Leadless pacemaker implantation after lead extraction for cardiac implanted electronic device infection.

BACKGROUND: Cardiac implanted electronic device (CIED) pocket and systemic infection remain common complications with traditional CIEDs and are associated with high morbidity and mortality. Leadless pacemakers may be an attractive pacing alternative for many patients following complete hardware removal for a CIED infection by eliminating surgical pocket-related complications as well as lower risk of recurrent complications. OBJECTIVE: To describe use and outcomes associated with leadless pacemaker implantation following extraction of a CIED system due to infection. METHODS: Patient characteristics and postprocedural outcomes were described in patients who underwent leadless pacemaker implantation at Duke University Hospital between November 11, 2014 and November 18, 2019, following CIED infection and device extraction. Outcomes of interest included procedural complications, pacemaker syndrome, need for system revision, and recurrent infection. RESULTS: Among 39 patients, the mean age was 71 ± 17 years, 31% were women, and the most frequent primary pacing indication was complete heart block (64.1%) with 9 (23.1%) patients being pacemaker dependent at the time of Micra implantation. The primary organism implicated in the CIED infection was Staphylococcus aureus (43.6%). Nine of the 39 patients had a leadless pacemaker implanted before or on the same day as their extraction procedure, and the remaining 30 patients had a leadless pacemaker implanted after their extraction procedure. During follow-up (mean 24.8 ± 14.7 months) after leadless pacemaker implantation, there were a total of 3 major complications: 1 groin hematoma, 1 femoral arteriovenous fistula, and 1 case of pacemaker syndrome. No patients had evidence of recurrent CIED infection after leadless pacemaker implantation. CONCLUSIONS: Despite a prior CIED infection and an elevated risk of recurrent infection, there was no evidence of CIED infection with a mean follow up of over 2 years following leadless pacemaker implantation at or after CIED system removal. Larger studies with longer follow-up are required to determine if there is a long-term advantage to implanting a leadless pacemaker versus a traditional pacemaker following temporary pacing when needed during the periextraction period in patients with a prior CIED infection.

Hands on: How to approach patients undergoing lead extraction.

Due to the growing number of patients treated with cardiac implantable electronic devices (CIEDs) there is an increased need for lead management, evaluation, and extraction. While CIED lead extraction has many indications, a consistent approach to preprocedural planning should be applied in all cases, including a thorough consultation with careful review of the patient's medical and device history, as well as a discussion of informed consent and shared decision-making with the patient and their loved ones. The use of chest X-ray, echocardiography, and computed tomography (CT) scan can further help with risk stratification and procedural planning. Intraprocedural echocardiography (transesophageal or intracardiac) is recommended and allows early recognition of cardiothoracic injury. Establishing an extraction team with cardiology/electrophysiology, anesthesiology, and CT surgery is is crucial to a successful and safe CIED extraction practice, including immediately available surgical backup. This hands-on review will address how to approach patients who are undergoing lead extraction, as well as several innovations in preprocedure and intraprocedural risk assessment.

Preprocedural computed tomography before cardiac implanted electronic device lead extraction: Indication, technique, and approach to interpretation.

Cardiac implantable electronic devices (CIEDs) frequently need to be extracted due to infection, hardware failure, and other causes. The extraction of the CIED is typically performed using percutaneous methods. While these procedures are mostly performed without incident there is a small risk of significant complications. Dedicated imaging pre-CEID removal to include the central veins and heart with multidetector computed tomography (MDCT) can be utilized to evaluate the lead course and termination, the integrity of the central veins and cardiac chambers, and identify potential complications that may alter the lead extraction procedure as well as reimplantation of subsequent leads. Indications for preprocedural imaging, the technique of dedicated preprocedural lead extraction MDCT, and the approach to the interpretation of the images is discussed in this review.

Implantable cardioverter-defibrillator lead revision following left ventricular assist device implantation.

