Effect of beta-blockers and exercise restriction on the prevention of sudden cardiac death in pediatric hypertrophic cardiomyopathy

BACKGROUND

Risk assessment tools and effective prevention strategies for sudden cardiac death (SCD) in pediatric patients with hypertrophic cardiomyopathy (HCM) have not been established. This study aimed to evaluate the efficacy of beta-blockers and exercise restriction for SCD prevention in this population.

METHODS

We retrospectively reviewed the medical records of patients aged <18 years who were diagnosed with HCM at our center between January 1996 and December 2021. SCD and aborted SCD were defined as SCD equivalents. We divided patients based on whether they were prescribed beta-blockers or exercise restriction and compared the outcomes among the groups. The primary outcome was the overall survival (OS), and the secondary outcome was the cumulative SCD equivalent rate. Outcomes were analyzed using Kaplan-Meier curves and Cox proportional hazard analysis. We also compared patients according to the occurrence of SCD equivalents to identify SCD risk predictors.

RESULTS

Among the 43 included patients [mean age, 7.7 (1.6-12.1) years; 23 male individuals], SCD equivalents occurred in 13 patients over 11.2 (4.5-15.6) years of follow-up, among whom 12 were resuscitated and 1 died. The OS rate was significantly higher in the beta-blocker and exercise restriction groups than in the non-beta-blocker and non-exercise restriction groups (81.3 % vs. 19.1 %, p < 0.01 and 57.4 % vs. 12.7 %, p < 0.01, respectively). Among the 13 patients with SCD equivalents, 5 had 9 recurrent SCD equivalents. A significant difference was observed between the SCD equivalent and non-SCD equivalent groups in the history of suspected arrhythmogenic syncope (p < 0.01) in the univariable but not in the multivariable analysis.

CONCLUSIONS

Beta-blockers and exercise restriction may decrease the risk of SCD in pediatric patients with HCM and should be considered for SCD prevention in this population, particularly because predicting SCD in these patients remains challenging.

The role of ICDs in patients with sarcoidosis-A comprehensive review

BACKGROUND

Implantable cardioverter defibrillator (ICD) use in cardiac sarcoidosis (CS) to prevent sudden cardiac death (SCD) is a potentially life-saving intervention. However, the factors that determine outcome in this cohort remains largely unknown. This review analyses CS patients with an ICD and highlights determinants of poor outcome.

OUTCOMES

Analysis of studies which used the 2014 HRS Consensus, 2017 AHA/ACC/HRS Guideline and 2022 ESC Guidelines showed that those with class I recommendations have higher incidences of ventricular arrhythmia (VA) than those with class II recommendations. Additionally, even those with normal left ventricular ejection fraction (LVEF) and CS are at high risk of VA and SCD.

SUMMARY

Compounding research emphasises the importance of cardiac imaging in those with sarcoidosis, with evidence to suggest a possible need for revision of the guidelines. Other variables such as demographics and ventricular characteristics may prove useful in predicting those to benefit most from ICD insertion.

Complications and inappropriate shocks in pediatric patients receiving a subcutaneous implantable cardioverter defibrilator

INTRODUCTION AND OBJECTIVES

There is limited evidence regarding the use of subcutaneous implantable cardioverter-defibrillators (S-ICD) in pediatric patients. The aim of this study was to determine the incidence of complications in these patients at our center, according to the type of ICD and patient size.

METHODS

We included all patients aged<18 years who received an S-ICD since 2016 at our center. As a control group, we also included contemporary patients (since 2014) who received a transvenous ICD (TV-ICD). The primary endpoint was a composite of complications and inappropriate shocks.

RESULTS

A total of 26 patients received an S-ICD (median age, 14 [5-17] years; body mass index [BMI], 20.2 kg/m2). Implantation was intermuscular in 23 patients (88%) and subserratus in the remainder. Two incisions were used in 24 patients (92%). In all patients, 2 zones were programmed: a conditional zone set at 230 (220-230) bpm, and a shock zone set at 250 bpm. Nineteen patients received a TV-ICD (median age, 11 [range, 5-16] years; BMI, 19.2 kg/m2, 79% single-chamber). Survival free from the primary endpoint at 5 years was 80% in the S-ICD group and 63% in the TV-ICD group (P=.54). Survival free from inappropriate shocks was similar (85% vs 89%, P=.86), while survival free from complications was higher in the S-ICD group (96% vs 57%, cloglog P=.016). There were no therapy failures in the S-ICD group, and no increased complication rates were observed in patients with BMI ≤20 kg/m2.

CONCLUSIONS

With contemporary implantation techniques and programming, S-ICD is a safe and effective therapy in pediatric patients. The number of inappropriate shocks is similar to TV-ICD, with fewer short- and mid-term complications.

Real-world data of patients affected by advanced heart failure treated with implantable cardioverter defibrillator and left ventricular assist device: Results of a multicenter observational study

BACKGROUND

Left ventricular assist device (L-VAD) implantation is increasingly used in patients with heart failure (HF) and most patients also have an implantable cardioverter defibrillator (ICD). Limited data are available on the incidence of ICD therapies and complications in this special setting. The aim of this study was to analyze the real-world incidence and predictors of ICD therapies, complications and interactions between ICD and L-VAD.

METHODS

We conducted a multicenter retrospective observational study in patients with advanced HF implanted with ICD and a continuous-flow L-VAD, followed-up in five advanced HF centers in Northern Italy.

RESULTS

A total of 234 patients (89.7% male, median age 59, 48.3% with ischemic etiology) were enrolled. After a median follow-up of 21 months, 66 patients (28.2%) experienced an appropriate ICD therapy, 22 patients (9.4%) an inappropriate ICD therapy, and 17 patients (7.3%) suffered from an interaction between ICD and L-VAD. The composite outcome of all ICD-related complications was reported in 41 patients (17.5%), and 121 (51.7%) experienced an L-VAD-related complication. At multivariable analysis, an active ventricular tachycardia (VT) zone and a prior ICD generator replacement were independent predictors of ICD therapies and of total ICD-related complications, respectively.

CONCLUSIONS

Real-world patients with both L-VAD and ICD experience a high rate of ICD therapies and complications. Our findings suggest the importance of tailoring device programming in order to minimize the incidence of unnecessary ICD therapies, thus sparing the need for ICD generator replacement, a procedure associated to a high risk of complications.

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.

Venous thoracic outlet syndrome, as a pitfall for cardiac implantable electronic device implantations

The subclavian vein is typically used in cardiovascular implantable electronic device (CIED) implantations. External stress on the subclavian vein can lead to lead-related complications. There are several causes of this stress, such as frequent upper extremity movements or external injury. Venous thoracic outlet syndrome (TOS) can also become the cause of external lead stress. However, the diagnosis of venous TOS can be challenging because subclavian venography can appear normal at first glance. We present a unique case of a device infection in a patient with venous TOS. A careful observation of the imaging studies is vital for diagnosing venous TOS and a leadless pacemaker implantation could be an alternative therapeutic option.

