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BACKGROUND: Pulsed field ablation (PFA) induces cell death through electroporation using ultrarapid electrical pulses. We sought to compare the procedural efficiency characteristics, safety, and efficacy of ablation of atrial fibrillation (AF) using PFA compared with thermal energy ablation. METHODS: We performed an extensive literature search and systematic review of studies that compared ablation of AF with PFA versus thermal energy sources. Risk ratio (RR) 95% confidence intervals (CI) were measured for dichotomous variables and mean difference (MD) 95% CI were measured for continuous variables, where RR

BACKGROUND: Pulsed field ablation (PFA) has emerged as a novel energy source for the ablation of atrial fibrillation (AF) using ultrarapid electrical pulses to induce cell death via electroporation. OBJECTIVE: The purpose of this study was to compare the safety and acute efficacy of ablation for AF with PFA vs thermal energy sources. METHODS: We performed an extensive literature search and systematic review of studies that evaluated the safety and efficacy of ablation for AF with PFA and compared them to landmark clinical trials for ablation of AF with thermal energy sources. Freeman-Tukey double arcsine transformation was used to establish variance of raw proportions followed by the inverse with the random-effects model to combine the transformed proportions and generate the pooled prevalence and 95% confidence interval (CI). RESULTS: We included 24 studies for a total of 5203 patients who underwent AF ablation. Among these patients, 54.6% (n = 2842) underwent PFA and 45.4% (n = 2361) underwent thermal ablation. There were significantly fewer periprocedural complications in the PFA group (2.05%; 95% CI 0.94-3.46) compared to the thermal ablation group (7.75%; 95% CI 5.40-10.47) (P = .001). When comparing AF recurrence up to 1 year, there was a statistically insignificant trend toward a lower prevalence of recurrence in the PFA group (14.24%; 95% CI 6.97-23.35) compared to the thermal ablation group (25.98%; 95% CI 15.75-37.68) (P = .132). CONCLUSION: Based on the results of this meta-analysis, PFA was associated with lower rates of periprocedural complications and similar rates of acute procedural success and recurrent AF with up to 1 year of follow-up compared to ablation with thermal energy sources.

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

BackgroundThe mechanisms for atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) catheter ablation are unclear. Non-PV organized atrial arrhythmias (PAC, AT, macro-reentrant AFL) are possible contributors; however the prevalence and effect of their ablation on recurrent AF are unknown. We hypothesize that the identification and ablation of non-PV organized atrial arrhythmias were associated with less AF recurrence.MethodsPatients who underwent repeat ablation for recurrent AF after prior PVI were retrospectively enrolled. The prevalence and characteristics of PV reconnections and non-PV organized atrial arrhythmias were identified. The outcomes of time to clinical AF recurrence, heart failure (HF) hospitalization, and mortality were analyzed in patients using multivariable adjusted Cox regression.ResultsIn 74 patients with recurrent AF (age 66 ± 9 years, left atrial volume index 38 ± 10 ml/m2, 59% persistent AF), PV reconnections were found in 46 patients (61%), macro-reentrant atrial flutter in 27 patients (36%), and focal tachycardia in 12 patients (16%). Mapping and ablation of non-PV organized atrial arrhythmias were associated with a reduced recurrence of late clinical AF (adjusted HR 0.26, CI 0.08-0.85, p = 0.03) and the composite outcome of recurrence of late AF, HF hospitalization, and mortality (adjusted HR 0.38, CI 0.17-0.85, p = 0.02), with median follow-up of 1.6 (IQR 0.7-6.3) years. The presence of PV reconnections or empiric linear ablation was not associated with reduction in clinical AF or composite endpoints.ConclusionThe ablation of non-PV organized atrial arrhythmias resulted in a reduction of late clinical AF recurrence and composite outcome. In this challenging population, alternate mechanisms beyond PV reconnections need to be considered. Prospective studies are needed.

