Indication For ICD Implantation Research Articles

The effect of bachmann bundle pacing on diastolic function in patients with non-obstructive HCM

Abstract Background and Objective Patients with non-obstructive HCM (nHCM) have advanced diastolic dysfunction and atrial remodeling, leading to increased heart failure hospitalisations. The objective of this study was to evaluate the role of Bachmann bundle pacing (BBP) in diastolic filling compared to right atrial appendage pacing (RAAP). Methods Forty patients with symptomatic nHCM and normal LV function were prospectively enrolled from January 2021 to June 2023. Inclusion criteria included electrocardiographic evidence of inter-atrial delay, E/e’ > 15, and an indication for ICD implantation. BBP was attempted in twenty patients, others underwent RAAP. A Biotronik Selectra 3D 40-S sheath was used for BBP in patients in whom initial lead implantation was unsuccessful. BBP was defined based on P-wave morphology and fluoroscopic lead position. The RV lead was implanted in the RV apex in all patients and the AV delay was optimized based on diastolic filling period and E/e’. Devices were programmed in DDD mode. During follow up, diastolic function, functional capacity, atrial fibrillation, and heart failure hospitalisations were assessed in both groups. Results Among the forty patients (age 48.2+7.8 yrs, males 75%, ESC-SCD Risk 4.3+0.6%), the baseline P wave duration, E/A, E/e’ were 138.4+16.4 ms, 2.5+0.5, and 17.5+2.4, respectively. Six patients (15%) had a history of paroxysmal AF (3 each in BBP and RAAP groups). Of the 16 patients (80%) who underwent successful BBP, the Selectra 3D 40-S sheath was used in 8 patients (Figure 1, Panel A). During BBP, a bachmann bundle potential was recorded in 7 of 16 patients (43.8%) (Figure 1, Panel C). The pacing threshold (1.5+0.5@0.4ms vs. 0.9+0.3@0.4ms, p=0.026) was higher and the atrial sensing (1.8+0.4 vs. 3.3+0.6, p=0.002) was lower in the BBP group compared to the RAAP group at 4 weeks and 6 months of follow up. There was an acute rise in threshold (2.1@0.4 ms) in 1 BBP patient at 4 weeks of follow up. Patients in the BBP group had a reduction in P wave duration compared to the patients in the RAAP group (-22.5 + 5.4 vs. +5.6 + 3.2 ms, p<0.001). During follow up (11.4 + 3.4 months), there was a significant improvement in diastolic function (E/e’), functional capacity (NYHA Class) and reduction in NT-proBNP in the BBB group compared to the RAAP group (Figure 1). The percentage of atrial pacing was similar in both groups (BBP 73.2 + 7.8 vs. RAAP 78.5 + 9.1 %, p=0.219). The risk of atrial fibrillation/tachycardia (12.5% vs. 35.0%, p=0.022) and heart failure hospitalisations (6.3% vs. 20%, p=0.042) was lower in the BBP group compared with RAAP during follow up. Conclusions BBP is safe and effective in improving diastolic function, functional capacity and heart failure hospitalizations in patients with nHCM.BBP Pacing using Selectra 3D 40-S SheathChange in E/e', NYHA, and NT-pro BNP

Swiss national cardiac device registry: changing trends in pacemaker and ICD procedures over the last two decades

Abstract Background The Swiss National Device and Ablation Registry (SwissEPnet) provides a comprehensive database for cardiac pacemaker and ICD procedures. All Swiss centers performing device implantations are obliged to provide their data in this web-based platform. The purpose of this study was to provide an in-depth look at pacemaker and Implantable -defibrillator (ICD) statistics and changing trends over the course of the last 20 years. Methods and Results We analyzed the database of pacemaker and ICD procedures between January 1, 2003, and December 31, 2022. During the study period, a total of 124 458 pacemaker and cardiac resynchronization (CRT) procedures (mean age 77.7 years; 59.7% male) were performed in 73 centers while 29 133 ICDs and CRT-D procedures (mean age 63.63 years; 80.2 % male) were performed in 56 centers in Switzerland. While the number of pacemaker procedures doubled in 20 years and there has been a constant increase in the mean age of patients receiving a pacemaker, the number of ICD procedures has more than tripled and now plateaued with a mean age which remained stable over time. Throughout the study period, the main indications for de novo pacemaker implantations were AV block in 41.7% of patients, followed by sick sinus syndrome combined with tachy-bradycardia syndrome (29.6%) and atrial fibrillation (AF) with slow ventricular conduction (13.7%). The main indication for ICD implantation was primary preventive (66.7%). Since 2016 there has been a decline in primary preventive interventions. Fluoroscopy and procedure durations remained stable over time in pacemaker and ICD procedures. Newer technologies, such as leadless pacemakers and CRT procedures required more fluoroscopy time, but this has also decreased over time. While regular battery changes remained stable (80% in pacemakers, 68% in ICDs), the proportion of DDD and CRT upgrades has increased. The overall reintervention rate due to device-associated infections was 2.4% in pacemaker- and 2.8% in ICD procedures. Since 2013, there has been a steady increase in lead removals/extractions, which were performed mainly due to device-related infections, but also because of lead dysfunctions and worsening electrical parameters. Conclusions In the last 20 years, there was a pronounced increase in the number of pacemaker procedures and a marked increase in the number of ICD procedures which has plateaued now. In younger technologies there is decreasing trend in fluoroscopy time by stable procedure times. Overall, there is a constant increase in mean age of patients receiving a pacemaker, while the mean age of patients receiving an ICD did not change during follow up. Female patients are constantly younger and undergo ICD implantation significantly less often than men. Despite of a stable infection rate, there has been a significant increase in lead removal and extractions in Switzerland.

