Comparison of novel intrinsic versus conventional antitachycardia pacing for ventricular tachycardia among implantable cardioverter-defibrillator recipients.

INTRODUCTION: Intrinsic antitachycardia pacing (iATP) is a novel automated antitachycardia pacing (ATP) that provides individual treatment to terminate ventricular tachycardia (VT). However, the clinical efficacy of iATP in comparison with conventional ATP is unknown. We aim to compare the termination rate of VT between iATP and conventional ATP in patients with implantable cardioverter-defibrillators using a unique setting of different sequential orders of both ATP algorisms. METHODS: Patients with the iATP algorithm were assigned to iATP-first and conventional ATP-first groups sequentially. In the iATP-first group, a maximum of seven iATP sequences were delivered, followed by conventional burst and ramp pacing. In contrast, in the conventional ATP-first group, two bursts and ramp pacing were initially programmed, followed by iATP sequences. We compared the success rates of VT termination in the first and secondary programmed ATP zones between the two groups. RESULTS: Fifty-eight and 56 patients were enrolled in the iATP-first and conventional ATP-first groups, and 67 and 44 VTs were analyzed in each group, respectively. At the first single ATP therapy, success rates were 64% and 70% in the iATP and conventional groups, respectively. At the end of the first iATP treatment zone, the success rate increased from 64% to 85%. Moreover, secondary iATP therapy following the failure of conventional ATPs increased the success rate from 80% to 93%. There was a significant benefit of alternative iATP for VT termination compared to secondary conventional ATP (100% vs. 33%, p = .028). CONCLUSIONS: iATP may be beneficial as a secondary therapy after failure of conventional ATP to terminate VT.

Implantable cardioverter-defibrillator lead failure and revision following transcutaneous bicaval valve (TricValve®) implantation.

INTRODUCTION: Tricuspid regurgitation is associated with significant morbidity and mortality, and occurs at a higher rate in patients with cardiovascular implantable electronic devices. Percutaneous strategies for managing tricuspid regurgitation are evolving, including the development of bicaval valve implantation which has been successfully used in patients with pacing leads. METHODS AND RESULTS: We present the first documented case of lead failure following TricValve® implantation, a dedicated self-expanding system for bicaval valve implantation, and the first successful lead revision procedure in this setting. CONCLUSION: The case illustrates important considerations in undertaking percutaneous intervention in patients with cardiovascular implantable electronic devices, and their ongoing management.

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.

Subcutaneous air entrapment after subcutaneous implantable cardioverter defibrillator implantation evaluated by computed tomography.

BACKGROUND: Inappropriate shock (IAS) caused by subcutaneous air entrapment (AE) in an early period after subcutaneous implantable cardioverter defibrillator (S-ICD) implantation has been reported, however, no detailed data on air volume are available. We evaluated the subcutaneous air volume after implantation and its absorption rate one week after implantation. METHODS: Patients who underwent S-ICD implantation in our hospital received chest CT scans immediately after implantation and followed up 1 week later. The total subcutaneous air volume, air around the generator, the distal electrode, and the proximal electrode within 3 cm were calculated using a three-dimensional workstation. Fat areas at the level of the lower edge of the generator were also analyzed. RESULT: Fifteen patients received CT immediately after implantation. The mean age was 45.6 ± 17.9 (66.7% of men), and the mean body mass index was 24.3 ± 3.3. The three-incision technique was applied in seven patients and two-incision technique was in the latter eight patients. The mean total subcutaneous air volume was 18.54 ± 7.50 mL. Air volume around the generator, the distal electrode, and the proximal electrode were 11.05 ± 5.12, 0.72 ± 0.72, and 0.88 ± 0.87 mL, respectively. Twelve patients received a follow-up CT 1 week later. The mean total subcutaneous air was 0.25 ± 0.45 mL, showing a 98.7% absorption rate. CONCLUSION: Although subcutaneous air was observed in all patients after S-ICD implantation, most of the air was absorbed within 1 week, suggesting a low occurrence of AE-related IAS after a week postoperation.