Childhood-onset hypertrophic cardiomyopathy caused by thin-filament sarcomeric variants

Up to 20% of children with sarcomeric hypertrophic cardiomyopathy (HCM) have disease-causing variants in genes coding for thin-filament proteins. However, data on genotype-phenotype correlations for thin-filament disease are limited. This study describes the natural history and outcomes of children with thin-filament-associated HCM and compares it to thick-filament-associated disease.Longitudinal data were collected from 40 children under 18 years with a disease-causing variant in a thin-filament protein from a single quaternary referral centre. Twenty-one (female n=6, 35.5%) were diagnosed with HCM at a median age of 13.0 years (IQR 8.3-14.0). Over a median follow-up of 5.0 years (IQR 4.0-8.5), three (14.3%) experienced one or more major adverse cardiac events (MACE) (two patients had an out-of-hospital arrest and eight appropriate implantable cardiac defibrillator (ICD) therapies in three patients). One gene carrier died suddenly at age 9 years. Compared with those with thick-filament disease, children with thin-filament variants more commonly experienced non-sustained ventricular tachycardia [NSVT; n=6 (28.6%) vs n=14 (10.8%), p=0.024] or underwent ICD insertion (thin, n=13 (61.9%) vs thick, n=50 (38.5%), p=0.040). However, there was no difference in the incidence of MACE (thin 2.47/100 pt years (95% CI 0.80 to 7.66) vs thick 3.63/100 pt years (95% CI 2.25 to 5.84)) or an arrhythmic event (thin 1.65/100 pt years (95% CI 0.41 to 6.58) vs thick 2.55/100 pt years (95% CI 1.45 to 4.48), p value 0.43).This study suggests that adverse events in thin-filament disease are predominantly arrhythmic and may occur in the absence of hypertrophy, but overall short-term outcomes do not differ significantly from thick-filament disease.

Impact of a Chronic Total Coronary Occlusion on the Incidence of Appropriate Implantable Cardioverter-Defibrillator Shocks and Mortality: A Substudy of the Dutch Outcome in ICD Therapy (DO-IT)) Registry

BACKGROUND

Chronic total coronary occlusions (CTO) substantially increase the risk for sudden cardiac death. Among patients with chronic ischemic heart disease at risk for sudden cardiac death, an implantable cardioverter defibrillator (ICD) is the favored therapy for primary prevention of sudden cardiac death. This study sought to investigate the impact of CTOs on the risk for appropriate ICD shocks and mortality within a nationwide prospective cohort.

METHODS AND RESULTS

This is a subanalysis of the nationwide Dutch-Outcome in ICD Therapy (DO-IT) registry of primary prevention ICD recipients in The Netherlands between September 2014 and June 2016 (n=1442). We identified patients with chronic ischemic heart disease (n=663) and assessed available coronary angiograms for CTO presence (n=415). Patients with revascularized CTOs were excluded (n=79). The primary end point was the composite of all-cause mortality and appropriate ICD shocks. Clinical follow-up was conducted for at least 2 years. A total of 336 patients were included, with an average age of 67±9 years, and 20.5% was female (n=69). An unrevascularized CTO was identified in 110 patients (32.7%). During a median follow-up period of 27 months (interquartile range, 24-32), the primary end point occurred in 21.1% of patients with CTO (n=23) compared with 11.9% in patients without CTO (n=27; P=0.034). Corrected for baseline characteristics including left ventricular ejection fraction, and the presence of a CTO was an independent predictor for the primary end point (hazard ratio, 1.82 [95% CI, 1.03-3.22]; P=0.038).

CONCLUSIONS

Within this nationwide prospective registry of primary prevention ICD recipients, the presence of an unrevascularized CTO was an independent predictor for the composite outcome of all-cause mortality and appropriate ICD shocks.

Infective Endocarditis Involving Implanted Cardiac Electronic Devices: JACC Focus Seminar 1/4

Cardiac implantable electronic device-related infective endocarditis (CIED-IE) encompasses a range of clinical syndromes, including valvular, device lead, and bloodstream infections. However, accurately diagnosing CIED-IE remains challenging owing in part to diverse clinical presentations, lack of standardized definition, and variations in guideline recommendations. Furthermore, current diagnostic modalities, such as transesophageal echocardiography and [18F]-fluorodeoxyglucose positron emission tomography-computed tomography have limited sensitivity and specificity, further contributing to diagnostic uncertainty. This can potentially result in complications and unnecessary costs associated with inappropriate device extraction. Six hypothetical clinical cases that exemplify the diverse manifestations of CIED-IE are addressed herein. Through these cases, we highlight the importance of optimizing diagnostic accuracy and stewardship, understanding different pathogen-specific risks for bloodstream infections, guiding appropriate device extraction, and preventing CIED-IE, all while addressing key knowledge gaps. This review both informs clinicians and underscores crucial areas for future investigation, thereby shedding light on this complex and challenging syndrome.

Cardiac implantable electronic devices and bloodstream infections: management and outcomes

BACKGROUND AND AIMS

Bloodstream infection (BSI) of any cause may lead to device infection in cardiac implantable electronic device (CIED) patients. Aiming for a better understanding of the diagnostic approach, treatment, and outcome, patients with an implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy and defibrillator (CRT-D) hospitalized with BSI were investigated.

METHODS

This is a single-centre, retrospective, cohort analysis including consecutive ICD/CRT-D patients implanted between 2012 and 2021. These patients were screened against a list of all hospitalized patients having positive blood cultures consistent with diagnosed infection in any department of a local public hospital.

RESULTS

The total cohort consisted of 515 patients. Over a median follow-up of 59 months (interquartile range 31-87 months), there were 47 BSI episodes in 36 patients. The majority of patients with BSI (92%) was admitted to non-cardiology units, and in 25 episodes (53%), no cardiac imaging was performed. Nearly all patients (85%) were treated with short-term antibiotics, whereas chronic antibiotic suppression therapy (n = 4) and system extraction (n = 3) were less frequent. Patients with BSI had a nearly seven-fold higher rate (hazard ratio 6.7, 95% confidence interval 3.9-11.2; P < .001) of all-cause mortality.

CONCLUSIONS

Diagnostic workup of defibrillator patients with BSI admitted to a non-cardiology unit is often insufficient to characterize lead-related endocarditis. The high mortality rate in these patients with BSI may relate to underdiagnosis and consequently late/absence of system removal. Efforts to increase an interdisciplinary approach and greater use of cardiac imaging are necessary for timely diagnosis and adequate treatment.

Unanticipated subcutaneous ICD end-of-service due to premature battery depletion and occurrence of lead fracture: A single centre experience

The use of subcutaneous ICDs (S-ICD) is growing over years despite increasing alerts on premature battery depletion (PBD) and lead fractures leading to unanticipated device replacements. In our single-centre study including 192 patients, per year analysis demonstrated that incidence of PBD is higher than previously reported with overall greatest battery replacement requirements around the fifth year of follow-up. The underlying issue appears to be limited to old series devices, but only a longer follow-up will clarify the real impact of this phenomenon on patient outcomes. PBD is an underestimated S-ICDs issue and if the hereby demonstrated trend were to be confirmed in latest device series, this would bring significant concerns to patient safety and huge economic expense to health system.

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.

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.

Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: Data from a multicenter experience

BACKGROUND

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF). Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs with a lower risk of short- and long-term of device-related complications and infections.The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation.