Detection of gene mutation in the prognosis of a patient with arrhythmogenic right ventricular cardiomyopathy: a case report

BackgroundArrhythmogenic right ventricular cardiomyopathy (ARVC), or more recently known as arrhythmogenic cardiomyopathy (ACM), is an heritable disorder of the myocardium characterized by progressive fibrofatty replacement the heart muscle and risk of ventricular arrhythmias and sudden cardiac death (SCD). We report a case study to demonstrate the role of gene mutation detection in risk stratification for primary prevention of SCD in a young patient diagnosed with ARVC.Case presentationA 15-year-old Asian (Vietnamese) male patient with no history of documented tachyarrhythmia or syncope and a family history of potential SCD was admitted due to palpitations. Clinical findings and work-up including cardiac magnetic resonance imaging (MRI) were highly suggestive of ARVC. Gene sequencing was performed for SCD risk stratification, during which PKP2 gene mutation was found. Based on the individualized risk stratification, an ICD was implanted for primary prevention of SCD. At 6 months post ICD implantation, the device detected and successfully delivered an appropriate shock to terminate an episode of potentially fatal ventricular arrhythmia. ICD implantation was therefore proven to be appropriate in this patient.ConclusionsWhile gene mutations are known to be an important factor in the diagnosis of ARVC according to the 2010 Task Force Criteria and recent clinical guidelines, their role in risk stratification of SCD remains controversial. Our case demonstrated that when used with other clinical factors and family history, this information could be helpful in identifying appropriate indication for ICD implantation.

P259 S–ICD OFFERS A POTENTIAL SYNERGISTIC THERAPY FOR HEART FAILURE PATIENTS WITH AN INDICATION FOR ICD IMPLANTATION AND CANDIDATES FOR CCM IMPLANTATION

Abstract CCM (cardiac contractility modulation) is a very promising therapy in heart failure patients as it allows, by increasing intracellular calcium handling, an improvement in cardiac contractility, ejection fraction, and patient quality of life. It delivers high–energy (7.5 V) and long–duration (about 20 milliseconds) pulses in absolute refractory period through the use of two leads on the right ventricular septum. It is indicated in patients with narrow QRS (< 130 msec) and ejection fraction between 25 and 45%. Therefore, a large proportion of patients suitable for CCM therapy also have an indication for ICD implantation. The coexistence of an ICD (single–chamber or dual–chamber) and CCM presupposes the presence of 3 leads in the right ventricle and possibly a catheter in the right atrium if a dual–chamber ICD is used. The presence of numerous leads increases the risk of infection, mechanical complications, and damage on the leads. In view of the above, the strategy we propose in patients with concomitant indication for ICD and CCM is the use of the subcutaneous defibrillator (S–ICD) in patients with potential indication for CCM, narrow QRS, no pacing indication, and ejection fraction <35%, thus limiting the number of leads and the risk of complications. In our center, we have started using this strategy with excellent clinical results and in the absence of complications. One of the cases treated with this strategy is a 60–year–old patient with nonischemic dilated myocardiopathy, ejection fraction 34%, QRS < 130 msec, NYHA class III, despite therapy with beta blockers, ARNI, SGLT2–i, MRA at the maximum dose. The patient, also considering the potential future need for CCM implantation, underwent S–ICD implantation. After 3 months, NYHA class III with reduced quality of life persisted (MLHFQ 82). Therefore, the patient successfully underwent CCM implantation, with marked improvement in symptoms (MLHFQ 71) and ejection fraction (43%) 3 months later. This strategy avoided the placement of additional leads in the right ventricle while ensuring protection from potentially fatal arrhythmias and improvement in contractile function and symptoms. We suggest the use of the subcutaneous defibrillator (S–ICD) in all patients in whom there might be an indication for the use of CCM and no need for pacing, ensuring maximum efficacy and reducing the risk of infection and leads related complications.

