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Background: Difficulty of lead extraction does not track well with procedural complications, but several small retrospective studies have lead fibrosis on computed tomography as an important indicator of difficult lead extraction. The purpose of the present study was to apply a standardized gated cardiac computed tomography (CT) protocol to assess fibrosis and study it prospectively to examine the need for powered sheaths and risk outcomes., Methods: We performed a prospective, blinded, multicenter, international study at high-volume lead extraction centers and included patients referred for transvenous lead extraction with at least one lead with a dwell time >1 year and ability to receive a cardiac CT. The degree of fibrosis (as measured by amount of lead adherence to vessel wall) was graded on a scale of 1 to 4 by dedicated CT readers in 3 zones (vein entry to superior vena cava, superior vena cava, and right atrium to lead tip). The primary outcome of the study was number of extractions requiring powered sheaths at zone 2 for each fibrosis group., Results: A total of 200 patients were enrolled in the trial with 196 completing full gated CT and lead extraction analysis. The primary endpoint of powered sheath (laser and mechanical) sheath use was significantly higher in patients with higher fibrosis seen on CT (scores 3+4; 67.8%) at the zone 2 compared to patients with lower fibrosis (scores 1+2; 38.6%; P <0.001). There were 5 major complications with 3 vascular lacerations all occurring in zone 2 in the study., Conclusions: Gated, contrasted CT can predict the need for powered sheaths by identification of fibrosis but did not identify an absolute low-risk cohort who would not need powered sheaths., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT03772704.

Background: High-power short-duration (HP-SD) radiofrequency ablation (RFA) has been proposed as a method for producing rapid and effective lesions for pulmonary vein isolation. The underlying hypothesis assumes an increased resistive heating phase and decreased conductive heating phase, potentially reducing the risk for esophageal thermal injury. The objective of this study was to compare the esophageal temperature dynamic profile between HP-SD and moderate-power moderate-duration (MP-MD) RFA ablation strategies., Methods: In patients undergoing pulmonary vein isolation, RFA juxtaposed to the esophagus was delivered in an alternate sequence of HP-SD (50 W, 8-10 s) and MP-MD (25 W, 15-20 s) between adjacent applications (distance, ≤4 mm). Esophageal temperature was recorded using a multisensor probe (CIRCA S-CATH). Temperature data included magnitude of temperature rise, maximal temperature, time to maximal temperature, and time return to baseline. In swine, a similar experimental design compared the effect of HP-SD and MP-MD on patterns of esophageal injury., Results: In 20 patients (68.9±5.8 years old; 60% persistent atrial fibrillation), 55 paired HP-SD and MP-MD applications were analyzed. The esophageal temperature dynamic profile was similar between HP-SD and MP-MD ablation strategies. Specifically, the magnitude of temperature rise (2.1 °C [1.4-3] versus 2.0 °C [1.5-3]; P =0.22), maximal temperature (38.4 °C [37.8-39.3] versus 38.5 °C [37.9-39.4]; P =0.17), time to maximal temperature (24.9±7.5 versus 26.3±6.8 s; P =0.1), and time of temperature to return to baseline (110±23.2 versus 111±25.1 s; P =0.86) were similar between HP-SD and MP-MD ablation strategies. In 6 swine, esophageal injury was qualitatively similar between HP-SD and MP-MD strategies., Conclusions: Esophageal temperature dynamics are similar between HP-SD and MP-MD RFA strategies and result in comparable esophageal tissue injury. Therefore, when using a HP-SD RFA strategy, the shorter application duration should not prompt shorter intervals between applications.

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The field of cardiac electrophysiology has been on the cutting edge of advanced digital technologies for many years. More recently, medical device development through traditional clinical trials has been supplemented by direct to consumer products with advancement of wearables and health care apps. The rapid growth of innovation along with the mega-data generated has created challenges and opportunities. This review summarizes the regulatory landscape, applications to clinical practice, opportunities for virtual clinical trials, the use of artificial intelligence to streamline and interpret data, and integration into the electronic medical records and medical practice. Preparation of the new generation of physicians, guidance and promotion by professional societies, and advancement of research in the interpretation and application of big data and the impact of digital technologies on health outcomes will help to advance the adoption and the future of digital health care.