METHODS

The study population included patients with a preexisting S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy.

RESULTS

The study population included 30 patients (25 male; median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population. Electromagnetic interference (EMI) occurred in 21 (70%) patients. The primary sensing vector was the one most significantly involved in determining EMI. Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector. The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks (IS) due to EMI. Six patients (20%) experienced appropriate shocks. No S-ICD extraction because of need for antitachycardia pacing, ineffective therapy or infection was reported.

CONCLUSIONS

Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS and undersensing in the post-operative period following LVAD implantation should be considered. Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.

Prior history of atrial fibrillation and arrhythmic outcomes: Data from the WEARIT-II prospective registry

INTRODUCTION

Wearable cardioverter defibrillator (WCD) is utilized in patients with assumed but not yet confirmed risk for sudden cardiac death (SCD). Many of these patients also present with atrial fibrillation (AF). However, the rate of WCD-detected ventricular or atrial arrhythmia events in this specific high-risk cohort is not well understood.

METHODS

In WEARIT-II, the cumulative probability of any sustained or nonsustained VT/VF (WCD-treated and nontreated), and atrial/supraventricular arrhythmias during WCD use was assessed using the Kaplan-Meier method by prior AF, with comparisons by the log-rank test. The incidence of ventricular and atrial arrhythmia events were expressed as events per 100 patient-years, and were analyzed by prior AF using negative binomial regression.

RESULTS

WEARIT-II enrolled 2000 patients, 557 (28%) of whom had AF before enrollment. Cumulative probability of any sustained or nonsustained WCD-detected VT/VF during WCD use was significantly higher among patients with a history of AF than without AF (6% vs. 3%, p = .001). Similarly, the recurrent rate of any sustained or nonsustained VT/VF was significantly higher in patients with prior AF versus no prior AF (131.5 events per 100 patient-years vs. 22.7 events per 100 patient-years, p = .001). Patients with prior AF also had a significantly higher burden of any WCD-detected atrial arrhythmias/SVT/inappropriate arrhythmias therapy (183.2 events per 100 patient-years vs. 74.8 events per 100 patient-years, p < .001).

CONCLUSION

Our results demonstrate that patients with a history of AF wearing the WCD for risk assessment have a higher incidence of ventricular arrhythmias that may facilitate the decision making for ICD implantation.

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.

Transvenous lead extraction safety and efficacy in infected and noninfected patients using mechanical-only tools: Prospective registry from a high-volume center

BACKGROUND

Transvenous lead extraction (TLE) is a well-established treatment option for patients with cardiac implantable electronic devices (CIED) complications.

OBJECTIVE

The purpose of this study was to evaluate the safety and efficacy of TLE in CIED infection and non-CIED infection patients.

METHODS

Consecutive patients who underwent TLE between 2016 and 2022 entered the EXTRACT Registry. Models of prediction were constructed for periprocedural clinical and procedural success and the incidence of major complications, including death in 30 days.

RESULTS

The registry enrolled 504 patients (mean age 66.6 ± 12.8 years; 65.7% male). Complete procedural success was achieved in 474 patients (94.0%) and clinical success in 492 patients (97.6%). The total number of major and minor complications was 16 (3.2%) and 51 (10%), respectively. Three patients (0.6%) died during the procedure. New York Heart Association functional class IV and C-reactive protein levels defined before the procedure were independent predictors of any major complication, including death in 30 days in CIED infection patients. The time since the last preceding procedure and platelet count before the procedure were independent predictors of any major complication, including death in 30 days in non-CIED infection patients.

CONCLUSIONS

TLE is safe and successfully performed in most patients, with a low major complication rate. CIED infection patients demonstrate better periprocedural clinical success and complete procedural success. However, CIED infection predicts higher 30-day mortality compared with non-CIED infection patients. Predictors of any major complication, including death in 30 days, differ between CIED infection and non-CIED infection patients.

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.

Left bundle branch pacing lead for sensing ventricular arrhythmias in implantable cardioverter-defibrillator: A pilot study (LBBP-ICD study)

BACKGROUND

Left bundle branch pacing (LBBP) has been suggested as an alternative modality for biventricular pacing in cardiac resynchronization therapy (CRT)-eligible patients. As it provides stable R-wave sensing, LBBP has been recently used to provide sensing of ventricular arrhythmia in patients receiving implantable cardioverter-defibrillator (ICD) with CRT.

OBJECTIVE

The aim of this study was to analyze the long-term safety and efficacy of the LBBP lead for appropriate detection of ventricular arrhythmia and delivery of antitachycardia pacing (ATP) in patients requiring defibrillator therapy with CRT.

METHODS

CRT-eligible patients who underwent successful LBBP-optimized ICD and LBBP-optimized CRT with defibrillator were enrolled. The LBBP lead was connected to the right ventricular-P/S port after capping the IS-1 connector plug of the DF-1-ICD lead. LBBP-optimized ICD or LBBP-optimized CRT with defibrillator was decided on the basis of correction of conduction system disease. Documented arrhythmic episodes and therapy delivered were analyzed.

RESULTS

Thirty patients were enrolled. The mean age was 59.7 ± 10.5 years. LBBP resulted in an increase in left ventricular ejection fraction from 29.9% ± 4.6% to 43.9% ± 11.2% (P < .0001). During a mean follow-up of 22.9 ± 12.5 months, 254 ventricular arrhythmic events were documented. Appropriate events (n = 225 [89%]) included nonsustained ventricular tachycardia (VT) (n = 212 episodes [94%]), VT (n = 8 [3.5%]), and ventricular fibrillation (n = 5 [2.5%]). ATP efficacy in terminating VT was 75%. Eleven percent of episodes (n = 29) were inappropriately detected because of T-wave oversensing. Inappropriate therapy (ATP) was delivered for 14 episodes (5.5%). Three patients (10%) had worsening of tricuspid regurgitation.

CONCLUSION

Sensing from the LBBP lead for arrhythmia detection is safe as ∼90% of the episodes were detected appropriately. Future studies with a dedicated LBBP-defibrillator lead along with algorithms to avoid oversensing can help in combining defibrillation with conduction system pacing.

Association of Device-Detected Atrial High-Rate Episodes With Long-term Cardiovascular and All-Cause Mortality: A Cohort Study

BACKGROUND

Device-detected atrial high-rate episodes (AHREs) were associated with an increased thromboembolic risk. Although limited data regarding the long-term prognosis of patients with AHRE were controversial, this study aimed to identify the association of device-detected AHRE with mortality.

METHODS

This observational study included patients with implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) placement and no history of atrial fibrillation (AF), atrial flutter (AFL), or atrial tachycardia (AT). During follow-up, patients with at least 1 day of AHRE duration ≥ 15 minutes were identified. The primary endpoint was cardiovascular mortality, and the secondary endpoint was all-cause mortality.