INTRODUCTION: Lead dysfunction can lead to serious consequences including failure to treat ventricular tachycardia or fibrillation (VT/VF). The incidence and mechanisms of lead dysfunction following left ventricular assist device (LVAD) implantation are not well-described. We sought to determine the incidence, mechanisms, timing, and complications of right ventricular lead dysfunction requiring revision following LVAD implantation. METHODS: Retrospective observational chart review of all LVAD recipients with pre-existing implantable cardioverter-defibrillator (ICD) from 2009 to 2018 was performed including device interrogation reports, laboratory and imaging data, procedural reports, and clinical outcomes. RESULTS: Among 583 patients with an ICD in situ undergoing LVAD implant, the median (interquartile range) age was 62.5 (15.7) years, 21% were female, and the types of LVADs included HeartWare HVAD (26%), HeartMate II (52%), and HeartMate III (22%). Right ventricular lead revision was performed in 38 patients (6.5%) at a median (25th, 75th) of 16.4 (3.6, 29.2) months following LVAD. Mechanisms of lead dysfunction included macrodislodgement (n = 4), surgical lead injury (n = 4), recall (n = 3), insulation failure (n = 8) or conductor fracture (n = 7), and alterations in the lead-myocardial interface (n = 12). Undersensing requiring revision occurred in 22 (58%) cases. Clinical sequelae of undersensing included failure to detect VT/VF (n = 4) and pacing-induced torsade de pointes (n = 1). Oversensing occurred in 12 (32%) and sequelae included inappropriate antitachycardia pacing ([ATP], n = 8), inappropriate ICD shock (n = 6), and ATP-induced VT (n = 1). CONCLUSION: The incidence of right ventricular lead dysfunction following LVAD implantation is significant and has important clinical sequelae. Physicians should remain vigilant for lead dysfunction after LVAD surgery and test lead function before discharge.

Predicting atrial fibrillation recurrence after ablation in patients with heart failure: Validity of the APPLE and CAAP-AF risk scoring systems.

BACKGROUND: Compared with medical therapy, catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) improves cardiovascular outcomes. Risk scores (CAAP-AF and APPLE) have been developed to predict the likelihood of AF recurrence after ablation, have not been validated specifically in patients with AF and HF. METHODS: We analyzed baseline characteristics, risk scores, and rates of AF recurrence 12 months postablation in a cohort of 230 consecutive patients with AF and HF undergoing PVI in the Duke Center for Atrial Fibrillation registry from 2009-2013. RESULTS: During a follow-up period of 12 months, 76 of 230 (33%) patients with HF experienced recurrent AF after ablation. The median APPLE and CAAP-AF scores were 1.5 ([Q1, Q3]: [1.0, 2.0]) and 4.0 ([Q1, Q3]: [3.0, 5.0]), respectively and were not different from those patients with and without recurrent AF. Freedom from AF was not different according to APPLE and CAAP-AF scores. Discrimination for recurrent AF with the CAAP-AF score was modest with a C-statistic of 0.60 (95% CI 0.52-0.67). Discrimination with the APPLE score was similarly modest, with a C-statistic of 0.54 (95% CI: 0.47-0.62). CONCLUSIONS: Validated predictive risk scores for recurrent AF after catheter ablation exhibit limited predictive ability in cohorts of AF and HF. Additional tools are needed to facilitate risk stratification and patient selection for AF ablation in patients with concomitant HF.

Outcomes Associated With Extraction Versus Capping and Abandoning Pacing and Defibrillator Leads.

BACKGROUND: Lead management is an increasingly important aspect of care in patients with cardiac implantable electronic devices; however, relatively little is known about long-term outcomes after capping and abandoning leads. METHODS: Using the 5% Medicare sample, we identified patients with de novo cardiac implantable electronic device implantations between January 1, 2000, and December 31, 2013, and with a subsequent lead addition or extraction ≥12 months after the de novo implantation. Patients who underwent extraction for infection were excluded. Using multivariable Cox proportional hazards models, we compared cumulative incidence of all-cause mortality, device-related infection, device revision, and lead extraction at 1 and 5 years for the extraction versus the cap and abandon group. RESULTS: Among 6859 patients, 1113 (16.2%) underwent extraction, whereas 5746 (83.8%) underwent capping and abandonment. Extraction patients tended to be younger (median, 78 versus 79 years; P<0.0001), were less likely to be male (65% versus 68%; P=0.05), and had shorter lead dwell time (median, 3.0 versus 4.0 years; P<0.0001) and fewer comorbidities. Over a median follow-up of 2.4 years (25th, 75th percentiles, 1.0, 4.3 years), the overall 1-year and 5-year cumulative incidence of mortality was 13.5% (95% confidence interval [CI], 12.7-14.4) and 54.3% (95% CI, 52.8-55.8), respectively. Extraction was associated with a lower risk of device infection at 5 years relative to capping (adjusted hazard ratio, 0.78; 95% CI, 0.62-0.97; P=0.027). There was no association between extraction and mortality, lead revision, or lead extraction at 5 years. CONCLUSIONS: Elective lead extraction for noninfectious indications had similar long-term survival to that for capping and abandoning leads in a Medicare population. However, extraction was associated with lower risk of device infections at 5 years.

