Does early detection of atrial fibrillation reduce the risk of thromboembolic events? Rationale and design of the Heartline study.

BACKGROUND: The impact of using direct-to-consumer wearable devices as a means to timely detect atrial fibrillation (AF) and to improve clinical outcomes is unknown. METHODS: Heartline is a pragmatic, randomized, and decentralized application-based trial of US participants aged ≥65 years. Two randomized cohorts include adults with possession of an iPhone and without a history of AF and those with a diagnosis of AF taking a direct oral anticoagulant (DOAC) for ≥30 days. Participants within each cohort are randomized (3:1) to either a core digital engagement program (CDEP) via iPhone application (Heartline application) and an Apple Watch (Apple Watch Group) or CDEP alone (iPhone-only Group). The Apple Watch Group has the watch irregular rhythm notification (IRN) feature enabled and access to the ECG application on the Apple Watch. If an IRN notification is issued for suspected AF then the study application instructs participants in the Apple Watch Group to seek medical care. All participants were "watch-naïve" at time of enrollment and have an option to either buy or loan an Apple Watch as part of this study. The primary end point is time from randomization to clinical diagnosis of AF, with confirmation by health care claims. Key secondary endpoint are claims-based incidence of a 6-component composite cardiovascular/systemic embolism/mortality event, DOAC medication use and adherence, costs/health resource utilization, and frequency of hospitalizations for bleeding. All study assessments, including patient-reported outcomes, are conducted through the study application. The target study enrollment is approximately 28,000 participants in total; at time of manuscript submission, a total of 26,485 participants have been enrolled into the study. CONCLUSION: The Heartline Study will assess if an Apple Watch with the IRN and ECG application, along with application-facilitated digital health engagement modules, improves time to AF diagnosis and cardiovascular outcomes in a real-world environment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04276441.

Effect of contact force on pulsed field ablation lesions in porcine cardiac tissue.

INTRODUCTION: Contact force has been used to titrate lesion formation for radiofrequency ablation. Pulsed field ablation (PFA) is a field-based ablation technology for which limited evidence on the impact of contact force on lesion size is available. METHODS: Porcine hearts (n = 6) were perfused using a modified Langendorff set-up. A prototype focal PFA catheter attached to a force gauge was held perpendicular to the epicardium and lowered until contact was made. Contact force was recorded during each PFA delivery. Matured lesions were cross-sectioned, stained, and the lesion dimensions measured. RESULTS: A total of 82 lesions were evaluated with contact forces between 1.3 and 48.6 g. Mean lesion depth was 4.8 ± 0.9 mm (standard deviation), mean lesion width was 9.1 ± 1.3 mm, and mean lesion volume was 217.0 ± 96.6 mm3 . Linear regression curves showed an increase of only 0.01 mm in depth (depth = 0.01 × contact force + 4.41, R2 = 0.05), 0.03 mm in width (width = 0.03 × contact force + 8.26, R2 = 0.13) for each additional gram of contact force, and 2.20 mm3 in volume (volume = 2.20 × contact force + 162, R2 = 0.10). CONCLUSION: Increasing contact force using a bipolar, biphasic focal PFA system has minimal effects on acute lesion dimensions in an isolated porcine heart model and achieving tissue contact is more important than the force with which that contact is made.

Rationale and design of the Lead Evaluation for Defibrillation and Reliability study: Safety and efficacy of a novel ICD lead design.

BACKGROUND: Implantable cardioverter defibrillators (ICD) are indicated for primary and secondary prevention of sudden cardiac arrest. Despite enhancements in design and technologies, the ICD lead is the most vulnerable component of the ICD system and failure of ICD leads remains a significant clinical problem. A novel, small-diameter, lumenless, catheter-delivered, defibrillator lead was developed with the aim to improve long-term reliability. METHODS AND RESULTS: The Lead Evaluation for Defibrillation and Reliability (LEADR) study is a multi-center, single-arm, Bayesian, adaptive design, pre-market interventional pivotal clinical study. Up to 60 study sites from around the world will participate in the study. Patients indicated for a de novo ICD will undergo defibrillation testing at implantation and clinical assessments at baseline, implant, pre-hospital discharge, 3 months, 6 months, and every 6 months thereafter until official study closure. Patients may be participating for a minimum of 18 months to approximately 3 years. Fracture-free survival will be evaluated using a Bayesian statistical method that incorporates both virtual patient data (combination of bench testing to failure with in-vivo use condition data) with clinical patients. The clinical subject sample size will be determined using decision rules for number of subject enrollments and follow-up time based upon the observed number of fractures at certain time points in the study. The adaptive study design will therefore result in a minimum of 500 and a maximum of 900 patients enrolled. CONCLUSION: The LEADR Clinical Study was designed to efficiently provide evidence for short- and long-term safety and efficacy of a novel lead design using Bayesian methods including a novel virtual patient approach.