BackgroundContemporary data on national trends and outcomes in cardiac resynchronization therapy with defibrillator (CRT-D) recipients following the 2012 updated guidelines has not been studied.ObjectivesThis study assessed the trends in long-term outcomes among CRT-D Medicare-aged recipients implanted in 2011-2015.MethodsPatients aged ≥65 years undergoing de novo CRT-D implantation in the National Cardiovascular Data Implantable Cardiac Defibrillator Registry from 2011-2015 with follow-up through 2017 using Medicare data were included and stratified by year of implant. Patient characteristics, in-hospital outcomes, and outcomes up to 2 years following implant were evaluated.ResultsAmong 53,174 patients (aged 75.6-6.4 years, 29.7% women) implanted with CRT-D from 2011 to 2015, there was an increase in implantations based on guideline-concordant recommendations (81.0% to 84.7%, P < .001). Compared to 2011, in-hospital procedural complications decreased in 2015 (3.9% vs 2.9%; adjusted odds ratio, 0.76, 95% confidence interval, 0.66-0.88, P < .001), driven in part by decreased lead dislodgement (1.4% vs 1.0%). After multivariable adjustment, there was a lower risk of all-cause hospitalization, cardiovascular hospitalization, and mortality at 2-year follow-up in 2015 as compared to 2011, while there were no differences in heart failure hospitalizations at follow-up.ConclusionAmong Medicare beneficiaries receiving CRT-D from 2011 to 2015, there was an increase in implantations based on guideline-concordant recommendations. Furthermore, there has been a reduction in in-hospital complications and long-term outcomes, including cardiovascular hospitalization, all-cause hospitalization, and mortality; however, there has been no difference in the risk of heart failure hospitalization after adjustment.

BACKGROUND: Limited data exists for outcomes in patients undergoing cardiovascular implantable electronic device (CIED) transvenous lead extraction (TLE) without clear indications for device reimplantation. The implantable loop recorder (ILR) may be an effective strategy for continuous monitoring in select individuals. OBJECTIVE: This retrospective analysis aims to investigate patients who have undergone ILR implant following TLE without CIED reimplantation. METHODS: Clinical data from consecutive patients who have undergone TLE with ILR implant and without CIED reimplantation from October 2016 to May 2020 at a single center were collected. RESULTS: Among 380 patients undergoing TLE, 28 (7.7%) underwent ILR placement without CIED reimplantation. TLE indications were systemic infection (n = 13, 46.4%), pain at the site (n = 8, 28.6%), device/lead malfunction (n = 4, 14.2%), and other. Devices extracted included: dual-chamber and single-chamber pacemaker (n = 14, 50%; n = 4, 14.2%), dual-chamber implantable cardiac defibrillator (n = 10; 35.7%), and cardiac-resynchronization therapy with defibrillator (n = 1, 3.5%). Reasons for no reimplantation included no longer meeting CIED criteria (n = 14, 50%), patient preference (n = 9, 32.1%), and no clear or inappropriate indication for initial CIED implantation (n = 5, 18%). During an average of 12.3 ± 13.1 months of follow-up, there were no lethal arrhythmias, and four (13.3%) patients underwent permanent pacemaker reimplantation due to symptomatic sinus bradycardia and atrioventricular block with syncope as discovered on ILR. Three patients died due to unknown causes (n = 1), noncardiac (n = 1), and acute coronary syndrome (n = 1). CONCLUSIONS: In patients undergoing TLE without reimplantation, an ILR may be an effective monitoring strategy in patients at low risk for cardiac arrhythmia.

BackgroundPatients with end-stage heart failure are at high risk for sudden cardiac death. However, implantable cardioverter-defibrillator (ICD) is not routinely implanted given the high competing risk of pump failure. A unique population worth separate consideration are patients with end-stage heart failure awaiting heart transplantation, as prolonged survival improves the chances of receiving transplant.ObjectiveTo compare clinical outcomes of heart failure patients with and without an ICD awaiting heart transplant.MethodsWe performed an extensive literature search and systematic review of studies that compared end-stage heart failure patients with and without an ICD awaiting heart transplantation. We separately assessed the rates of total mortality, sudden cardiac death, nonsudden cardiac death, and heart transplantation. Risk ratio (RR) and 95% confidence intervals were measured using the Mantel-Haenszel method. The random effects model was used owing to heterogeneity across study cohorts.ResultsTen studies with a total of 36,112 patients were included. A total of 62.5% of patients had an ICD implanted. Patients with an ICD had decreased total mortality (RR 0.60, 95% CI 0.51-0.71, P

