Cardiac implantable electronic device-induced tricuspid regurgitation: Implications and management.

Tricuspid regurgitation (TR) secondary to cardiac implantable electronic devices (CIEDs) has been well documented and is associated with worse cardiovascular outcomes. A variety of mechanisms have been proposed including lead-induced mechanical disruption of the tricuspid valvular or subvalvular apparatus and pacing-induced electrical dyssynchrony. Patient characteristics such as age, sex, baseline atrial fibrillation, and pre-existing TR have not been consistent predictors of CIED-induced TR. While two-dimensional echocardiography is helpful in assessing the severity of TR, three-dimensional echocardiography has significantly improved accuracy in identifying the etiology of TR and whether lead position contributes to TR. Three-dimensional echocardiography may therefore play a future role in optimizing lead positioning during implant to reduce the risk of CIED-induced TR. Optimal lead management strategies in addition to percutaneous interventions and surgery in alleviating TR are very important.

Comparison between TightRail rotating dilator sheath and GlideLight laser sheath for transvenous lead extraction.

BACKGROUND: There are limited data on the comparative analyses of TightRail rotating dilator sheath (Philips) and laser sheath for lead extraction. OBJECTIVE: To evaluate the effectiveness and safety of the TightRail sheath as a primary or secondary tool for transvenous lead extraction (TLE). METHODS: Retrospective cohort analysis of 202 consecutive patients who underwent TLE using either TightRail sheath and/or GlideLight laser sheath (Philips) in our hospital. The study population was divided into three groups: Group A underwent TLE with laser sheath only (N = 157), Group B with TightRail sheath only (N = 22), and Group C with both sheaths (N = 23). RESULTS: During this period, 375 leads in 202 patients were extracted, including 297 leads extracted by laser sheath alone, 45 leads by TightRail sheath alone, and 33 by both TightRail sheath and laser sheaths. The most common indications included device infection (44.6%) and lead-related complications (44.1%). The median age of leads was 8.9 years. TightRail sheath (Group B) achieved similar efficacy as a primary extraction tool compared with laser sheath (Group A), with complete procedure success rate of 93.3% (vs. 96.6%, P = .263) and clinical success rate of 100.0% (vs. 98.1%, P = .513). Among 32 leads in which Tightrail was used after laser had failed (Group C), the complete procedure success rate was 75.8%. No significant difference in procedural adverse events was observed. CONCLUSION: Our single-center experience confirms that the TightRail system is an effective first-line and second-line method for TLE. Further investigation is required to guide the selection of mechanical and laser sheaths in lead extraction cases.

Management of patients with interrupted inferior vena cava requiring electrophysiology procedures.

BACKGROUND: Interrupted inferior vena cava (IVC) is a rare venous anomaly that complicates the treatment of patients who require electrophysiology (EP) procedures. METHODS: We describe five consecutive cases of patients with interrupted IVC who presented to the EP laboratory requiring interventional procedures including catheter ablation for atrial fibrillation and supraventricular tachycardia and left atrial appendage closure. All cases were successfully completed utilizing a variety of approaches to vascular access including transseptal puncture via transhepatic and internal jugular approaches. CONCLUSION: Procedures in the EP lab can be performed successfully in patients with interrupted IVC.

The management of cardiac implantable electronic device lead perforations: a multicentre study.