P119 WHEN THE ELECTROCARDIOGRAM CHANGES YOUR DIAGNOSIS

Abstract Sarcomeric hypertrophic cardiomyopathy is among the most common genetic cardiovascular diseases.Clinical,electrocardiographic and echocardiographic evaluation plays a crucial role in the diagnosis and initial framing of the hypertrophic phenotype. A 51–year–old Caucasian man with multiple myeloma,previous autologous transplant,undergoing chemotherapy for disease recurrence,without cardiovascular risk factors or family history of MCV or MCI came to our outpatient clinic for a follow–up visit.At another center,cardiac amyloidosis was diagnosed due to the echocardiogram finding of concentric left ventricular hypertrophy. Patient asymptomatic for angor,NYHAI dyspnea,heart palpitation,syncope,presented with rhythmic cardiac action,2/6 systolic murmur at centrum and tip,no central or peripheral stasis.On ecg sinus bradycardia at fc57 bpm,PR202 msec,high QRS V4–V6 voltages with negative T waves in infero–lateral site,suggestive for left ventricular hypertrophy. On echocardiogram:concentric left ventricular hypertrophy with posterolateral papillary hypertrophy,preserved contractile function,FE 62%,grade I diastolic dysfunction,no signs of elevated filling pressures,left atrium and right ventricle in normal range;tripartite aortic valve in absence of gradients,prolapse of the LAM(A1–A2)with mild grade insufficiency,mild tricuspid insufficiency. At cardiac MRI:non–dilated left ventricle with concentric hypertrophy,maximum thickness 16mm at basal SIV level,apical inferior wall,15mm anterior wall,anterolateral media,apex systolic obliteration 14mm,FE 64%.Right ventricle and atria in normal.T2–STIR sequences tenuous hyperintensity at infero–lateral media wall,inferior apical wall and lateral,increased T2 mapping in relation to myocardial edema. Subendocardial LGE of middle infero–lateral,apical lateral and postero–medial papillary wall,slight increase in native T1 mapping,ECV 27%,picture of sarcomeric hypertrophic heart disease.Holter ecg showed no arrhythmias;at HCM score low risk,no indication for ICD implantation. The patient was undergoing genetic screening test for HCM.The presence of left ventricular hypertrophy may mimic different forms of hypertrophic cardiomyopathy,leading to misdiagnosis or delayed diagnosis.Differential diagnosis,ecg and specific use of imaging tests are of paramount importance.

198 ROLE OF CARDIAC MAGNETIC RESONANCE IMAGING IN ARRHYTMICH RISK STRATIFICATION

Abstract Introduction Danon disease (DD) is a rare multi-systemic disorder firstly described by Danon et al. in 1981 and characterized by a triad consisting with hypertrophic cardiomyopathy, skeletal myopathy, and intellectual disability. It is an inherited dominant X-linked condition, due to mutations in the lysosome-associated membrane protein 2 (LAMP2) gene. Typically, males present a more severe phenotype with earlier onset and rapid heart failure progression with extracardiac manifestations; female patients manifest a milder phenotype with later onset and isolated cardiac involvement. Female carriers may develop dilated cardiomyopathy (DCM). In recent years, it has been described a severe arrhythmogenic phenotype, particularly in women, with a high risk of sudden cardiac death (SCD). Case presentation Case 1 is a 16 y.o. woman referred to our outpatient cardiomyopathies clinic, diagnosed with left ventricle (LV) hypertrophy on the basis of ECG and echocardiography, performed in 2016, in view of cutaneous nevus surgical exeresis. At echocardiographic evaluation we found an asymmetric LV hypertrophy with preserved LV ejection fraction (LVEF 65%). A cMRI was performed, showing mild LV thickening and left ventricular hypertrabeculation morphology, mainly in the LV lateral wall, but not all criteria for LV noncompaction (NC) were satisfied. There was no late gadolinium enhancement (LGE) accumulation. She underwent a genetic screening with inconclusive results, so we started a clinical outpatient follow-up showing no significant arrhythmias at ECG Holter and no limitation of physical activities. In 2021, when she was 21 yo, her father died suddenly and no autoptic examination was performed. A genetic exam was repeated, highlighting a LAMP2 gene mutation. In 2016 her 3 years older sister, Case 2, underwent a familiar screening. She had a long history of mild dyspnea occurring during exertion. Echocardiography showed asymmetric hypertrophy with marked thickening of infero-lateral wall (25 mm,) with normal systolic function (EF 70%). She underwent a cMRI, highlighting diffuse asymmetric hypertrophy (max 24 mm) with LGE in lateral wall and lower septum. First genetic test was nonconclusive but after her father's death another test was performed, demonstrating LAMP2 gene mutation. In 2021 a follow-up cMRI showed markedly reduced myocardial thickness of the apex, with a pattern of noncompaction myocardial. We found a LVEF at lower limits, depressed longitudinal function (MAPSE 8 mm) and manly severe progression of fibrotic degeneration. ECG Holter revealed premature ventricular complex, in absence of nonsustained ventricular tachycardia. Following the evolution of fibrosis, cardioverter defibrillator (ICD) implantation was performed. Case 1 was clinically stable during strict follow-up. Conclusion Cardiac magnetic resonance imaging (cMRI) may be useful in arrhythmic risk stratification, accurate systolic dysfunction evaluation, and proper timing and indication for ICD implantation.

Usefulness of the MADIT-ICD Benefit Score in a Large Mixed Patient Cohort of Primary Prevention of Sudden Cardiac Death.