Impact of redo ablation for atrial fibrillation on patient-reported outcomes and quality of life.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF) is frequently used for the purpose of rhythm control and improved quality of life (QoL). Although success rates are high, a significant proportion of patients require redo ablation. Data are scarce on patient-centered outcomes and QoL in patients undergoing redo AF ablation. We aimed to assess QoL and clinical outcomes using a large prospectively maintained patient-reported outcomes (PRO) registry. METHODS: All patients undergoing redo AF ablation (2013-2016) at our center were enrolled in a prospective registry for outcomes and assessed for QoL using automated PRO surveys (baseline, 3 and 6 months after ablation, every 6 months thereafter). Data were collected over 3 years of follow-up. The atrial fibrillation symptom severity scale (AFSSS) was used as the main measure for QoL. Additional variables included patient-reported improvement, AF burden, and AF-related healthcare utilization including emergency room (ER) visits and hospitalizations. RESULTS: A total of 848 patients were included (28% females, mean age 63.8, 51% persistent AF). By automated PRO, significant improvement in QoL was noted (baseline median AFSSS of 12 [5-18] and ranged between 2 and 4 on subsequent assessments; p < .0001), with ≥70%of patients reported remarkable improvement in their AF-related symptoms. The proportion of patients in AF at the time of baseline survey was 36%, and this decreased to <8% across all time points during follow-up (p < .0001). AF burden was significantly reduced (including frequency and duration of episodes; p < .0001), with an associated decrease in healthcare utilization after 6 months from the time of ablation (including ER visits and hospitalizations; p < .0001). The proportion of patients on anticoagulants or antiarrhythmics decreased on follow-up across all time points (p < .0001 for all variables). CONCLUSION: Most patients derive significant QoL benefit from redo AF ablation; with reduction of both AF burden and healthcare utilization.

Antibacterial Envelope to Prevent Cardiac Implantable Device Infection.

BACKGROUND: Infections after placement of cardiac implantable electronic devices (CIEDs) are associated with substantial morbidity and mortality. There is limited evidence on prophylactic strategies, other than the use of preoperative antibiotics, to prevent such infections. METHODS: We conducted a randomized, controlled clinical trial to assess the safety and efficacy of an absorbable, antibiotic-eluting envelope in reducing the incidence of infection associated with CIED implantations. Patients who were undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator were randomly assigned, in a 1:1 ratio, to receive the envelope or not. Standard-of-care strategies to prevent infection were used in all patients. The primary end point was infection resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death, within 12 months after the CIED implantation procedure. The secondary end point for safety was procedure-related or system-related complications within 12 months. RESULTS: A total of 6983 patients underwent randomization: 3495 to the envelope group and 3488 to the control group. The primary end point occurred in 25 patients in the envelope group and 42 patients in the control group (12-month Kaplan-Meier estimated event rate, 0.7% and 1.2%, respectively; hazard ratio, 0.60; 95% confidence interval [CI], 0.36 to 0.98; P = 0.04). The safety end point occurred in 201 patients in the envelope group and 236 patients in the control group (12-month Kaplan-Meier estimated event rate, 6.0% and 6.9%, respectively; hazard ratio, 0.87; 95% CI, 0.72 to 1.06; P<0.001 for noninferiority). The mean (±SD) duration of follow-up was 20.7±8.5 months. Major CIED-related infections through the entire follow-up period occurred in 32 patients in the envelope group and 51 patients in the control group (hazard ratio, 0.63; 95% CI, 0.40 to 0.98). CONCLUSIONS: Adjunctive use of an antibacterial envelope resulted in a significantly lower incidence of major CIED infections than standard-of-care infection-prevention strategies alone, without a higher incidence of complications. (Funded by Medtronic; WRAP-IT ClinicalTrials.gov number, NCT02277990.).

Outcomes of atrial fibrillation ablation in patients with or without silent pulmonary veins from prior ablation procedure.