Expanded application of wearable cardioverter defibrillators beyond current guidelines: proposal for a European register explained through single clinical scenarios.

The wearable cardioverter defibrillator (WCD) is becoming a more and more widely used instrument for the prevention of sudden cardiac death of patients either with a secondary prevention implantable cardioverter defibrillator indication or with a transient high risk of sudden cardiac death. Although clinical practice has demonstrated a benefit of protecting patients for a period as long as 3-6 months with such devices, the current European guidelines concerning ventricular arrhythmias and sudden cardiac death are still extremely restrictive in the patient selection in part because of the costs derived from such a prevention device, in part because of the lack of robust randomised trials.To illustrate expanded use cases for the WCD, four real-life clinical cases are presented where patients received the device slightly outside the established guidelines. These cases demonstrate the broader utility of WCDs in situations involving acute myocarditis, thyrotoxicosis, pre-excited atrial fibrillation and awaiting staging/prognosis of a lung tumour. The findings prompt expansion of the existing guidelines for WCD use to efficiently protect more patients whose risk of arrhythmic cardiac death is transient or uncertain. This could be achieved by establishing a European register of the patients who receive a WCD for further analysis.

Technical note: Minimizing CIED artifacts on a 0.35 T MRI-Linac using deep learning.

BACKGROUND: Artifacts from implantable cardioverter defibrillators (ICDs) are a challenge to magnetic resonance imaging (MRI)-guided radiotherapy (MRgRT). PURPOSE: This study tested an unsupervised generative adversarial network to mitigate ICD artifacts in balanced steady-state free precession (bSSFP) cine MRIs and improve image quality and tracking performance for MRgRT. METHODS: Fourteen healthy volunteers (Group A) were scanned on a 0.35 T MRI-Linac with and without an MR conditional ICD taped to their left pectoral to simulate an implanted ICD. bSSFP MRI data from 12 of the volunteers were used to train a CycleGAN model to reduce ICD artifacts. The data from the remaining two volunteers were used for testing. In addition, the dataset was reorganized three times using a Leave-One-Out scheme. Tracking metrics [Dice similarity coefficient (DSC), target registration error (TRE), and 95 percentile Hausdorff distance (95% HD)] were evaluated for whole-heart contours. Image quality metrics [normalized root mean square error (nRMSE), peak signal-to-noise ratio (PSNR), and multiscale structural similarity (MS-SSIM) scores] were evaluated. The technique was also tested qualitatively on three additional ICD datasets (Group B) including a patient with an implanted ICD. RESULTS: For the whole-heart contour with CycleGAN reconstruction: 1) Mean DSC rose from 0.910 to 0.935; 2) Mean TRE dropped from 4.488 to 2.877 mm; and 3) Mean 95% HD dropped from 10.236 to 7.700 mm. For the whole-body slice with CycleGAN reconstruction: 1) Mean nRMSE dropped from 0.644 to 0.420; 2) Mean MS-SSIM rose from 0.779 to 0.819; and 3) Mean PSNR rose from 18.744 to 22.368. The three Group B datasets evaluated qualitatively displayed a reduction in ICD artifacts in the heart. CONCLUSION: CycleGAN-generated reconstructions significantly improved both tracking and image quality metrics when used to mitigate artifacts from ICDs.

Cardiac implantable electronic devices in female patients: Esthetic, breast implant, and anatomic considerations.