Leukocyte iNOS is required for inflammation and pathological remodeling in ischemic heart failure.

In the failing heart, iNOS is expressed by both macrophages and cardiomyocytes. We hypothesized that inflammatory cell-localized iNOS exacerbates left ventricular (LV) remodeling. Wild-type (WT) C57BL/6 mice underwent total body irradiation and reconstitution with bone marrow from iNOS-/- mice (iNOS-/-c) or WT mice (WTc). Chimeric mice underwent coronary ligation to induce large infarction and ischemic heart failure (HF), or sham surgery. After 28 days, as compared with WTc sham mice, WTc HF mice exhibited significant (p < 0.05) mortality, LV dysfunction, hypertrophy, fibrosis, oxidative/nitrative stress, inflammatory activation, and iNOS upregulation. These mice also exhibited a ~twofold increase in circulating Ly6Chi pro-inflammatory monocytes, and ~sevenfold higher cardiac M1 macrophages, which were primarily CCR2- cells. In contrast, as compared with WTc HF mice, iNOS-/-c HF mice exhibited significantly improved survival, LV function, hypertrophy, fibrosis, oxidative/nitrative stress, and inflammatory activation, without differences in overall cardiac iNOS expression. Moreover, iNOS-/-c HF mice exhibited lower circulating Ly6Chi monocytes, and augmented cardiac M2 macrophages, but with greater infiltrating monocyte-derived CCR2+ macrophages vs. WTc HF mice. Lastly, upon cell-to-cell contact with naïve cardiomyocytes, peritoneal macrophages from WT HF mice depressed contraction, and augmented cardiomyocyte oxygen free radicals and peroxynitrite. These effects were not observed upon contact with macrophages from iNOS-/- HF mice. We conclude that leukocyte iNOS is obligatory for local and systemic inflammatory activation and cardiac remodeling in ischemic HF. Activated macrophages in HF may directly induce cardiomyocyte contractile dysfunction and oxidant stress upon cell-to-cell contact; this juxtacrine response requires macrophage-localized iNOS.

Cardiac implantable electronic device removal in patients with left ventricular assist device associated infections.

INTRODUCTION: Heart failure patients with left ventricular assist devices (LVADs) are at risk for infection. Cardiac implantable electronic devices (CIEDs) are commonly present in these patients. The course of infections in patients with an LVAD and a CIED is not well described. METHODS AND RESULTS: We identified 6 patients with a durable LVAD that underwent CIED removal because of an LVAD associated infection (LVADI). Patient and infection characteristics, management strategy, and clinical outcomes are described. All 6 patients were male, and the mean age was 59.6 years (range 43-72). Four of 6 patients had an ischemic cardiomyopathy, and 3 patients were diabetic. The median creatinine clearance for patients was 40.5 mg/dL (range 19-65). Five of 6 patients had a continuous flow LVAD placed as destination therapy. Four of 6 patients had a previous LVADI managed medically before the current infection leading to CIED removal. The indication for CIED removal was a bloodstream infection in 5 of 6 patients. Three of these patients had potential vegetations identified by echocardiography on device leads. The mean implanted age of the removed leads was 62 months (range 1-179), and 1 of the 6 patients experienced a procedural complication (hematoma) from CIED removal. Four of 6 patients that underwent CIED removal for an LVADI had recurrence of infection. Five of 6 patients died during the initial presentation or from repeat presentation for infection. CONCLUSION: Despite CIED removal for an LVADI, recurrent infections are common and mortality remains high.

Preprocedural ECG-gated computed tomography for prevention of complications during lead extraction.

