Primary Preventive Implantation Research Articles

Incidence of ventricular arrhythmias after implantable cardioverter-defibrillator implantation or replacement, and driving restriction consequences

BackgroundFollowing implantation/replacement of an implantable cardioverter-defibrillator, patients are legally subjected to variable lengths of driving restrictions based on the indication (1 and 3 months after primary and secondary prevention, respectively; 1 week after device replacement). AimTo assess the incidence of ventricular arrhythmia during the theoretical driving restriction period in a large cohort of patients. MethodsPatients who underwent implantable cardioverter-defibrillator implantation for primary or secondary prevention or device replacement between 2015 and 2021 were included retrospectively. The primary endpoint was the occurrence of ventricular arrhythmia during the theoretical driving restriction period, as defined by guidelines. ResultsA total of 914 patients were analysed, including 654 first implantations (438 and 216 for primary and secondary prevention, respectively) and 260 device replacements. The primary outcome occurred in 2/438 patients (0.004%) during the 1-month period following device implantation for primary prevention and in 25/216 patients (11.5%) during the 3-month period following device implantation for secondary prevention; it did not occur in the 1-week period following device replacement. The monthly calculated risk of harm remained below the accepted threshold of 0.005% for each group. ConclusionsPrimary prevention patients, such as those who have undergone device replacement, have a low risk of ventricular arrhythmia, which could lead to a reduction in their driving restriction period. Secondary prevention patients experienced a higher risk of recurrent ventricular arrhythmia, supporting the 3-month driving restriction period.

Survival benefit of ICD implantation for primary prevention in dilated cardiomyopathy

Objectives: Dilated cardiomyopathy (DCM) represents a significant cause of heart failure unrelated to ischemic heart disease, posing a high risk of sudden cardiac death (SCD) due to low left ventricular ejection fraction (LVEF). This study evaluates the survival benefits of implantable cardiac defibrillators (ICDs) for primary prevention in DCM patients. Methods: We enrolled 52 symptomatic non-ischemic cardiomyopathy patients (LVEF ≤ 35%, NYHA class II-III) eligible for ICD implantation in Afshar Hospital, Yazd, Iran, from 2014 to 2015. Exclusion criteria included those with ischemic indications or requiring cardiac resynchronization therapy. We divided patients into ICD recipients and those on a waiting list, collected the baseline data (age, functional class, LVEF), then followed up with patients to assess mortality rates. Results: Among 45 patients, 64.5% received ICDs while 35.5% were on the waiting list. The mean age was 57±13 years, predominantly male (67.3%). The ICD group had a significantly lower mortality rate (17.3%) than the waiting list group (42.7%, p = 0.54). Although age and functional class did not significantly predict outcomes, lower LVEF was a crucial factor for long-term survival. Despite some studies suggesting no survival benefit in non-ischemic heart failure, our findings highlight the efficacy of ICDs in reducing mortality among DCM patients. Conclusions: ICD implantation in DCM patients substantially reduces all-cause mortality compared to those awaiting the procedure, underscoring the importance of timely ICD deployment for primary prevention in this population.

Ventricular arrhythmia events in patients with implantable cardioverter-defibrillator before and after the treatment with sodium-glucose co-transporter 2 inhibitors