INTRODUCTION: The implantation of a cardiac implantable electronic device (CIED) can have esthetic and psychological consequences on patients. We explore a heart team model for care coordination and discuss esthetic approaches for improved cosmetic outcomes in patients undergoing (CIED)-related procedures or de novo implantation. METHODS: Patients undergoing CIED surgery for approved indications between June 2015 and June 2022 were identified. Patients were included when surgical care was provided by a collaborative relationship between the primary electrophysiologist and the plastic surgeon. Patient demographics, details of the surgical procedure, information on breast implants, complications, and outcomes related to cosmesis were recorded. RESULTS: Twenty-two female patients were included in this study. The mean age was 50.2 ± 18.2 years. The mean follow-up duration was 2.2 ± 5.5 months. The top two indications for the procedure included CIED generator change (n = 9, 41%) and implantable cardioverter-defibrillator (ICD) implantation (n = 7, 32%). The most common reasons for involving plastic surgery in the procedure included surgery near breast implants (n = 10, 45%) and device displacement or discomfort (n = 8, 36%). CIED pocket position was prepectoral in 10 cases (45%), subpectoral in 11 patients (50%), and intramuscular in one patient (4.5%). The majority of the patients (20, 91%) had cosmetically acceptable results postprocedure. One patient (4.5%) had breast asymmetry on the CIED side, and another continued to have skin erosion over the CIED and leads. CONCLUSION: A heart team approach incorporating the expertize of cardiac electrophysiology and plastic surgery is essential for providing optimal care for patients with breast implants and patients requesting esthetic appeal.

Efficacy and Safety of Stereotactic Radiotherapy in Patients With Recurrent Ventricular Tachycardias: The Czech Experience.

BACKGROUND: Stereotactic arrhythmia radiotherapy (STAR) has been proposed recently in patients with refractory ventricular tachycardia (VT). OBJECTIVES: The purpose of this study was to describe the efficacy and safety of STAR in the Czech Republic. METHODS: VT patients were recruited in 2 expert centers after at least 1 previously failed catheter ablation (CA). A precise strategy of target volume determination and CA was used in 17 patients treated from December 2018 until June 2022 (EFFICACY cohort). This group, together with an earlier series of 19 patients with less-defined treatment strategies, composed the SAFETY cohort (n = 36). A dose of 25 Gy was delivered. RESULTS: In the EFFICACY cohort, the burden of implantable cardioverter-defibrillator therapies decreased, and this drop reached significance for direct current shocks (1.9 ± 3.2 vs 0.1 ± 0.2 per month; P = 0.03). Eight patients (47%) underwent repeated CA for recurrences of VT during 13.7 ± 11.6 months. In the SAFETY cohort (32 procedures, follow-up >6 months), 8 patients (25%) presented with a progression of mitral valve regurgitation, and 3 (9%) required intervention (median follow-up of 33.5 months). Two cases of esophagitis (6%) were seen with 1 death caused by the esophago-pericardial fistula (3%). A total of 18 patients (50%) died during the median follow-up of 26.9 months. CONCLUSIONS: Although STAR may not be very effective in preventing VT recurrences after failed CA in an expert center, it can still modify the arrhythmogenic substrate, and when used with additional CA, reduce the number of implantable cardioverter-defibrillator shocks. Potentially serious sides effects require close follow-up.

Effect of age on in-hospital outcomes of transvenous lead extraction for infected cardiac implantable electronic device.

BACKGROUND: The real-world data on the safety profile of transvenous lead extraction (TLE) for infected cardiac implantable electronic devices (CIED) among elderly patients is not well-established. This study aimed to evaluate the hospital outcomes between patients of different age groups who underwent TLE for infected CIED. METHOD: Using the Nationwide Readmissions Database, our study included patients aged ≥18 years who underwent TLE for infected CIED between 2017 and 2020. We divided the patients into four groups: Group A. Young (<50 years), Group B. Young intermediate (50-69 years old), Group C. Older intermediate (70-79 years old), and Group D. Octogenarian (≥80 years old). We then analyzed the in-hospital outcome and 30-day readmission between these age groups. RESULTS: A total of 10,928 patients who were admitted for TLE of infected CIED were included in this study: 982 (9.0%) patients in group A, 4,234 (38.7%) patients in group B, 3,204 (29.3%) patients in group C and 2,508 (23.0%) of patients in group D. Our study demonstrated that the risk of early mortality increased with older age (Group B vs. Group A: OR: 1.92, 95% CI: 1.19-3.09, p < .01; Group C vs. Group A: OR: 2.47, 95% CI: 1.51-4.04, p < .01; Group D vs. Group A: OR: 2.82, 95% CI: 1.69-4.72, p < .01). The risk of non-home discharge also increased in elderly groups (Group B vs. Group A: OR: 1.89; 95% CI: 1.52-2.36; p < .01; Group C vs. Group A: OR: 2.82; 95% CI 2.24-3.56; p < .01; Group D vs. Group A: OR: 4.16; 95% CI: 3.28-5.28; p < .01). There was no significant difference in hospitalization length and 30-day readmission between different age groups. Apart from a higher rate of open heart surgery in group A, the procedural complications were comparable between these age groups. CONCLUSION: Elderly patients had worse in-hospital outcomes in early mortality and non-home discharge following the TLE for infected CIED. There was no significant difference between elderly and non-elderly groups in prolonged hospital stay and 30-day readmission. Elderly patients did not have a higher risk of procedural complications.