RESULTS

During a mean follow-up period of 4.2 years, AHREs were detected in 124 of 343 (36.2%) patients. Of these, 44 deaths (35.5%) occurred in 124 patients with AHREs, which was significantly higher than those without AHREs (43 of 219; 19.6%; P = 0.001). The multivariate analysis revealed that patients with AHRE had a significantly higher risk of cardiovascular (hazard ratio [HR], 2.40; 95% confidence interval [CI], 1.23-4.67; P = 0.010), and all-cause mortality (HR, 2.31; 95% CI, 1.49-3.59; P < 0.001). Further analysis indicated that this association remained significant in patients with higher burden (≥ 6 hours) but not in patients with lower burden (≥ 15 minutes to 6 hours). Notably, even after excluding the patients diagnosed with clinical AF during follow-up, the remaining patients with AHREs still exhibited a higher risk of cardiovascular and all-cause mortality compared with patients without AHREs.

CONCLUSIONS

AHREs were prevalent in ICD or CRT-D recipients with no history of clinical AF, AFL, or AT and were associated with more than twice the risk of cardiovascular and all-cause mortality.

CLINICAL TRIAL REGISTRATION

No. ChiCTR-ONRC-13003695.

Evaluation of patients with implantable cardioverter-defibrillator in a Latin American tertiary center

INTRODUCTION

Despite advancements in implantable cardioverter-defibrillator (ICD) technology, sudden cardiac death (SCD) remains a persistent public health concern. Chagas disease (ChD), prevalent in Brazil, is associated with increased ventricular tachycardia (VT) and ventricular fibrillation (VF) events and SCD compared to other cardiomyopathies.

METHODS

This retrospective observational study included patients who received ICDs between October 2007 and December 2018. The study aims to assess whether mortality and VT/VF events decreased in patients who received ICDs during different time periods (2007-2010, 2011-2014, and 2015-2018). Additionally, it seeks to compare the prognosis of ChD patients with non-ChD patients. Time periods were chosen based on the establishment of the Arrhythmia Service in 2011. The primary outcome was overall mortality, assessed across the entire sample and the three periods. Secondary outcomes included VT/VF events and the combined outcome of death or VT/VF.

RESULTS

Of the 885 patients included, 31% had ChD. Among them, 28% died, 14% had VT/VF events, and 37% experienced death and/or VT/VF. Analysis revealed that period 3 (2015-2018) was associated with better death-free survival (p = .007). ChD was the only variable associated with a higher rate of VT/VF events (p < .001) and the combined outcome (p = .009).

CONCLUSION

Mortality and combined outcome rates decreased gradually for ICD patients during the periods 2011-2014 and 2015-2018 compared to the initial period (2007-2010). ChD was associated with higher VT/VF events in ICD patients, only in the first two periods.

The impact of supraventricular arrhythmias on the outcomes of guideline-compliant implantable cardioverter defibrillator programming

INTRODUCTION

Several implantable cardioverter defibrillators (ICD) programming strategies are applied to minimize ICD therapy, especially unnecessary therapies from supraventricular arrhythmias (SVA). However, it remains unknown whether these optimal programming recommendations only benefit those with SVAs or have any detrimental effects from delayed therapy on those without SVAs. This study aims to assess the impact of SVA on the outcomes of ICD programming based on 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement and 2019 focused update on optimal ICD programming and testing guidelines.

METHODS

Consecutive patients who underwent ICD insertion for primary prevention were classified into four groups based on SVA status and ICD programming: (1) guideline-concordant group (GC) with SVA, (2) GC without SVA, (3) nonguideline concordant group (NGC) with SVA, and (4) NGC without SVA. Cox proportional hazard models were analyzed for freedom from ICD therapies, shock, and mortality.

RESULTS

Seven hundred and seventy-two patients (median age, 64 years) were enrolled. ICD therapies were the most frequent in NGC with SVA (24.0%), followed by NGC without SVA (19.9%), GC without SVA (11.6%), and GC with SVA (8.1%). Guideline concordant programming was associated with 68% ICD therapy reduction (HR 0.32, p = .007) and 67% ICD shock reduction (HR 0.33, p = .030) in SVA patients and 44% ICD therapy reduction in those without SVA (HR 0.56, p = .030).

CONCLUSION

Programming ICDs in primary prevention patients based on current guidelines reduces therapy burden without increasing mortality in both SVA and non-SVA patients. A greater magnitude of reduced ICD therapy was found in those with supraventricular arrhythmias.

New advances in management and treatment of cardiac implantable electronic devices infections

Cardiac implantable electronic devices (CIED) are increasingly used worldwide, and infection of these devices remains one of the most feared complications.CIED infections (CDIs) represent a challenge for physicians and the healthcare system in general as they require prolonged hospitalization and antibiotic treatment and are burdened by high mortality and high costs, so management of CDIs must be multidisciplinary.The exact incidence of CDIs is difficult to define, considering that it is influenced by various factors mainly represented by the implanted device and the type of procedure. Risk factors for CDIs could be divided into three categories: device related, patient related, and procedural related and the etiology is mainly sustained by Gram-positive bacteria; however, other etiologies cannot be underestimated. As a matter of fact, the two cornerstones in the treatment of these infections are device removal and antimicrobial treatment. Finally, therapeutic drug monitoring and PK/PD correlations should be encouraged in all patients with CDIs receiving antibiotic therapy and may result in a better clinical outcome and a reduction in antibiotic resistance and economic costs.In this narrative review, we look at what is new in the management of these difficult-to-treat infections.

Relationship of Mild to Moderate Impairment of Left Ventricular Ejection Fraction With Fatal Ventricular Arrhythmic Events in Cardiac Sarcoidosis

BACKGROUND

Current guidelines recommend placing an implantable cardiac defibrillator for patients with cardiac sarcoidosis and a severely impaired left ventricular ejection fraction (LVEF) of ≤35%. In this study, we determined the association between mild or moderate LVEF impairment and fatal ventricular arrhythmic event (FVAE).

METHODS AND RESULTS

We retrospectively analyzed 401 patients with cardiac sarcoidosis without sustained ventricular arrhythmia at diagnosis. The primary end point was an FVAE, defined as the combined endpoint of documented ventricular tachycardia or ventricular fibrillation and sudden cardiac death. Two cutoff points for LVEF were used: a sex-specific lower threshold of normal range of LVEF (52% for men and 54% for women) and an LVEF of 35%, which is used in the current guidelines. During a median follow-up of 3.2 years, 58 FVAEs were observed, and the 5- and 10-year estimated incidences of FVAEs were 16.8% and 23.0%, respectively. All patients were classified into 3 groups according to LVEF: impaired LVEF group, mild to moderate impairment of LVEF group, and maintained LVEF group. Multivariable competing risk analysis showed that both the impaired LVEF group (hazard ratio [HR], 3.24 [95% CI, 1.49-7.04]) and the mild to moderate impairment of LVEF group (HR, 2.16 [95% CI, 1.04-4.46]) were associated with a higher incidence of FVAEs than the maintained LVEF group after adjustment for covariates.

CONCLUSIONS

Patients with cardiac sarcoidosis are at a high risk of FVAEs, regardless of documented ventricular arrhythmia at the time of diagnosis. In patients with cardiac sarcoidosis, mild to moderate impairment of LVEF is associated with FVAEs.

First implantable cardiac defibrillator insertions in New South Wales, 2005-2020: an analysis of linked administrative data

OBJECTIVES

To determine the annual numbers of first ICD insertions in New South Wales during 2005-2020; to examine health outcomes for people who first received ICDs during this period.

