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Background: Infection is a well-recognized complication of cardiovascular implantable electronic device (CIED) implantation, including the more recently available subcutaneous implantable cardioverter-defibrillator (S-ICD). Although the AHA/ACC/HRS guidelines include recommendations for S-ICD use, currently there are no clinical trial data that address the diagnosis and management of S-ICD infections. Therefore, an expert panel was convened to develop consensus on these topics., Methods: A process mapping methodology was used to achieve a primary goal - the development of consensus on the diagnosis and management of S-ICD infections. Two face-to-face meetings of panel experts were conducted to recommend useful information to clinicians in individual patient management of S-ICD infections., Results: Panel consensus of a stepwise approach in the diagnosis and management was developed to provide guidance in individual patient management., Conclusion: Achieving expert panel consensus by process mapping methodology in S-ICD infection diagnosis and management was attainable, and the results should be helpful in individual patient management., (© 2020 Wiley Periodicals LLC.)

Extraction of transvenous leads via the femoral route might be needed when extraction via the implant vein fails or when retained lead fragments exist. The skill set required for this procedure is unique as it relies on the ability to snare and the use of a variety of shelf tools. In this era of leadless pacing, this skill set might be called upon more frequently. In this article, we review the data, tools, and procedural steps of femoral lead extraction and retrieval/extraction of leadless pacemakers., (© 2019 Wiley Periodicals, Inc.)

Background: The Micra clinical trials have enrolled more than 2500 patients without any reported device-related infections that required removal during follow-up. Leadless pacemakers might be more resistant to bacterial seeding due to smaller surface area and a greater tendency for encapsulation., Objective: To analyze the incidence and outcomes of serious infectious events (SIEs: bacteremia or endocarditis) that developed during follow-up in patients with history of Micra leadless pacemaker implantation., Methods: SIE and outcomes were characterized based upon adverse event reports. Among 720 patients implanted with Micra in the investigational device exemption trial, we identified 16 patients who had documented 21 SIEs during follow-up., Results: Among patients with SIEs, mean age was 71.9 ± 11.7 years. SIEs occurred at a mean 4.8 ± 4.5 months after implant and patients were followed for 13.1 ± 9.1 months after documentation of SIE. All events were adjudicated as unrelated to the Micra device or procedure. Bacteremia was documented to be related to a gram-positive organism in 13 events (seven Staphylococcus, three Streptococcus, two Enterococcus, and one uncharacterized gram-positive bacteria), and gram-negative organisms in three events. In five events, the type of organism was not characterized (two patients with endocarditis). No persistent cases of bacteremia after antibiotic cessation were seen over the duration of follow-up CONCLUSION: In this small series of Micra patients who developed SIEs postimplant, the occurrence of bacteremia and/or endocarditis did not appear to lead to persistent bacteremia off antibiotics; most events resolved with antibiotic treatment., (© 2019 Wiley Periodicals, Inc.)

Background: Consensus statements on lead extraction give consideration to open surgical removal in the setting of large vegetations, to mitigate the risk of massive embolism that may occur with percutaneous lead removal. Vacuum-assisted debulking (VD) of large vegetations as an adjunct to percutaneous lead extraction may provide an opportunity to mitigate these risks., Methods: We retrospectively identified all patients undergoing lead extraction at our institution for endovascular infection from 2012 to 2018 and stratified them into two groups based on presence of adjunctive VD (n = 6) or without VD (no-VD, n = 39). VD was performed with the AngioVac system (Angio-Dynamics, Latham, NY, USA)., Results: Across the cohort, mean age was 62 ± 15 years, ejection fraction was 41 ± 16%, and 39% had end-stage renal disease on dialysis. Defibrillator systems were present in 71%, and 22% had cardiac resynchronization devices. Mean duration of the oldest extracted lead was 6.3 ± 4.9 years. There were no significant differences in baseline covariates between groups. Those in the VD group were significantly less likely to have Staphylococcus aureus as a causative organism (P = .04). In the VD group, vegetations targeted for debulking ranged in size from 1.8 to 6 cm (longest dimension). There were no operative deaths or clinically evident embolic events in either group. The overall nonfatal complication rate in the VD group was higher (33.3% vs 2.3%, P = .043)., Conclusion: VD can be performed as an adjunct to percutaneous lead extraction with a reasonable safety profile. The relative safety and efficacy of this approach removal requires further study., (© 2019 Wiley Periodicals, Inc.)

