Transvenous ICD Research Articles

B-PO02-217 NOVEL SOLUTION TO THE MIGRATION OF A TRANSVENOUS ICD PULSE GENERATOR

Migration of a submammary transvenous ICD (TV-ICD) pulse generator is an uncommon event that can be exacerbated by the presence of a saline breast implant, and can impact defibrillation threshold (DFT). Device relocation may become necessary. To describe the successful relocation of a submammary TV-ICD to a mid-axillary pocket of a prior subcutaneous ICD (S-ICD), in a patient whose device migrated anterior to a saline breast implant resulting in an acute change in shock impedance. N/A A 38-year-old female with a history of bi-lateral saline breast implants (2000) and malignant mitral valve prolapse with PVC-induced ventricular fibrillation underwent a secondary-prevention S-ICD implant, which was eventually removed for inappropriate shocks. A single-chamber TV ICD was then implanted in a left-sided submammary position, underneath a saline breast implant. Four months after implant there was an acute rise in high-voltage (HV) impedance (> 110 ohms), corresponding to migration of the TV ICD generator anterior to the breast implant (Figure A and B). Patient declined re-location to the prior submammary position and a traditional pre-pectoral (infraclavicular) position (for aesthetic reasons). As such, the TV ICD pulse generator was repositioned to the mid-axillary position, previously used for the S-ICD implant (Figure C and D). DFT was successful (45 ohms) and HV impedance normalized and remained within normal range at follow-up (Figure E and F). Implantation of TV ICD pulse generator in the mid-axillary location can be considered for patients in whom submammary or infraclavicular positions are either not desired or not feasible.

Lead Abandonment and Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) Implantation in a Cohort of Patients With ICD Lead Malfunction.

Background: When an implantable-cardioverter defibrillator (ICD) lead becomes non-functional, a recommendation currently exists for either lead abandonment or removal. Lead abandonment and subcutaneous ICD (S-ICD) implantation may represent an additional option for patients who do not require pacing. The aim of this study was to investigate the outcomes of a strategy of lead abandonment and S-ICD implantation in the setting of lead malfunction.Methods: We analyzed all consecutive patients who underwent S-ICD implantation after abandonment of malfunctioning leads and compared their outcomes with those of patients who underwent extraction and subsequent reimplantation of a single-chamber transvenous ICD (T-ICD).Results: Forty-three patients underwent S-ICD implantation after abandonment of malfunctioning leads, while 62 patients underwent extraction and subsequent reimplantation of a new T-ICD. The two groups were comparable. In the extraction group, no major complications occurred during extraction, while the procedure failed and an S-ICD was implanted in 4 patients. During a median follow-up of 21 months, 3 major complications or deaths occurred in the S-ICD group and 11 in the T-ICD group (HR 1.07; 95% CI 0.29–3.94; P = 0.912). Minor complications were 4 in the S-ICD group and 5 in the T-ICD group (HR 2.13; 95% CI 0.49–9.24; P = 0.238).Conclusions: In the event of ICD lead malfunction, extraction avoids the potential long-term risks of abandoned leads. Nonetheless the strategy of lead abandonment and S-ICD implantation was feasible and safe, with no significant increase in adverse outcomes, and may represent an option in selected clinical settings. Further studies are needed to fully understand the potential risks of lead abandonment.Clinical Trial Registration: URL: ClinicalTrials.gov Identifier: NCT02275637

B-AB10-01 INAPPROPRIATE SUBCUTANEOUS DEFIBRILLATOR SHOCKS IN A PATIENT WITH A STERNAL ABSCESS

Inappropriate shocks from a subcutaneous defibrillator (S-ICD) cause significant morbidity. We present a rare case of inappropriate S-ICD shocks due to oversensing in a patient with a sternal abscess. N/A A 29 year old female with a history of endocarditis requiring aortic and mitral valve replacement, tricuspid valve repair, and VT arrest underwent S-ICD implant one year ago. She presented with recurrent endocarditis and sepsis. During her hospital course, she had multiple ICD shocks, which were found to be inappropriate on device interrogation. Tachycardia therapies were disabled. S-ICD sensing configuration had been set to the secondary vector per the automatic programming algorithm. There was oversensing in secondary (tip to can) and alternate (tip to ring) sensing configurations (Figure 1A), but none in the primary (ring to can) sensing vector. A Chest CT scan revealed a fluid collection at the anterior sternum surrounding the S-ICD lead and osteomyelitis (Figure 1B, 1C). She developed complete heart block and underwent sternal debridement, valve surgery, and S-ICD explant. She subsequently received a transvenous bi-ventricular ICD after appropriate antimicrobial therapy. To our knowledge, this is the first reported case of a sternal abscess involving the distal parasternal sensing electrode of an S-ICD causing oversensing and leading to inappropriate shocks. Awareness of this risk, especially in post-sternotomy patients, is important in the management of S-ICD malfunction.