INTRODUCTION: Pulmonary venous (PV) electrical recovery underlies most arrhythmia recurrences after atrial fibrillation (AF) ablation. Little is known about procedural profiles and outcomes of patients with electrically silent PVs upon redo ablation for AF. METHODS: In a prospectively maintained registry, we enrolled 838 consecutive patients (2013-2016) undergoing redo ablation procedures. Ablation procedures targeted the PVs, the PV antra, and non-PV sites at operators' discretion. Procedural profiles and clinical outcomes were assessed. The primary outcome was freedom from AF after a 3-month blanking period. The secondary outcome was improvement in quality of life. RESULTS: Most patients undergoing redo AF ablation (n = 684, 82%) had PV reconnection while the remaining 154 (18%) had electrically silent PVs. Patients with recurrent AF and electrically silent PVs were older (66 vs. 64 years, p = .02), had more prior ablation procedures (median 2 IQR 1-3 vs 1 IQR 1-2 p = .001), were more likely to have non-paroxysmal AF (62% vs. 49%, p = .004) and atrial flutter (48% vs. 29%, p = .001) and had significantly larger left atrial volumes (89 vs. 81 ml, p = .003). Patients with silent PVs underwent a more extensive non-PV ablation strategies with antral extension of prior ablation sets in addition to ablation of the roof, appendage, inferior to the right PVs, peri-mitral flutter lines, cavotricuspid isthmus lines and ablation in the coronary sinus. Upon one year of follow-up, patients with electrically silent PVs were less likely to remain free from recurrent atrial arrhythmias (64% vs. 76%, p = .008). Regardless of PV reconnection status, redo ablation resulted in improvement in quality of life. CONCLUSION: Rhythm control with extensive ablation allowed maintenance of sinus rhythm in about two thirds of patients with silent PVs during redo AF ablation procedures. Regardless of PV reconnection status, redo ablation resulted in improvement in quality of life. This remains a challenging group of patients, highlighting the need to better understand non-PV mediated AF.

The utility of a novel mapping algorithm utilizing vectors and global pattern of propagation for scar-related atrial tachycardias.

BACKGROUND: Activation maps of scar-related atrial tachycardias (AT) can be challenging to interpret due to difficulty in inaccurate annotation of electrograms, and an arbitrarily predefined mapping window. A novel mapping software integrating vector data and applying an algorithmic solution taking into consideration global activation pattern has been recently described (Coherent™, Biosense Webster "Investigational"). OBJECTIVE: We aimed to assess the investigational algorithm to determine the mechanism of AT compared with the standard algorithm. METHODS: This study included patients who underwent ablation of scar-related AT using the Carto 3 and the standard activation algorithm. The mapping data were analyzed retrospectively using the investigational algorithm, and the mechanisms were evaluated by two independent electrophysiologists. RESULTS: A total of 77 scar-related AT activation maps were analyzed (89.6% left atrium, median tachycardia cycle length of 273 ms). Of those, 67 cases with a confirmed mechanism of arrhythmia were used to compare the activation software. The actual mechanism of the arrhythmia was more likely to be identified with the investigational algorithm (67.2% vs. 44.8%, p = .009). In five patients with dual-loop circuits, 3/5 (60%) were correctly identified by the investigational algorithm compared to 0/5 (0%) with the standard software. The reduced atrial voltage was prone to lead to less capable identification of mechanism (p for trend: .05). The investigational algorithm showed higher inter-reviewer agreement (Cohen's kappa .62 vs. .47). CONCLUSIONS: In patients with scar-related ATs, activation mapping algorithms integrating vector data and "best-fit" propagation solution may help in identifying the mechanism and the successful site of termination.

Cost-Effectiveness Analyses of an Absorbable Antibacterial Envelope for Use in Patients at Increased Risk of Cardiac Implantable Electronic Device Infection in Germany, Italy, and England.

