation of esophageal mucosa. Topical steroids are recommended as first line pharmacologic therapy in EoE. We aimed to determine the efficacy of topical steroids in inducing histologic and clinical remission in children and adults with EoE. METHODS: We performed a systematic search of the MEDLINE, EMBASE, Scopus, and Cochrane library databases for studies investigating the efficacy of topical steroids in EoE. We collected data on the number of patients, dose and duration of therapy, complete and partial histological response, and clinical improvement. We performed meta-analysis of placebo-controlled randomized clinical trials using Review Manager version 5.2. We used funnel plots to evaluate for publication bias. RESULTS: Five studies that included 174 patients with EoE were included in the meta-analysis. Topical fluticasone was administered in three studies involving 114 patients, and topical budesonide in two studies involving 60 patients. Patients treated with topical steroids, as compared with placebo, had higher complete histological remission (odds ratio [OR] 20.81, 95% confidence interval [CI] 7.03, 61.63) and partial histological remission (OR 32.20, 95% CI 6.82, 152.04). There was a trend towards improvement in clinical symptoms with topical steroids as compared with placebo but it did not reach statistical significance (OR 2.72, 95 %CI 0.90, 8.23). CONCLUSIONS: Topical corticosteroids seem to be effective in inducing histological remission but may not have similar significant impact in improving clinical symptoms of EoE. Studies with large sample size are needed to uniformly validate symptom improvement in EoE.

A systematic review and meta-analysis comparing radiofrequency catheter ablation with medical therapy for ventricular tachycardia in patients with ischemic and non-ischemic cardiomyopathies.

BACKGROUND: In patients with cardiomyopathy, radiofrequency catheter ablation (CA) for ventricular tachycardia (VT) is an adjunctive and alternative treatment option to long-term anti-arrhythmic drug therapy. We sought to compare CA with medical therapy for the management of VT in patients with ischemic and non-ischemic cardiomyopathies. METHODS: MEDLINE, Cochrane, and ClinicalTrials.gov databases were evaluated for relevant studies. RESULTS: Eleven studies with 2126 adult patients were included (711 in CA, 1415 in medical therapy). In the randomized controlled trial (RCT) analysis, CA reduced risk of recurrent VT (risk ratio (RR) 0.79 [95% CI 0.67 to 0.93], p = 0.005), ICD shocks (RR 0.64 [95% CI 0.45 to 0.89] p = 0.008), and cardiac hospitalizations (RR 0.76 [95% CI 0.63 to 0.92] p = 0.005). There was no difference in all-cause mortality (RR 0.94, p = 0.71). In combined RCT and observational study analysis, there was a trend for reduction in all-cause mortality (RR 0.75 [95% CI 0.55 to 1.02] p = 0.07). In subgroup analysis of studies with mean left ventricular ejection fraction (LVEF) < 35%, CA demonstrated reduction in mortality (RR 0.71, p = 0.004), ICD shocks (RR 0.63, p = 0.03), VT recurrence (RR 0.76, p = 0.004), and cardiac hospitalizations (RR 0.75, p = 0.02). The subgroup of early CA prior to ICD shocks demonstrated reduction in ICD shocks (RR 0.57, p < 0.001) and VT recurrence (RR 0.74, p = 0.01). CONCLUSIONS: CA for VT demonstrated a lower risk of VT recurrence, ICD shocks, and hospitalization in comparison to medical therapy. The subgroups of early CA and LVEF < 35% demonstrated better outcomes.

Solving the Reach Problem: A Review of Present and Future Approaches for Addressing Ventricular Arrhythmias Arising from Deep Substrate.

Ventricular tachycardia (VT) is a significant cause of morbidity and mortality in patients with ischaemic and non-ischaemic cardiomyopathies. In most patients, the primary strategy of VT catheter ablation is based on the identification of critical components of reentry circuits and modification of abnormal substrate which can initiate reentry. Despite technological advancements in catheter design and improved ability to localise abnormal substrates, putative circuits and site of origins of ventricular arrhythmias (VAs), current technologies remain inadequate and durable success may be elusive when the critical substrate is deep or near to critical structures that are at risk of collateral damage. In this article, we review the available and potential future non-surgical investigational approaches for treatment of VAs and discuss the viability of these modalities.

Incidence and risk factors of atrial fibrillation and atrial arrhythmias in people living with HIV: a systematic review and meta-analysis.