AIMS: Lead perforation is a rare, well-known complication of cardiac implantable electronic device (CIED) implants, whose management is mostly not evidence-based. Main management strategies include conservative approach based on clinical and lead function follow-up vs. routine invasive lead revision approach. This study compared the complications of both strategies by composite endpoint, including recurrent perforation-related symptoms, recurrent pericardial effusion (PEf), lead dysfunction, and device infection during 12 month follow-up. METHODS AND RESULTS: Multicentre retrospective analysis, inquiring data from imaging studies, device interrogation, pericardiocentesis, and clinical charts of patients with suspected perforating leads between 2007 and 2014 in five hospitals. All cases were reviewed by electrophysiologist and defined as definite perforations by suggestive symptoms along with lead perforation on imaging, bloody PEf on pericardiocentesis shortly after implant, or right ventricular (RV) lead non-capture along with diaphragmatic stimulation upon bipolar pacing. Clinical outcomes associated with both management approaches were compared, with respect to the composite endpoint. The study included 48 definitive perforation cases: 22 managed conservatively and 26 via lead revision. Conservative management was associated with an increased composite endpoint compared with lead revision (8/22 vs. 1/26; P = 0.007). The dominant complication among the conservative cohort was appearance of cardiac tamponade during follow-up; 5/6 occurring in cases which presented with no or only mild PEf and were treated by antiplatelets/coagulants during or shortly after CIED implantation. CONCLUSION: A conservative management of CIED lead perforation is associated with increased complications compared with early lead revision. Lead revision may be the preferred management particularly in patients receiving antiplatelets/coagulants.

Reduced appropriate implantable cardioverter-defibrillator therapy after cardiac resynchronization therapy-induced left ventricular function recovery: a meta-analysis and systematic review.

AIMS: For patients undergoing cardiac resynchronization therapy (CRT) with implantable cardioverter-defibrillator (ICD; CRT-D), the effect of an improvement in left ventricular ejection fraction (LVEF) on appropriate ICD therapy may have significant implications regarding management at the time of ICD generator replacement. METHODS AND RESULTS: We conducted a meta-analysis to determine the effect of LVEF recovery following CRT on the incidence of appropriate ICD therapy. A search of multiple electronic databases identified 709 reports, of which 6 retrospective cohort studies were included (n = 1740). In patients with post-CRT LVEF ≥35% (study n = 4), the pooled estimated rate of ICD therapy (5.5/100 person-years) was significantly lower than patients with post-CRT LVEF <35% [incidence rate difference (IRD): -6.5/100 person-years, 95% confidence interval (95% CI): -8.8 to -4.2, P < 0.001]. Similarly, patients with post-CRT LVEF ≥45% (study n = 4) demonstrated lower estimated rates of ICD therapy (2.3/100 person-years) compared with patients without such recovery (IRD: -5.8/100 person-years, 95% CI: -7.6 to -4.0, P < 0.001). Restricting analysis to studies discounting ICD therapies during LVEF recovery (study n = 3), patients with LVEF recovery (≥35 or ≥45%) had significantly lower rates of ICD therapy compared with patients without such recovery (P for both <0.001). Patients with primary prevention indication for ICD, regardless of LVEF recovery definition, had very low rates of ICD therapy (0.4 to 0.8/100-person years). CONCLUSION: Recovery of LVEF post-CRT is associated with significantly reduced appropriate ICD therapy. Patients with improvement of LVEF ≥45% and those with primary prevention indication for ICD appear to be at lowest risk.

Increased perforation risk with an MRI-conditional pacing lead: a single-center study.

BACKGROUND: Magnetic resonance imaging (MRI) has been considered contraindicated in patients with cardiac pacemakers (PPMs). Recently, Medtronic (MDT) MRI SureScan PPM (Medtronic Inc., Minneapolis, MN, USA) and leads were introduced into clinical practice in the United States of America. OBJECTIVE: To compare MDT CapSureFix 5086 MRI SureScan lead-associated perforation and dislodgement rates with MDT non-MRI SureScan active fixation leads. METHODS: We retrospectively analyzed the records of all patients implanted with MDT CapSureFix 5086 MRI SureScan leads as well as all patients implanted with MDT 4076 and 5076 leads at our institution from April 2011 to April 2014. RESULTS: Four of 72 patients implanted with MDT CapSureFix 5086 MRI SureScan leads (5.5%) had evidence of lead perforation, necessitating pericardiocentesis in three cases and lead revision in one case. Three of the four perforations were delayed perforations, presenting more than 3 weeks postimplant. Two patients implanted with MDT CapSureFix 5086 MRI SureScan leads (2.8%) had lead dislodgement. Of 420 patients implanted with MDT non-MRI SureScan leads, there were two perforations (0.47%) and four dislodgements (0.9%). There were significantly increased lead perforations associated with MDT CapSureFix 5086 MRI SureScan leads (P = 0.005) and a nonsignificant trend toward increased dislodgements (P = 0.18) when compared with MDT non-MRI SureScan leads. CONCLUSION: In contradiction to prior studies, this retrospective study suggests an increased perforation rate with MDT CapSureFix 5086 MRI SureScan leads. Most perforations were delayed perforations, presenting more than 3 weeks postimplant. Higher volume prospective studies with longer follow-up are needed to confirm our findings.