Background: Decision-making in primary prevention is not always trivial and many clinical scenarios are not reflected in current guidelines. To help evaluate a patient’s individual risk, a new score to predict the benefit of an implantable defibrillator (ICD) for primary prevention, the MADIT-ICD benefit score, has recently been proposed. The score tries to predict occurrence of ventricular arrhythmias and non-arrhythmic death based on data from four previous MADIT trials. We aimed at examining its usefulness in a large single-center register of S-ICD patients with various underlying cardiomyopathies. Methods and results: All S-ICD patients with a primary preventive indication for ICD implantation from our large single-center database were included in the analysis (n = 173). During a follow-up of 1227 ± 978 days, 27 patients developed sustained ventricular arrhythmias, while 6 patients died for non-arrhythmic reasons. There was a significant correlation for patients with ischemic cardiomyopathy (ICM) (n = 29, p = 0.04) to the occurrence of ventricular arrhythmia. However, the occurrence of ventricular arrhythmias could not sufficiently be predicted by the MADIT-ICD VT/VF score (p = 0.3) in patients with (n = 142, p = 0.19) as well as patients without structural heart disease (n = 31, p = 0.88) and patients with LV-EF < 35%. Of the risk factors included in the risk score calculation, only non-sustained ventricular tachycardias were significantly associated with sustained ventricular arrhythmias (p = 0.02). Of note, non-arrhythmic death could effectively be predicted by the proposed non-arrhythmic mortality score as part of the benefit score (p = 0.001, r = 0.3) also mainly driven by ICM patients. Age, diabetes mellitus, and a BMI < 23 kg/m2 were key predictors of non-arrhythmic death implemented in the score. Conclusion: The MADIT-ICD benefit score adds a new option to evaluate expected benefit of ICD implantation for primary prevention. In a large S-ICD cohort of primary prevention, the value of the score was limited to patients with ischemic cardiomyopathy. Future research should evaluate the performance of the score in different subgroups and compare it to other risk scores to assess its value for daily clinical practice.

The subcutaneous defibrillator in patients with low BMI - insights from a large European multicenter registry

Abstract Funding Acknowledgements Type of funding sources: None. Background The subcutaneous implantable cardioverter defibrillator (S-ICD) has become an alternative to transvenous ICDs (tv-ICD), especially in young patients without a need for pacing. One of the current limitations of the S-ICD is the relatively large size of the generator compared to tv-ICDs. There is little evidence whether the size of the current S-ICD generator is associated with an elevated risk of device-related complications in patients with a low body mass index (BMI). Purpose To compare the device-related complications and long-term outcomes in a large real world cohort of S-ICD recipients in patients with a BMI &amp;lt;18 kg/m2 compared to patients with a BMI &amp;gt;18 kg/m2. Methods The iSuSI registry is a European, multi-center, open-label, independent, and physician-initiated observational registry. A total of twenty-two Public and Private Healthcare Institutions from 4 different countries in Europe were involved in the registry. All consecutive patients meeting current guideline indications for ICD implantation and undergoing implantation of a S-ICD device (Boston Scientific, Marlborough, Massachusetts, USA) at 21 European institutions enrolled in the registry were used for the current analysis. Patients were classified into two cohorts, depending on the BMI at the time of device implantations: BMI &amp;lt; 18 kg/m2 versus &amp;gt; 18 kg/m2. Results Out of a total of 1497 pts, 58 pts (3.9%) had a BMI &amp;lt; 18 kg/m2. Patients with BMI &amp;lt;18 kg/m2 were younger (44.6±2.4 vs 50.8±0.4; p=0.004) and more frequently female (58.6% vs 22.3%, p&amp;lt;0.001). No differences in any of the other baseline characteristic were observed. Implantation techniques resulted comparable between the groups (Rates of 2-incision technique: 87.8% vs 91.9%; p=0.256; inter-muscular placement: 89.7% vs 83.3%; p=0.198). Of note, the mean PRAETORIAN score at implantation of patients with BMI &amp;lt;18 kg/m2 was significantly lower (33.8±9.1 vs 54.1±47.3; p=0.035), although the vast majority of pts in both cohorts qualify as at low risk of conversion failure (100% vs 91.4%; p=0.436). Over a median follow up time of 22.4 [11.6–36.8] months, both overall device-related complications (5.2% vs 7.4%) and rates of inappropriate shocks (12.0% vs 8.8%) resulted comparable between the two groups (p =0.517 and p=0.385, respectively). Figure1 reports Kaplan-Meier curves reporting the combined incidence of device-related complications and inappropriate shocks in the two groups (log-rank p = 0.576). Conclusion No difference in device-related complications and long-term outcomes after S-ICD implantation were observed in patients with BMI &amp;lt;18 kg/m2 compared to the remaining recipients from a large, multi-centered S-ICD registry. Figure 1: Kaplan-Meier-survival curve for the combined endpoint of inappropriate shocks (IAS) and device-related complications (DRC)