OBJECTIVES: To model the cost-effectiveness of the TYRX Absorbable Antibacterial Envelope when used in patients at increased risk of cardiac implantable electronic device (CIED) infection in the context of 3 European healthcare systems: Germany, Italy, and England. METHODS: A decision tree model with a lifetime horizon was populated using data from the Worldwide Randomized Antibiotic Envelope Infection Prevention Trial, a large multicenter randomized controlled trial. Use of the antibacterial envelope adjunctive to standard of care was compared to standard of care infection prevention alone. Patients in the model were divided into subgroups based on presence of factors known to increase infection risk. RESULTS: The antibacterial envelope had the most favorable cost-effectiveness profile when patients had previously experienced CIED infection, had a history of immunosuppressive therapy, or had a Prevention of Arrhythmia Device Infection Trial (PADIT) score indicating high risk of infection (scores ≥6) at cost-effectiveness thresholds of €50 000 in Germany (assumed in the absence of an official threshold), €40 000 in Italy, and £30 000 in England. Probabilistic sensitivity analysis indicated that the antibacterial envelope was likely to be cost-effective in patients with other risk factors (including replacement of high power CIEDs, generator replacement with lead modification, and PADIT scores indicating intermediate risk of infection) when used with some device types and in some countries. CONCLUSIONS: The absorbable antibacterial envelope was associated with cost-effectiveness ratios below European benchmarks in selected patients at increased risk of infection, suggesting the envelope provides value for European healthcare systems by reducing CIED infections.

Antibiotic eluting envelopes: evidence, technology, and defining high-risk populations.

Cardiovascular implantable electronic devices (CIED) are effective and important components of modern cardiovascular care. Despite the dramatic improvements in the functionality and reliability of these devices, over time patients are at risk for developing several morbidities, the most feared of which are local and systemic infections. Despite significant financial investment and aggressive therapy with hospitalization, intravenous antibiotics, and transvenous lead extraction, the outcomes include a 1-year mortality rate as high as 25%. This risk of infection has increased over time, likely due to the increased complexity of the surgical interventions required to insert and replace these devices. The only way to reduce this morbidity and mortality is to prevent these infections, and other than preoperative antibiotics, there were little data supporting effective therapy until the WRAP-IT trial provided randomized data showing that pocket infections can be reduced by 60% at 12 months and major CIED infections reduced by 40% at 1 year with the use of the absorbable antibiotic eluting envelope in patient CIED procedures at high risk of infection. Not all CIED procedures are at high risk of infection and justify the use of the envelope, but cost-effectiveness data support the use of the antibiotic envelope particularly in patients with defibrillator replacements, revisions, and upgrades, such as to a resynchronization device and in patients with prior CIED infection, history of immunocompromise, two or more prior procedures, or a history of renal dysfunction.

Infections associated with cardiac electronic implantable devices: economic perspectives and impact of the TYRX™ antibacterial envelope.

The occurrence of cardiac implantable electronic devices (CIED) infections and related adverse outcomes have an important financial impact on the healthcare system, with hospitalization length of stay (2-3 weeks on average) being the largest cost driver, including the cost of device system extraction and device replacement accounting for more than half of total costs. In the recent literature, the economic profile of the TYRX™ absorbable antibacterial envelope was analysed taking into account both randomized and non-randomized trial data. Economic analysis found that the envelope is associated with cost-effectiveness ratios below USA and European benchmarks in selected patients at increased risk of infection. Therefore, the TYRX™ envelope, by effectively reducing CIED infections, provides value according to the criteria of affordability currently adopted by USA and European healthcare systems.

Use of healthcare claims to validate the Prevention of Arrhythmia Device Infection Trial cardiac implantable electronic device infection risk score.

AIM: The Prevention of Arrhythmia Device Infection Trial (PADIT) infection risk score, developed based on a large prospectively collected data set, identified five independent predictors of cardiac implantable electronic device (CIED) infection. We performed an independent validation of the risk score in a data set extracted from U.S. healthcare claims. METHODS AND RESULTS: Retrospective identification of index CIED procedures among patients aged ≥18 years with at least one record of a CIED procedure between January 2011 and September 2014 in a U.S health claims database. PADIT risk factors and major CIED infections (with system removal, invasive procedure without system removal, or infection-attributable death) were identified through diagnosis and procedure codes. The data set was randomized by PADIT score into Data Set A (60%) and Data Set B (40%). A frailty model allowing multiple procedures per patient was fit using Data Set A, with PADIT score as the only predictor, excluding patients with prior CIED infection. A data set of 54 042 index procedures among 51 623 patients with 574 infections was extracted. Among patients with no history of prior CIED infection, a 1 unit increase in the PADIT score was associated with a relative 28% increase in infection risk. Prior CIED infection was associated with significant incremental predictive value (HR 5.66, P < 0.0001) after adjusting for PADIT score. A Harrell's C-statistic for the PADIT score and history of prior CIED infection was 0.76. CONCLUSION: The PADIT risk score predicts increased CIED infection risk, identifying higher risk patients that could potentially benefit from targeted interventions to reduce the risk of CIED infection. Prior CIED infection confers incremental predictive value to the PADIT score.