STUDY DESIGN

Retrospective cohort study; analysis of linked administrative health data.

SETTING, PARTICIPANTS

All first insertions of ICDs in NSW, 2005-2020.

MAIN OUTCOME MEASURES

Annual numbers of first ICD insertions, and of emergency department presentations and hospital re-admissions 30 days, 90 days, 365 days after first ICD insertions; all-cause and disease-specific mortality (to ten years after ICD insertion).

RESULTS

During 2005-2020, ICDs were first inserted into 16 867 people (18.5 per 100 000 population); their mean age was 65.7 years (standard deviation, 13.5 years; 7376 aged 70 years or older, 43.7%), 13 214 were men (78.3%). The annual number of insertions increased from 791 in 2005 to 1256 in 2016; the first ICD insertion rate increased from 15.5 in 2005 to 18.9 per 100 000 population in 2010, after which the rate was stable until 2019 (19.8 per 100 000 population). Of the 16 778 people discharged alive from hospital after first ICD insertions, 54.4% presented to emergency departments within twelve months, including 1236 with cardiac arrhythmias (7.4%) and 434 with device-related problems (2.6%); 56% were re-admitted to hospital, including 1944 with cardiac arrhythmias (11.5%) and 2045 with device-related problems (12.1%). A total of 5624 people who received first ICDs during 2005-2020 (33.3%) died during follow-up (6.7 deaths per 100 person-years); the survival rate was 94.4% at one year, 76.5% at five years, and 54.2% at ten years.

CONCLUSIONS

The annual number of new ICDs inserted in NSW has increased since 2005. A substantial proportion of recipients experience device-related problems that require re-admission to hospital. The potential harms of ICD insertion should be considered when assessing the likelihood of preventing fatal ventricular arrhythmia.

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.

Predictors of the right ventricular perforation caused by active-fixation pacing and defibrillator leads: A single-centre experience

INTRODUCTION

Active-fixation leads have been associated with higher incidence of cardiac perforation. Large series specifically evaluating radiographic predictors of right ventricular (RV) lead perforation are lacking.

METHODS

We conducted a retrospective observational study including 1691 consecutive patients implanted with an active fixation pacing and defibrillator lead at our institution between January 2015 and January 2021. Fourteen patients who had clinically relevant RV perforation caused by pacemaker and implantable cardioverter-defibrillator leads were included in the study.

RESULTS

Univariate and multivariate analyses were used to identify predictors of RV perforation. In multivariate analysis, lead slack score (odds ratio [OR]: 3.694, 95% confidence interval [CI]: 1.066-12.807; p = .039), change in lead slack height (OR: 1.218, 95% CI: 1.011-1.467; p = .038) and width (OR: 1.253, 95% CI: 1.120-1.402; p = .001), left ventricular ejection fraction (OR: 0.995, 95% CI: 0.910-1.088; p = .032) were independent predictors of RV perforation.

CONCLUSION

Fluoroscopic predictors of RV perforation associated with RV lead can be easily determined during implantation. Identification of these predictors may prevent the sequelae of RV perforation associated with active-fixation leads.

Detecting deceased patients on cardiac device remote monitoring: A case series and management guide for cardiac device services

BACKGROUND

Remote monitoring (RM) of implantable cardiac devices provides substantial and complex information, presenting new challenges such as detection of a patient's death.

OBJECTIVE

This study aims to describe RM transmissions indicating death and propose a management strategy for services.

METHODS

The study included consecutive ambulatory outpatients whose deaths were detected via RM. Clinical and device data were collected from electronic records, and ethical approval was obtained from the service's institutional review board.

RESULTS

Over a 9-year period (2014-2023), 28 patients were detected. The deceased patients had implantable cardioverter-defibrillators, pacemakers, and implantable loop recorders. In 54% of the cases, the patient's death had already been recognized. Alert transmissions indicating death were commonly related to ventricular arrhythmia events, but also due to lead measurements, and implantable loop recorder battery status. Several diagnostic features may indicate a patient's death. The most reliable was the presenting electrogram, demonstrating base rate pacing with no capture. Device diagnostics, lead parameters, and arrhythmia recordings may indicate death; however, not all cases present with recordings and diagnosis may not be conclusive. A majority (82%) had ventricular arrhythmia at the time of death. In cases where defibrillator shocks were delivered, the arrhythmia reinitiated shortly after successful cardioversion. Delayed therapy was observed, and some patients did not receive defibrillator shocks because of discriminators or because the arrhythmia rate fell below the shock zone.

CONCLUSION

Detecting a patient death via RM presents unique challenges and considerations for services. Standard operational policies and legal consultation should be established to address the implications.

Arrhythmias and Sudden Cardiac Death

Ventricular tachyarrhythmias remain a major cause of sudden cardiac arrest (SCA) that leads to sudden cardiac death (SCD). Primary prevention strategies to prevent SCD include promoting a healthy lifestyle, following United States Preventive Service Task Force recommendations related to cardiovascular disease, and controlling comorbid conditions. For a patient experiencing SCA, early cardiopulmonary resuscitation and defibrillation should be performed. Implantable cardioverter defibrillators are more effective at secondary prevention compared with drug therapy but medications such as amiodarone, beta-blockers, and sotalol may be helpful adjuncts to reduce the risk of SCD or improve a patient's symptoms (eg, palpitations and inappropriate defibrillator shocks).

Trends in cardiac implantable electronic device utilization in adults with congenital heart disease: a US nationwide analysis

BACKGROUND

Adults with congenital heart disease (ACHD) have increased risk of arrhythmias warranting implantation of cardiac implantable electronic devices (CIEDs), which may parallel the observed increase in survival of ACHD patients over the past few decades. We sought to characterize the trends and outcomes of CIED implantation in the inpatient ACHD population across US from 2005 to 2019.

METHODS

A retrospective analysis of the Nationwide Inpatient Sample (NIS) identified 1,599,519 unique inpatient ACHD admissions (stratified as simple (85.1%), moderate (11.5%), and complex (3.4%)) using the International Classification of Diseases 9/10-CM codes. Hospitalizations for CIED implantation (pacemaker, ICD, CRT-p/CRT-d) were identified and the trends analyzed using regression analysis (2-tailed p < 0.05 was considered significant).

RESULTS

A significant decrease in the hospitalizations for CIED implantation across the study period [3.3 (2.9-3.8)% in 2005 vs 2.4 (2.1-2.6)% in 2019, p < 0.001] was observed across all types of devices and CHD severities. Pacemaker implantation increased with each age decade, whereas ICD implantation rates decreased over 70 years of age. Complex ACHD patients receiving CIED were younger with a lower prevalence of age-related comorbidities, however, had a greater prevalence of atrial/ventricular tachyarrhythmias and complete heart block. The observed inpatient mortality rate was 1.2%.

CONCLUSIONS

In a nationwide analysis, we report a significant decline in CIED implantation between 2005 and 2019 in ACHD patients. This may either be due to a greater proportion of hospitalizations resulting from other complications of ACHD or reflect a declining need for CIED due to advances in medical/surgical therapies. Future prospective studies are needed to elucidate this trend further.