Transitioning to Palliative Care in an Italian Cardiac Intensive Care Unit Network.

BACKGROUND: Recent data indicate that end-of-life management for patients affected by acute decompensated heart failure in cardiac intensive care units is aggressive, with late or no engagement of palliative care teams. OBJECTIVE: To assess current palliative care and end-of-life practices in a contemporary Italian multicenter registry of patients with cardiogenic shock due to acute decompensated heart failure. METHODS: A survey-based approach was used to collect data on palliative care and end-of-life management practices. The AltShock-2 registry enrolled patients with cardiogenic shock from 12 participating centers. A subset of 153 patients with cardiogenic shock due to acute decompensated heart failure enrolled between March 2020 and March 2023 was analyzed, with a focus on early engagement of palliative care teams and deactivation of implantable cardioverter-defibrillators (ICDs). RESULTS: "Do not resuscitate" orders were documented in patient records in only 5 of 12 centers (42%). Palliative care teams were engaged for 21 of 153 enrolled patients (13.7%). Among the 51 patients with ICDs, 6 of 17 patients who died (35%) had defibrillator deactivation. Of the 17 patients who died, 13 died in the hospital and 4 died within 6 months after discharge; 1 patient had ICD deactivation supported by palliative care services at home. CONCLUSIONS: Therapy-limiting practices, including ICD deactivation, are not routine in the Italian centers participating in this study. The results emphasize the importance of integrating palliative care as a simultaneous process with intensive care to address the unmet needs of these patients and their families.

Ten years of subcutaneous defibrillator therapy: Consolidated clinical evidence and future perspectives.

The subcutaneous implantable cardioverter defibrillator (S-ICD) was developed as an alternative to the traditional transvenous implantable cardioverter defibrillator (TV-ICD), aiming to provide easier implantation, simplified detection algorithm of malignant ventricular arrhythmias and prevention from placing components in the cardiovascular system. The S-ICD is implanted subcutaneously or intramuscularly with the generator placed in the left midaxillary line and the lead tunneled subcutaneously in the left para-sternal region. Preimplant electrocardiogram screening is recommended to prevent implantation in patients at high risk of T wave over-sensing. Currently, the S-ICD is unsuitable for patients requiring pacing or cardiac resynchronization. Since the beginning, the S-ICD underwent extensive preclinical investigation until the first prospective multicentre trial demonstrating high efficacy and safety led to market release. While earlier studies focused on younger patients with higher ejection fraction, more recent studies showed favorable outcomes even in patients with comorbidities similar to those typically observed in patients receiving TV-ICD. The development of second and third generation devices has contributed to reduce inappropriate shocks and overcome previous limitations. The aim of this paper is to review the evidence in the literature over the past decade supporting S-ICD as a valid alternative to TV-ICD in terms of safety and efficacy, highlighting the improvements in technology, as well as outcomes.

Implantable cardioverter defibrillator use in arrhythmogenic right ventricular cardiomyopathy in North America and Europe.