BACKGROUND: Preprocedural multidetector computed tomography (MDCT) may identify patients at risk for mechanical complications during lead extraction. METHODS: To describe the use and feasibility of computed tomography scanning for preprocedural planning of lead extraction, we conducted a retrospective study of high-risk patients, who underwent electrocardiogram (ECG)-gated MDCT before planned lead extraction between January 1, 2012, and March 30, 2013. RESULTS: Among 30 patients the mean age was 63 ± 15 years, 60% were male, and 20% had prior sternotomy. Most devices were left sided (93%) and 24 had implantable defibrillators (80%). Indications for extraction included lead malfunction (n = 15; 50%), class I lead advisories (n = 11; 37%), and infection (n = 10; 33%). Overall, there were 65 leads extracted (mean 2.1 leads per patient). One extraction procedure was deferred due to MDCT evidence of significant myocardial perforation with the lead tip > 1 cm beyond the epicardium (n = 1, 3%). MDCT suggestion of lead adherence to central venous structures (n = 13, 43%) was associated with significantly longer laser times (88 ± 71 seconds vs 30 ± 37 seconds, P = 0.02) and larger sheath size (14.9 ± 1.3 vs 13.5 ± 1.2 French, P = 0.02). MDCT evidence of central venous occlusion or stenosis was not associated with increased laser times. Excluding the patient with MDCT evidence of significant perforation, clinical success was achieved in all patients (n = 29/29). CONCLUSIONS: ECG-gated MDCT scanning before lead extraction may facilitate the identification of significant perforation and patients at high risk for mechanical complication.

Efficacy and Safety of Adjunctive and Primary Use of the TightRail Mechanical Cutting Sheath for Lead Extraction.

BACKGROUND: Rotational cutting tools are increasingly used in transvenous lead extraction. There are limited data on their safety and efficacy, particularly when used adjunctively for stalled progression. The aim of this study was to evaluate the utilization, safety, and effectiveness of mechanical rotational cutting tools for transvenous lead extraction. METHODS: Patients undergoing transvenous lead extraction at a single tertiary center (April 2015 to January 2021, n=586) were included in this retrospective analysis. The study characterized the 251 patients (42.8%) whose cases involved the TightRail mechanical cutting tool. RESULTS: Among 251 patients, 526 leads were extracted and TightRail was used for 70.5%. The TightRail was used adjunctively with the laser for 65.2% of leads, 97.8% of the time as the second tool after stalled progression. Using a multivariable logistic regression model, we found that active-fixation leads (odds ratio, 2.78 [95% CI, 1.62-4.78]; P=0.0002), dual-coil leads (odds ratio, 3.39 [95% CI, 1.87-6.16]; P<0.0001), and lead dwell time (odds ratio, 1.16 [95% CI for 1-year increase, 1.11-1.21]; P<0.0001) were factors independently associated with adjunctive TightRail use. Stalled progression requiring TightRail occurred most often in the innominate vein and superior vena cava (59.3%). The clinical success rate was 96.8%, and the rate of major adverse events was 2.8%. Only 1 major adverse event was observed during TightRail use. CONCLUSIONS: Rotational cutting with TightRail was used in 42.8% of transvenous lead extractions, predominantly in an adjunctive manner after stalled laser progression in the innominate vein and superior vena cava, and more frequently for dual-coil and leads with longer dwell times. Adjunctive TightRail use carries a low risk of major complications.

Lead Extraction and Mortality Among Patients With Cardiac Implanted Electronic Device Infection.

Importance: Complete hardware removal is a class I recommendation for cardiovascular implantable electronic device (CIED) infection, but practice patterns and outcomes remain unknown. Objective: To quantify the number of Medicare patients with CIED infections who underwent implantation from 2006 to 2019 and lead extraction from 2007 to 2019 to analyze the outcomes in these patients in a nationwide clinical practice cohort. Design, Setting, and Participants: This cohort study included fee-for-service Medicare Part D beneficiaries from January 1, 2006, to December 31, 2019, who had a de novo CIED implantation and a CIED infection more than 1 year after implantation. Data were analyzed from January 1, 2005, to December 31, 2019. Exposure: A CIED infection, defined as (1) endocarditis or infection of a device implant and (2) documented antibiotic therapy. Main Outcomes and Measures: The primary outcomes of interest were device infection, device extraction, and all-cause mortality. Time-varying multivariable Cox proportional hazards regression models were used to evaluate the association between extraction and survival. Results: Among 1 065 549 patients (median age, 78.0 years [IQR, 72.0-84.0 years]; 50.9% male), mean (SD) follow-up was 4.6 (2.9) years after implantation. There were 11 304 patients (1.1%) with CIED infection (median age, 75.0 years [IQR, 67.0-82.0 years]); 60.1% were male, and 7724 (68.3%) had diabetes. A total of 2102 patients with CIED infection (18.6%) underwent extraction within 30 days of diagnosis. Infection occurred a mean (SD) of 3.7 (2.4) years after implantation, and 1-year survival was 68.3%. There was evidence of highly selective treatment, as most patients did not have extraction within 30 days of diagnosed infection (9202 [81.4%]), while 1511 (13.4%) had extraction within 6 days of diagnosis and 591 (5.2%) had extraction between days 7 and 30. Any extraction was associated with lower mortality compared with no extraction (adjusted hazard ratio [AHR], 0.82; 95% CI, 0.74-0.90; P < .001). Extraction within 6 days was associated with even lower risk of mortality (AHR, 0.69; 95% CI, 0.61-0.78; P < .001). Conclusions and Relevance: In this study, a minority of patients with CIED infection underwent extraction. Extraction was associated with a lower risk of death compared with no extraction. The findings suggest a need to improve adherence to guideline-directed care among patients with CIED infection.