The Importance of Nitric Oxide and Oxidative Stress in Atrial High-Rate Episodes in Patients with Cardiac Devices

OBJECTIVE

Atrial High Rate Episodes (AHRE) are subclinical atrial tachyarrhythmias detectable by cardiac implantable electronic devices (CIEDs). AHREs have been associated with an increased risk of developing atrial fibrillation (AF), thromboembolism, cardiovascular and cerebrovascular events, and mortality. Although recent studies have assessed the value of oxidative stress markers in patients with AF, the relationships between AHRE and oxidative stress markers, including nitric oxide, has not yet been elucidated. This study aims to investigate the relationship between these markers and AHRE.

METHOD

This prospective, cross-sectional study comprised 180 patients with CIEDs. The study population was divided into two groups based on the presence (n = 78) and absense (n = 102) of AHRE to analyze its association with biomarkers.

RESULTS

The AHRE (+) group was significantly older, had a higher prevalence of hypertension, higher NT-proBNP (508.8 ± 249 pg/mL vs. 415.3 ± 292.1; P = 0.037), MDA levels (20.9 ± 4.1 μmol/L vs. 19.1 ± 3.1 μmol/L; P = 0.006), and iNOS activity (1,935.9 ± 326.1 pg/mL vs. 1,677.4 ± 363.2 pg/mL; P < 0.001). Logistic regression analysis identified age, hypertension, MDA (odds ratio [OR]: 1.131, 95%CI: 1.009 - 1.268, P = 0.035), inducible nitric oxide synthase (iNOS) activity (OR = 1.002, 95% CI = 1.001 - 1.003, P < 0.001), and endothelial nitric oxide synthase (eNOS) activity (OR = 0.990, 95% CI = 0.986 - 0.984, P < 0.001) as independent predictors of AHRE.

CONCLUSION

The study findings indicated that plasma levels of NT-proBNP, MDA, nitric oxide, and the expression of iNOS and eNOS were significantly associated with AHRE. Moreover, elevated plasma MDA concentrations, increased iNOS activity, and decreased eNOS activity were identified as independent predictors of AHRE.

The BLISTER Score: A Novel, Externally Validated Tool for Predicting Cardiac Implantable Electronic Device Infections, and Its Cost-Utility Implications for Antimicrobial Envelope Use

BACKGROUND

Antimicrobial envelopes reduce the incidence of cardiac implantable electronic device infections, but their cost restricts routine use in the United Kingdom. Risk scoring could help to identify which patients would most benefit from this technology.

METHODS

A novel risk score (BLISTER [Blood results, Long procedure time, Immunosuppressed, Sixty years old (or younger), Type of procedure, Early re-intervention, Repeat procedure]) was derived from multivariate analysis of factors associated with cardiac implantable electronic device infection. Diagnostic utility was assessed against the existing PADIT score (Prior procedure, Age, Depressed renal function, Immunocompromised, Type of procedure) in both standard and high-risk external validation cohorts, and cost-utility models examined different BLISTER and PADIT score thresholds for TYRX (Medtronic; Minneapolis, MN) antimicrobial envelope allocation.

RESULTS

In a derivation cohort (n=7383), cardiac implantable electronic device infection occurred in 59 individuals within 12 months of a procedure (event rate, 0.8%). In addition to the PADIT score constituents, lead extraction (hazard ratio, 3.3 [95% CI, 1.9-6.1]; P<0.0001), C-reactive protein >50 mg/L (hazard ratio, 3.0 [95% CI, 1.4-6.4]; P=0.005), reintervention within 2 years (hazard ratio, 10.1 [95% CI, 5.6-17.9]; P<0.0001), and top-quartile procedure duration (hazard ratio, 2.6 [95% CI, 1.6-4.1]; P=0.001) were independent predictors of infection. The BLISTER score demonstrated superior discriminative performance versus PADIT in the standard risk (n=2854, event rate: 0.8%, area under the curve, 0.82 versus 0.71; P=0.001) and high-risk validation cohorts (n=1961, event rate: 2.0%, area under the curve, 0.77 versus 0.69; P=0.001), and in all patients (n=12 198, event rate: 1%, area under the curve, 0.8 versus 0.75, P=0.002). In decision-analytic modeling, the optimum scenario assigned antimicrobial envelopes to patients with BLISTER scores ≥6 (10.8%), delivering a significant reduction in infections (relative risk reduction, 30%; P=0.036) within the National Institute for Health and Care Excellence cost-utility thresholds (incremental cost-effectiveness ratio, £18 446).

CONCLUSIONS

The BLISTER score (https://qxmd.com/calculate/calculator_876/the-blister-score-for-cied-infection) was a valid predictor of cardiac implantable electronic device infection, and could facilitate cost-effective antimicrobial envelope allocation to high-risk patients.

Prognosis of pacing-dependent patients with cardiovascular implantable electronic devices

BACKGROUND

Data on the prognostic significance of pacing dependency in patients with cardiovascular implantable electronic devices (CIEDs) are sparse.

METHODS

The prognostic significance of pacing dependency defined as absence of an intrinsic rhythm ≥ 30 bpm was determined in 786 patients with CIEDs at the authors' institution using univariate and multivariate regression analysis to identify predictors of all-cause mortality.

RESULTS

During 49 months median follow-up, death occurred in 63 of 130 patients with pacing dependency compared to 241 of 656 patients without pacing dependency (48% versus 37%, hazard ratio [HR] 1.34; 95% confidence interval [CI]: 1.02-1.78, P = 0.04). Using multivariate regression analysis, predictors of all-cause mortality included age (HR 1.07; 95% CI: 1.05-1.08, P < 0.01), history of atrial fibrillation (HR 1.32, 95% CI: 1.03-1.69, P < 0.01), chronic kidney disease (HR 1.28; 95% CI: 1.00-1.63, P = 0.048) and New York Heart Association (NYHA) class ≥ III (HR 2.00; 95% CI: 1.52-2.62, P < 0.01), but not pacing dependency (HR 1.15; 95% CI: 0.86-1.54, P = 0.35).

CONCLUSIONS

In contrast to age, atrial fibrillation, chronic kidney disease and heart failure severity as indexed by NYHA functional class III or IV, pacing dependency does not appear to be an independent predictor of all-cause mortality in patients with CIEDs.

Outcomes Following Implantable Cardioverter-Defibrillator Insertion in Patients 80 Years of Age or Older: A Statewide Population Cohort Study

BACKGROUND

Patients ≥ 80 years of age are underrepresented in major implantable cardioverter-defibrillator (ICD) trials, and real-world data are lacking. In this study, we sought to assess ICD utilisation, outcomes, and their predictors, in an unselected statewide population including patients ≥ 80 years old.

METHODS

We extracted details of ICDs implanted from 2009 to 2018 in New South Wales (NSW), Australia from the Centre for Health Record Linkage administrative data sets. Analysis was stratified into age groups of < 60 years, 60-79 years, and ≥ 80 years.