Background: In the WRAP-IT trial (Worldwide Randomized Antibiotic Envelope Infection Prevention), adjunctive use of an absorbable antibacterial envelope resulted in a 40% reduction of major cardiac implantable electronic device infection without increased risk of complication in 6983 patients undergoing cardiac implantable electronic device revision, replacement, upgrade, or initial cardiac resynchronization therapy defibrillator implant. There is limited information on the cost-effectiveness of this strategy. As a prespecified objective, we evaluated antibacterial envelope cost-effectiveness compared with standard-of-care infection prevention strategies in the US healthcare system., Methods: A decision tree model was used to compare costs and outcomes of antibacterial envelope (TYRX) use adjunctive to standard-of-care infection prevention versus standard-of-care alone over a lifelong time horizon. The analysis was performed from an integrated payer-provider network perspective. Infection rates, antibacterial envelope effectiveness, infection treatment costs and patterns, infection-related mortality, and utility estimates were obtained from the WRAP-IT trial. Life expectancy and long-term costs associated with device replacement, follow-up, and healthcare utilization were sourced from the literature. Costs and quality-adjusted life years were discounted at 3%. An upper willingness-to-pay threshold of $150 000 per quality-adjusted life year was used to determine cost-effectiveness, in alignment with the American College of Cardiology/American Heart Association practice guidelines and as supported by the World Health Organization and contemporary literature., Results: The base case incremental cost-effectiveness ratio of the antibacterial envelope compared with standard-of-care was $112 603/quality-adjusted life year. The incremental cost-effectiveness ratio remained lower than the willingness-to-pay threshold in 74% of iterations in the probabilistic sensitivity analysis and was most sensitive to the following model inputs: infection-related mortality, life expectancy, and infection cost., Conclusions: The absorbable antibacterial envelope was associated with a cost-effectiveness ratio below contemporary benchmarks in the WRAP-IT patient population, suggesting that the envelope provides value for the US healthcare system by reducing the incidence of cardiac implantable electronic device infection. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02277990.

Background: Many centers continue to routinely perform transesophageal echocardiograms before atrial fibrillation (AF) ablation procedures in patients treated with direct oral anticoagulants (DOACs). One study suggested that the procedures could be done without transesophageal echocardiogram but used intracardiac echocardiography imaging of the appendage from the right ventricular outflow. This study aimed to assess the safety of ablation for AF without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage in DOAC compliant patients., Methods: All patients undergoing AF ablation at the Cleveland Clinic (2011-2018) were enrolled in a prospectively maintained data registry. All consecutive patients presenting with AF or atrial flutter on DOAC were included. Periprocedural thromboembolic complications were assessed., Results: A total of 900 patients were included. Their median CHA 2 DS 2 -VASc score was 2 (interquartile range 1-3). All were on DOACs (333 rivaroxaban, 285 dabigatran, 281 apixaban, and 1 edoxaban). Thromboembolic complications occurred in 4 patients (0.3%): 2 ischemic strokes, 1 transient ischemic attack without residual deficit, and 1 splenic infarct; all with no further complications. Bleeding complications occurred in 5 patients (0.4%): 2 pericardial effusions (1 intraoperative, 1 after 30 days, both drained), 3 groin hematomas (1 of them due to needing heparin for venous thrombosis, none required interventions). No patients required emergent surgeries., Conclusions: In DOAC compliant patients who present for ablation in AF/atrial flutter, the procedures could be performed without transesophageal echocardiogram screening or intracardiac echocardiography imaging of the appendage; with low risk of complications.

Artificial intelligence (AI) and machine learning (ML) in medicine are currently areas of intense exploration, showing potential to automate human tasks and even perform tasks beyond human capabilities. Literacy and understanding of AI/ML methods are becoming increasingly important to researchers and clinicians. The first objective of this review is to provide the novice reader with literacy of AI/ML methods and provide a foundation for how one might conduct an ML study. We provide a technical overview of some of the most commonly used terms, techniques, and challenges in AI/ML studies, with reference to recent studies in cardiac electrophysiology to illustrate key points. The second objective of this review is to use examples from recent literature to discuss how AI and ML are changing clinical practice and research in cardiac electrophysiology, with emphasis on disease detection and diagnosis, prediction of patient outcomes, and novel characterization of disease. The final objective is to highlight important considerations and challenges for appropriate validation, adoption, and deployment of AI technologies into clinical practice.