BACKGROUND AND AIMS: Implantable cardioverter-defibrillators (ICDs) are critical for preventing sudden cardiac death (SCD) in arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aims to identify cross-continental differences in utilization of primary prevention ICDs and survival free from sustained ventricular arrhythmia (VA) in ARVC. METHODS: This was a retrospective analysis of ARVC patients without prior VA enrolled in clinical registries from 11 countries throughout Europe and North America. Patients were classified according to whether they received treatment in North America or Europe and were further stratified by baseline predicted VA risk into low- (<10%/5 years), intermediate- (10%-25%/5 years), and high-risk (>25%/5 years) groups. Differences in ICD implantation and survival free from sustained VA events (including appropriate ICD therapy) were assessed. RESULTS: One thousand ninety-eight patients were followed for a median of 5.1 years; 554 (50.5%) received a primary prevention ICD, and 286 (26.0%) experienced a first VA event. After adjusting for baseline risk factors, North Americans were more than three times as likely to receive ICDs {hazard ratio (HR) 3.1 [95% confidence interval (CI) 2.5, 3.8]} but had only mildly increased risk for incident sustained VA [HR 1.4 (95% CI 1.1, 1.8)]. North Americans without ICDs were at higher risk for incident sustained VA [HR 2.1 (95% CI 1.3, 3.4)] than Europeans. CONCLUSIONS: North American ARVC patients were substantially more likely than Europeans to receive primary prevention ICDs across all arrhythmic risk strata. A lower rate of ICD implantation in Europe was not associated with a higher rate of VA events in those without ICDs.

Differences in underlying cardiac substrate among S-ICD recipients and its impact on long-term device-related outcomes: Real-world insights from the iSUSI registry.

BACKGROUND: Outcome comparisons among subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients with nonischemic cardiomyopathies are scarce. OBJECTIVE: The aim of this study was to evaluate differences in device-related outcomes among S-ICD recipients with different structural substrates. METHODS: Patients enrolled in the i-SUSI (International SUbcutaneouS Implantable cardioverter defibrillator registry) project were grouped according to the underlying substrate (ischemic vs nonischemic) and subgrouped into dilated cardiomyopathy, hypertrophic cardiomyopathy, Brugada syndrome (BrS), arrhythmogenic right ventricular cardiomyopathy (ARVC). The main outcome of our study was to compare the rates of appropriate and inappropriate shocks and device-related complications. RESULTS: Among 1698 patients, the most common underlying substrate was ischemic (31.7%), followed by dilated cardiomyopathy (20.5%), BrS (10.8%), hypertrophic cardiomyopathy (8.5%), and ARVC (4.4%). S-ICD for primary prevention was more common in the nonischemic cohort (70.9% vs 65.4%; P = .037). Over a median (interquartile range) follow-up of 26.5 (12.6-42.8) months, no differences were observed in appropriate shocks between ischemic and nonischemic patients (4.8%/y vs 3.9%/y; log-rank, P = .282). ARVC (9.0%/y; hazard ratio [HR] 2.492; P = .001) and BrS (1.8%/y; HR 0.396; P = .008) constituted the groups with the highest and lowest rates of appropriate shocks, respectively. Device-related complications did not differ between groups (ischemic: 6.4%/y vs nonischemic: 6.1%/y; log-rank, P = .666), nor among underlying substrates (log-rank, P = .089). Nonischemic patients experienced higher rates of inappropriate shocks than did ischemic S-ICD recipients (4.4%/y vs 3.0%/y; log-rank, P = .043), with patients with ARVC (9.9%/y; P = .001) having the highest risk, even after controlling for confounders (adjusted HR 2.243; confidence interval 1.338-4.267; P = .002). CONCLUSION: Most S-ICD recipients were primary prevention nonischemic cardiomyopathy patients. Among those, patients with ARVC tend to receive the most frequent appropriate and inappropriate shocks and patients with BrS the least frequent appropriate shocks.

The economics of heart failure care.