Renal Response in Patients with Chronic Kidney Disease Predicts Outcome Following Cardiac Resynchronization Therapy.

BACKGROUND: Chronic kidney disease (CKD) severity is associated with increased morbidity and mortality in congestive heart failure. There is a paucity of data regarding renal improvement after cardiac resynchronization therapy (CRT) and its potential impact on clinical outcomes, especially in patients with severe CKD. METHOD: This was a retrospective analysis of a prospectively collected cohort of 260 patients with CKD undergoing CRT at a single center. Renal function was compared before and after CRT. The primary end point was a composite of death, heart transplant, and left ventricular assist device (LVAD), assessed at 5 years. RESULTS: Patients with more severe CKD demonstrated increased risk of death, transplant, or LVAD following CRT (P = 0.015). Renal response (estimated glomerular filtration rate improvement ≥10 mL/min/1.73 m(2) ) was observed in 14% of all patients and 28% of patients with stage IV CKD. Independent predictors of renal response included left ventricular ejection fraction improvement (odds ratio [OR] 1.06, confidence interval [CI] 1.01-1.10), angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use (OR 4.31, CI 1.08-17.23), and advanced CKD stage (OR 2.19, CI 1.14-4.23). Renal response independently decreased hazard of the primary outcome (HR 0.24, CI 0.08-0.73, P = 0.01). Renal responders with stage IV CKD had 80% 5-year event-free survival, compared to 0% for nonrenal responders in stage IV (P = 0.03). CONCLUSION: Although severity of CKD is associated with poorer outcome after CRT, improvement in renal function can occur in patients across all CKD stages. Renal responders, including those with stage IV CKD, demonstrate favorable 5-year outcomes. Assessment of renal response may help better prognostic outcomes following CRT.

Does prior valve surgery change outcome in patients treated with cardiac resynchronization therapy?

AIMS: Cardiac valve surgery (CVS) has been implicated as a potential barrier to optimal response after cardiac resynchronization therapy (CRT) though prospective data regarding outcome remains limited. We sought to determine CRT response in patients with a prior history of CVS. METHODS AND RESULTS: We performed a retrospective analysis of a prospectively acquired cohort of CRT patients with history of CVS. Echocardiographic response was evaluated at baseline and 6 months. The coprimary endpoints were time to first heart failure (HF) hospitalization and a composite of all-cause mortality, transplantation and left ventricular assist device (LVAD) assessed over a 3-year follow-up period. The study group consisted of 569 patients undergoing CRT. Of these, 86 patients had a history of CVS (46.5% aortic, 37.2% mitral, 16.3% combined, and tricuspid), and were compared to 483 patients with no history of CVS. Baseline clinical and echocardiographic characteristics were not significantly different between the groups except for a higher incidence of atrial fibrillation (AF; 74.4% vs. 55.3%; P = 0.001), coronary artery bypass surgery (CABG; 58.1% vs. 38.7%; P = 0.001), and longer QRS duration (167.6 ± 29.3 milliseconds vs. 159.4 ± 27.5 milliseconds; P = 0.01) in those with prior CVS. Survival with respect to HF hospitalization and composite outcome was comparable in both groups. Echocardiographic response (improvement in left ventricular ejection fraction of ≥10%) was similar. No difference in clinical or echocardiographic outcome was found by type of valve surgery performed. CONCLUSION: Despite a higher incidence of AF, CABG, and longer QRS duration, history of CVS is not associated with worse clinical or echocardiographic outcome after CRT.

QRS morphology, left ventricular lead location, and clinical outcome in patients receiving cardiac resynchronization therapy.