B-PO01-097 DO APPLE IPHONE 12 MAGSAFE MAGNETS TRIGGER MAGNET MODE IN CARDIAC DEVICES?

Cardiac devices (pacemaker and defibrillators) have a magnet sensitive switch. Magnet application on a pacemaker generally causes an asynchronous pacing mode. Magnet application on a defibrillator temporarily suspends all anti-tachycardia therapies. Suspending anti-tachycardia therapies on a defibrillator can result in inhibition of potential life-saving therapies. The new Apple iPhone 12 line contain new magnets as part of their MagSafe charging system. Apple has recently released a warning for their iPhone 12 series and MagSafe accessories to keep a safe distance of more than 6 inches away from cardiac devices. This study aims to study the safety of Apple iPhone 12 with MagSafe near cardiac devices and to see how often then may trigger magnet mode. During clinic device checks or in hospital new cardiac device implant or generator changes, an Apple iPhone 12 with MagSafe cover will be used to see if magnet mode can be triggered on the cardiac device. Three sites were tested (<6 inches), holding the phone near the mouth, near the ear on the cardiac device implanting side and physically on top of the device. Magnet mode was first confirmed by using a standard medical grade device magnet while connected to an ECG or device interrogator. The Apple iPhone 12 with MagSafe cover was tested at 3 different sites to see if magnet mode could be triggered. The Apple iPhone 12 was tested on 30 devices for a total of 90 different positions. Manufacturer breakdown was 18 from Abbott, 10 from Medtronic and 2 from Boston Scientific. Device type breakdown was 20 pacemakers, 10 transvenous ICD and 1 SubQ ICD. Magnet response occurred in 0/30 near mouth position, 0/30 ear position and 3/30 over the device position. The 3 magnet responses were on Abbott pacemakers. One magnet response was easy to induce on an older generation of Abbott CRT pacemaker before generator change. The other 2 magnet responses were on current generation of Abbott pacemakers but was very positional. Apple iPhone 12 with MagSafe can be safely used with cardiac devices in normal phone use. Even with extreme close contact, only 10% of the time we were able to elicit magnet response. On current generation of devices, it was very positional to elicit magnet response.

B-PO02-063 ELECTROGRAM R-WAVE AMPLITUDE FOR DIFFERENT SENSING VECTORS ACROSS DIFFERENT POSTURES FOR PATIENTS WITH AN EXTRAVASCULAR IMPLANTABLE CARDIOVERTER DEFIBRILLATOR

The extravascular (EV) ICD lead is in the substernal space. The amplitude of the sensed R-wave is less than that of transvenous ICDs. Because the lead does not move with the heart, R-wave amplitude may vary with posture. To characterize postural and temporal R-wave amplitude variability from near-field (Ring1-Ring2) and far-field (Ring1-Can) sensing vectors using data from the EV ICD clinical, pilot study. We studied 17 patients with scheduled follow-up at pre-hospital discharge, 2, 6, and 12 weeks. Unfiltered sinus rhythm R waves for Ring1-Ring2 and Ring1-Can vectors were recorded with each patient in 7 postures: supine, lying on right and left sides, prone, sitting, bending over and standing. R-wave amplitude was measured across time, posture and vector. The mean and standard deviation across patients was calculated for each posture, follow-up time, and vector. The Figure plots R-wave amplitude. The averaged R-wave amplitude was 1.86±0.93mV for Ring1-Ring2, 2.22±1.33mV for Ring1-Can. It was marginally greater for Ring1-Can than Ring1-Ring2 (p=0.076). Neither changed significantly over time (p=0.33). Posture-related changes were significant for sitting versus standing on Ring1-Can (p=0.002) and for bending over versus lying on left for Ring1-Ring2 (p=0.031). In clinical follow-up of 354 patient-months, decreases in R-wave amplitude caused transient oversensing but no inappropriate therapies. For both EV ICD sensing vectors, R-wave amplitude is stable over the first 12 weeks. Despite minor postural changes, R-wave amplitude variability did not cause inappropriate therapy.

Utilization of Subcutaneous Cardioverter-Defibrillator in Poland and Europe-Comparison of the Results of Multi-Center Registries.