Background: Defibrillation threshold (DFT) testing is recommended with the subcutaneous implantable cardioverter defibrillator (SICD)., Objective: To describe first shock efficacy for appropriate SICD therapies stratified by the presence of implant DFT testing., Methods: We reviewed all patients receiving SICDs at our institution and stratified them based on whether implant DFT testing was performed. Appropriate shocks were reviewed to see if ventricular tachycardia/ventricular fibrillation (VT/VF) terminated with a single shock. First shock efficacy was stratified by implant DFT status., Results: 178 patients implanted with SICDs and followed in our center were included in this study. Of these, 135 (76%) underwent DFT testing (DFT (+) group). In the DFT (+), 80 appropriate shocks were needed to treat 69 episodes of VT/VF. The first shock was effective in 61 out of 69 episodes (88.4%), whereas multiple shocks were required to terminate VT/VF in the remaining eight episodes. Among 43 patients without implant DFT testing (DFT (-) group), 20 appropriate shocks to treat 17 episodes of VT/VF occurred in seven patients. VT/VF was successfully terminated with the first shock in 16 out of 17 episodes (first shock efficacy 94.1 %). There was no significant difference in first shock effectiveness between those with and without implant DFT testing (P  =  0.97)., Conclusion: A strategy that omits DFT testing at implant did not appear to compromise the effectiveness of the SICD. These data suggest that routine DFT testing at SICD implant might not be necessary. Randomized trials are needed to confirm this finding., (© 2018 Wiley Periodicals, Inc.)

Background: Atrioventricular junctional (AVJ) ablation and pacemaker implantation are indicated when pharmacotherapy fails to achieve adequate rate control in atrial fibrillation (AF). The purpose of our study is to assess the feasibility and safety of concurrent Micra leadless transcatheter pacemaker implantation and AVJ ablation., Methods: We retrospectively assessed patients who underwent Micra implantation and concurrent AVJ ablation at three institutions between August 2014 and March 2016. All patients and devices were followed at baseline and at 1, 3, 6, and 12 months postimplantion., Results: Twenty-one patients with permanent AF (median age 77 [range: 62-88], female 15 [71.4%]) underwent successful Micra implantation followed by concurrent AVJ ablation. There was no device dislodgement or malfunction during the 12-month follow-up. Complete 12-month electrical performance data were available in 14 patients (67%). Among patients with the complete data set, median pacing thresholds at implant and at 1, 3, 6, and 12 months were 0.5 V (range: 0.25-0.88), 0.44 V (range: 0.25-2.0), 0.5 V (range: 0.25-1.63), 0.5 V (range: 0.25-1.13), and 0.5 V (range: 0.25-1.13) at a pulse width of 0.24 msec, respectively. Two patients died due to noncardiac causes during follow-up. There were no patients with major device-related complications., Conclusions: Concurrent Micra implantation and AVJ ablation is feasible and appears safe. There was no device dislodgement, malfunction, or significant pacing threshold rise requiring device reimplantation during the 12-month follow-up. This combined approach can be considered for patients with AF with suboptimal rate control who have failed AF catheter ablation and/or pharmacotherapy., (© 2018 Wiley Periodicals, Inc.)

Background: Octogenarians account for a significant percentage of patients with indwelling pacemakers or defibrillators., Objectives: To determine procedural outcomes and long-term survival after lead extraction (LE) in octogenarians., Methods: We retrospectively identified all patients who underwent defibrillator or pacemaker LE at our institution between January 1, 2007 and May 31, 2016. Patients were stratified based on age into two groups: <80 years old (Group 1, n = 674) or ≥80 (Group 2, n = 100). Outcomes were determined by medical records review and query of the Social Security Death Index., Results: Patients in Group 2 were more likely to be hypertensive (77% vs 61%, P = 0.02), more like to have coronary artery disease (50% vs 39%, P = 0.049), and more likely to be extracted for infectious indications (47% vs 33%, P = .009). The number of leads extracted per procedure was 2.0 ± 0.8 and the mean dwell time of the oldest extracted lead was 5.6 ± 4.3 years, without significant differences between groups. Extraction procedure success (Group 1: 94.7%, Group 2: 96%, P = 0.808) and procedural deaths (Group 1: 0.9% vs Group 2: 0%, P = 1.0) were similar. There was no significant difference in survival up to 3 years following LE between groups., Conclusion: At experienced centers, LE can be performed safely in octogenarians with procedural success rates and long-term survival comparable to younger individuals., (© 2017 Wiley Periodicals, Inc.)