Abstract Background The role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the treatment of chronic heart failure is expanding. However, the timing of implantable cardioverter-defibrillator (ICD) implantation for primary prevention in relation to the use of SGLT2i remains unclear. A small case series has described appropriate shocks from ICD in two patients following the initiation of SGLT2i, but a comprehensive analysis is lacking in the literature. Methods This study aimed to investigate the rate of ventricular arrhythmic burden and appropriate anti-tachycardia therapy from ICD before and after the initiation of SGLT2i therapy. We conducted a retrospective single-center analysis, comparing ventricular events from home monitoring reports three months before and three months after SGLT2i therapy initiation. Results Seventeen patients were enrolled in the study. At baseline, clinical characteristics were as follows: 13 (76%) were male, 9 (53%) had ischemic, 2 (12%) had valvular, and 6 (35%) had idiopathic cardiomyopathy. The mean end-diastolic volume (EDV) was 203 ± 90 ml, and the mean left ventricular ejection fraction was 0.36 ± 0.09. All patients were treated with beta-blockers, 14 (82%) with sacubitril-valsartan, 13 (76%) with aldosterone antagonists, 16 (94%) with furosemide, and 5 (29%) with amiodarone. SGLT2i started with dapagliflozin for 13 patients (76%), empagliflozin for 3 patients (18%), and canagliflozin for 1 patient (6%). Ten patients (59%) had single-chamber or dual-chamber ICDs, and 7 had implantable cardiac resynchronization therapy (CRT) defibrillators. In the three months before SGLT2i treatment, 4/17 patients had non-sustained ventricular tachycardia (NSVT), compared to 8/17 (23% vs. 47%, p-value 0.23) patients with NSVT after treatment. Seven patients (41%) experienced an increase in the rate of NSVT events, with one patient having 28 NSVT events after treatment versus none before treatment. No patients had anti-tachycardia therapy in the three months before treatment, while in the three months after SGLT2i treatment, 1 patient had ventricular tachycardia treated with anti-tachycardia pacing (110 days after the beginning of the treatment), and 2 patients had ventricular tachycardia treated with appropriate shocks (2 and 25 days after the initiation of SGLT2i treatment). Conclusion This small retrospective analysis revealed an increase in ventricular arrhythmic events in the three months following the initiation of SGLT2i. These findings highlight the need for a more extensive analysis to establish a stronger statistical correlation.

Clinical impact of ICD implantation in octogenarians: a longitudinal cohort study

Abstract Background The implantation of defibrillators (ICDs) in patients over 80 years old is becoming increasingly common; however, evidence-based data regarding the actual clinical benefit in this population remain limited and contradictory. While age seems not to affect mortality and arrhythmia risk in octogenarians undergoing secondary prevention, the mortality reduction benefit given by ICD implantation for primary prevention appears to decrease with advancing age, likely due to the high number of non-arrhythmic deaths. Purpose This study aims to assess the long-term incidence of ventricular arrhythmias and mortality in a real-world cohort of octogenarian patients undergoing ICD implants. Methods This was an observational, retrospective, longitudinal cohort study. Demographic, clinical, and radiological data were collected for all patients undergoing ICD implantation between 2014 and 2021. Deaths from all causes and significant arrhythmic events (sustained ventricular tachycardias and ventricular fibrillation) detected during routine device controls and remote monitoring were recorded. Then was performed an univariate Kaplan-Meier analysis, stratifying the population by age in relation to the two study endpoints: ventricular arrhythmias and all-cause mortality. Results Out of a total of 700 patients, 512 underwent ICD implantation before the age of 80 (mean age at implantation 64±12), while 188 underwent ICD implantation after the age of 80 (mean age at implantation 82±3.2). No significant differences were found between these two groups in terms of gender (82% vs. 83% male; p 0.12), indication for implantation (74% vs. 75% primary prevention; p 0.79), and the presence of late gadolinium enhancement (LGE) on cardiac MRI (68% vs. 77%; p 0.14). Octogenarians were more frequently affected by ischemic heart disease (54% vs. 65%; p 0.01) and were more frequently treated with Amiodarone (17% vs. 24%; p 0.02). At the end of the average 8-year follow-up, octogenarians had significantly higher all-cause mortality than younger patients (HR=2.35 [1.88-3.16]; p<0.05), with survival curves diverging from 3 years after implantation. However, ventricular arrhythmic events were significantly reduced in octogenarian patients (HR=0.88 [0.87-0.89]; p<0.05). Conclusions In a real-world population of octogenarian patients, the clinical benefit of ICD implantation for primary prevention appears diminished, considering the trade-off between ventricular arrhythmias and mortality, in both ischemic and non-ischemic cardiomyopathy patients.