The implantation of a subcutaneous cardioverter-defibrillator (S-ICD) may be used instead of a traditional transvenous system to prevent sudden cardiac death. Our aim was to compare the characteristics of S-ICD patients from the multi-center registry of S-ICD implantations in Poland with the published results of the European Snapshot Survey on S-ICD Implantation (ESSS-SICDI). We compared data of 137 Polish S-ICD patients with 68 patients from the ESSS-SICDI registry. The groups did not differ significantly in terms of sex, prevalence of ischemic cardiomyopathy, concomitant diseases, and the rate of primary prevention indication. Polish patients had more advanced heart failure (New York Heart Association (NYHA) class III: 11.7% vs. 2.9%, NYHA II: 48.9% vs. 29.4%, NYHA I: 39.4% vs. 67.7%, p < 0.05 each). Young age (75.9% vs. 50%, p < 0.05) and no vascular access (7.3% vs. 0%, p < 0.05) were more often indications for S-ICD. The percentage of patients after transvenous system removal due to infections was significantly higher in the Polish group (11% vs. 1.5%, p < 0.05). In the European population, S-ICD was more frequently chosen because of patients’ active lifestyle and patients’ preference (both 10.3% vs. 0%, p < 0.05). Our analysis shows that in Poland, compared to other European countries, subcutaneous cardioverters-defibrillators are being implanted in patients at a more advanced stage of chronic heart failure. The most frequent reason for choosing a subcutaneous system instead of a transvenous ICD is the young age of a patient.

The Subcutaneous ICD: A Review of the UNTOUCHED and PRAETORIAN Trials.

The ICD is an important part of the treatment and prevention of sudden cardiac death in many high-risk populations. Traditional transvenous ICDs (TV-ICDs) are associated with certain short- and long- term risks. The subcutaneous ICD (S-ICD) was developed in order to avoid these risks and complications. However, this system is associated with its own set of limitations and complications. First, patient selection is important, as S-ICDs do not provide pacing therapy currently. Second, pre-procedural screening is important to minimise T wave and myopotential oversensing. Finally, until recently, the S-ICD was primarily used in younger patients with fewer co-morbidities and less structural heart disease, limiting the general applicability of the device. S-ICDs achieve excellent rates of arrhythmia conversion and have demonstrated noninferiority to TV-ICDs in terms of complication rates in real-world studies. The objective of this review is to discuss the latest literature, including the UNTOUCHED and PRAETORIAN trials, and to address the risk of inappropriate shocks.

Comparative Study between Subcutaneous and Endovascular Defibrillator Recipients Regarding Tolerance to the Implant Procedure and Perception of Quality of Life.

ResumoFundamentoO cardioversor-desfibrilador implantável subcutâneo (S-CDI) é uma alternativa segura ao sistema convencional do CDI transvenoso (TV-CDI) para evitar morte súbita.ObjetivoComparar o impacto do tipo de sistema de CDI e técnica cirúrgica na qualidade de vida dos pacientes, bem como a gravidade do desconforto e da dor, entre receptores de S-CDI e TV-CDI.MétodosPacientes consecutivamente implantados com um sistema S-CDI foram pareados com pacientes com um sistema TV-CDI. Além disso, foram incluídos os pacientes submetidos ao implante de S-CDI após a remoção de um TV-CDI, devido a complicações. Foram avaliadas a qualidade de vida (medida com o questionário de saúde de 12 itens) e a gravidade da dor e desconforto. Significância estatística foi definida como p < 0,05.ResultadosForam analisados 64 pacientes implantados com S-CDI ou TV-CDI sob anestesia local e sedação consciente. Pacientes com sistemas S-CDI e TV-CDI não diferiram significativamente nos escores de qualidade de vida. Os pacientes com S-CDI apresentaram maior nível de dor peri-operatória; nenhuma diferença foi encontrada em relação à gravidade da dor intra-operatória. A magnitude do desconforto estético e dos distúrbios do sono não diferiu entre os grupos.O S-CDI foi implantado em 7 pacientes adicionais após a remoção de um TV-CDI. Todos exceto um desses pacientes recomendaram o sistema S-CDI.ConclusõesO tipo de sistema de CDI e a técnica cirúrgica têm impacto insignificante na qualidade de vida dos pacientes. Estes resultados sugerem que a sedação consciente, fornecida por uma equipe experiente de eletrofisiologia, pode ser considerada uma alternativa à anestesia geral para o manejo de pacientes submetidos ao implante de S-CDI.