Colchicine for the Prevention of Recurrent Arrhythmia After Catheter Ablation of Atrial Fibrillation: Results of a Single-Center, Retrospective Study.

BACKGROUND: There is evidence to suggest that colchicine reduces the risk of recurrent atrial fibrillation (AF) after catheter ablation; however, the tolerability and safety of colchicine in routine practice is unknown. METHODS: Patients undergoing catheter ablation for AF who received colchicine after ablation were matched 1:1 to patients who did not by age, sex, and renal function. Recurrent AF was compared between groups categorically at 12 months and via propensity weighted Cox proportional hazards models with and without a 3-month blanking period. RESULTS: Overall, 180 patients (n = 90 colchicine and n = 90 matched controls) were followed for a median (Q1, Q3) of 10.3 (7.0, 12.0) months. Mean age was 65.3 ± 9.1 years, 33.9% were women, mean CHA2DS2-VASc score was 2.9 ± 1.5, and 51.1% had persistent AF. Most patients (70%) received colchicine 0.6 mg daily for a median of 30 days. In the colchicine group, 55 patients (61.1%) were receiving at least one known interacting medication with colchicine. After ablation, one patient required colchicine dose reduction and four patients required discontinuation. After adjusting for covariate imbalance using propensity weighting, no significant association between colchicine use and AF recurrence was identified (adjusted hazard ratio 0.94, 95% confidence interval [CI] 0.48-1.85; p = 0.853). No significant association was found between colchicine use and all-cause hospitalizations (adjusted odds ratio 0.74, 95% CI 0.28-1.96; p = 0.548). CONCLUSION: Despite the frequent presence of drug-drug interactions, a 30-day course of colchicine is well-tolerated after AF ablation; however, we did not observe any association between colchicine and lower rates of AF recurrence or hospitalization.

Cases of Azygous Coil Extraction.

BACKGROUND: Procedural and clinical outcomes of patients undergoing extraction or removal of azygous coils are not well characterized. OBJECTIVE: Evaluate outcomes in patients who undergo device extraction with an azygous coil in situ. METHODS: Patients undergoing extraction with an azygous coil in situ between May 2015 and January 2021 were included in this retrospective single-center analysis. Outcomes included procedural success, use of laser and mechanical cutting tools during the procedure, procedural complications, and mortality. RESULTS: We identified 2 patients undergoing device extraction with an azygous coil in situ with a dwell time greater than 12 months. The patients were male, aged 73 and 83 years. Both had a history of hypertension, atrial fibrillation, heart failure (ejection fractions <15% and 20%), and cardiomyopathy (nonischemic and ischemic), and presented with an infection (case 1 with a single-chamber ICD and Staphylococcus aureus bacteremia, case 2 with a cardiac resynchronization therapy defibrillator pocket infection). The mean dwell time of all 6 leads extracted was 6.43 years (range 1.33-12.63 years), and the 2 azygous coils had dwell times of 1.33 and 6.04 years. In case 1, the azygous coil was inferior to the cardiac silhouette, while in case 2 it was superior. A 14F laser sheath was employed to remove both azygous coils. Both extractions were a complete procedural success in which all leads were removed completely without intraoperative complications. CONCLUSION: These cases demonstrate the variable courses of azygous coils, provide proof of concept that they can be removed safely, and illustrate that azygous coils can be removed with the same techniques that are commonly used to remove other types of leads.