THE INTELLIGENT USE OF ADRENALINE

Abstract Case Report A 52–year–old patient experienced anterior and inferior ST–elevation myocardial infarction, leading to cardiogenic shock necessitating invasive hemodynamic and pharmacological support. During angiography, an intra–aortic balloon pump (IABP) was inserted, and a norepinephrine infusion along with dobutamine was initiated, showing partial clinical and laboratory improvement. Critical disease in all three vessels was detected, prompting angioplasty with stenting of the right coronary artery and left anterior descending artery. Echocardiography revealed severe reduction in left ventricular systolic function (ejection fraction 10%). Despite revascularization and intensive support, the patient‘s hemodynamic status deteriorated (SCAI D), necessitating the addition of adrenaline (0.03 μg/kg/min) to the ongoing dobutamine infusion, suspending noradrenaline. Subsequent days showed gradual improvement, allowing for withdrawal from amine support and discontinuation of the IABP. Follow–up included a cardiac MRI displaying severe systolic dysfunction (EF 21%), extensive ischemic–pattern delayed enhancement across three–vessel distribution. Given the persistent severe left ventricular dysfunction, the patient underwent subcutaneous defibrillator implantation for primary prevention after optimizing anti–remodeling therapy. Despite optimized medical therapy and cycles of levosimendan, the patient experienced heart failure exacerbation, requiring hospitalization (INTERMACS 3). Considering the clinical condition and absence of contraindications, the patient was listed for heart transplantation. Due to refractory hemodynamic instability despite inotropic agents, a left ventricular assist device was implanted as a bridge to transplantation. Roughly 6 months later, the patient successfully underwent heart transplantation without acute complications. Conclusions Very low doses of adrenaline demonstrate increased sensitivity to β2 receptors over α receptors, thereby enhancing mean arterial pressure and peripheral perfusion. At the cardiac level, it induces an increase in both heart rate and coronary blood flow, while peripherally reducing resistances, predominantly due to the prevalence of β2 receptors in skeletal muscle. This improvement contributes to the enhancement of ventricular–arterial coupling. In conditions characterized by a primary pump deficit, such as cardiogenic shock, the use of low–dose adrenaline emerges as a valid therapeutic option.

Compliance with Guideline-Directed Medical Therapy and Early Implantable Cardioverter-Defibrillator Activation in Heart Failure: A Retrospective Study.

This study was conducted to evaluate compliance with guideline-directed optimal medical therapy (OMT) and its association with early implantable cardioverter-defibrillator (ICD) activation in patients with heart failure and reduced ejection fraction (HFrEF). Retrospective data from 307 patients who underwent ICD implantation for primary prevention from 2011 to 2017 were collected and analyzed. Among the study participants, only 23.8% received the maximum tolerated dose of OMT prior to ICD implantation, with 59.0% receiving all three OMT medication groups. No significant difference in OMT compliance was found between patients with ischemic cardiomyopathy (ICM) and those with non-ischemic dilated cardiomyopathy (DCM). However, DCM patients received ICDs more frequently at the time of diagnosis than ICM patients (13.8% vs. 0.7%). Early ICD activation (within 3 months) occurred in only one patient who had not received appropriate OMT, representing 0.7% of all ICM patients. Furthermore, early activation was also infrequent in patients who received OMT (2.9% of ICM patients and 2.6% of DCM patients). Echocardiography follow-up data revealed that 20.4% of ICM patients and 29.8% of DCM patients who did not receive OMT before ICD implantation showed improvement in the left ventricular ejection fraction (EF) to 35% or more. This study found suboptimal compliance with OMT prior to ICD implantation in HFrEF patients. The results showed that early ICD activation was rare in all patient groups, especially those who did not receive the prescribed 3 months of OMT. More research is needed to investigate longer waiting periods for the evaluation of potential EF improvement, and to better evaluate the eligibility of HFrEF patients for ICD. The current findings have potential implications for clinical practice and patient outcomes.

Role of Biomarkers of Myocardial Injury to Predict Adverse Outcomes in Hypertrophic Cardiomyopathy.