Subcutaneous Versus Transvenous Implantable Defibrillator in Patients with Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiomyopathy. Implantable Cardioverter Defibrillator (ICD) is important for prevention of sudden cardiac death (SCD) in patients at high risk. In recent years the subcutaneous ICD (S-ICD) has emerged as a viable alternative to the transvenous ICD (TV-ICD). The S-ICD does not require intravascular access, but cannot provide antitachycardia pacing therapy (ATP). Objective: To assess the real world incidence of ICD therapy in patients with HCM implanted with TV-ICD versus S-ICD.Methods: We compared the incidence of ATP and shock therapies between all HCM patients with S-ICD and TV-ICD enrolled in the Boston Scientific ALTITUDE database. Cumulative Kaplan Meier incidence was used to compare therapy free survival and Cox proportional hazard ratios were calculated. We performed an unmatched as well as propensity match analysis. Results: We included 2462 patients with TV-ICD and 716 patients with S-ICD followed for an average of 1348 {plus minus} 989 days. Patients with HCM and TV-ICD had significantly higher rate of device therapy as compared to those with S-ICD (31.1 vs. 14.7 therapies /100 patient year; p<0.001), driven by a high incidence of ATP therapy in the TV-ICD group which accounted for more than 67% of therapies delivered. Shock incidence was similar between groups, both in the general and in the matched cohorts. Conclusions: Patients with HCM and S-ICD had significantly lower therapy rate than patients with TV-ICD without difference in shock therapy, suggesting potentially unnecessary ATP therapy. Empiric ATP programing in patients with HCM may be unbeneficial.

Long-Term clinical outcomes of subcutaneous implantable defibrillator therapy in patients with heart failure and reduced ejection fraction: a single center experience

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): P. JACON consultant: Boston Scientific France Introduction The implantable cardioverter defibrillator (ICD) is the most effective therapy for prevention of sudden cardiac death in high-risk patients with heart failure and reduced ejection fraction (HFrEF). The subcutaneous implantable cardioverter defibrillator (S-ICD) has been considered as a comparable and relatively safer alternative to transvenous ICD in patients (pts) without pacing indication. Purpose Our aim was to assess the clinical "real-life" outcomes of S-ICD in patients with HFrEF and primary or secondary prevention, over a long-term follow-up (FU) period after S-ICD implantation. Methods All pts with HFrEF (left ventricular ejection fraction ≤35%) implanted with a S-ICD and a FU above 6 months were included in a cross-sectional monocentric study. Pts were followed by remote monitoring. Results 88 pts were included (52 ± 12.8 years old, male 87.5%). Indications were: primary 92% and secondary 8% prevention (ischemic cardiopathy 46%; dilated 46%; hypertrophic 5%; congenital 2%; valvular 1%). The mean left ventricular ejection fraction was 27%. 9 pts had a previous transvenous ICD implanted, but required revision because of infection or lead defects. The mean FU period was 33 ± 18 months with a mortality rate of 10% (S-ICD-related death secondary to inappropriate (inap) shocks for one patient). 5 pts underwent S-ICD system extraction after a mean FU period of 30 ± 21 months. Reasons were infectious complication (1 pt), pacing indication (2 pts) and S-ICD lead dysfunction (2 pts). Extraction after heart transplant was performed in 4 pts. During FU, 18 pts (20.5%) experienced at least one therapy: 8 pts (9%) with appropriate (ap) (3.3% per year) and 11 pts (12%) with inap shocks (4.36% per year). A total number of 24 ap shocks have been observed (3 ± 4 ap shocks per patient, several shocks for 3 pts), the first shock occurred after a mean FU period of 24 ± 14 months. 2 pts were referred to VT ablation and no recurrence of events was observed after medical therapy modification for the other pts. For the 11 pts with inap shocks, time to the first event was 19 ± 20 months. Reasons were: supraventricular arrhythmias (18%), T wave (36%) and noise (54%) oversensing. There was 1.8 ± 1.6 shock per patient with several shocks for 4 pts. Among pts with inap shocks, 2 pts required S-ICD system extraction, 1 pt died, while reprogramming and medical therapy options were efficient in other pts. Conclusion In pts with HFrEF at high risk of sudden cardiac death, S-ICD has proven to be effective in treating ventricular arrhythmias. However, more investigations must be conducted to explain the real-life high rate of inappropriate therapies. Abstract Figure. Survival-free from therapies curve

Prognostic impact of subcutaneous implantable cardioverter-defibrillator appropriate and inappropriate shocks