Predictors of long-term outcomes greater than 10 years after cardiac resynchronization therapy implantation.

BACKGROUND: Cardiac resynchronization therapy (CRT) is indicated in patients with medically refractory heart failure and wide QRS duration. While much is known about predictors of left ventricular (LV) remodeling after CRT implantation and short-term mortality, limited data exist on long-term outcomes after CRT placement. METHODS: We retrospectively reviewed all patients undergoing CRT implantation at our center between 2003 and 2008 and examined mortality using institutional electronic records, social security death index, and online obituary search. We included only patients with preimplant echoes with LV ejection fraction (LVEF) 35% or below. Variable selection was performed using stepwise regression and models were compared using goodness-of-fit criteria. A final model was validated with the bootstrap regression method. RESULTS: Out of the 877 CRT patients undergoing implantation during this time, 287 (32.7%) survived longer than 10 years. Significant (P < .05) predictors of survival in our multivariate model were age, left ventricular diastolic diameter, sex, presence of nonischemic vs ischemic cardiomyopathy, QRS duration, atrial fibrillation, BNP levels, and creatinine levels at the time of CRT implantation. A model using the odds ratios from these variables had a receiver operating curve with an area under the curve score of 0.816 (standard error, 0.019) at predicting survival or freedom from LVAD or heart transplant for longer than 10 years after CRT implantation. The specificity for factors 3 or above and 5 or above was 68% and 77%, respectively. CONCLUSION: A large proportion of patients are still alive 10 years after CRT implantation. Variables at the time of CRT implant can help provide prognostic information to patients and electrophysiologists to determine the long-term benefit and survival of patients after CRT implantation.

Baseline Right Ventricular Dysfunction Predicts Worse Outcomes in Patients Undergoing Cardiac Resynchronization Therapy Implantation.

INTRODUCTION: Cardiac resynchronization therapy (CRT) has been shown to improve survival in patients with systolic heart failure, wide QRS duration, and left-bundle-branch-block. However, CRT outcomes stratified by right ventricular (RV) function at implant have not been well studied. METHODS: We retrospectively reviewed patients at Cleveland Clinic who underwent CRT implantation (n = 777) from 2003 to 2011 with a diagnosis of heart failure, echocardiography with both pre-CRT left ventricular ejection fraction (LVEF) ≤35% and available post-CRT echocardiography at 6 months post-implant. CRT response was defined as LVEF improvement ≥5%. Patients were separated into 2 groups: normal or mild RV dysfunction (n = 570) labeled Normal RV; moderate to severe dysfunction (n = 207) labeled RV DYSFXN based on qualitative echocardiography assessment. Survival was calculated as time from CRT implant to death, left ventricular assist device implant, or heart transplant. RESULTS: CRT response was significantly higher in patients with Normal RV (67%) compared with patients with RV DYSFXN (56%; P = .006). Kaplan-Meier analysis showed that CRT patients with Normal RV had significantly greater survival compared with patients with RV DYSFXN (P < .001). In multivariable Cox regression accounting for a priori covariates, RV DYSFXN was associated with worse survival (HR 1.41 [95% CI: 1.14-1.75], P = .002) and lower CRT response (HR 0.66 [95% CI: 0.44-0.97], P = .03). CONCLUSION: Baseline RV dysfunction at CRT implant is an important predictor of worsened left ventricular remodeling and survival in CRT patients.

The gap between what patients know and desire to learn about their cardiac implantable electronic devices.