AIMS: Several studies have reported a poor outcome with cardiac resynchronization therapy (CRT) in non-left bundle branch block (LBBB) patients. Although the left ventricular (LV) lead location is an important determinant of the clinical outcome, there is scant information regarding its role in non-LBBB patients. This study sought to examine the impact of electrical and anatomical location of the LV lead in relation to baseline QRS morphology on the CRT outcome. METHODS AND RESULTS: A left ventricular lead electrical delay (LVLED) was measured intra-procedurally as an interval between QRS onset on the surface electrocardiogram (ECG) to the peak of sensed electrogram on LV lead and corrected for QRS width. The impact of the LVLED on time to first heart failure hospitalization (HFH), and composite outcome of all-cause mortality, HFH, LVAD implantation, and cardiac transplantation at 3 years was assessed. Among 144 patients (age 67 ± 12 years, QRS duration 156 ± 28 ms, non-LBBB 43%), HFH was higher in non-LBBB compared with LBBB (43.5 vs. 24%, P = 0.015). Within LBBB, patients with the long LVLED (≥50%) had 17% HFH vs. 53% in the short LVLED (<50%), P = 0.002. Likewise in non-LBBB, patients with the long LVLED compared with the short LVLED had a lower HFH (36 vs. 61%, P = 0.026). In adjusted Cox proportional hazards model, the long LVLED in LBBB and non-LBBB was associated with an improved outcome. Specifically, in non-LBBB, LVLED ≥50% was associated with improved event-free survival with respect to time to first HFH (HR: 0.34; P = 0.011) and composite outcome (HR: 0.41; P = 0.019). CONCLUSION: Cardiac resynchronization therapy delivered from an LV pacing site characterized by the long LVLED was associated with the favourable outcome in LBBB and non-LBBB patients.

Lead Extraction and Baffle Stenting in a Patient with Transposition of the Great Arteries.

This case report discusses a 42-year-old male with dextro-transposition of the great arteries (D-TGA) status post Mustard repair and sick sinus syndrome status post dual-chamber pacemaker implant, who developed symptomatic superior vena cava (SVC) baffle stenosis. He was treated with a combined pacemaker extraction and subsequent SVC baffle stenting. The case highlights the complexities of treating SVC baffle stenosis in the presence of cardiac implantable devices and demonstrates the efficacy of this combined approach. Furthermore, the authors delve into the intricacies of D-TGA, its surgical history, and the long-term complications associated with atrial switch procedures.

A leadless ventricular pacemaker providing atrioventricular synchronous pacing in the real-world setting: 12-Month results from the Micra AV post-approval registry.

BACKGROUND: Advances in leadless pacemaker technology have enabled accelerometer-based atrioventricular (AV) synchronous pacing by sensing atrial mechanical contraction. OBJECTIVE: The purpose of this study was to report the performance of the Micra AV leadless pacemaker from the worldwide Micra AV post-approval registry (PAR) through 12 months. METHODS: The Micra AV PAR is a prospective, single-arm, observational registry designed to assess the safety and effectiveness of Micra AV in a real-world setting. For the present interim analysis, major complications and system revisions through 12 months were summarized and compared to a historical cohort of 2667 patients implanted with a transvenous dual-chamber pacing system. RESULTS: The device was successfully implanted in 796 of 801 patients (99.4%) at 97 centers in 19 countries. Micra AV patients were older (74.1 years vs 71.1 years; P < .0001) with a higher incidence of renal disease (22.3% vs 9.8%; P < .0001) compared with transvenous dual-chamber patients. Through 12 months, the major complication rate was 3.7% in Micra AV patients compared with 8.8% in transvenous dual-chamber patients (hazard ratio 0.42; 95% confidence interval 0.28-0.61; P < .001). The system revision rate was 1.5% in Micra AV patients compared with 5.5% for transvenous dual-chamber patients (hazard ratio 0.25; 95% confidence interval 0.13-0.47; P < .001); this reduction was largely driven by the absence of lead dislodgments requiring revision. The median AV synchrony index was 79.4% (interquartile range 65.2%-86.4%) in patients paced >90%. CONCLUSION: The Micra AV leadless pacemaker was implanted with a high rate of success in patients with multiple comorbidities, with a significantly lower rate of complications and system revisions through 12 months compared to a historical cohort of patients with transvenous dual-chamber pacemakers.