Heart failure (HF) poses a significant economic burden in the US, with costs projected to reach $70 billion by 2030. Cost-effectiveness analyses play a pivotal role in assessing the economic value of HF therapies. In this review, we overview the cost-effectiveness of HF therapies and discuss ways to improve patient access. Based on current costs, guideline directed medical therapies for HF with reduced ejection fraction provide high economic value except for sodium-glucose cotransporter-2 inhibitors, which provide intermediate economic value. Combining therapy with the four pillars of medical therapy also has intermediate economic value, with incremental cost-effectiveness ratios ranging from $73,000 to $98,500/ quality adjusted life-years. High economic value procedures include cardiac resynchronization devices, implantable cardioverter-defibrillators, and coronary artery bypass surgery. In contrast, advanced HF therapies have previously demonstrated intermediate to low economic value, but newer data appear more favorable. Given the affordability challenges of HF therapies, additional efforts are needed to ensure optimal care for patients. The recent Inflation Reduction Act contains provisions to reform policy pertaining to drug price negotiation and out-of-pocket spending, as well as measures to increase access to existing programs, including the Medicare low-income subsidy. On a patient level, it is also important to encourage patient and physician awareness and discussions surrounding medical costs. Overall, a broad approach to improving available therapies and access to care is needed to reduce the growing clinical and economic morbidity of HF.

[Perioperative management for cardiovascular implantable electronic devices]. / Perioperatives Management bei der Versorgung mit aktiven Rhythmusimplantaten.

Cardiovascular implantable electronic devices (CIED) are an important part of modern cardiology and careful perioperative planning of these procedures is necessary. All information relevant to the indication, the procedure, and the education of the patient must be available prior to surgery. This provides the basis for appropriate device selection. Preoperative antibiotic prophylaxis and perioperative anticoagulation management are essential to prevent infection. After surgery, postoperative monitoring, telemetric control, and device-based diagnostics are required before discharge. These processes need to be adapted to the increasing trend towards outpatient care. This review summarises perioperative management based on practical considerations.

Fundamental Electrophysiology Principles Related to Perioperative Management of Cardiovascular Implantable Electronic Devices.

An increasing number of patients undergoing elective or emergency surgery in the United States have a cardiovascular implantable electronic device. Practice advisories and consensus statements have been issued by the American Society of Anesthesiologists and the Heart Rhythm Society, advocating a multidisciplinary approach. Unfortunately, anesthesia providers often find themselves in a situation in which they are left to manage these devices independently. At the University of Washington Medical Center, an anesthesiology-based service to manage these devices has existed for more than a decade. Many problems with devices have been observed, including confusing rhythms, failure of magnets to provide the desired change in device function, and actual device malfunction. With these clinical case examples taken from the authors' collective experience, this article provides an in-depth understanding of some key electrophysiology principles relevant to cardiovascular implantable electronic device function and appropriate perioperative management.

Management of arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a disease characterised by fibrofatty replacement of the ventricular myocardium due to specific mutations, leading to ventricular arrhythmias and sudden cardiac death. Treating this condition can be challenging due to progressive fibrosis, phenotypic variations and small patient cohorts limiting the feasibility of conducting meaningful clinical trials. Although widely used, the evidence base for anti-arrhythmic drugs is limited. Beta-blockers are theoretically sound, yet their efficacy in reducing arrhythmic risk is not robust. Additionally, the impact of sotalol and amiodarone is inconsistent with studies reporting contradictory results. Emerging evidence suggests that combining flecainide and bisoprolol may be efficacious.Radiofrequency ablation has shown some potential in disrupting ventricular tachycardia circuits, with combined endo and epicardial ablation yielding better results which could be considered at the index procedure. In addition, stereotactic radiotherapy may be a future option that can decrease arrhythmias beyond simple scar formation by altering levels of Nav1.5 channels, Connexin 43 and Wnt signalling, potentially modifying myocardial fibrosis.Future therapies, such as adenoviruses and GSk3b modulation, are still in early-stage research. While implantable cardioverter-defibrillator implantation is a key intervention for reducing arrhythmic death, the risks of inappropriate shocks and device complications must be carefully considered.