Background: Dofetilide is one of the only anti-arrhythmic agents approved for atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF). However, postapproval data and safety outcomes are limited. In this study, we assessed the incidence and predictors of LVEF improvement, safety, and outcomes in patients with AF with LVEF ≤35% without prior implantable cardioverter defibrillator, cardiac resynchronization therapy, or AF ablation., Methods: An analysis of 168 consecutive patients from 2007 to 2016 was performed. Incidences of adverse events, drug continuation, implantable cardioverter defibrillator and cardiac resynchronization therapy implantation, LVEF improvement (>35%) and recovery (≥50%), AF recurrence, and AF ablation were determined. Multivariable regression analysis to identify predictors of LVEF improvement/recovery was performed., Results: The mean age was 64±12 years. Dofetilide was discontinued before hospital discharge in 46 (27%) because of QT prolongation (14%), torsades de pointe or polymorphic ventricular tachycardia/fibrillation (6% [sustained 3%, nonsustained 3%]), ineffectiveness (5%), or other causes (3%). At 1 year, 43% remained on dofetilide. Freedom from AF was 42% at 1 year, and 40% underwent future AF ablation. LVEF recovered (≥50%) in 45% and improved to >35% in 73%. Predictors of LVEF improvement included presence of AF during echocardiogram (odds ratio, 4.22 [95% CI, 1.71-10.4], P =0.002), coronary artery disease (odds ratio, 0.35 [95% CI, 0.16-0.79], P =0.01), left atrial diameter (odds ratio, 0.52 per 1 cm increase [95% CI, 0.30-0.90], P =0.01), and LVEF (odds ratio, per 1% increase, 1.09 [95% CI, 1.02-1.16], P =0.006). The C statistic was 0.78., Conclusions: In patients with LVEF ≤35%, who are potential implantable cardioverter defibrillator candidates, treated with dofetilide as an initial anti-arrhythmic strategy for AF, drug discontinuation rates were high, and many underwent future AF ablation. However, most patients had improvement in LVEF, obviating the need for primary prevention implantable cardioverter defibrillator.

Background: Current understanding of the impact of cardiac implantable electronic device (CIED) infection is based on retrospective analyses from medical records or administrative claims data. The WRAP-IT (Worldwide Randomized Antibiotic Envelope Infection Prevention Trial) offers an opportunity to evaluate the clinical and economic impacts of CIED infection from the hospital, payer, and patient perspectives in the US healthcare system., Methods: This was a prespecified, as-treated analysis evaluating outcomes related to major CIED infections: mortality, quality of life, disruption of CIED therapy, healthcare utilization, and costs. Payer costs were assigned using medicare fee for service national payments, while medicare advantage, hospital, and patient costs were derived from similar hospital admissions in administrative datasets., Results: Major CIED infection was associated with increased all-cause mortality (12-month risk-adjusted hazard ratio, 3.41 [95% CI, 1.81-6.41]; P <0.001), an effect that sustained beyond 12 months (hazard ratio through all follow-up, 2.30 [95% CI, 1.29-4.07]; P =0.004). Quality of life was reduced ( P =0.004) and did not normalize for 6 months. Disruptions in CIED therapy were experienced in 36% of infections for a median duration of 184 days. Mean costs were $55 547±$45 802 for the hospital, $26 867±$14 893, for medicare fee for service and $57 978±$29 431 for Medicare Advantage (mean hospital margin of -$30 828±$39 757 for medicare fee for service and -$6055±$45 033 for medicare advantage). Mean out-of-pocket costs for patients were $2156±$1999 for medicare fee for service, and $1658±$1250 for medicare advantage., Conclusions: This large, prospective analysis corroborates and extends understanding of the impact of CIED infections as seen in real-world datasets. CIED infections severely impact mortality, quality of life, healthcare utilization, and cost in the US healthcare system. Registration: URL: https://www.clinicaltrials.gov Unique Identifier: NCT02277990.