BackgroundStereotactic ablative radiotherapy (SAbR) is an emerging therapy for refractory ventricular tachycardia (VT). However, the current workflow is complicated, and the precision and safety in patients with significant cardiorespiratory motion and VT targets near the stomach may be suboptimal.ObjectiveWe hypothesized that automated 12-lead electrocardiogram (ECG) mapping and respiratory-gated therapy may improve the ease and precision of SAbR planning and facilitate safe radiation delivery in patients with refractory VT.MethodsConsecutive patients with refractory VT were studied at 2 hospitals. VT exit sites were localized using a 3-D computational ECG algorithm noninvasively and compared to available prior invasive mapping. Radiotherapy (25 Gy) was delivered at end-expiration when cardiac respiratory motion was ≥0.6 cm or targets were ≤2 cm from the stomach.ResultsIn 6 patients (ejection fraction 29% ± 13%), 4.2 ± 2.3 VT morphologies per patient were mapped. Overall, 7 out of 7 computational ECG mappings (100%) colocalized to the identical cardiac segment when prior invasive electrophysiology study was available. Respiratory gating was associated with smaller planning target volumes compared to nongated volumes (71 ± 7 vs 153 ± 35 cc, P < .01). In 2 patients with inferior wall VT targets close to the stomach (6 mm proximity) or significant respiratory motion (22 mm excursion), no GI complications were observed at 9- and 12-month follow-up. Implantable cardioverter-defibrillator shocks decreased from 23 ± 12 shocks/patient to 0.67 ± 1.0 (P < .001) post-SAbR at 6.0 ± 4.9 months follow-up.ConclusionsA workflow including computational ECG mapping and protocol-guided respiratory gating is feasible, is safe, and may improve the ease of SAbR planning. Studies to validate this workflow in larger populations are required.

Catheter ablation improves clinical outcomes in atrial fibrillation (AF) patients with heart failure (HF) with reduced ejection fraction (HFrEF). However, the role of catheter ablation in HF with a preserved ejection fraction (HFpEF) is less clear. We performed a literature search and systematic review of studies that compared AF recurrence at one year after catheter ablation of AF in patients with HFpEF versus those with HFrEF. Risk ratio (RR; where a RR

Chronotropic incompetence (CI) in patients with heart failure is common and associated with impaired exercise intolerance and adverse outcomes. This study sought to determine the effects of closed loop stimulation (CLS) rate-adaptive pacing on functional capacity in patients with heart failure with reduced ejection fraction (HFrEF) and CI implanted with cardiac resynchronization therapy (CRT) devices.A randomized, blinded, cross-over designed trial enrolled patients with HFrEF and CI implanted with a Biotronik CRT-D to complete a quality of life questionnaire, 6-min walk distance (6MWD), and cardiopulmonary exercise testing after two programmed periods: 1-week period of CLS and 1-week period of standard accelerometer (DDDR).Nine patients (6 males, mean age 71.4 years, 7 with New York Heart Association Class III, mean ejection fraction 39 ± 8%) were enrolled. Quality of life trended higher in CLS as compared to DDDR (550.8 ± 123.9 vs 489.3 ± 164.9, p = 0.06). There were no differences between CLS and DDDR in 6MWD (293.1 ± 90.2 m vs 315.1 ± 95.5 m, p = 0.52), peak heart rate (HR) 110.7 ± 14.7 bpm vs 109.7 bpm ± 14.1, p = 0.67), or peak VO2 (12.3 ± 4.9 ml/kg/min vs 12.9 ± 5.9, p = 0.47). As tests were submaximal as indicated by low respiratory exchange ratios (0.98 ± 0.11 vs 1.0 ± 0.8, p = 0.35), VE/VCO2 slope also showed no difference between CLS and DDDR (35.8 ± 5.6 vs 35.4 ± 5.7, p = 0.65). Five patients (56%) preferred CLS programming (p = 1.0).In patients with HFrEF and CI implanted with a CRT-D, peak HR, peak VO2, and 6MWD were equivalent, while there was a trend toward improved quality of life in CLS as compared to DDDR.URL: https://www.clinicaltrials.gov . Unique identifier: NCT02693262.

Atrial fibrillation (AF) is frequently present in patients with heart failure (HF) and an implantable cardioverter-defibrillator (ICD). This study aims to identify clinical factors associated with a baseline history of AF in ICD recipients, and compares subsequent clinical outcomes in those with and without a baseline history of AF.We studied 566 consecutive first-time ICD recipients at an academic center between 2011 and 2018. Logistic regression multivariable analyses were used to identify clinical factors associated with a baseline history of AF at the time of ICD implant. Cox-proportional hazard regression models were constructed for multivariate analysis to examine associations between a baseline history of AF with subsequent clinical outcomes, including ICD therapies, HF readmission, and all-cause mortality.Of all patients, 201 (36%) had a baseline history of AF at the time of ICD implant. In multivariate analyses, clinical factors associated with a baseline history of AF included hypertension, valvular heart disease, body weight, PR interval, and serum creatinine level. After multivariate adjustment for potential confounders, a baseline history of AF was associated with an increased risk of anti-tachycardia pacing (HR = 1.84, 95% CI = 1.19-2.85, P = .006), appropriate ICD shocks (HR = 1.80, 95% CI = 1.05-3.09, P = .032), and inappropriate ICD shocks (HR = 3.72, 95% CI = 1.7-7.77, P = .0001), but not other adverse outcomes.Among first-time ICD recipients, specific clinical characteristics were associated with a baseline history of AF at the time of ICD implant. After adjustment for potential confounders, a baseline history of AF was associated with a higher risk of all ICD therapies in follow-up.