BACKGROUND: Advancement of digital technology now allows patients to have access to data from their cardiac implantable electronic devices (CIEDs). However, patients' understanding regarding CIED data and perceived personal usability remain unclear. The present study is a prospective survey to examine patients' understanding of their CIEDs and their perception of what is important. METHODS: We screened 400 patients between July and December 2018 who presented to our outpatient clinic for a CIED interrogation. Patients received a one-page questionnaire asking baseline demographics, their perception about their own knowledge about their device, and multiple-choice questions in seven basic categories: type of CIED, original indication, functionality, manufacturer, number of active leads, estimated battery life, and number of shocks received. We compared these answers to their interrogation reports to assess accuracy. We also asked participants what they would like to be aware of regarding their CIED. RESULTS: From this cohort, 344 of 400 (86%) (62.9 ± 12.8 years and 64 % males) agreed to take the survey and were included in the analysis. At baseline, 63.2% agreed or strongly agreed that they were knowledgeable about their devices. The overwhelming majority of patients demonstrated CIED knowledge deficits in at least one content area (n = 294, 86%), or more than two content areas (n = 176, 51%). Patients agreed or strongly agreed that they had a desire to have information regarding each of the following: battery life (84%), activity level (79%), heart rate trend (75%), and ventricular arrhythmias (74%). CONCLUSION: There is a large discrepancy in patients' level of knowledge regarding their CIEDs and their wish to know more details. Future technologies should satisfy providers' goals to educate their patients with basic information and fulfill patients' desire to obtain more data from their CIEDs.

Association between pre-ablation bariatric surgery and atrial fibrillation recurrence in morbidly obese patients undergoing atrial fibrillation ablation.

AIMS: Obesity decreases arrhythmia-free survival after atrial fibrillation (AF) ablation by mechanisms that are not fully understood. We investigated the impact of pre-ablation bariatric surgery (BS) on AF recurrence after ablation. METHODS AND RESULTS: In this retrospective observational cohort study, 239 consecutive morbidly obese patients (body mass index ≥40 kg/m2 or ≥35 kg/m2 with obesity-related complications) were followed for a mean of 22 months prior to ablation. Of these patients, 51 had BS prior to ablation, and our primary outcome was whether BS was associated with a lower rate of AF recurrence during follow-up. Adjustment for confounding was performed with multivariable Cox proportional hazard models and propensity-score based analyses. During a mean follow-up of 36 months after ablation, 10/51 patients (20%) in the BS group had recurrent AF compared with 114/188 (61%) in the non-BS group (P < 0.0001). In the BS group, 6 patients (12%) underwent repeat ablation compared with 77 patients (41%) in the non-BS group, (P < 0.0001). On multivariable analysis, the association between BS and lower AF recurrence remained significant. Similarly, after weighting and adjusting for the inverse probability of the propensity score, BS was still associated with a lower hazard of AF recurrence (hazard ratio 0.14, 95% confidence interval 0.05-0.39; P = 0.002). CONCLUSION: Bariatric surgery is associated with a lower AF recurrence after ablation. Morbidly obese patients should be considered for BS prior to AF ablation, though prospective multicentre studies should be performed to confirm our novel finding.

Repeat ablation or medical management alone for recurrent arrhythmias after ablation of persistent atrial fibrillation.

INTRODUCTION: Management of persistent atrial fibrillation (PersAF) remains challenging, and many patients are left on medical therapy after a failed first ablation. In patients with recurrent symptomatic arrhythmias after PersAF ablation, we aimed to compare outcomes of repeat ablation and medical therapy versus medical therapy alone. METHODS AND RESULTS: All 682 consecutive patients with recurrent symptomatic arrhythmia after a first ablation for PersAF at our institution (2005-2012) were included. Repeat ablation with continuation of medical therapy was performed in 364 patients (Group 1) and 318 were only medically managed (Group 2). The outcome of interest was freedom from arrhythmia recurrence beyond a 3-month blanking period. Separate analyses were performed to assess this endpoint totally off antiarrhythmics (primary endpoint) or alternatively with/without use of antiarrhythmics (secondary endpoint). Over a median follow-up of 26 months, 41.5% of Group 1 patients met the primary endpoint and remained free from arrhythmia recurrence off antiarrhythmics (vs. 14.5% in Group 2, P < 0.0001). At last follow-up, antiarrhythmics continued to be required for rhythm control in 40.1% and 46.2% of patients in Groups 1 and 2, respectively (P < 0.0001). The secondary endpoint was met in 60.2% versus 32.1% of patients in Groups 1 and 2, respectively (P < 0.0001). In multivariable Cox analyses, repeat ablation was associated with significant reduction in arrhythmia recurrences compared to medical therapy alone (HR 0.48, 95% CI 0.35-0.65, P < 0.0001). CONCLUSION: In patients with recurrent symptomatic arrhythmia after ablation of PersAF, repeat ablation was associated with significant reduction in arrhythmia recurrences compared to routine medical therapy alone.

Success of pacemaker remote monitoring using app-based technology: Does patient age matter?