Cardioprotective and antiapoptotic effects of heme oxygenase-1 in the failing heart.

BACKGROUND: Heme oxygenase-1 (HO-1) is an inducible stress-response protein that imparts antioxidant and antiapoptotic effects. However, its pathophysiological role in cardiac remodeling and chronic heart failure (HF) is unknown. We hypothesized that induction of HO-1 in HF alleviates pathological remodeling. METHODS AND RESULTS: Adult male nontransgenic and myocyte-restricted HO-1 transgenic mice underwent either sham operation or coronary ligation to induce HF. Four weeks after ligation, nontransgenic HF mice exhibited postinfarction left ventricular (LV) remodeling and dysfunction, hypertrophy, fibrosis, oxidative stress, apoptosis, and reduced capillary density, associated with a 2-fold increase in HO-1 expression in noninfarcted myocardium. Compared with nontransgenic mice, HO-1 transgenic HF mice exhibited significantly (P<0.05) improved postinfarction survival (94% versus 57%) and less LV dilatation (end-diastolic volume, 46+/-8 versus 85+/-32 microL), mechanical dysfunction (ejection fraction, 65+/-9% versus 49+/-16%), hypertrophy (LV/tibia length 4.4+/-0.4 versus 5.2+/-0.6 mg/mm), interstitial fibrosis (11.2+/-3.1% versus 18.5+/-3.5%), and oxidative stress (3-fold reduction in tissue malondialdehyde). Moreover, myocyte-specific HO-1 overexpression in HF promoted tissue neovascularization and ameliorated myocardial p53 expression (2-fold reduction) and apoptosis. In isolated mitochondria, mitochondrial permeability transition was inhibited by HO-1 in a carbon monoxide (CO)-dependent manner and was recapitulated by the CO donor tricarbonylchloro(glycinato)ruthenium(II) (CORM-3). HO-1-derived CO also prevented H2O2-induced cardiomyocyte apoptosis and cell death. Finally, in vivo treatment with CORM-3 alleviated postinfarction LV remodeling, p53 expression, and apoptosis. CONCLUSIONS: HO-1 induction in the failing heart is an important cardioprotective adaptation that opposes pathological LV remodeling, and this effect is mediated, at least in part, by CO-dependent inhibition of mitochondrial permeability transition and apoptosis. Augmentation of HO-1 or its product, CO, may represent a novel therapeutic strategy for ameliorating HF.

Optimizing mechanically sensed atrial tracking in patients with atrioventricular-synchronous leadless pacemakers: A single-center experience.

BACKGROUND: Atrioventricular (AV)-synchronous single-chamber leadless pacing using a mechanical atrial sensing algorithm produced high AV synchrony in clinical trials, but clinical practice experience with these devices has not yet been described. OBJECTIVE: To describe pacing outcomes and programming changes with AV-synchronous leadless pacemakers in clinical practice. METHODS: Consecutive patients without persistent atrial fibrillation who received an AV-synchronous leadless pacemaker and completed follow-up between February 2020 and April 2021 were included. We evaluated tracking index (atrial mechanical sense followed by ventricular pace [AM-VP] divided by total VP), total AV synchrony (sum of AM-ventricular sense [AM-VS], AM-VP, and AV conduction mode switch), use of programming optimization, and improvement in AV synchrony after optimization. RESULTS: Fifty patients met the inclusion criteria. Mean age was 69 ± 16.8 years, 24 (48%) were women, 24 (48%) had complete heart block, and 17 (34%) required ≥50% pacing. Mean tracking index was 41% ± 34%. Thirty-five patients (70%) received ≥1 programming change. In 36 patients with 2 follow-up visits, tracking improved by +9% ± 28% (P value for improvement = .09) and +18% ± 19% (P = .02) among 15 patients with complete heart block. Average total AV synchrony increased from 89% [67%, 99%] to 93% [78%, 100%] in all patients (P = .22), from 86% [52%, 98%] to 97% [82%, 99%] in those with complete heart block (P = .04), and from 73% [52%, 80%] to 78% [70%, 85%] in those with ≥50% pacing (P = .09). CONCLUSION: In patients with AV-synchronous leadless pacemakers, programming changes are frequent and are associated with increased atrial tracking and increased AV synchrony in patients with complete heart block.