BACKGROUND: Cardiovascular diseases in people living with HIV (PLWH) are becoming increasingly relevant as HIV/AIDS has become more treatable with the advent of highly efficacious antiretroviral therapy. Previous studies suggested that HIV infection is an independent risk factor for atrial arrhythmia. This study aims to collectively analyze these studies to elucidate the incidence and risk factors of atrial arrhythmia in PLWH. METHODS: Full-text assessments and data extraction were performed from available literature. Atrial arrhythmia was defined as atrial fibrillation or atrial flutter. Incidence rate, risk, and potential risk factors of atrial arrhythmia in PLWH were catalogued, after which random-effects models were used to estimate pooled summary statistics. PRISMA standardized meta-analysis guidelines were followed. RESULTS: Analysis of 94,928 PLWH had an averaged incidence rate of 6.4 cases of atrial arrhythmia per 1000 person-years. Risk of atrial arrhythmia was significantly higher in PLWH than in the general population (RR 1.35; 95% CI 1.19-1.53). Sex had no association with the risk of incidental atrial arrhythmia in PLWH (RR 1.47; 95% CI 0.95-2.28). Black race (RR 0.68; 95% CI 0.47-0.97) was associated with decreased risk, whereas lower CD4 counts (RR 1.80; 95% CI 1.18-2.77) and increased viral load (RR 1.57; 95% CI 1.19-2.09) suggested increased risk of atrial arrhythmia in PLWH. CONCLUSIONS: HIV infection is a risk factor of atrial arrhythmia. Providers should be aware of the increased burden of atrial arrhythmia in PLWH and continue to encourage treatment of HIV infection while managing cardiovascular risk factors and screening for arrhythmias in symptomatic patients.

Effect of weight loss on recurrence of atrial fibrillation after ablative therapy: a systematic review and meta-analysis.

BACKGROUND: Landmark trials have shown superiority of ablative therapy over medical therapy in certain subpopulation with atrial fibrillation (AF). Previous studies have demonstrated an association between weight loss and reduced rates of recurrence of AF after ablation. The objective of this study is to determine if weight loss reduces the recurrence of AF after ablation. METHODS: An extensive literature search and systematic review of studies of weight loss on recurrence of AF after ablative therapy was performed. Risk ratio (RR) and 95% confidence intervals were measured for weight loss group versus control group in each study, and comparative analysis as well as subgroup analysis was made. RESULTS: Eight studies with a total of 1,425 patients were included. Overall, studies of patients who lost weight demonstrated lower recurrence of AF (RR 0.35; 95% CI 0.18-0.67). However, subgroup analysis of studies which included patients who lost ≥10% weight loss from baseline showed lower recurrence of AF (RR 0.18; 95% 0.03-0.89), whereas studies which included patients with <10% weight loss did not (RR 1.00; 95% 0.51-1.96). Studies of patients who had less than 12-month history of AF (RR 0.24; 95% CI 0.11-0.57) and those who lost weight prior to ablation (RR 0.40; 95% CI 0.20-0.79) also had lower recurrence of AF. CONCLUSION: Weight loss is associated with lower long-term recurrence of AF after ablative therapy. Studies of patients with ≥10% weight loss, less than 12-month history of AF, and weight loss prior to ablation experience lower recurrence of AF.

Wide area circumferential ablation for pulmonary vein isolation using radiofrequency versus laser balloon ablation.

Background: Persistent atrial fibrillation (AF) is associated with high recurrence rates of AF and atypical atrial flutters or tachycardia (AFT) postablation. Laser balloon (LB) ablation of the pulmonary vein (PV) ostia has similar efficacy as radiofrequency wide area circumferential ablation (RF-WACA); however, an approach of LB wide area circumferential ablation (LB-WACA) may further improve success rates. Objective: To evaluate freedom from atrial tachyarrhythmia (AFT/AF) recurrence postablation using RF-WACA versus LB-WACA in persistent AF patients. Methods: This was a retrospective multicenter study. Patients were followed for up to 24 months via office visits, Holter, and/or device monitoring. The primary endpoint was freedom from AFT/AF after a single ablation procedure. Secondary endpoints included freedom from AF, freedom from AFT, first-pass isolation of all PVs, and procedural complications. Results: Two hundred and four patients were studied (LB-WACA: n = 103; RF-WACA: n = 101). Patients' baseline characteristics were similar except patients in the RF-WACA group were older (64 vs. 68, p = .03). First-pass isolation was achieved more often during LBA (LB-WACA: 88% vs. RF-WACA 75%; p = .04). Procedure (p = .36), LA dwell (p = .41), and fluoroscopy (p = .44) time were similar. The mean follow-up was 506 ± 279 days. Sixty-six patients had arrhythmic events including 24 AFT and 59 AF recurrences. LB-WACA group had higher arrhythmia-free survival (p = .009) after single ablation procedures. In the multivariate Cox regression model, RF-WACA was associated with a higher recurrence of AFT compared with LB-WACA (Adjusted HR 3.16 [95% CI: 1.13-8.83]; p = .03). Conclusions: LB-WACA was associated with higher freedom from atrial arrhythmias mostly driven by the lower occurrence of AFT compared with RF-WACA.