P228 WEARABLE DEFIBRILLATOR IN CLINICAL PRACTICE. MULTIANNUAL MULTI–CENTER EXPERIENCE

Abstract Introduction Heart failure with reduced left ventricular ejection function (LVEF) represents a life–threatening condition for patients (pts). A period of time of 40–90 days, in optimal medical therapy, is indicated to evaluate the recovery of the LVEF and the indication to ICD implantation. In this period, from 1% to 5% of pts can experience sudden death. We evaluated the usefulness of the wearable cardioverter defibrillator (WCD) as a temporary antiarrhythmic therapy in the interval from discharge to the three–month follow–up. Methods From December 2015 to December 2021, 174 consecutive pts (141 M (81%); mean age 62 years ± 11.6 years) were discharged with reduced FE &amp;lt; 35% in OMT, with WCD and were re–evaluated within 3 months to establish indication for ICD implantation. Results 110 pts (63.2%) recovered LVEF at 3 months and left the indication to ICD. 9 pts refused and/or returned the WCD due to poor compliance (5.2%); 52 pts (29.9%) did not recover LVEF and were implanted with ICD. The WCD was worn continuously by the majority of pts with good compliance for 87.4 ± 52.0 days (range 1 ÷ 303 days), for 22.08 hours / day. 23 episodes of AF were correctly recognized; 10 TVNS&amp;gt; 10 sec; 1 episode of VF in 1 patient in which 1 shock was correctly delivered. 1 inappropriate shock was delivered on tachycardic AF. During the WCD wearing period, 3 deaths occurred (1.7%): in 2 pts due to refractory HF (one of these pts had VF correctly recognized and treated by the WCD but degenerated into pulseless activities); 1 death for terminal cancer). The use of WCD has progressively increased over the years (from 4.5 LV / yy in 2015–16 to 45 LV / yy in 2020–21). Conclusions The use of WCD has gradually increased in clinical practice for patients who have not yet developed clear indications for ICD implantation. In the majority of them, ventricular dysfunction is transient. Wearable cardioverter defibrillator represents additional security during this period. Continuous monitoring makes it possible to identify supraventricular and ventricular arrhythmias, improving therapeutic appropriateness and in general the patients have excellent compliance with the device. Further studies are needed to substantiate this strategy.

C9 SUBCUTANEOUS IMPLANTABLE CARDIOVERTER DEFIBRILLATOR IN PATIENTS WITH LOW BMI: REAL–WORLD DATA FROM A EUROPEAN MULTICENTER ANALYSIS

Abstract Background One of the current limitations of the S–ICD is the relatively large size of the generator compared to the TV (transvenous) ICD. There is little evidence whether the size of the current S–ICD generator is associated with an elevated risk of device–related complications in patients with a low body mass index (BMI). Purpose Aim of this study was to compare the device–related complications and long–term outcomes in a large real world cohort of S–ICD recipients in patients with a BMI &amp;lt;18 kg/m2 compared to patients with a BMI &amp;gt;18 kg/m2. Methods All consecutive patients meeting current guideline indications for ICD implantation and undergoing implantation of a S–ICD device (Boston Scientific, Marlborough, Massachusetts, USA) at 21 European institutions enrolled in the extended ELISIR registry were used for the current analysis. Patients were classified into two cohorts, depending on the BMI at the time of device implantations: BMI &amp;lt; 18 kg/m2 versus &amp;gt; 18 kg/m2. Results Out of a total of 1497 pts, 58 pts (3.9%) had a BMI &amp;lt; 18 kg/m2. Patients with BMI &amp;lt;18 kg/m2 were younger (44.6±2.4 vs 50.8±0.4; p = 0.004) and more frequently female (58.6% vs 22.3%, p &amp;lt; 0.001). No differences in any of the other baseline characteristic were observed. Implantation techniques resulted comparable between the groups (rates of 2–incision technique: 87.8% vs 91.9%; p = 0.256; inter–muscular placement: 89.7% vs 83.3%; p = 0.198). Of note, the mean PRAETORIAN score at implantation of patients with BMI &amp;lt;18 kg/m2 was significantly lower (33.8±9.1 vs 54.1±47.3; p = 0.035), although the vast majority of patients in both cohorts qualified as at low risk of conversion failure (100% vs 91.4%; p = 0.436). Over a median follow up time of 22.4 [11.6–36.8] months, both overall device–related complications (5.2% vs 7.4%) and rates of inappropriate shocks (12.0% vs 8.8%) resulted comparable between the two groups (p = 0.517 and p = 0.385, respectively). Figure 1 reports Kaplan–Meier curves showing the combined incidence of device–related complications and inappropriate shocks in the two groups (log–rank p = 0.576). Conclusion No differences in device–related complications and long–term outcomes after S–ICD implantation were observed in patients with BMI &amp;lt;18 kg/m2 compared to the remaining recipients in a large multicentered real–world analysis.

Prediction of appropriate ICD therapy in patients with ischemic heart failure

BackgroundPrevious studies show inconsistent results on the role of innervation imaging (with I-123-mIBG) and perfusion imaging in predicting appropriate ICD therapy (aICDth). These studies included patients with both dilated and ischemic cardiomyopathy. This study compared the ability of 123I-mIBG imaging along with perfusion imaging (using thallium-199) to predict aICDth in patients with ischemic heart failure (IHF) in relation to indication for ICD implantation (primary vs. secondary prevention of sudden cardiac death (SCD)). MethodsmIBG/thallium SPECT imaging were performed before ICD implantation in 80 patients with IHF: 49 candidates for primary and 31 for secondary SCD prevention. ResultsDuring a mean follow-up of 18 months, the imaging results could not predict patients with appropriate ICD therapy among patients with ICD implants for primary SCD prevention.While in the secondary SCD prevention group, those who received a ICDth had significantly larger summed scores of regional perfusion and innervation impairment, but not higher heart-to-mediastinal mIBG ratio. The best results to predict aICDth were using mIBG summed score (cut-off point > 34%, sensitivity 72%, specificity 100%, AUC 0.909, P < 0.0001). ConclusionThe prognostic value of innervation and perfusion imaging in patients with IHF differ based on indication for ICD implantation (primary vs. secondary prevention of SCD).