BACKGROUND: Remote monitoring (RM) improves patient outcomes. App-based RM is a novel technology that enables transmission of implantable device data using smart devices. Limited data exist on the impact of age and sex on the use of app-based RM. OBJECTIVE: To examine the impact of age and sex on the proportion of pacemaker patients who activated app-based RM, time from order to activation, and patient follow-up transmission adherence per guidelines. METHODS: A retrospective analysis was performed using deidentified data from U.S. pacemaker patients enrolled in the Medtronic CareLink database with an app-based monitor (MyCareLink Smart™). Activation was defined as first RM transmission and was considered early if it occurred < 90 days from order. Adherence analysis was limited to patients with ≥12 months' follow-up from activation and excluded transmissions < 90 days from activation. RESULTS: Of 48,016 patients assigned app-based RM, 40,511 (84.4%) activated their device; of these, 31,640 (65.9%) activated their device early. Among 14,232 activated patients (with 12 months' follow-up), 12,743 (89.5%) were considered adherent to guidelines by transmitting at least once more within 3-12 months following their activation transmission. While there were statistical differences in activation, early activation, and adherence among age and sex groups due to large sample sizes, the differences were not clinically significant and the majority of older patients were able to successfully use app-based RM. CONCLUSIONS: Most patients in this large and first-of-its kind reported cohort used smart devices to successfully activate app-based RM technology and remained adherent per guidelines irrespective of age or sex.

Removal of subcutaneous defibrillator shocking coils: Lessons to learn for future extraction of subcutaneous defibrillator systems.

BACKGROUND: Subcutaneous shocking coils (SQC) have been used to lower defibrillation thresholds in certain patient populations. There are limited data regarding the extraction complexity of these leads. The goal of this study is to describe our SQC extraction experience and identify challenges that may be of importance with the increase in utilization and extraction of fully subcutaneous defibrillator systems. METHODS: We studied consecutive patients who underwent lead removal at our institution during which a Medtronic 6996SQ (Medtronic plc, Minneapolis, MN, USA) was removed RESULTS: Twenty-one patients (54.5 ± 14 years, 85.7% male) underwent procedures where at least one lead removed was a SQC. Mean ejection fraction was 27.7% and 11 patients had prior ventricular arrhythmia. Median SQC age was 177 days and the age of the oldest SQC removed was 3,041 days. Infection was the indication for removal in 14 patients. One removal was performed surgically and 20 were completed percutaneously. Three procedures required additional incisions beyond the device pocket and tie-down sleeve to complete the SQC lead removal due to dense adhesions. One removal procedure required the use of a laser sheath to relieve fibrosis. Complications in this group did not appear related to SQC removal. CONCLUSIONS: Drawing from our SQC removal experience, there may be a need for additional incisions and extra tools to complete removal of older subcutaneous implantable cardioverter defibrillator leads.

Persistent Atrial Fibrillation Ablation With or Without Contact Force Sensing.

INTRODUCTION: Arrhythmia recurrences remain common after ablation of persistent atrial fibrillation (PersAF). Contact force (CF)-sensing catheters have been introduced for objective assessment of contact during radiofrequency application and have been suggested to improve outcomes in ablation of paroxysmal AF, but little is known about their role in PersAF ablation. We aimed to compare the procedural profiles and outcomes of (PersAF) ablation with or without using CF-sensing catheters. METHODS: All consecutive patients undergoing first time ablation for PersAF between April 2014 and January 2015 at the Cleveland Clinic were included. Substrate modification was performed in addition to isolation of the pulmonary veins. Success rates were determined off antiarrhythmics over 1 year of follow-up. RESULTS: The study included 174 patients (77 CF and 97 non-CF). Ablation with CF-sensing catheters resulted in shorter procedures (median 204 vs. 216 minutes, P = 0.04) and shorter fluoroscopy time (36 vs. 48 minutes, P = 0.0005), without statistical difference in radiation dose (225 vs. 270 milligrays, P = 0.1). Arrhythmia recurrences were less likely to be observed in the CF-sensing group (27.6% vs. 46.4%, P = 0.01, log-rank P = 0.004). In multivariable Cox analyses, the use of CF-sensing catheters was associated with a lower risk of arrhythmia recurrence (hazard ratio 0.49, 95% confidence interval 0.27-0.85, P = 0.01). CONCLUSIONS: Compared to non-CF sensing, the use of CF-sensing catheters for PersAF ablation is associated with shorter procedures, shorter fluoroscopy time, and reduction in arrhythmia recurrences.