Electrical delay in apically positioned left ventricular leads and clinical outcome after cardiac resynchronization therapy.

INTRODUCTION: In recent studies, an anatomical apical left ventricular (LV) lead pacing location has been associated with deleterious outcome after cardiac resynchronization therapy (CRT). The differential impact of the LV lead electrical location in these patients remains unknown. METHODS AND RESULTS: Thirty-one consecutive CRT patients (mean age 71.7 ± 12.7 years, 55% left bundle-branch block [LBBB] morphology) with an apical LV lead and LV lead electrical delay (LVLED) were studied. Anatomical LV lead location was determined via review of coronary venography and chest radiographs. Electrical location was assessed through intraprocedural LVLED measurement. Patients were dichotomized into either "long" LVLED (LVLED ≥ 50% of QRS) or "short" LVLED groups (LVLED < 50%). Patients in the long LVLED group demonstrated significantly greater freedom from a primary composite endpoint of all-cause death, heart failure hospitalization, and cardiac transplantation at 2 years (81% vs 30%, P = 0.007 vs short LVLED patients). Longer LVLED was also associated with more favorable LV remodeling (LV end-systolic volume -41.9 ± 10.3 mL vs -4.3 ± 17.2 mL; P = 0.05), and greater improvement in LV ejection fraction (+9.4 ± 2.9% vs +2.3 ± 7.5%; P = 0.04). Even after multivariate adjustment, LVLED remained an independent predictor of the primary composite endpoint (HR 0.47, P = 0.031). CONCLUSIONS: Electrical lead localization, as estimated by LVLED ≥ 50%, is associated with improved long-term clinical outcome and measures of LV remodeling in patients with apical LV leads. Intraprocedural LVLED assessment may provide incremental utility in targeting lead placement even in conventionally unfavorable anatomical segments.

Cardiac Contractility Modulation for Heart Failure: Current and Future Directions.

Cardiac contractility modulation (CCM) is a Food and Drug Administration-approved device-based therapy for patients with heart failure. The system delivers biphasic electric stimulation to the ventricular myocardium during the absolute refractory period to augment left ventricular contraction. CCM therapy promotes acute and chronic changes at the cellular level, leading to favorable remodeling throughout the myocardium. CCM improves quality of life, New York Heart Association class, left ventricular ejection fraction, peak oxygen uptake, and the composite end point of cardiovascular death and heart failure hospitalizations. This review will focus on the biological basis, indications, and evidence for CCM, as well as the future applications of this technology.

Real-World Disparities in Remote Follow-Up of Cardiac Implantable Electronic Devices and Impact of the COVID-19 Pandemic: A Single-Center Experience.

Background Remote monitoring (RM) of cardiac implantable electronic devices has been shown to improve cardiovascular morbidity and mortality. To date, no studies have investigated disparities in use and delivery of RM. This study was performed to investigate if racial and socioeconomic disparities are present in cardiac implantable electronic device RM. Methods and Results This was a retrospective observational cohort study at a single tertiary care center in the United States. Patients who received a newly implanted cardiac implantable electronic device or device upgrade between January 2017 and December 2020 were included. Patients were classified as RM positive (RM+) when they underwent at least ≥2 remote interrogations per year during follow-up. Of all eligible patients, 2520 patients were included, and 34% were women. The mean follow-up was 25 months. Mean age was 71±14 years. Pacemakers constituted 66% of implanted devices, whereas 26% were implantable cardioverter-defibrillators, and 8% were cardiac resynchronization therapy with implantable cardioverter-defibrillators. Most patients (83%) were of European American ancestry. During follow-up, 66% of patients were classified as RM+. Patients who were younger, European American, college-educated, lived in a county with higher median household income, and were active on the hospital's patient portals were more frequently RM+. In an adjusted regression model, RM+ remained associated with the use of the online patient portal (odds ratio [OR], 2.889 [95% CI, 2.387-3.497]), presence of an implantable cardioverter-defibrillator (OR, 1.489 [95% CI, 1.207-1.835]), advanced college degree (OR, 1.244 [95% CI, 1.014-1.527]), and lastly with European American ancestry (P<0.05). During the years of the COVID-19 pandemic, the number of RM+ patients increased, whereas the association with ancestry and ethnicity decreased. Conclusions Despite being offered to all patients at implantation, significant disparities were present in cardiovascular implantable electronic device RM in this cohort. Disparities were partly reversed during COVID-19. Further studies are needed to examine health center- and patient-specific factors to overcome these barriers, and to facilitate equal opportunities to participate in RM.