How to get the optimal defibrillation lead parameters using myocardial perfusion scintigraphy in patients with coronary artery disease.

The conventional criteria for a defibrillation lead (DL) implantation don't take into account presence of scar or deep ischemia in the myocardium. This may impair a proper functioning of the DL. We sought to optimize the DL implantation placement using rest myocardial perfusion scintigraphy (MPS), which allow detecting areas of myocardial hypoperfusion (MH). To study the influence of MH and scarring, detected by MPS, on the DL parameters in patients with coronary artery disease (CAD). 69 patients (male-65, age 64.8 ± 7.7years) with CAD and indications for ICD implantation were enrolled. Two days before ICD implantation all patients underwent MPS at rest. Then patients were divided in 2 groups. In the 1st group DL was implanted considering MPS results: to the septal position, if the most significant MH were detected in the apical segments, and to the apical position, if MH were in the septal segments. In the 2nd group DL was implanted using the conventional approach without considering MPS results. Clinical 12months follow-up was performed with ICD interrogation. Patients of both groups were comparable by clinical and scintigraphic parameters. In the same time, in the 1st group pacing threshold was lower (p < 0.0001) and ventricle signal amplitude was higher (p < 0.0001) comparing with the 2nd group at all control points. The presence of MH detected by MPS in the area of the DL placement worsens its parameters. The results of MPS in patients with CAD can be useful for optimization of DL placement.

The role of entirely subcutaneous ICD™ systems in patients with dilated cardiomyopathy

BackgroundThe subcutaneous implantable-cardioverter defibrillator (S-ICD™, Boston Scientific, Natick, MA, USA) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICD™ use, long-term data are still limited, especially in subgroups. Dilated cardiomyopathy (DCM) is a common reason for the implantation of an ICD. However, there are no sufficient data on the performance of the S-ICD™ in this patient cohort. Materials and methodsAll S-ICD™ patients with DCM as the main indication for ICD implantation (n=47 patients) in our large-scaled single-center S-ICD™ registry (n=294 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 22.9±18.5 months. ResultsA total of 47 patients with DCM as the underlying structural heart disease received an S-ICD™ in our institution. Mean left ventricular ejection fraction was 37±12% and a 28% had a history of ventricular tachyarrhythmia. During follow-up eight ventricular tachyarrhythmias were adequately terminated in three patients. In four patients, oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector. There was no need for a change to a cardiac resynchronization (CRT) system while one system was changed to a VVI-ICD due to S-ICD™ wound infection. ConclusionThe S-ICD™ seems to be a valuable option for the prevention of SCD in patients with DCM and no indication for CRT. As clinically relevant ventricular arrhythmias consisted of ventricular fibrillation or fast ventricular tachycardia in all patients in our cohort, no change to transvenous ICDs for anti-tachycardia pacing delivery was necessary.

Outcome differences and device performance of the subcutaneous ICD in patients with and without structural heart disease.

The performance of the subcutaneous ICD (S-ICD™) has been described in different kinds of heart disease and has been proven to be an important advance in prevention of sudden cardiac death (SCD). While positive experiences with the S-ICD™ initially came from collectives of patients without structural heart diseases, positive results have also been collected from cohorts with structural heart disease. All S-ICD™ patients with either ischemic cardiomyopathy (ICM), dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) as the main indication for ICD implantation (n = 144 patients) or electrical heart disease/idiopathic ventricular fibrillation (n = 83 patients) in our large-scaled single-center S-ICD™ registry were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 18 ± 15months. Baseline characteristics were significantly different between the two groups in most categories. In contrast, there was no difference concerning neither appropriate nor inappropriate shock delivery between the two groups. Also other outcome parameters such as need for surgical revisions and all-cause mortality did not differ. There was a significant difference between the first- and second-generation S-ICDs™ in inadequate shocks mainly driven by patients with HCM. In our study, S-ICD™ performance was similar in patients with and without structural heart disease. Decision pro- or contra-S-ICD™ should be made rather on the basis of expected shock rate and probability of the need for future anti-tachycardia or anti-bradycardia pacing than in dependence of the underlying heart disease.

Performance of the entirely subcutaneous ICD in borderline indications.