Abstract Funding Acknowledgements Type of funding sources: None. Background Previous studies have shown an adverse prognosis for patients with transvenous implantable cardioverter-defibrillators (ICD) who receive both appropriate and inappropriate shocks. There is a paucity of data regarding the prognosis of inappropriate shocks in patients with a subcutaneous ICD (S-ICD). Purpose To assess and characterize S-ICD appropriate (AS) and inappropriate shocks (IAS) and their impact on mortality. Methods Single center observational registry of 162 consecutive patients who underwent S-ICD implantation for primary and secondary prevention between November 2009 and September 2020. Only follow-up data of at least 6 months was analysed to identify predictors of both IAS and AS and their mortality impact. Results A total of 144 patients were included in the analysis. Mean age was 42.2 ± 16.6 years and 75% of the patients were male. One hundred and four patients (72.2%) implanted the S-ICD in primary prevention. The most common etiology was ischemic cardiomyopathy (22.9%) followed by hypertrophic cardiomyopathy (18.8%) and dilated idiopathic cardiomyopathy (14.6%). During a mean follow-up of 42.3 ± 29.9 months a total of 48 patients (33.3%) experienced at least one S-ICD shock. Twenty-nine (20.1%) patients received AS due to VT/VF and 31 patients (21.5%) received IAS. Eighteen (58.1%) of the IAS were due to oversensing/noise/discrimination errors and the remaining due to supraventricular tachycardia. Overall, patients with AS (HR 4.93, 95% CI 1.58-15.36, p = 0.006) and higher number of total AS (HR 1.10, 95% CI 1.00-1.20, p = 0.044) were associated with higher mortality during follow-up. S-ICD IAS therapy did not affect overall mortality (HR 1.71, 95% CI 0.21-14.0, p = 0.616). Conclusions: In patients with S-ICD, those who receive AS, in contrast to IAS, seem to have a worse prognosis. Large scale studies are needed to confirm this hypothesis and to explain this findings. Abstract Figure. Survival curves for AS and IAS

Five year outcomes of the subcutaneous implantable cardioverter-defibrillator EFFORTLESS (evaluation of factors impacting clinical outcome and cost effectiveness of the S-ICD) registry

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Boston Scientific OnBehalf EFFORTLESS Registry Introduction Patients (pts) implanted with transvenous (TV) implantable cardioverter-defibrillator (ICD) experience complications (Cx) associated with TV leads and inappropriate shocks (IAS) for atrial fibrillation (AF) or other supraventricular tachycardias (SVT). The EFFORTLESS S-ICD Registry is a 5-year (yr) follow-up (f/u) study of pts implanted with the subcutaneous ICD (S-ICD). Purpose To report on the 5-yr outcomes of pts with a wide range of S-ICD indications implanted with early generation devices. Methods Pts were enrolled at 43 centers February 2011-December 2014. Kaplan-Meier Cx, appropriate shock (AS), and IAS rates are reported. Results 994 pts (495 retrospective) were enrolled in the EFFORTLESS study and 984 pts (28% female, 48 ± 17 yrs, BMI 27 ± 6 kg/m2, ejection fraction 43 ± 18%) underwent S-ICD implantation. Mean study f/u was 4.4 ± 1.6 yrs. The pt cohort had diverse etiologies: 31% ischemic heart disease, 19% non-ischemic cardiomyopathy, 11% hypertrophic cardiomyopathy, 17% channelopathies, and 20% of pts miscellaneous. Total system- and procedure-related Cx (table) were 9.4% at 5 yrs. AS and IAS rates at 5 yrs were 15.9% and 16.9%, respectively and the IAS rates for AF/SVT and t wave oversensing were 3.1% and 5.8%, respectively. More pts experienced Cx and IAS in the first yr than in yrs 2-5 altogether (8.7 vs 8.2%), the most common as a result of discomfort/erosion (38%), IAS (26%), system infection (9%), and premature battery depletion (9%). Of these late Cx, 74% were experienced by retrospective pts. Spontaneous conversion efficacy for the first shock and final shocks was 89.7% and 97.7%. Of the 91 (9.2%) deaths reported, none were associated with the S-ICD system or procedure. Cause of death was cardiac for 40 pts, non-cardiac for 40 pts, other for 4 pts, and unknown for 7 pts. Only 20 (2.0%) pts had their S-ICD replaced for a TV device for pacing: 4 bradycardia, 7 anti-tachycardia, and 9 for biventricular pacing. Conclusions The EFFORTLESS registry provides 5-year follow-up for a diverse, large, multinational S-ICD registry. Complications primarily occurred in the first year but remained low through 5 years. Inappropriate shock rates were typically observed in older generation devices prior to introduction of the SMART Pass filter. Replacement for TV-ICD due to the need for pacing was rare. Outcome 30 day 1 yr 2 yr 3 yr 4 yr 5yr Annual Complications (Kaplan-Meier) 2.0 5.3 6.8 7.6 8.6 9.4 1.9 IAS, overall (Kaplan-Meier) 1.7 8.7 11.6 13.1 14.6 16.9 3.4 IAS, t wave oversensing 3.4 5.8 1.2