This study aimed to compare the safety and efficacy of third-generation P2Y12 inhibitors versus clopidogrel in combination with oral anticoagulation (OAC) with or without aspirin in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI).We performed a systematic review including both prospective and retrospective studies that compared dual and triple antithrombotic regimens for bleeding and major adverse cardiac events (MACE) in patients with AF undergoing PCI. We analysed rates of bleeding and MACE by P2Y12 inhibitor choice. Risk ratio (RR) 95% CIs were measured using the Mantel-Haenszel method. Where study heterogeneity was low (I2

Obesity and atrial fibrillation (AF) are growing epidemics with significant overlap in co-morbidities. Multiple smaller studies have evaluated the effects of weight loss and risk factor modification on recurrence of AF, reduction in AF burden and improvement in AF symptom severity. The objective of this study was to determine if a modest weight loss of ≥10% of initial body weight is enough to improve outcomes in overweight or obese patients with established AF. We performed an extensive literature search and systematic review of studies that compared weight loss of ≥10% versus weight loss of less than 10% or weight gain and assessed outcomes including recurrence of AF as determined through a Holter monitor, AF burden and improvement in AF symptom severity. Risk ratio 95% confidence intervals (CI) were measured for dichotomous variables and mean difference (MD) 95% CI were measured for continuous variables, where MD >0 favors the group with ≥10% weight loss. Five studies with a total of 548 patients were included. Patients who lost ≥10% of their initial body weight experienced less recurrence of AF (risk ratio 0.29; 95% CI 0.19 to 0.44) and a larger reduction in reported event frequency (MD 1.74; 95% CI 0.70 to 2.79), episode duration (MD 2.14; 95% CI 0.04 to 4.23), global episode severity (MD 1.89; 95% CI 1.34 to 2.45), and symptom severity (MD 5.36; 95% CI 3.75 to 6.97). In conclusion, weight loss is associated with less risk of recurrent AF, reduction in AF burden, and improvement in AF symptom severity.

This study sought to prospectively evaluate the prevalence, risk factors, and short-term major clinical outcomes of mobile thrombus detected on transvenous leads in patients undergoing lead extraction.The prevalence and clinical significance of thrombus on transvenous leads in patients undergoing lead extraction is not well characterized.Consecutive patients undergoing transvenous lead extraction for noninfectious indications were enrolled. Preoperative transesophageal echocardiograms were performed prospectively for all patients to examine for mobile thrombus. Anticoagulation was not started for thrombus unless other indications were present. Clinical endpoints of mortality and cardiovascular morbidity (symptomatic pulmonary embolism, myocardial infarction, or cerebrovascular accident) were assessed at a minimum of 2-month follow-up.A total of 108 patients underwent lead extraction for noninfectious indications. Lead thrombi were detected in 20 (18.5%) patients and all were

A 16-year-old female with symptomatic Wolff-Parkinson-White (WPW) syndrome underwent catheter ablation of a left-sided lateral accessory pathway. The accessory pathway was eliminated with the first ablation lesion; however, the patient immediately developed complete heart block (CHB). At first, complete heart block was thought to be due to ablation of left atrial extension of the AV node, and pacemaker therapy was considered. However, careful ECG analysis revealed that the development of CHB was in fact due to bump injury to the AV node during transseptal catheterization. Conservative management allowed resolution of AV nodal conduction without need for a permanent pacemaker.

Background: Complications associated with cardiovascular implantable electronic devices may necessitate device and lead removal. An open approach to removal may be electively chosen in cases with high risk of complications or those requiring additional concomitant cardiac surgery. This study aimed to investigate outcomes of patients who underwent elective open lead extractions (OLE) at two large tertiary care centers. Methods: The records of 29 patients undergoing elective OLE were analyzed through retrospective chart review. Results: 69 total leads were extracted from 29 patients (77% completely, 23% partially). The average age of the oldest leads was 13.3 ± 11.3 years. Infective endocarditis with severe valvular insufficiency requiring valvular intervention (41%)—an infectious etiology, and tricuspid valve intervention to correct RV lead‐related severe TR (38%)—a noninfectious etiology, were the most common reasons for OLE. 38% of the patients had additional co‐primary or secondary indications for open extraction, such as CABG and pericardiectomies. The rate of major complications and procedural failure was 3% each (1/29). 30‐day survival was 100%, and 1‐year survival was 92%. The average length of hospital stay was 15 days and higher among those undergoing OLE for infectious indications. Conclusion: Open lead extractions offered a similar clinical success rate (97%) to transvenous extractions in this cohort and may be a viable alternative for those necessitating valvular intervention or when the risk of complications from TLE is considered very high. [ABSTRACT FROM AUTHOR]