Serum troponins and CK-MB (creatine kinase-MB) are readily detectable and reliable cardiac-specific biomarkers of subclinical myocardial injury. This study explores the roles of cTnI (cardiac troponin I) and CK-MB in hypertrophic cardiomyopathy (HCM). This study included 1045 patients with HCM who had baseline cTnI and CK-MB measurements at Fuwai Hospital between 1999 and 2019. Patients were excluded if they had undergone percutaneous coronary intervention or coronary artery bypass grafting, or had renal failure. Five end points were studied: all-cause death, cardiovascular death, noncardiovascular death, sudden cardiac death, and other cardiovascular death. Cox regression was used to assess the associations of cTnI and CK-MB levels with outcomes. Nine hundred seventy patients with available follow-up data were finally analyzed (mean age, 49.3 years; 36.4% female). During the median 4.3-year follow-up period, 87 patients reached the end points. Higher cTnI (per 0.05 ng/mL increase) and CK-MB (per 1 IU/L increase) levels were associated with increased risks of all-cause death (cTnI: adjusted hazard ratio [HR], 1.038, P<0.001; CK-MB: adjusted HR, 1.021, P=0.004), cardiovascular death (cTnI: adjusted HR, 1.040, P<0.001; CK-MB: adjusted HR, 1.025, P=0.006), and sudden cardiac death (cTnI: adjusted HR, 1.045, P<0.001; CK-MB: adjusted HR, 1.032, P=0.001). Patients with elevated levels of both cTnI and CK-MB had worse prognoses than patients with an elevated level of either biomarker alone and patients who did not have an elevated level of either biomarker. Addition of the binary indicator elevation of both cTnI and CK-MB significantly improved the discrimination and reclassification abilities of the standard HCM Risk- sudden cardiac death model (C statistics: P=0.002; net reclassification improvement, 0.652; integrated discrimination improvement, 0.064). Comprehensive evaluations of biomarkers of myocardial injury, cTnI and CK-MB, have considerable value for predicting adverse outcomes among patients with HCM. Routine cTnI and CK-MB assessments may help to guide implantable cardioverter defibrillator implantation for primary prevention in HCM.

Evaluation and Management of Sudden Death Risk in Repaired Tetralogy of Fallot.

Although substantial progress has been made to prevent sudden cardiac death in repaired tetralogy of Fallot patients, ventricular arrhythmia and sudden death continue to be major causes of morbidity and mortality in these patients. Greater survival in contemporary cohorts has been attributed to enhanced surgical techniques, more effective management of heart failure, and increased efforts in risk stratification and management of ventricular arrhythmias. More recently, our understanding of predictive risk factors has evolved into personalized risk prediction tools that rely on comprehensive demographic, imaging, functional, and electrophysiological data. However, the universal applicability of these different scoring systems is limited due to differences between study cohorts, types of anatomic repair, imaging modalities, and disease complexity. Noninvasive risk stratification is critical to identify those who may derive benefit from catheter ablation or cardioverter defibrillator implantation for primary prevention. Ultimately, assessment and risk stratification by a multidisciplinary team is crucial to analyze the various complex factors for every individual patient and discuss further options with patients and their families.

Predicting long-term survival after de novo cardioverter-defibrillator implantation for primary prevention: A population based study

BackgroundImplantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death in patients with left ventricular dysfunction. While short-term mortality benefit of ICD insertion has been established in landmark randomized controlled trials, little is known about the long-term outcomes of patients with ICDs in clinical practice. In this paper, we describe the long-term survival of patients following de novo ICD implantation for primary prevention in clinical practice and determine the factors which help predict survival after ICD implant. MethodsRetrospective population-based study of all patients receiving a de novo ICD for primary prevention in Ontario, Canada from 2007 to 2011 using the Ontario ICD Database housed within ICES. Simple random selection was used to split the population into a derivation and internal validation cohort in a ratio of 2:1. Cox proportional hazards regression was used to determine predictors of interest and predict 10-year survival, model performance was assessed using calibration and validation. ResultsIn the derivation cohort (n = 3399), mean age was 65.3 years (standard deviation [SD] = 11.0), 664 patients were female (19.5 %) and 2344 patients (69.0 %) had ischemic cardiomyopathy. Ten year survival was 45.7 % (95 % confidence interval [CI] 44.0 %–47.4 %). The final prediction model included age, sex, disease factors (ischemic vs nonischemic cardiomyopathy, left ventricular ejection fraction) and patient factors (symptoms, comorbidities), and biomarkers at the time of ICD assessment. This model had good discrimination and calibration in derivation (0.79, 95 % CI 0.77, 0.81) and validation samples (0.78, 95 % CI 0.76, 0.79). ConclusionsA combination of demographic and clinical factors determined at baseline can be used to predict 10-year survival in patients with implantable cardioverter-defibrillators with good accuracy. Our findings help to identify individuals at risk of long-term mortality and may be useful in targeting future prevention strategies to enhance longevity in this high-risk population.