Subcutaneous and single-chamber transvenous defibrillators: a nationwide matched control study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction / Background Subcutaneous implantable cardioverter–defibrillators (S-ICD) was designed to avoid complications of single-chamber transvenous implantable cardioverter-defibrillators (VVI ICD) by using an entirely extra-thoracic placement. Purpose Our objective was to compare outcomes following first VVI ICD or S-ICD implantation in an exhaustive nationwide matched cohort. Methods This French longitudinal cohort study was based on the national hospitalization database covering hospital care from for the entire population. All adults (age ≥18 years) hospitalized in French hospitals From January 1, 2010 to September 1, 2020, who underwent a VVI ICD or S-ICD implantation were included. Patients with a previous pacemaker or ICD or with a history of infective endocarditis were excluded. Multivariable analyses for clinical outcomes during the whole follow-up in the groups of interests were performed using a Cox model with all baseline characteristics and reporting hazard ratio. Owing to the non-randomized nature of the study, and considering for significant differences in baseline characteristics, propensity-score matching was also used to control for potential confounders of the treatment outcome relationship. Results 21,667 patients were included in the cohort, 19,493 patients had a transvenous VVI ICD and 2,174 had a subcutaneous ICD. Mean age was 61.2 ± 13.2 years in the VVI ICD group and 52.3 ± 17.5 years in the S-ICD goup. Coronary artery disease was present in 71.6% of patients with a VVI ICD and 48.2% of patients with a S-ICD. Mean follow-up was 28.8 ± 31.8 months. S-ICD patients had a significant higher rate of all-cause death (HR: 1.684, 95%CI: 1.309-2.165, p &amp;lt; 0.001). There were no significant differences in cardiovascular death (HR: 1.092, 95%CI: 0.697-1.711, p = 0.70) and infective endocarditis (HR: 0.354, 95%CI: 0.067-1.433, p = 0.15) between the two groups Using propensity score, 1,582 patients with VVI ICD were matched 1:1 with S-ICD patients. Mean follow-up was 4.5 ± 7.2 months. In the matched analysis, there were no significant differences in all-cause death (HR: 1.090, 95%CI: 0.728-1.633, p = 0.68) and cardiovascular death (HR: 1.167, 95%CI: 0.603-2.260, p = 0.65) between the two groups. A trend toward a lower risk of infective endocarditis in the S-ICD group was also observed without reaching significance (HR : 0.219, 95%CI: 0.047-1.017, p = 0.053). A sensitivity analysis in patients with coronary artery disease in the matched cohort was performed. Same trends were observed without significant differences in all-cause death and cardiovascular death. Conclusion Our nationwide study highlighted a higher risk of all-cause death in patients treated with subcutaneous which however was not statistically significant after propensity score matching. No differences regarding cardiovascular mortality was found. An interesting trend toward diminution of infective endocarditis was also observed without reaching significancy.

Long‐term incidence of upper extremity venous obstruction in implantable cardioverter defibrillator patients

Very little is known about the long-term prevalence of severe venous obstruction and occlusion in patients with transvenous implantable cardioverter-defibrillator leads. The objective of the current investigation was to elucidate the incidence and prevalence and to identify predisposing conditions in an ICD cohort over a long follow-up period. Based on a prospective database, we analyzed consecutive patients who received an ICD implantation in our hospital between 06/1988 and 2009 as well as all corresponding follow-up data until 02/2018. Cavographies were used for analysis, and all patients with at least one device replacement and one follow-up cavography were included. Over a mean follow-up period of 94 ± 50 months, severe venous obstruction was found in 147 (33%) of 448 patients. Kaplan-Meier analysis shows a severe obstruction or occlusion in 50% of patients after a period of 14.3 years. The total number of leads (p<.001, HR 2.01, CI 2.000-2.022), an advanced age (p=.004, HR 1.023 per year, CI 1.022-1.024) and the presence of dilated cardiomyopathy (p=.035, HR 1.49, CI 1.47-1.51) were predictive of venous obstruction whereas the presence of anticoagulation was not. Severe obstruction of the access veins after ICD implantation occurs frequently and its prevalence shows a nearly linear increase over long-time follow-up. Multiple leads, an advanced age and DCM as underlying disease are associated with an increased risk of venous obstruction while the role of anticoagulation to prevent venous obstruction in ICD patients is unclear.