Subcutaneous implantable cardioverter-defibrillator troubleshooting in patients with a left ventricular assist device: A case series and systematic review.

BACKGROUND: There are limited data on the performance of the subcutaneous implantable cardioverter-defibrillator (S-ICD) in patients with a left ventricular assist device (LVAD). OBJECTIVE: The purpose of this study was to describe the clinical course and outcomes of patients with both an S-ICD and an LVAD at our institution and via a systematic review of published studies. METHODS: We performed a retrospective cohort study of all patients who underwent LVAD implantation from 2009 to 2019 at Duke University Hospital. We also performed a systematic review of studies involving patients with an S-ICD and LVAD using the PubMed/Embase databases. RESULTS: Of 588 patients undergoing LVAD implantation with a preexisting implantable cardioverter-defibrillator, 4 had an S-ICD in situ after LVAD implantation. All 4 patients developed electromagnetic interference (EMI) in the primary/secondary vectors after LVAD implantation, resulting in inappropriate implantable cardioverter-defibrillator shocks in 2 patients. Sensing in the alternate vector was adequate immediately postoperatively in 1 patient. Postoperative undersensing was present in the alternate vector in 3 patients but improved at first outpatient follow-up in 2 patients, allowing tachy therapies to be reenabled. Eight studies involving 27 patients were identified in the systematic review. EMI was common and frequently absent in the alternate vector (6 of 7 patients). CONCLUSION: Undersensing and EMI are common after LVAD implantation in patients with an S-ICD in situ, particularly in the primary and secondary sensing vectors. Undersensing in the alternate vector may improve during follow-up, obviating the need for device revision or extraction.

Lead Extraction for Cardiovascular Implantable Electronic Device Infection in Patients With Left Ventricular Assist Devices.

OBJECTIVES: The goal of this study was to assess the utility of transvenous lead extraction for cardiovascular implantable electronic device (CIED) infection in patients with a left ventricular assist device (LVAD). BACKGROUND: The use of transvenous lead extraction for the management CIED infection in patients with a durable LVAD has not been well described. METHODS: Clinical and outcomes data were collected retrospectively among patients who underwent lead extraction for CIED infection after LVAD implantation at Duke University Hospital. RESULTS: Overall, 27 patients (n = 6 HVAD; n = 15 HeartMate II; n = 6 Heartmate III) underwent lead extraction for infection. Median (interquartile range) time from LVAD implantation to infection was 6.1 (2.5 to 14.9) months. Indications included endocarditis (n = 16), bacteremia (n = 9), and pocket infection (n = 2). Common pathogens were Staphylococcus aureus (n = 10), coagulase-negative staphylococci (n = 7), and Enterococcus faecalis (n = 3). Sixty-eight leads were removed, with a median lead implant time of 5.7 (3.6 to 9.2) years. Laser sheaths were used in all procedures, with a median laser time of 35.0 s (17.5 to 85.5s). Mechanical cutting tools were required in 11 (40.7%) and femoral snaring in 4 (14.8%). Complete procedural success was achieved in 25 (93.6%) patients and clinical success in 27 (100%). No procedural failures or major adverse events occurred. Twenty-one patients (77.8%) were alive without persistent endovascular infection 1 year after lead extraction. Most were treated with oral suppressive antibiotics after extraction (n = 23 [82.5%]). Persistent infection after extraction occurred in 4 patients and was associated with 50% 1-year mortality. CONCLUSIONS: Transvenous lead extraction for LVAD-associated CIED infection can be performed safely with low rates of persistent infection and 1-year mortality.

Cardiovascular Implantable Electronic Device Surgery Following Left Ventricular Assist Device Implantation.