The management of patients with heart failure in Sweden: a survey conducted among physicians in Sweden

Abstract Background Guideline-directed medical therapy (GDMT) improves outcomes in patients with heart failure (HF) with reduced ejection fraction (HFrEF). However, real-world studies highlight underutilization of GDMT. Purpose To describe physicians´ general knowledge and opinions on GDMT use, diagnostic workup, and follow-up care in HF in Sweden. Methods A survey comprising 42 multiple-choice questions about HF and its management was sent by mail to a random sample of 828 physicians including any specialist, general practitioners (GP) and interns in Sweden during 2021 and 2022. Answers were reported as percentages and comparisons were made by specialty (general practitioners vs specialists) by the chi-square test. Results 168 physicians (60% males, median age 43) responded to the survey (response rate: 20%), of whom 41% GPs, 18% cardiologists and 13% internists, 24% specialists in training, and 4% other specialists; 72% of participants report to meet less than 10 HF patients per week. Electrocardiography and a New York Heart Association class evaluation are mostly performed once a year by GPs (46%) and at every outpatient visit by other specialists (40%). Echocardiography is mostly requested if there is clinical deterioration (60%). 85% of the participants reported to never assess patient-reported parameters and outcomes with questionnaires. One-third of participants screen for iron deficiency only if there is anemia, and 45% do it every year. Figure 1 reports the major measured obstacles to implementation of GDMT in HFrEF; there were no significant differences according to specialty or age of participants. Implantable cardioverter defibrillation (ICD) implantation for primary prevention of sudden death is deemed appropriate by most responders regardless of aetiology (69%) and patient age (74%). ICD or cardiac resynchronization therapy is considered by most after the three months from optimization of GDMT (61%). Specialists answered correctly to questions to test knowledge on GDMT more often than GPs. 86% of participants think that GDMT should be implemented as much as possible, but only 7% estimate that full optimization is reached in more than 75% of their patients. The main reasons why patients with HFrEF do not receive optimal HF medical therapy (Figure 2) reflect the concern about side effects as well as possible knowledge deficiencies. To maximize the adherence to guidelines, 27% reported that patients should be regularly evaluated in tertiary care and 50% in nurse-led clinics, although for 29% of respondents such facilities are not present. Conclusion Obstacles to GDMT implementation according to physicians in Sweden are mainly related to potential side effects, lack of knowledge and structural aspects, including the lack of availability of nurse-led clinics. Improving implementation may require novel strategies, such as improved access to cardiology specialists, more generalizable trials, and potentially screening for GDMT indications.Figure 1Figure 2

Mortality and appropriate therapies in ischaemic ICD recipients according to the electrophysiological study