RESULTS

A total of 9304 patients (mean age 66.1 ± 13.1 years; 12.1% ≥ 80 years) had de novo ICD placement at an average rate of 1163 ± 122 patients per annum, with more implants in men in all age groups. After adjusting for NSW population size by sex, age group, and calendar year, mean implantation rates were 5.5 ± 0.6, 63.2 ± 8.6, and 52.7 ± 10.8 per 100,000 persons per annum in patients aged < 60 years, 60-79 years, and ≥ 80 years, respectively. In-hospital mortality was 0.4% and did not differ among age groups. However, 1-year mortality was 2.1%, 5.9%, and 10.7%, in those < 60 years, 60-79 years, and ≥ 80 years of age, respectively (P < 0.001), with hazard ratios for those aged ≥ 80 years of 4.3 (95% confidence interval [CI] 3.1-6.0) and those aged 60-79 years of 2.6 (95% CI 1.9-3.5) relative to those aged < 60 years (both P < 0.001) after adjusting for ICD indications, sex, implantation year, referral source, and comorbidities. In those aged ≥ 80 years, age > 83 years, congestive cardiac failure, chronic renal failure, neurodegenerative disease, and a higher Charlson comorbidity index score were each independent predictors of 1-year mortality.

CONCLUSIONS

ICD use in patients aged ≥ 80 years and 60-79 years was 10-fold that in patients aged < 60 years, and perioperative outcomes were good in all ages, but there was substantially increased 1-year mortality in those aged ≥ 80 years. Careful selection based on age and comorbidity may further reduce 1-year mortality in patients ≥ 80 years old receiving ICDs.

Current perspectives of sudden cardiac death management in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disorder characterized by left ventricular hypertrophy. Sudden cardiac death (SCD) is a rare but the most catastrophic complication in patients with HCM. Implantable cardioverter-defibrillators (ICDs) are widely recognized as effective preventive measures for SCD. Individualized risk stratification and early intervention in HCM can significantly improve patient prognosis. In this study, we review the latest findings regarding pathogenesis, risk stratification, and prevention of SCD in HCM patients, highlighting the clinic practice of cardiovascular magnetic resonance imaging for SCD management.

Caudal fluoroscopic guidance for the insertion of transvenous pacing leads

BACKGROUND

Pneumothorax is a well-recognized complication of cardiac implantable electronic device (CIED) insertion. While AP fluoroscopy alone is the most commonly imaging technique for subclavian or axillary access, caudal fluoroscopy (angle 40°) is routinely used at our institution. The caudal view provides additional separation of the first rib and clavicle and may reduce the risk of pneumothorax. We assessed outcomes at our institution of AP and caudal fluoroscopic guided pacing lead insertion.

METHODS

Retrospective cohort study of consecutive patients undergoing transvenous lead insertion for pacemakers, defibrillators, and cardiac resynchronization therapy devices between 2011 and 2023. Both de novo and lead replacement/upgrade procedures were included. Data were extracted from operative, radiology, and discharge reports. All patients underwent postprocedure chest radiography.

RESULTS

Three thousand two hundred fifty-two patients underwent insertion of pacing leads between February 2011 and March 2023. Mean age was 71.1 years (range 16-102) and 66.7% were male. Most (n = 2536; 78.0%) procedures used caudal guidance to obtain venous access, while 716 (22.0%) procedures used AP guidance alone. Pneumothoraxes occurred in five (0.2%) patients in the caudal group and five (0.7%) patients in the AP group (p = .03). Subclavian contrast venography was performed less frequently in the caudal group (26.2% vs. 42.7%, p < .01).

CONCLUSION

Caudal fluoroscopy for axillary/subclavian access is associated with a lower rate of pneumothorax and contrast venography compared with an AP approach.

Managing ventricular arrhythmias and implantable cardiac defibrillator shocks after left ventricular assist device implantation

Continuous flow left ventricular assist devices (CF-LVADs) have been shown to reduce mortality and morbidity in patients with advanced heart failure with reduced ejection fraction. However, ventricular arrhythmias (VA) are common, are mostly secondary to underlying myocardial scar, and have a higher incidence in patients with pre-LVAD VA. Sustained VA is well tolerated in the LVAD patient but can result in implantable defibrillator (ICD) shocks, right ventricular failure, hospitalizations, and reduced quality of life. There is limited data regarding best practices for the medical management of VA as well as the role for procedural interventions in patients with uncontrolled VA and/or ICD shocks. Vast majority of CF-LVAD patients have a preexisting cardiovascular implantable electronic device (CIED) and ICD and/or cardiac resynchronization therapies are continued in many. Several questions, however, remain regarding the efficacy of ICD and CRT following CF-LVAD. Moreover, optimal CIED programming after CF-LVAD implantation. Therefore, the primary objective of this review article is to provide the most up-to-date evidence and to provide guidance on the clinical significance, pathogenesis, predictors, and management strategies for VA and ICD therapies in the CF-LVAD population. We also discuss knowledge gaps as well as areas for future research.

Clinical Trajectories and Long-Term Outcomes of Alcoholic Versus Other Forms of Dilated Cardiomyopathy

BACKGROUND

Alcoholic cardiomyopathy (ACM) is a form of dilated cardiomyopathy (DCM) occurring secondary to long-standing heavy alcohol use and is associated with poor outcomes, but the cause-specific risks are insufficiently understood.

METHOD

Between 1997 and 2018, we identified all patients with a first diagnosis of ACM or DCM. The cumulative incidence of different causes of hospitalisation and mortality in the two groups was calculated using the Fine-Gray and Kaplan-Meier methods.

RESULTS

A Total of 1,237 patients with ACM (mean age 56.3±10.1 years, 89% men) and 17,211 individuals with DCM (mean age 63.6±13.8 years, 71% men) were identified. Diabetes (10% vs 15%), hypertension (22% vs 31%), and stroke (8% vs 10%) were less common in ACM than DCM, whereas obstructive lung disease (15% vs 12%) and liver disease (17% vs 2%) were more prevalent (p<0.05). Cumulative 5-year mortality was 49% in ACM vs 33% in DCM, p<0.0001, multivariable adjusted hazards ratio 2.11 (95% confidence interval 1.97-2.26). The distribution of causes of death was similar in ACM and DCM, with the predominance of cardiovascular causes in both groups (42% in ACM vs 44% in DCM). 5-year cumulative incidence of heart failure hospitalisations (48% vs 54%) and any somatic cause (59% vs 65%) were also similar in ACM vs DCM. At 1 year, the use of beta blockers (55% vs 80%) and implantable cardioverter defibrillators (3% vs 14%) were significantly less often used in ACM vs DCM.

CONCLUSIONS

Patients with ACM had similar cardiovascular risks and hospitalisation patterns as other forms of DCM, but lower use of guideline-directed cardiovascular therapies and greater mortality.

[Whether to implant a defibrillator or not? The Possibility of Using the MADIT-ICD Benefit Score Calculator in Real Practice]

AIM

To study the predictive capabilities of the MADIT-ICD Benefit Score calculator in assessing the benefit of implantable cardioverter defibrillator (ICD) placement for the primary prevention of sudden cardiac death (SCD).

MATERIAL AND METHODS

This study included 388 patients with NYHA II-IV functional class chronic heart failure (CHF) with a left ventricular ejection fraction (LVEF) ≤35 % who underwent ICD placement for the primary prevention of SCD. Patients were followed up for two years to record the endpoints of first-time paroxysmal sustained ventricular tachyarrhythmia (VT) or non-arrhythmic death.