The subcutaneous ICD (S-ICD™) is an important advance in device therapy for prevention of sudden cardiac death (SCD). In some patients, decision pro- or contra-ICD implantation is particularly challenging due to inconsistent data on risk of ventricular tachyarrhythmias or sudden cardiac death, rare entities, special medical or family history, or patients' wishes. Whether decision-making in these borderline cases has been facilitated with the new option of a S-ICD™ is unknown. All patients with an implanted S-ICD™ without a class I or IIa recommendation for primary prophylaxis of sudden cardiac death in the current guidelines (n = 30 patients) in our large-scaled single-centre S-ICD™ registry (n = 249 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 40months. In all patients S-ICD™ implantation was performed for primary prevention of SCD. Of all 30 patients with an overall mean age of 40.5 ± 15.6years, 17 were male (57%). The mean left ventricular ejection fraction (LVEF) was 54.5 ± 9.9%. Indication were highly variable and ranged from structural heart disease, nsVT and LV-EF > 35% to patients with polymorphic non-sustained ventricular tachycardia (nsVT) and suspect syncope. During follow-up, six episodes of sustained ventricular tachyarrhythmias and four episodes of ventricular fibrillation (VF) were adequately terminated in three patients (10%). Two of these patients were implanted for polymorphic nsVT and previous syncope without structural heart disease. In three patients, T-wave-oversensing and in one patient also P-wave-oversensing resulted in an inappropriate shock (five in total), two additional episodes of oversensing ended before shock delivery. There were no S-ICD™ system-related infections. In five patients S-ICD™ replacement was performed due to battery depletion (four regular, one premature). In five patients, ablation procedures were performed after implantation (four because of frequent symptomatic ventricular extra beats, one because of atrial flutter). Change to a transvenous system was necessary in two patients due to need for antibradycardia pacing. The use of the S-ICD™ was safe in patients with borderline or unclear indication for ICD implantation in our study. Of note, during a relatively short mean follow-up there were several appropriate therapies, especially for VF in these patients. On the other hand, oversensing also occurred in about 10% of patients, while lead problems were not problematic in this collective. S-ICD™ implantation may be considered as a possible alternative in cases of borderline indications and clinical uncertainty when decision pro-ICD implantation is made. Incidence of arrhythmias was quite high and mostly consisted of VF. Nevertheless, patient education seems even more important as there is a considerable risk for inappropriate therapies as well.

P5977Predicting significant ventricular arrhythmias in STEMI patients: never-ending challenge, still more place for myocardial deformation imaging?

Abstract Background Malignant ventricular arrhythmias in STEMI patients carry ominous prognosis including sudden cardiac death (SCD). According to the current guidelines only EF&lt;35%, 40 days after STEMI, is indication for ICD implantation. Recently, index of myocardial dispersion (IMD) estimated by myocardial deformation imaging (speckle tracking echocardiography) was documented to provide better risk stratification. Aim To define whether quantification of myocardial mechanics early after pPCI using modern echocardiography offers information more to predict malignant arrhythmias during the first year after STEMI. Methods In the 226 consecutive STEMI patients (pts) 57.8±10.4yr, 71.7% males, in PREDICT-VT study (NCT03263949) treated with pPCI early echo (5±2 days) was done including conventional parameters and comprehensive speckle tracking LV deformation analysis with longitudinal (L), circumferential (C) strain (S;%) and strain rate (SR, 1/sec) and rotational LV mechanics. ROC analysis was performed to identify the best parameters to predict composite end-point defined as secondary VF, sustained/non-sustained VT and SCD, 48h after pPCI and during the first year of follow up. Results Twenty two patients (9.7%) reached the end-point. Classical parameters of LV systolic function, including LVEF, wall motion score index; global, systolic LS, CS and parameters of diastolic dysfunction were not significant predictors of the malignant arrhythmias. Early L SR, systolic C SR, IMD of global rotation and late rotation rate predicted the primary end-point (table). Parameter ROC area 95% CI p Cutt-off Sens Spec Longirudinal mechanics SR E (1/sec) 0.687 0.577–0.796 0.019 0.69 64 65 IMD S (ms) 0.752 0.666–0.838 0.002 66.1 71 72 Circumferencial mechanics SR S (1/sec) 0.732 0.613–0.852 0.002 −1.22 71 67 Rotational mechanics Global IMD (ms) 0.329 0.177–0.481 0.036 82.9 63 62 Late rotation rate IMD (ms) 0.318 0.196–0.442 0.026 41.1 65 64 Conclusion Myocardial deformation imaging offers deeper insight into complex mechanical abnormalities during LV contraction and relaxation in longitudinal, circumferential and rotational directions (impaired and asynchronous deformations) in STEMI patients and predicts serious arrhythmic events.

P988Implantable cardioverter defibrillators in patients with electrical heart disease and hypertrophic cardiomyopathy - data from the German device Registry

Abstract Background Implantable cardioverter- defibrillator (ICD) therapy is established for prevention of sudden cardiac death (SCD) in different entities. However, data from large patient cohorts on patients with electrical heart disease of hypertrophic cardiomyopathy (HCM) is rare. Therefore, we investigated these patients by analysing registry data from a multi-center “real-life” registry. Methods The German Device Registry (DEVICE) is a nationwide, prospective registry with one-year follow-up investigating 5450 patients receiving device implantations in 50 German centres. The present analysis of DEVICE focussed on patients with electrical heart disease or HCM who received an ICD for primary or secondary prevention. Results 174 patients with HCM and 112 patients with electrical heart disease were compared with 5164 other ICD patients. Median follow-up was 17.0 months. Patients in the control group were significantly older. Of note, overall mortality after one year was 1.8% in HCM patients, 6.6% in patients with electrical heart disease and 7.3% in the control group. Patients in the control group presented significantly more severe comorbidities. In contrast to HCM patients and the control group where primary prevention was the major indication for ICD implantation 77.5% of patients with electrical heart disease received an ICD for secondary prevention. The number of surgical revisions was higher in patients with electrical heart disease. Conclusion Data from the present registry display a surprisingly high mortality in patients with electrical heart disease equivalent to the control group. A high proportion of patients who received an ICD for secondary prevention may be regarded as a major determinant for these results while severe comorbidities such as diabetes, hypertension and renal failure are major determinants for mortality in the control cohort.