Objectives: This study compared risks associated with magnetic resonance imaging (MRI) in patients with non-MRI conditional and MRI conditional pacing and defibrillator systems with particular attention to clinically actionable outcomes., Background: While recipients of new MRI conditional pacemaker and defibrillator systems may undergo MRI scanning with very low risk, safety and regulatory concerns persist regarding such scanning in recipients of non-MRI conditional systems., Methods: Patients with any cardiac device who were referred for MRI were prospectively enrolled at a single center and underwent scanning at 1.5 Tesla. Pre- and postscan lead characteristic changes, system integrity, and symptoms were analyzed. A comparison was made between non-MRI conditional and MRI conditional devices., Results: 105 patients were evaluated allowing for comparison of 97 scans with non-MRI conditional devices and 16 scans with MRI conditional devices. The cohort included those with pacemaker dependency, defibrillator, and cardiac resynchronization devices. Small, nonsignificant changes were observed in lead characteristics following scanning, and there was no significant difference when comparing non-MRI and MRI conditional devices. Lead parameter changes did not require lead revision or programming changes. No device reset, failures, or premature scan termination was observed., Conclusions: 1.5 T MRI scanning in patients with MRI conditional and non-MRI conditional cardiac devices was performed with similar, low clinical risk., (© 2017 Wiley Periodicals, Inc.)

Background: The UNTOUCHED study will assess the safety and efficacy of the subcutaneous implantable cardioverter defibrillator (S-ICD) in the most common cohort of patients receiving ICDs. The primary goal is to evaluate the inappropriate shock (IAS)-free rate in primary prevention patients with a reduced ejection fraction (EF) and compare with a historical control of transvenous ICD patients with similar programming., Methods and Results: The UNTOUCHED study is a global, multicenter, prospective, nonrandomized study of patients undergoing de novo S-ICD implantation for primary prevention of sudden cardiac death with a left ventricular EF ≤35%. The primary end point of this trial is freedom from IAS at 18 months. The lower 95% confidence bound of the observed incidence will be compared to a performance goal of 91.6%, which was derived from the IAS rate in MADIT-RIT. The secondary end points are all-cause shock-free rate at 18 months, and system- and procedure-related complication-free rate at 1 month and 6 months. Enrollment of a minimum of 1,100 subjects from up to 200 centers worldwide is planned based on power calculations of the primary and principal secondary end points., Conclusions: This trial will provide important data regarding the rates of inappropriate and appropriate shock therapy in real-world use of the S-ICD in the most common group of patients receiving ICDs., (© 2016 Wiley Periodicals, Inc.)

Background: New-onset postoperative atrial fibrillation (POAF) occurs in up to 30% of patients undergoing coronary artery bypass grafting (CABG). POAF is associated with short- and long-term mortality., Methods: To identify the true incidence and time course of recurrent atrial fibrillation (AF) in patients with POAF, we prospectively assigned 23 patients with POAF to receive an implantable loop recorder (ILR; Medtronic Inc., Minneapolis, MN, USA) for the detection of recurrent AF. Two electrophysiologists independently adjudicated monthly ILR transmissions to classify recurrent AF. We defined AF as any episode lasting ≥6 minutes., Results: The cohort included 23 subjects averaging 69.1 ± 7.2 years of age. Their mean CHADS 2 score averaged 1.9 ± 0.8. Note that 26.1% underwent direct current cardioversion prior to discharge; 95.7% left the hospital taking amiodarone and 26.1% warfarin. A total of 14 patients (60.9%) experienced recurrent AF. AF first recurred within 3 months in nine patients (39.1%), and in 10 patients AF emerged or continued beyond 3 months. Eight of 17 (47.1%) patients followed for at least 1 year experienced AF recurrence beyond 1 year of CABG. The time from surgery to first AF episode averaged 143 ± 22.5 days. Long-term monitoring shows that 60.9% of patients with POAF develop recurrent AF., Conclusion: POAF may represent a propensity for recurrent paroxysmal atrial fibrillation, and not simply a transient consequence of postoperative stress and inflammation. Better detection of recurrent AF might identify patients at risk for stroke who would benefit from continuing anticoagulation., (© 2016 Wiley Periodicals, Inc.)