OBJECTIVES: This study sought to determine the indications, characteristics, and outcomes of cardiovascular implantable electronic device (CIED) surgery in patients with LVAD. BACKGROUND: Many patients with a left ventricular assist device (LVAD) will require implantable cardioverter-defibrillator generator change or device revision or are candidates for de novo implantable cardioverter-defibrillator implantation following LVAD implantation. METHODS: We performed an observational retrospective study of all LVAD recipients who subsequently underwent CIED surgery at Duke University Hospital from 2009 to 2019. RESULTS: A total of 159 patients underwent CIED surgery following LVAD implantation, including generator change (n = 93), device revision (n = 38), and de novo implant (n = 28). The median (interquartile range) time from LVAD implantation to CIED surgery was 18.1 months (5.5 to 35.1 months). Pre-operative risk for infection was elevated in the overall cohort with a median (interquartile range) Prevention of Arrhythmia Device Infection Trial (PADIT) score of 7.0 (5.0 to 9.0). Pocket hematoma occurred in 21 patients (13.2%) following CIED surgery. Antimicrobial envelops were used in 43 patients (27%). Device infection due to CIED surgery occurred in 5 (3.1%) patients and occurred only in patients who developed post-operative pocket hematoma (p < 0.001). Mortality at 1 year following CIED surgery was 20% (n = 32). CONCLUSIONS: CIED surgery following LVAD implantation is associated with an increased risk for pocket hematoma and CIED infection. Further studies are needed to determine the risk-benefit ratio of CIED surgery in patients with LVADs.

Effectiveness of catheter ablation of atrial fibrillation according to heart failure etiology.

BACKGROUND: Catheter ablation is an important rhythm control therapy in patients with atrial fibrillation (AF) with concomitant heart failure (HF). The objective of this study was to assess the comparative efficacy of AF ablation patients with ischemic vs nonischemic heart failure. METHODS: We conducted a retrospective, observational cohort study of patients with HF who underwent AF ablation. Outcomes were compared based on HF etiology and included in-hospital events, symptoms (Mayo AF Symptom Inventory [MAFSI]), and functional status (New York Heart Association class) and freedom from atrial arrhythmias at 12 months. RESULTS: Among 242 patients (n = 70 [29%] ischemic, n = 172 [71%] nonischemic), patients with nonischemic cardiomyopathy were younger (mean age 64 ± 11.5 vs 69 ± 9.1, P = .002), more often female (36% vs 17%, P = .004), and had higher mean left-ventricular ejection fraction (47% vs 42%, P = .0007). There were no significant differences in periprocedural characteristics, including mean procedure time (243 ± 74.2 vs 259 ± 81.8 minutes, P = .1) and nonleft atrial ablation (17% vs 20%, P = .6). All-cause adverse events were similar in each group (15% vs 17%, P = .7). NYHA and MAFSI scores improved significantly at follow-up and did not differ according to HF etiology (P = .5; P = .10-1.00 after Bonferroni correction). There were no significant differences in freedom from recurrent atrial arrhythmia at 12-months between ischemic (74%) and nonischemic patients (78%): adjusted RR 0.63, 95% confidence interval 0.33-1.19. CONCLUSIONS: Catheter ablation in patients with AF and concomitant heart failure leads to significant improvements in functional and symptom status without significant differences between patients with ischemic vs nonischemic HF etiology.

Catheter ablation of atrial fibrillation in patients with diabetes mellitus.

BACKGROUND: Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF). Few studies have compared clinical outcomes after catheter ablation between patients with and those without DM. OBJECTIVE: The purpose of this study was to compare AF ablation outcomes in patients with and those without DM. METHODS: We performed a retrospective analysis of 351 consecutive patients who underwent first-time AF ablation. Clinical outcomes included freedom from recurrent atrial arrhythmia, symptom burden (Mayo AF Symptom Inventory score), cardiovascular and all-cause hospitalizations, and periprocedural complications. RESULTS: Patients with DM (n = 65) were older, had a higher body mass index, more persistent AF, more hypertension, and larger left atrial diameter (P <.05 for all). Median (Q1, Q3) total radiofrequency duration [64.0 (43.6, 81.4) minutes vs 54.3 (39.2, 76.4) minutes; P = .132] and periprocedural complications (P = .868) did not differ between patients with and those without DM. After a median follow-up of 29.5 months, arrhythmia recurrence was significantly higher in the DM group compared to the no-DM group after adjustment for baseline differences (adjusted hazard ratio [HR] 2.24; 95% confidence [CI] 1.42-3.55; P = .001). There was a nonsignificant trend toward higher AF recurrence with worse glycemic levels (HR 1.29; 95% CI 0.99-1.69; P = .064). CONCLUSION: Although safety outcomes associated with AF ablation were similar between patients with and those without DM, arrhythmia-free survival was significantly lower among patients with DM. Poor glycemic control seems to an important risk factor for AF recurrence.