Predictors of cardiovascular implantable electronic device dependence at long-term follow-up after alcohol septal ablation in hypertrophic cardiomyopathy patients.

BACKGROUND: The most common complication of alcohol septal ablation (ASA) is transient periprocedural high-grade AV block (HGAVB). To date, no long-term follow-up of cardiovascular implantable electronic device (CIED) utilization after ASA has been reported. We hypothesized that CIED dependence on long-term follow-up can be predicted by ECG or procedural characteristics. METHODS: We analyzed all patients with HCM who underwent ASA from December 1998 to December 2019 and received their first CIED within 30 days after ASA for HGAVB. All follow-up interrogations were reviewed. CIED dependence was defined as ventricular pacing of ≥ 5%. RESULTS: A total of 138 patients with HCM underwent ASA. Of these, 35 had a prior device and were excluded. Of the remaining 103 patients, 25 patients received a CIED for HGAVB within 30 days after ASA. Average follow-up duration was 10.1 years. On long-term follow-up, 16 patients (64%) were found to be CIED-dependent. Baseline characteristics, including pre- and post-ASA ECG, were not significantly different between dependent and non-dependent patients. The only predictor for CIED dependence was > 1 ml of alcohol injected (OR 6.0, p = 0.031). CONCLUSIONS: CIED implantation after ASA is common. Almost two thirds of patients who received a CIED for post-procedural HGAVB were CIED-dependent on long-term follow-up. CIED dependence can be predicted by the amount of injected alcohol > 1 ml.

Cardiovascular implantable electronic device replacement infections and prevention: results from the REPLACE Registry.

BACKGROUND: Infection following cardiovascular implantable electronic device (CIED) replacement is a serious complication, and rates of infection have increased. Analysis of procedural and clinical data from device replacement procedures collected by the REPLACE Registry may provide insights into infection prevention strategies and outcomes. METHODS: We prospectively evaluated procedural complications in patients undergoing CIED replacement over 6 months from 72 U.S. sites. Major and minor infections were predefined and adjudicated by an independent blinded clinical events committee. Data regarding infection prevention strategies and infectious outcomes were analyzed for their potential relationships. RESULTS: A total of 1,744 patients were included in REPLACE. All patients received preoperative intravenous antibiotics and 68.7% received postoperative systemic antibiotic therapy. CIED infection developed in 22 patients (1.3%), of which 14 cases were major (0.8%, 95% confidence interval [CI] 0.4%-1.3%) and eight were minor (0.5%, 95% CI 0.2%-0.9%). Patients with infections were more likely to have had postoperative hematomas (five of 22 [22.7%] vs 17 of 1,722 [0.98%], P = 0.002). Participating sites experiencing infection rates >5% were more likely to use povidone-iodine for topical antisepsis, had lower implantation volume, and had patients with higher Charlson Comorbidity Index (2.79 vs 2.32, 95% CI for difference 0.08-0.86, P = 0.019). CONCLUSIONS: In this multicenter prospective study with 6 months of follow-up, infections associated with CIED replacements were surprisingly infrequent, possibly due to the use of preoperative antibiotics. Patients with infections were more likely to have had a postoperative hematoma, and sites with higher infection rates had sicker patients and lower overall procedural volume.