Background: St. Jude Riata/Riata ST defibrillator leads (St. Jude Medical, Sylmar, CA, USA) were recalled by the Food and Drug Administration in 2011 for an increased rate of failure. More than 227,000 leads were implanted and at least 79,000 patients still have active Riata leads. Studies have examined clinical predictors of lead failure in Riata leads, but none have addressed the effect of implantable cardioverter defibrillator (ICD) generator exchange on lead failure. The purpose of this study is to assess the effect of ICD generator exchange on the rate of electrical failure in the Riata lead at 1 year., Methods: A retrospective chart review was conducted in patients who underwent implantation of a Riata/Riata ST lead at one center. Patients with a functioning Riata lead (with/without externalized conductor) at the time of ICD exchange were compared to controls with Riata leads implanted for a comparable amount of time who did not undergo generator replacement., Results: Riata leads were implanted in 1,042 patients prior to the recall and 153 of these patients underwent generator exchange without lead replacement. Conductor externalization was noted in 21.5% of Riata leads in the ICD exchange cohort, which was not different from the control group (19.2%; P = 0.32). Two leads failed in the first year after generator replacement (1.5%) which did not significantly differ from the control group (2.0%; P = 0.57). At change-out, 54% received a commanded shock (18.6 ± 0.9 J) that did not result in any change in the high-voltage lead impedance (46.1 ± 1.1 ohms)., Conclusions: Conductor externalization was seen frequently in our cohort of patients. ICD generator exchange did not accelerate the rate of Riata lead failure at 1 year. Although both the control and the change-out cohorts failed at a rate much greater than nonrecalled leads, generator exchange did not appear to add to the problem., (©2015 Wiley Periodicals, Inc.)

Background: Little data exist on long-term outcomes following extraction of implantable cardioverter defibrillator (ICD) leads, particularly for noninfectious indications. We sought to identify predictors of long-term survival after ICD lead extraction., Methods: We retrospectively reviewed ICD lead extractions at our institution (n = 508). Procedural outcomes and long-term survival were ascertained by medical records review., Results: Indication for lead extraction was infection in 32.5% and lead failure in 61.8%. Mean dwell time of the oldest extracted lead was 5.1 ± 5.9 years. Complete procedural success was achieved in 96.5% of cases. Major procedure-related complications occurred in 1.6% with six periprocedural deaths. During a mean follow-up of 866 ± 798 days, survival was significantly worse among patients with infection as the indication for extraction. At 1 year after extraction, survival among those with infection was 88.2%, compared to 95.0% in the lead failure cohort (P < 0.001). Procedural failure was a significant predictor of long-term mortality, even after excluding periprocedural deaths. In multivariate models, the presence of chronic kidney disease, increased number of leads requiring extraction, lower ejection fraction, and procedural failure were predictors of mortality., Conclusion: Despite high rates of procedural success, infectious indication for ICD lead extraction is associated with increased long-term mortality. In contrast, among patients undergoing extraction for lead failure, long-term survival was excellent. The presence of procedural failure was a significant predictor of long-term mortality. Further studies will be necessary to better understand the mechanisms by which procedural failure may adversely impact long-term outcomes., (© 2015 Wiley Periodicals, Inc.)

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common supraventricular tachycardia. Ablation of the slow pathway is the treatment of choice for recurrent episodes despite adequate medical therapy. We present an uncommon case of AVNRT ablation using a superior vena cava approach in a patient with bilateral common femoral vein occlusion. This approach appears to be a safe alternative in patients with an absence of an inferior venous access., (©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.)