Background: There is paucity of data regarding radiofrequency ablation for ventricular tachycardia (VT) in patients with cardiogenic shock and concomitant VT refractory to antiarrhythmic drugs on mechanical support., Methods: Patients undergoing VT ablation at our center were enrolled in a prospectively maintained registry and screened for the current study (2010-2017)., Results: All 21 consecutive patients with cardiogenic shock and concomitant refractory ventricular arrhythmia undergoing bailout ablation due to inability to wean off mechanical support were included. Median age was 61 years, 86% were men, median left ventricular ejection fraction was 20%, 81% had ischemic cardiomyopathy, and PAINESD score was 18±5. The type of mechanical support in place before the procedure was intra-aortic balloon pump in 14 patients (67%), Impella CP in 2, extracorporeal membrane oxygenation in 2, extracorporeal membrane oxygenation and intra-aortic balloon pump in 2, and extracorporeal membrane oxygenation and Impella CP in 1. Endocardial voltage maps showed myocardial scar in 19 patients (90%). The clinical VTs were inducible in 13 patients (62%), whereas 6 patients had premature ventricular contraction-induced ventricular fibrillation/VT (29%), and VT could not be induced in 2 patients (9%). Activation mapping was possible in all 13 with inducible clinical VTs. Substrate modification was performed in 15 patients with scar (79%). After ablation and scar modification, the arrhythmia was noninducible in 19 patients (91%). Seventeen (81%) were eventually weaned off mechanical support successfully, but 6 (29%) died during the index admission from persistent cardiogenic shock. Patients who had ventricular arrhythmia and cardiogenic shock on presentation had a trend toward lower in-hospital mortality compared with those who presented with cardiogenic shock and later developed ventricular arrhythmia., Conclusions: Bailout ablation for refractory ventricular arrhythmia in cardiogenic shock allowed successful weaning from mechanical support in a large proportion of patients. Mortality remains high, but the majority of patients were discharged home and survived beyond 1 year.

Background The value of patient-reported outcomes (PRO) is increasingly recognized in patient-centered care. Longitudinal data collection may be challenging and cost prohibitive. Automation of PRO collection may complement routine clinical follow-up, especially for procedures aiming to improve quality of life, such as atrial fibrillation (AF) ablation. Methods We aimed to develop a fully automated platform to collect PRO and evaluate its first clinical application in a prospective cohort of AF ablation. The duration of follow-up and data availability were assessed with automated PRO and routine follow-up versus routine follow-up alone (primary outcome). Quality of life and healthcare utilization (secondary outcomes) by PRO were assessed. Results Between 2013 and 2016, 2175 patients were eligible to receive 10 903 PRO assessment invitations, and the automated platform sent all invitations as programmed. More follow-up assessments were obtained with automated PRO and routine follow-up compared with routine follow-up alone (12 859 versus 10 248; P<0.0001) which allowed longer duration of follow-up (378 versus 217 days, 74% increase; P<0.0001). By automated PRO, a large number of disease-specific variables were collected and showed improvement in quality of life (baseline median AF symptom severity score AFSSS of 12 [6-18] and ranged between 2 and 3 on subsequent assessments; P<0.0001). This improvement was also true for each of the AFSSS individual components ( P<0.0001). In PRO, there was a significant reduction in AF burden (such as frequency and duration of episodes; P<0.0001) and associated healthcare utilization (including emergency visits and hospitalizations; P<0.0001) after the ablation procedures. Conclusions A fully automated system for PRO collection enhanced clinical follow-up and allowed collection of disease-specific data when applied in a prospective cohort of AF ablation.