Determinants of Response to Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) is a well-established treatment modality for ambulatory patients with heart failure (HF) who have prolonged QRS, left bundle branch block, reduced left ventricular (LV) ejection fraction, and New York Heart Association class II-IV. CRT has been shown to induce reverse LV remodeling and improve HF symptoms and clinical outcomes. About one-third of CRT recipients are considered non-responders. Patient selection, LV lead location, LV lead selection, multipoint pacing, and optimization of the atrioventricular and ventriculo-ventricular intervals were all shown to be associated with a better CRT response rate. Herein, we review the determinants of CRT response.

Short- and Long-Term Risk of Lead Dislodgement Events: Real-World Experience From Product Surveillance Registry.

BACKGROUND: Lead dislodgement (LD) has been one of the most common early complications after cardiovascular implantable electronic device implant. However, limited data are available on the clinical characteristics and long-term outcomes of LD events. The aim of this study was to examine the risk factors, clinical significance, and management strategies of LD events after cardiovascular implantable electronic device implant. METHODS: This study was a retrospective cohort analysis of 20 683 patients who underwent cardiovascular implantable electronic device implant between January 1, 2010 and January 31, 2020 in Medtronic's Product Surveillance Registry, with a mean follow-up time of 3.3±2.5 SD years. The study population was divided into 2 groups: group A with LD events (N=350) and group B without LD events (N=20 333). RESULTS: During this period, 350 patients (1.69%) had LD events involving 371 leads (0.95%), among a total of 39 060 leads implanted. Passive fixation type (right atrium pacing lead, P=0.041), lower sensing amplitude (right ventricle defibrillating lead, P=0.020), and lower lead impedance at implant (right atrium pacing lead, P=0.009) were associated with increased LD risk. Multivariate analysis showed female sex (hazard ratio, 1.520, P=0.008) and higher body mass index (hazard ratio, 1.012, P=0.001) were independently associated with increased risk of LD events. LD events were not associated with significant changes in the long-term risks of cardiac and overall mortality. In group A, repositioning the dislodged leads increased the risk of a second LD event compared with implanting new leads (P=0.012). CONCLUSIONS: Female sex and higher body mass index were associated with higher risk of LD events in the Product Surveillance Registry. Among patients with dislodged leads, implanting new leads was associated with lower risk of future LD events. Further studies on how to reduce LD risk and to improve management of these events are needed. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01524276.

Complication rates associated with pacemaker or implantable cardioverter-defibrillator generator replacements and upgrade procedures: results from the REPLACE registry.

BACKGROUND: Prospective studies defining the risk associated with pacemaker or implantable cardioverter-defibrillator replacement surgeries do not exist. These procedures are generally considered low risk despite results from recent retrospective series reporting higher rates. METHODS AND RESULTS: We prospectively assessed predefined procedure-related complication rates associated with elective pacemaker or implantable cardioverter-defibrillator generator replacements over 6 months of follow-up. Two groups were studied: those without (cohort 1) and those with (cohort 2) a planned transvenous lead addition for replacement or upgrade to a device capable of additional therapies. Complications were adjudicated by an independent events committee. Seventy-two US academic and private practice centers participated. Major complications occurred in 4.0% (95% confidence interval, 2.9 to 5.4) of 1031 cohort 1 patients and 15.3% (95% confidence interval, 12.7 to 18.1) of 713 cohort 2 patients. In both cohorts, major complications were higher with implantable cardioverter-defibrillator compared with pacemaker generator replacements. Complications were highest in patients who had an upgrade to or a revised cardiac resynchronization therapy device (18.7%; 95% confidence interval, 15.1 to 22.6). No periprocedural deaths occurred in either cohort, although 8 later procedure-related deaths occurred in cohort 2. The 6-month infection rates were 1.4% (95% confidence interval, 0.7 to 2.3) and 1.1% (95% confidence interval, 0.5 to 2.2) for cohorts 1 and 2, respectively. CONCLUSIONS: Pacemaker and implantable cardioverter-defibrillator generator replacements are associated with a notable complication risk, particularly those with lead additions. These data support careful decision making before device replacement, when managing device advisories, and when considering upgrades to more complex systems.