RESULTS

According to the results of calculation with the MADIT-ICD Benefit Score calculator, 276 (71 %) patients had a high risk of VT (score ≥7) and 150 (39 %) had a high risk of non-arrhythmic death (score ≥3). 336 (94%) patients would benefit from an ICD: 148 (38 %) with a high level of probability and 218 (56 %) with a medium level of probability. According to the incidence of endpoints, VT episodes predominated in the low-ICD benefit group (36%), while the high-ICD benefit group had a relatively high incidence of non-arrhythmic death (12%).

CONCLUSION

The results obtained for a cohort of Russian patients with CHF and reduced LVEF indicated that the use of the MADIT-ICD Benefit Score in routine clinical practice does not improve the stratification of SCD risk compared to the traditional approach to selecting patients with CHF for ICD based on the LVEF value.

Multilevel Venous Obstruction in Patients with Cardiac Implantable Electronic Devices

Background and Objectives: The nature of multilevel lead-related venous stenosis/occlusion (MLVSO) and its influence on transvenous lead extraction (TLE) as well as long-term survival remains poorly understood. Materials and Methods: A total of 3002 venograms obtained before a TLE were analyzed to identify the risk factors for MLVSO, as well as the procedure effectiveness and long-term survival. Results: An older patient age at the first system implantation (OR = 1.015; p < 0.001), the number of leads in the heart (OR = 1.556; p < 0.001), the placement of the coronary sinus (CS) lead (OR = 1.270; p = 0.027), leads on both sides of the chest (OR = 7.203; p < 0.001), and a previous device upgrade or downgrade with lead abandonment (OR = 2.298; p < 0.001) were the strongest predictors of MLVSO. Conclusions: The presence of MLVSO predisposes patients with cardiac implantable electronic devices (CIED) to the development of infectious complications. Patients with multiple narrowed veins are likely to undergo longer and more complex procedures with complications, and the rates of clinical and procedural success are lower in this group. Long-term survival after a TLE is similar in patients with MLVSO and those without venous obstruction. MLVSO probably better depicts the severity of global venous obstruction than the degree of vein narrowing at only one point.

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.

Risk of Appropriate Implantable Cardioverter-Defibrillator Therapies and Sudden Cardiac Death in Patients With Heart Failure With Improved Left Ventricular Ejection Fraction

BACKGROUND

The benefit of implantable cardioverter-defibrillator (ICD) therapy is controversial in patients who have heart failure with improved left ventricular ejection fraction (EF) to >35% after implantation (HFimpEF).

METHODS

Databases (Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar) were queried for studies in patients with ICD that reported the association between HFimpEF and arrhythmic events (AEs), defined as the combined incidence of ventricular arrhythmias, appropriate ICD intervention, and sudden cardiac death (primary composite end point).

RESULTS

A total of 41 studies and 38,572 patients (11,135 with HFimpEF, 27,437 with persistent EF ≤35%) were included; mean follow-up was 43 months. HFimpEF was associated with decreased AEs (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.32 to 0.47; annual rate [AR] 4.1% vs 8%, p <0.01). Super-responders (EF ≥50%) had less risk of AEs than did patients with more modest reverse remodeling (EF >35% and <50%, OR 0.25, 95% CI 0.14 to 0.46, AR 2.7% vs 6.2%, p <0.01). Patients with HFimpEF who had an initial primary-prevention indication had less risk of AEs (OR 0.43, 95% CI 0.3 to 0.61, AR 5.1% vs 10.3%, p <0.01). Among patients with primary prevention who had never received appropriate ICD therapy at the time of generator change, HFimpEF was associated with decreased subsequent AEs (OR 0.26, 95% CI 0.12 to 0.59, AR 1.6% vs 4.8%, p <0.01). In conclusion, HFimpEF is associated with reduced, but not eliminated, risk for AEs in patients with ICDs. The decision to replace an ICD in subgroups at less risk should incorporate shared decision making based on risks for subsequent AEs and procedural complications.

Estimated Glomerular Filtration Rate and Implantable Cardioverter-Defibrillator in Nonischemic Systolic Heart Failure: Extended Follow-Up of DANISH

BACKGROUND

Patients with heart failure and chronic kidney disease (CKD) may have an increased risk of death from causes competing with arrhythmic death, which could have implications for the efficacy of implantable cardioverter-defibrillators (ICDs). We examined the long-term effects of primary prophylactic ICD implantation, compared with usual care, according to baseline CKD status in an extended follow-up study of DANISH (Danish Study to Assess the Efficacy of ICDs in Patients With Nonischemic Systolic Heart Failure on Mortality).

METHODS AND RESULTS

In the DANISH trial, 1116 patients with nonischemic heart failure with reduced ejection fraction were randomized to receive an ICD (N=556) or usual care (N=550). Outcomes were analyzed according to CKD status (estimated glomerular filtration rate ≥/<60 mL/min per 1.73 m2) at baseline. In total, 1113 patients had an available estimated glomerular filtration rate measurement at baseline (median estimated glomerular filtration rate 73 mL/min per 1.73 m2), and 316 (28%) had CKD. During a median follow-up of 9.5 years, ICD implantation, compared with usual care, did not reduce the rate of all-cause mortality (no CKD, HR, 0.82 [95% CI, 0.64-1.04]; CKD, HR, 1.02 [95% CI, 0.75-1.38]; Pinteraction=0.31) or cardiovascular death (no CKD, HR, 0.77 [95% CI, 0.58-1.03]; CKD, HR, 1.05 [95% CI, 0.73-1.51]; Pinteraction=0.20), irrespective of baseline CKD status. Similarly, baseline CKD status did not modify the beneficial effects of ICD implantation on sudden cardiovascular death (no CKD, HR, 0.57 [95% CI, 0.32-1.00]; CKD, HR, 0.65 [95% CI, 0.34-1.24]; Pinteraction=0.70).

CONCLUSIONS

ICD implantation, compared with usual care, did not reduce the overall mortality rate, but it did reduce the rate of sudden cardiovascular death, regardless of baseline kidney function in patients with nonischemic heart failure with reduced ejection fraction.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00542945.

Metabolomics Profiling Predicts Ventricular Arrhythmia in Patients with an Implantable Cardioverter Defibrillator

Implantable cardioverter defibrillators (ICDs) reduce sudden cardiac death (SCD) when patients experience life-threatening ventricular arrhythmias (LTVA). However, current strategies determining ICD patient selection and risk stratification are inefficient. We used metabolomics to assess whether dysregulated metabolites are associated with LTVA and identify potential biomarkers. Baseline plasma samples were collected from 72 patients receiving ICDs. Over a median follow-up of 524.0 days (range 239.0-705.5), LTVA occurred in 23 (31.9%) patients (22 effective ICD treatments and 1 SCD). After confounding risk factors adjustment for age, smoking, secondary prevention, and creatine kinase MB, 23 metabolites were significantly associated with LTVA. Pathway analysis revealed LTVA associations with disrupted metabolism of glycine, serine, threonine, and branched chain amino acids. Pathway enrichment analysis identified a panel of 6 metabolites that potentially predicted LTVA, with an area under the receiver operating characteristic curve of 0.8. Future studies are necessary on biological mechanisms and potential clinical use.