The entirely subcutaneous ICDTM system in patients with congenital heart disease: experience from a large single-centre analysis.

The subcutaneous implantable cardioverter-defibrillator (S-ICDTM) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICDTM use, long-term data are still limited, especially in subgroups such as adult patients with congenital heart diseases. This cohort is of high interest because of the difficult anatomic conditions in these patients. All S-ICDTM patients with an underlying congenital heart disease (CHD) resulting in an indication for ICD implantation (n = 20 patients) in our large-scaled single-centre S-ICDTM registry (n = 249 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 36 months. Primary prevention of SCD was the indication for implantation of an S-ICDTM in six patients (30%). Of all 20 patients with an overall mean age of 40.5 ± 11.5 years, 12 were male (60%). The mean left ventricular ejection fraction was 46.5 ± 11.3%. Nine episodes of ventricular tachycardia (two monomorphic and seven polymorphic) were adequately terminated in three patients (15%). In two patients, T-Wave-Oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector or activation of the SMART PASSTM filter. There were no S-ICDTM system-related infections. In one patient, surgical revision was necessary due to a persistent haematoma. The S-ICDTM seems to be a valuable option for the prevention of SCD in patients with various CHDs and complex anatomical anomalies. The S-ICDTM is safe and works effectively, also in these complex patients. Inadequate shock delivery was rare and could be managed by reprogramming.

Feasibility of entirely subcutaneous ICD™ systems in patients with coronary artery disease.

The subcutaneous ICD (S-ICD™) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICD™ use, long-term data are still limited, especially in subgroups. Among several cardiac diseases that prone to SCD, coronary artery disease (CAD) carries several peculiarities that may hamper S-ICD™ therapy in this cohort. CAD can lead to an ischemic cardiomyopathy (ICM) with a reduced left-ventricular ejection fraction (LVEF) and bundle branch blocks, which can be difficult for ICD sensing and discrimination of arrhythmia. CAD is mainly driven by risk factors such as diabetes mellitus, which put these patients at an elevated risk for infectious complications of cardiac devices. Furthermore, in ICM myocardial scars are frequent and are a potential substrate for ventricular tachycardia, which may be accessible for antitachycardia pacing. At the moment, it remains unclear if there is a value of S-ICD™ therapy in this subgroup. Therefore, this study analysed patients with CAD. All S-ICD™ patients with CAD as the main indication for ICD implantation (n = 45 patients) in our large-scaled single-center S-ICD™ registry (n = 249 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 22.5 ± 8.3months. Primary prevention of SCD was the indication for implantation of an S-ICD™ in 28 patients (62%). Of all 45 patients with an overall mean age of 58.1 ± 11.4years, 40 were male (88%). The mean LVEF was 37.7 ± 12.6%. Three episodes of ventricular arrhythmia (one monomorphic, one polymorphic, one ventricular fibrillation) were adequately terminated in three patients (7%). In only one patient, oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector. 15 of the examined 45 patients previously had a transvenous ICD, which was explanted due to system-related infections. In only two patients, S-ICD™ was changed to transvenous ICD because of the need of antibradycardia stimulation. There were no S-ICD™ system-related infections. The S-ICD™ seems to be a valuable option for the prevention of SCD in CAD patients. Patients with systemic infections of a transvenous ICD and, therefore, a need for an alternative might benefit from the absence of intracardiac leads as the S-ICD™ is safe and works flawlessly in these patients. Inadequate shock delivery was very rare, while every episode of ventricular arrhythmia was terminated by the first shock.

Pan-Asia United States PrEvention of Sudden Cardiac Death Catheter Ablation Trial (PAUSE-SCD): rationale and study design.

The role of catheter ablation as an adjunct and alternative to ICD implantation is not known in patients at risk for recurrent ventricular tachycardia (VT) and sudden cardiac death (SCD) across Asia. Patients with nonischemic etiologies of cardiomyopathy, which are highly prevalent in Asia, have not been previously enrolled in randomized trials of VT ablation. To evaluate whether preemptive catheter ablation in patients with monomorphic VT and an indication for ICD implantation results in improved clinical outcomes compared to ICD implantation with standard medical therapy alone. To examine the natural history of ablation outcomes in the absence of background ICD therapy in patients that refuse randomization. The PAUSE-SCD study (NCT02848781) is a prospective, multi-center, randomized controlled trial enrolling patients with structural heart disease (EF < 50%) with an indication for ICD implantation. Patients are randomized in a 1:1 fashion to two treatment arms: ICD with ablation and ICD with standard medical therapy alone. A prospective registry cohort was designed to follow the outcomes of patients who refuse ICD and randomization but elect to receive catheter ablation as primary therapy. The primary endpoint is defined as a composite of recurrent VT, cardiovascular rehospitalization, and death. Pre-specified secondary endpoints include each of the individual components of the primary endpoint in addition to comparison between randomized and registry patients. The PAUSE-SCD study is a prospective, multi-center, randomized, and controlled trial examining the impact of preemptive catheter ablation on cardiovascular outcomes in patients with an indication for ICD at risk for recurrent VT and SCD. It represents the first multi-center VT ablation study in Asia, with a design intended to provide insights into the role of both ICD and ablation therapy in a predominantly nonischemic population.