Abstract Aims Current guidelines recommend ICD implantation for primary prevention in patients with ischaemic heart disease and LVEF ≤35%. We aimed to access the value of the EP study in prediction of the arrhythmic events in ischaemic patients with reduced EF (≤35%) who underwent EPS and ICD implantation and do address the impact of ICD implantation on the all-cause mortality. Methods We compared the risk for all-cause mortality in ischaemic patients with negative and positive EPS with and without ICD implantation and compared the risk for appropriate therapy according to the results of the EP study of patients who underwent ICD implantation in our institution. The median follow-up was 84 months. Results Of 235 patients, who underwent EPS, 115 were negative (noninducible to VT). These patients were more likely to be female and did not differ in age, presence of diabetes, hypertension, atrial fibrillation or ejection fraction. Kaplan-Meier survival analysis showed that there was no difference in mortality between the 2 groups (49.6% vs 44.2%, p=0.419). ICD was implanted in 168 patients: there was no difference in mortality between them (47%) and patients without implanted ICD (46.6%), p=0.861. This was true for patients with negative and positive EPS (p=0.136 and p=0.554, respectively) Of 167 patients who underwent ICD implantation, 66 had negative EPS. Kaplan-Meier analysis showed that these patients were significantly less likely to receive appropriate therapy (7.6% vs 25.7%, p=0.003) and appropriate shock (0% vs 10.9%, p=0.004. The time to first appropriate ICD therapy was significantly longer in EPS negative patients (112 vs 93 months, p&amp;lt;0.001). The incidence of inappropriate therapies was similar in both groups (2.6% vs 5.8%, p=0.221). Conclusion ICD implantation does not reduce mortality in ischaemic patients with reduced EF and both positive and negative EPS. Patients with negative EPS and implanted ICD had much lower incidence of appropriate ICD therapies and no appropriate shocks. The policy of implanting ICDs to all ischaemic patients with EF&amp;lt;35% should be reconsidered.ICD shocks according to the EPS resultsMortality with and without ICD

Abstract 15327: Clinical Outcomes of Methamphetamine-Associated Cardiomyopathy Compared to Ischemic Cardiomyopathy: A Single Institution Retrospective Longitudinal Study

Background: Methamphetamine-associated cardiomyopathy (MAC) leads to significant morbidity and mortality. The benefit of implantable cardioverter-defibrillator (ICD) in this population is poorly characterized. Aims: To evaluate ICD use and outcomes in patients with MAC compared to ischemic cardiomyopathy (ICM). Methods: Electronic health record (EHR) was queried for all heart failure hospitalizations using ICD-9 codes between 2011 and 2019. Patients with an EF ≤ 35% were included. The MAC cohort was derived from this population and defined by ICD-9 code or positive urine toxicology and compared to ICM cohort. Baseline characteristics and outcomes were extracted from the EHR. MACE was defined as death, ventricular tachycardia, cardiac arrest, rehospitalization, atrial fibrillation (AF) or stroke. Results: The study included 294 patients in the MAC group and 373 patients in the ICM group. MAC patients were younger (56 vs 61 years, p&lt;0.001) compared to ICM (table 1). Readmission rates for heart failure at one year were similar (13% vs 11.2%, p=ns). Significantly fewer patients with MAC had ICD for primary prevention (15.0% vs 27.9%, p&lt;0.001). Mortality and AF were lower in MAC compared to ICM, however VT (2.38% vs 5.09%, p=0.072) and cardiac arrest (6.1% vs 7.8%, p=0.408) were similar between the two groups. MACE outcomes were worse in the ICM cohort (38.3% vs 21.1%, p=0.012) than MAC. In the MAC cohort, ICD presence was associated with 56.82% incidence of MACE compared to 40.00% without ICD (OR = 1.97, CI 1.032-3.77, p = 0.040) mainly due to higher AF hospitalization (22% vs 8%, p=0.01). Conclusion: ICM patients had higher mortality and atrial fibrillation compared to MAC. ICD implantation for primary prevention was not associated with reduced mortality, however this cohort had higher AF hospitalization. We need further studies to assess the benefit of ICD in MAC.

Abstract 16010: Sudden Death in the Systemic Right Ventricle: Single Center Study of Dextro-Transposition of the Great Arteries Palliated With Atrial Switch