Clinical outcomes of conduction system pacing compared to biventricular pacing in patients requiring cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is well-established therapy in patients with reduced left ventricular ejection fraction (LVEF) and bundle branch block or indication for pacing. Conduction system pacing (CSP) using His-bundle pacing (HBP) or left bundle branch area pacing (LBBAP) has been shown to be a safe and more physiological alternative to BVP. OBJECTIVE: The purpose of this study was to compare the clinical outcomes between CSP and BVP among patients undergoing CRT. METHODS: This observational study included consecutive patients with LVEF ≤35% and class I or II indications for CRT who underwent successful BVP or CSP at 2 major health care systems. The primary outcome was the composite endpoint of time to death or heart failure hospitalization (HFH). Secondary outcomes included subgroup analysis in left bundle branch block as well as individual endpoints of death and HFH. RESULTS: A total of 477 patients (32% female) met inclusion criteria (BVP 219; CSP 258 [HBP 87, LBBAP 171]). Mean age was 72 ± 12 years, and mean LVEF was 26% ± 6%. Comorbidities included hypertension 70%, diabetes mellitus 45%, and coronary artery disease 52%. Paced QRS duration in CSP was significantly narrower than BVP (133 ± 21 ms vs 153 ± 24 ms; P <.001). LVEF improved in both groups during mean follow-up of 27 ± 12 months and was greater after CSP compared to BVP (39.7% ± 13% vs 33.1% ± 12%; P <.001). Primary outcome of death or HFH was significantly lower with CSP vs BVP (28.3% vs 38.4%; hazard ratio 1.52; 95% confidence interval 1.082-2.087; P = .013). CONCLUSION: CSP improved clinical outcomes compared to BVP in this large cohort of patients with indications for CRT.

Clinical outcomes of left bundle branch area pacing compared to right ventricular pacing: Results from the Geisinger-Rush Conduction System Pacing Registry.

BACKGROUND: Left bundle branch area pacing (LBBAP) has been shown to be a feasible option for patients requiring ventricular pacing. OBJECTIVE: The purpose of this study was to compare clinical outcomes between LBBAP and RVP among patients undergoing pacemaker implantation METHODS: This observational registry included patients who underwent pacemaker implantations with LBBAP or RVP for bradycardia indications between April 2018 and October 2020. The primary composite outcome included all-cause mortality, heart failure hospitalization (HFH), or upgrade to biventricular pacing. Secondary outcomes included the composite endpoint among patients with a prespecified burden of ventricular pacing and individual outcomes. RESULTS: A total of 703 patients met inclusion criteria (321 LBBAP and 382 RVP). QRS duration during LBBAP was similar to baseline (121 ± 23 ms vs 117 ± 30 ms; P = .302) and was narrower compared to RVP (121 ± 23 ms vs 156 ± 27 ms; P <.001). The primary composite outcome was significantly lower with LBBAP (10.0%) compared to RVP (23.3%) (hazard ratio [HR] 0.46; 95%T confidence interval [CI] 0.306-0.695; P <.001). Among patients with ventricular pacing burden >20%, LBBAP was associated with significant reduction in the primary outcome compared to RVP (8.4% vs 26.1%; HR 0.32; 95% CI 0.187-0.540; P <.001). LBBAP was also associated with significant reduction in mortality (7.8% vs 15%; HR 0.59; P = .03) and HFH (3.7% vs 10.5%; HR 0.38; P = .004). CONCLUSION: LBBAP resulted in improved clinical outcomes compared to RVP. Higher burden of ventricular pacing (>20%) was the primary driver of these outcome differences.