Slow VT treatment in a contemporary population of primary prevention ICD recipients

Abstract Funding Acknowledgements Type of funding sources: None. Background Implantable cardioverter defibrillator (ICD) is an effective therapy for sudden cardiac death (SCD). 2015 HRS/EHRA/APHRS/SOLAECE expert consensus document suggests long VT detection, above 185 bpm, as optimal ICD programming to reduce unnecessary therapies in primary prevention (PP). Purpose The aim of our study is to evaluate incidence, safety and efficacy of ICD treatment for VT arrhythmias below 185 bpm, in a contemporary population of PP ICD recipients with long detection intervals (LDI), morphological discrimination algorithm and antitachycardia pacing therapies (ATP) before shock. Methods We conducted a single centre retrospective study enrolling 236 patients implanted with a primary-prevention indication from January 2013 to June 2019. Patients were implanted with single or dual chamber single-lead transvenous ICD. All patients had standard device setting with long (at least 20 s in VT and 7 s in VF) VT/VF detection above 150 bpm and therapies starting from 171 with up to 5 ATP and multiple shocks. PainFREE-like bursts and Schaumann-like ramps ATP were always set in VT zone. Of each patient we collected a detailed report of up to five appropriate events and three inappropriate events. Arrhythmia diagnosis was confirmed from 3 independent expert physicians. Date of the event, cycle length, type of morphology (polymorphic or monomorphic), therapies with their effect were collected. Results During a mean follow-up of 42 months, 47 (20 %) and 18 (8%) patients had at least one appropriate and inappropriate activation, respectively. The detailed-events analysis shows that 16 (7%) patients had 38 (30%) appropriate events with rate &amp;lt;188 bpm. At these rate ATP were 97% effective. 14 (38%) of inappropriate activations were caused by arrythmias with ventricular rate below 188 bpm and half of these received a shock; 30% of inappropriate shocks were due to arrhythmia with rate &amp;lt;188 bpm. 73% of treated events, with rate &amp;lt;188 bpm, were appropriate. Only 5.6% (n = 10) of ATP attempts cause arrhythmia acceleration. Conclusions One third of detected arrhythmias had a rate below 188 bpm and 73% were true VT. In this slow VT zone, ATP had a high success rate with low percentage of acceleration.

Subcutaneous implantable cardioverter defibrillator: Can it overtake its transvenous counterpart.

Over the past decade, the emergence of the subcutaneous implantable cardioverter defibrillator (S-ICD) has provided cardiologists with an option to provide both primary or secondary prevention treatment of sudden cardiac death (SCD) without the associated risks that come with the use of intracardiac leads. S-ICD may prove to be a useful option in those who are young, have thromboembolic risk, immunodeficiency states, unfavorable anatomy due to adult congenital heart disease (ACHD). This article reviews the existing literature to determine whether S-ICD can prove to be a safe alternative in comparison to Transvenous implantable cardioverter defibrillator (TV-ICD) and in which patient population should S-ICD be considered over TV-ICD.

Electromagnetic interference from left ventricular assist device in patients with transvenous implantable cardioverter-defibrillator.

Many advanced heart failure patients have both a left ventricular assist device (LVAD) and an implantable cardioverter-defibrillator (ICD). This study examines incidence, clinical impact, and management of LVAD-related EMI. We performed a three-center retrospective analysis of transvenous ICD implanted patients with LVAD implanted between January 1, 2005 and December 31, 2020. The primary outcome was EMI after LVAD implantation, categorized as LVAD-related noise or telemetry interference. The rate of LVAD-related EMI among the 737 patients (mean age 58.6 ± 12.8 years) studied was 5.0%. Telemetry interference (1.5%) compromised ICD interrogation in all patients. This was resolved successfully with use of a metal shield, encased wand, radiofrequency tower, different ICD programmer or by increasing distance between ICD programmer and LVAD (n=6). ICD replacement was required to reestablish successful communication in three patients. LVAD-related noise (3.5%) led to oversensing (n=4), inappropriate mode switches (n=4), noise reversion (n=3), inhibition of pacing (n=2), inappropriate detection as atrial fibrillation (AF) (n=2) and inappropriate detection as ventricular tachycardia (VT) and/or ventricular fibrillation (VF) (n=2). This noise interference persisted (n=3), resolved spontaneously (n=16), resolved with programming change (n=6) or required lead revision (n=1). EMI from LVAD impacts ICD function, although, the incidence rate is low. Physicians implanting both, LVAD in patients with ICD (more common) or ICD in patients with LVAD, should be aware of possible interferences. Telemetry failure not resolved by metal shielding was overcome by ICD generator replacement to a different manufacturer. In most cases, LVAD-related noise resolves spontaneously.