Introduction: The incidence and risk factors for sudden cardiac death (SCD) in patients with systemic right ventricle (sRV) and D-TGA palliated with atrial switch procedures is not well understood. Methods: This cohort was examined retrospectively for the composite end point of SCD, sustained ventricular tachycardia (VT) &gt;30 s or appropriate ICD therapy for VT. Clinical characteristics of those with and without the end point were compared using the Kruskal-Wallis or Chi-square test as appropriate. Results: The composite end point occurred in 15 of 148 (10%) patients (63.5% male) at a mean age of 36.4 (SD 10.3) years. SCD occurred in 6 patients (n=2 successfully resuscitated), sustained VT in 6 patients and ICD therapy for VT in 3 patients who had previously received a primary prevention ICD. Patients with SCD/VT had lower sRV ejection fraction (EF) compared to patients without SCD/VT [28±11 vs 40±10%, P&lt;0.001]. The odds ratio of SCD/VT in patients with sRVEF≤35% compared to sRVEF&gt;35% was 13.3 (95% CI 2.8 - 64.4). Kaplan Meier analysis of time to SCD/VT stratified by sRV EF is presented in figure. QRS duration, QRS fragmentation, QTc and history of systemic AV valve surgery were not significantly associated with SCD/VT. Non-sustained ventricular tachycardia (NSVT) on Holter monitoring occurred more frequently in SCD/VT patients (80 vs 39%, p=0.003). All 11 survivors of SCD/VT received an ICD; appropriate ICD therapy occurred in 27% of these patients during follow-up. Conclusion: SCD or VT occurred in one-tenth of D-TGA patients palliated with atrial switch, predominantly in 3 rd and 4 th decade of life. Reduced sRV EF was the most important association and ICD implantation for primary prevention of SCD is a reasonable consideration in those with reduced sRV EF.

ICD/CRT-D Registry Ain Shams University Hospitals

Abstract Background The idea of the ICD registry was prompted from the National Coverage Decision that was published by the Centers for Medicare and Medicaid Services (CMS) in 2005 and based on the Sudden Cardiac Death in Heart Failure Trial, Ain Shams University Hospitals aim to take the lead by documenting the first ICD/CRT-D Registry in Egypt. Aim of the Work To capture the characteristics, treatments, and outcomes of patients receiving ICDs to improve care for patients receiving ICDs and CRT-Ds in Egypt. Methods 102 consecutive patient that received an ICD/CRT-D (initial or generator change) for primary or secondary prevention of SCD and came for ICD/CRT-D follow up at Ain Shams University hospitals pacemaker outpatient clinics in a timeline of one year (7-2019 till 11-2020). Results Males were around two thirds of cases (68.6%), and more than half of cases (52%) were smokers. Implantation for primary prevention of SCD was in 58.8% of patients. Most of cases had their ICDs follow-up at a time between 1 to 3 years after implantation. HFrEF was significantly more common in primary prevention group (93.3%) of patients of primary prevention group, while IsHD was the most common comorbidity in patients that had ICD implantation for secondary prevention of SCD (66.7% of them). Total complication rate was 6.86% including, pocket hematoma occurred in 2.9% of cases, and lead dislodgment that required repositioning without a plan to add a transvenous lead occurred in 3.9% of cases. Beta Blockers and Amiodarone were the most common drugs used among patients as regard 88.2% and 65.7% respectively. VTs and NSVTs were the most frequent post implantation events among the studied cases 45.1% and 42.2% respectively. 52% of patients had ATP therapy to events, Failed ATP therapy occurred in 60% of them. 33.3% of patient received ICD shock therapy, Inappropriate Shocks was in 20.6% of them. 50.9% of the patients had a bradycardia pacing as about 34% of patient had CRT-D for pump failure. VF detection zone interval was significantly longer in primary prevention group. No significant differences according to implantation indication regarding VT2 zone interval. Regarding VT1 zone; monitor only was the mainly action in 58.7% of patients. Only 20.6% of patients had VT1 zone off. Conclusion This observational and descriptive study provides strong evidence that ICD has an effective role to improve survival in primary and secondary prevention of SCD. We noticed increase in implantation rate of ICD for primary prevention of SCD who gain great benefits from the device later on, minimal complication rate of ICD implantation.

High-risk imaging characteristics in left ventricular apex for the life-threatening arrhythmic events in Japanese hypertrophic cardiomyopathy patients.