Background: Pulmonary vein (PV) stenosis remains a feared complication of atrial fibrillation ablation. Little is known about outcomes in patients with severe PV stenosis, especially about repeat ablations., Methods: In 10 368 patients undergoing atrial fibrillation ablation (2000-2015), computed tomography scans were obtained 3 to 6 months after ablation. The clinical outcomes in severe PV stenosis were determined., Results: Severe PV stenosis was diagnosed in 52 patients (0.5%). This involved mostly the left superior PV (51% of severely stenosed veins). Percutaneous interventions were performed in 43 patients, and complications occurred in 5: 3 PV ruptures, 1 stroke, and 1 phrenic injury. Over a median follow-up of 25 months, 41 (79%) patients remained arrhythmia free. Repeat ablation was performed in 15 patients (7 from the main series and 8 from prior ablation at other institutions); of whom 10 had PV stents in place. Conduction recovery was noted in all but 2 of the stenosed or stented PVs, and areas with recovery were targeted with antral ablation. Lasso entrapment within stents occurred in 2 patients but eventually freed without complications. After redo ablation, preplanned stenting was performed in 3 patients and computed tomographic scans showed progression of concomitant stenoses in 1 patient (moderate to severe). No procedure-related deaths occurred., Conclusions: The incidence of severe PV stenosis is low but remains associated with significant morbidity. In patients with recurrent arrhythmia, conduction recovery at the stenosed or stented veins is common. Care must be taken to ablate antrally to avoid stenosis progression. In patients with prior PV stents, we suggest to avoid using Lasso., (© 2018 American Heart Association, Inc.)

Background: Atrial fibrillation recurrence after initial long-term success of catheter ablation has been described, yet not well studied. We assessed the electrophysiological findings and outcomes of repeat ablation procedures in this setting., Methods and Results: Between 2000 and 2015, 10 378 patients underwent atrial fibrillation ablation and were enrolled in a prospectively maintained data registry. From this registry, we included all 137 consecutive patients who had initial long-term success, defined as freedom from recurrent arrhythmia for >36 months off antiarrhythmics, then underwent repeat ablation for recurrent atrial fibrillation. The median arrhythmia-free period that defined long-term success was 52 months (41-68 months). In redo ablations, reconnection along at least one of the pulmonary veins (PVs) was found in 111 (81%) patients. Reconnection along a left superior, left inferior, right superior, and right inferior PV was found in 64%, 62%, 50%, and 54% of patients, respectively, and were reisolated. Additional non-PV ablations were performed in 127 (92.7%) patients: posterior wall (46%), septal to right PVs (49%), superior vena cava (35%), roof lines (52%), and cavotricuspid isthmus (33%). After a median follow-up of 17 months (5-36.9 months), 103 patients (75%) were arrhythmia free (79 off antiarrhythmics, 24 on antiarrhythmics)., Conclusions: PV reconnection is the most common electrophysiological finding in patients with atrial fibrillation recurrence after long-term success, but with lower rates than what had been reported for early recurrences. In our experience, repeat ablations in this setting involve complex ablation approaches to reisolate the PVs and modify the atrial substrate and are associated with good success rates., (© 2018 American Heart Association, Inc.)

Background: Cardiac implantable electronic device infections have been on the rise. A high-risk population is that with renal disease, especially dialysis. We aimed to assess procedural profiles and clinical outcomes of transvenous lead extraction for cardiac implantable electronic device infection based on renal disease status., Methods and Results: In 1420 consecutive patients undergoing transvenous lead extraction of infected cardiac implantable electronic devices (1996-2012), we assessed procedural profiles and clinical outcomes in 3 groups: normal renal function (group 1, n=1159), renal dysfunction not requiring dialysis (group 2, n=163), and dialysis (group 3, n=98). A total of 3182 infected leads were extracted. Dialysis patients had shorter lead dwell times and were less likely to require transvenous lead extraction tools but as likely to require femoral workstations. There were higher overall rates of procedure-related complications in dialysis patients (12% versus ≈6% in nondialysis) with no difference in the major complication rates ( P =not significant). Complete procedural success rates were 94%, 96%, and 94% in groups 1, 2, and 3, respectively ( P =not significant). There were 4 intraprocedural deaths in group 1 versus none in groups 2 and 3. Mortality rates were significantly higher in dialysis patients both at 1 and 6 months ( P <0.0001 for both). In multivariable analyses, dialysis status was independently associated with increased mortality risk at 1 and 6 months. Other factors associated with mortality were lead material retention, functional (New York Heart Association) class, and occurrence of procedural complications., Conclusions: In patients with cardiac implantable electronic device infection, dialysis status did not seem to add complexity to transvenous lead extraction but was independently associated with increased mortality at 1 and 6 months., (© 2018 American Heart Association, Inc.)