Rate and impact on patient outcome and healthcare utilization of complications requiring surgical revision: Subcutaneous versus transvenous implantable defibrillator therapy

Comparison data on management of device-related complications and their impact on patient outcome and healthcare utilization between subcutaneous implantable cardioverter-defibrillator (S-ICD) and transvenous ICD (TV-ICD) are lacking. We designed this prospective, multicentre, observational registry to compare the rate, nature, and impact of long-term device-related complications requiring surgical revision on patient outcome and healthcare utilization between patients undergoing S-ICD or TV-ICD implantation. A total of 1099 consecutive patients who underwent S-ICD or TV-ICD implantation were enrolled. Propensity matching for baseline characteristics yielded 169 matched pairs. Rate, nature, management, and impact on patient outcome of device-related complications were analyzed and compared between two groups. During a mean follow-up of 30 months, device-related complications requiring surgical revision were observed in 20 patients: 3 in S-ICD group (1.8%) and 17 in TV-ICD group (10.1%; p = .002). Compared with TV-ICD patients, S-ICD patients showed a significantly lower risk of lead-related complications (0% vs. 5.9%; p = .002) and a similar risk of pocket-related complications (0.6 vs. 2.4; p = .215) and device infection (0.6% vs. 1.2%; p = 1.000). Complications observed in S-ICD patients resulted in a significantly lower number of complications-related rehospitalizations (median 0 vs. 1; p = .013) and additional hospital treatment days (1.0 ± 1.0 vs. 6.5 ± 4.4 days; p = .048) compared with TV-ICD patients. Compared with TV-ICD, S-ICD is associated with a lower risk of complications, mainly due to a lower risk of lead-related complications. The management of S-ICD complications requires fewer and shorter rehospitalizations.

Device-related infection in de novo transvenous implantable cardioverter-defibrillator Medicare patients

Cardiac device infection is a serious complication of implantable cardioverter-defibrillator (ICD) placement and requires complete device removal with accompanying antimicrobial therapy for durable cure. Recent guidelines have highlighted the need to better identify patients at high risk of infection to assist in device selection. To estimate the prevalence of infection in de novo transvenous (TV) ICD implants and assess factors associated with infection risk in a Medicare population. A retrospective cohort study was conducted using 100% Medicare administrative and claims data to identify patients who underwent de novo TV-ICD implantation (July 2016-December 2017). Infection within 720 days of implantation was identified using ICD-10 codes. Baseline factors associated with infection were identified by univariable logistic regression analysis of all variables of interest, including conditions in Charlson and Elixhauser comorbidity indices, followed by stepwise selection criteria with a P ≤ .25 for inclusion in a multivariable model and a backwards, stepwise elimination process with P ≤ .1 to remain in the model. A time-to-event analysis was also conducted. Among 26,742 patients with de novo TV-ICD, 519 (1.9%) developed an infection within 720 days post implant. While more than half (54%) of infections occurred during the first 90 days, 16% of infections occurred after 365 days. Multivariable analysis revealed several significant predictors of infection: age <70 years, renal disease with dialysis, and complicated diabetes mellitus. The rate of de novo TV-ICD infection was 1.9%, and identified risk factors associated with infection may be useful in device selection.

Implantation of a subcutaneous implantable cardioverter-defibrillator in a patient with epicardial defibrillation patches

The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to provide an alternative to the transvenous implantable cardioverter-defibrillator (TV-ICD), because it is implanted without any transvenous or epicardial leads. Studies demonstrating the safety and effectiveness of the S-ICD have been published, indicating that it is a good alternative for a variety of patients eligible for a TV-ICD system.1 However, the implantation of an S-ICD in patients with epicardial defibrillation patches is not well documented and remains unclear. Herein, we describe the implantation of S-ICD in a patient with epicardial defibrillation patches and a conductor breakage in the ICD shock circuit.