Background: The ability of computed tomography (CT) characteristics to predict the difficulty of transvenous lead extraction (TLE) is an evolving subject. Objective: To identify CT characteristics associated with increased TLE difficulty. Methods: All consecutive patients undergoing TLE at the University of California San Diego from January 2018 to February 2022 were analyzed, utilizing the UC San Diego Lead Extraction Registry. Patients underwent cardiac‐gated chest CT scans with intravenous contrast; all scans were reviewed by a single radiologist. Lead extraction was performed per standard institutional protocol with the initial use of a laser sheath and crossover to a mechanical sheath as needed. Multivariable linear and logistic regression analyses were performed to identify predictors of individual lead‐removal fluoroscopy time and mechanical sheath use, as markers of extraction difficulty. Results: A total of 343 patients were analyzed. The mean age of the study population was 63.8 ± 15.4 years; 71% were male. The mean lead dwell‐in duration was 8.6 ± 5.7 years. In multivariable linear regression analysis, venous occlusion detected on CT was independently associated with higher individual lead‐removal fluoroscopy time (p = 0.004), when adjusting for clinical characteristics such as lead dwell time. In multivariable logistic regression analysis, calcification and venous occlusion were independently associated with a higher need for mechanical sheath use during TLE (odds ratio:5.08, p < 0.001, 95% CI: 2.54–10.46) and (odds ratio:3.72, p < 0.001, 95% CI: 1.89–7.35), respectively. Conclusion: In patients undergoing TLE, venous occlusion identified by chest CT is associated with increased fluoroscopy time. Patients with lead‐associated calcification or venous occlusion detected by chest CT are each five and three times more likely to require crossover from laser to a mechanical sheath. [ABSTRACT FROM AUTHOR]

Aims The extravascular implantable cardioverter-defibrillator (EV ICD) has been shown to be safe and effective for patients at risk of sudden cardiac death, but little is known about EV ICD lead removal in humans. This analysis aimed to characterize the EV ICD lead removal experience thus far. Methods and results This was a retrospective analysis of lead removals from the EV ICD Pilot, Pivotal, and Continued Access Studies. Patients with a successful EV ICD implant who underwent lead removal were included. The main objective was lead removal success. Ancillary objectives included characterizing technique used, procedure complications, and reimplantation status. An EV ICD system was successfully implanted in 347 patients across the 3 studies (25.9% female; 53.4 ± 13.3 years; left ventricular ejection fraction: 39.7 ± 15.9). Of these patients, 29 (8.4%) underwent lead removal with a mean lead dwell time of 12.6 ± 14.3 months (0.2–58.4). The main reason for lead removal was lead dislodgement (n = 9, 31.0%). Lead removal was successful in 27/29 (93.1%) cases [100% (19/19) success rate <1 year and 80% (8/10) success rate >1 year post-implant]. Simple traction was used in 22/26 (84.6%) and extraction tools in 4/26 (15.4%) successful cases where technique was known. No complications were reported for any of the removal procedures. All 11 EV ICD reimplant attempts were successful. Conclusion Complete removal of the EV ICD lead was successful in 93.1% of cases, and simple traction was sufficient in most instances. Based on these results, lead removal from the substernal space was safe and achievable up to 3 years post-implant. [ABSTRACT FROM AUTHOR]

For patients with end-stage heart failure, the use of mechanical circulatory support has increased in the last decade due to improved outcomes with durable left ventricular assist devices. The management of these complex patients requires coordinated care by a multidisciplinary team including cardiac electrophysiologists because atrial and ventricular arrhythmias are prevalent in this population. There have been an increasing number of studies that attempt to address issues regarding arrhythmia management in patients with left ventricular assist devices. The purpose of this review is to provide electrophysiologists with an evidence-based approach to manage a broad spectrum of arrhythmia issues in these patients.

Catheter ablation of PVCs is highly successful and has become the hallmark treatment for symptomatic or highly prevalent cases. However, few studies exist that evaluate the outcomes of ablation and likely mechanisms of PVC recurrence beyond 1 year of follow-up.