Left ventricular (LV) apical aneurysm is known to be associated with the life-threatening arrhythmic events in hypertrophic cardiomyopathy (HCM). However, the current 2014 ESC guideline has not included apical aneurysm as a major risk factor for sudden cardiac death and 2018 JCS guideline includes it only as a modulator, while it has been included as a new major risk marker in 2020 AHA/ACC guideline. Therefore, we sought to identify high-risk imaging characteristics in LV apex which is associated with a higher occurrence of ventricular tachycardia/fibrillation (VT/VF). In 99 consecutive Japanese HCM patients (median age, 65years; 59 males) undergoing implantable cardioverter-defibrillator (ICD) implantation for primary prevention following cardiac magnetic resonance including late gadolinium enhancement (LGE), the occurrence of appropriate ICD interventions for VT/VF was evaluated for 6.2 (median) years after ICD implantation. Overall, appropriate ICD interventions occurred in 43% with annual rates of 7.0% for appropriate interventions. Kaplan-Meier analysis demonstrated that the presence of LV apical aneurysm was significantly associated with a higher occurrence of appropriate interventions (annual rates 18.9% vs. 6.4%, P = 0.013). Similarly, patients with high LV mid-to-apex pressure gradient (annual rates 14.9% vs. 6.2%, P = 0.022) and presence of apical LGE (annual rates 10.9% vs. 4.0%, P = 0.001) experienced appropriate interventions more frequently. An aneurysm, high-pressure gradient, and LGE in an apex are associated with VT/VF. These characteristics in apex should be kept in mind when implanting ICD in Japanese HCM patients as a primary prevention.

Single- Versus Dual-Chamber Implantable Cardioverter-Defibrillator for Primary Prevention of Sudden Cardiac Death in the United States.

Background Routine addition of an atrial lead during an implantable cardioverter-defibrillator (ICD) implantation for primary prevention of sudden cardiac death, in patients without pacing indications, was not shown beneficial in contemporary studies. We aimed to investigate the use and safety of single- versus dual-chamber ICD implantations in these patients. Methods and Results Using the National Inpatient Sample database, we identified patients with no pacing indications who underwent primary-prevention ICD implantation in the United States between 2015 and 2019. Sociodemographic and clinical characteristics, as well as in-hospital complications, were analyzed. Multivariable logistic regression was used to identify predictors of in-hospital complications. An estimated total of 15 940 patients, underwent ICD implantation for primary prevention of sudden cardiac death during the study period, 8860 (55.6%) received a dual-chamber ICD. The mean age was 64 years, and 66% were men. In-hospital complication rates in the dual-chamber ICD and single-chamber ICD group were 12.8% and 10.7%, respectively (P<0.001), driven by increased rates of pneumothorax/hemothorax (4.6% versus 3.4%; P<0.001) and lead dislodgement (3.6% versus 2.3%; P<0.001) in the dual-chamber ICD group. Multivariable analyses confirmed atrial lead addition as an independent predictor for "any complications" (odds ratio [OR], 1.1 [95% CI, 1.0-1.2]), for pneumo/hemothorax (odds ratio, 1.1 [95% CI, 1.0-1.4]), and for lead dislodgement (odds ratio, 1.3 [95% CI, 1.1-1.6]). Conclusions Despite lack of evidence for clinical benefit, dual-chamber ICDs are implanted for primary prevention of sudden cardiac death in a majority of patients who do not have pacing indication. This practice is associated with increased risk of periprocedural complications. Avoidance of routine implantation of atrial leads will likely improve safety outcomes.

The Association between Statin Dosage and Malignant Ventricular Arrhythmias in Patients with Primary Prevention Implantable Cardioverter-defibrillators for Ischemic Cardiomyopathy

Background: Malignant ventricular arrhythmias are a common cause of death in ischemic heart diseases. Implantable cardioverter-defibrillators (ICDs) demonstrate significant efficacy in reducing mortality linked to ventricular arrhythmias. Statins exhibit the potential to stabilize the atherosclerotic and ischemic burden, thereby potentially manifesting indirect anti-arrhythmic effects. This study evaluated the relationship between statin levels and arrhythmic events in patients with primary prevention ICDs for ischemic cardiomyopathy. Methods: This study was conducted as a retrospective observational study at a single center, involving consecutive patients who were admitted to the cardiology outpatient clinic and underwent primary prevention ICD. The study population was stratified into two groups based on statin usage. Results: This study included a cohort of 80 patients diagnosed with ischemic cardiomyopathy who underwent primary prevention implantation of ICDs. Group 1 consisted of 24 patients who were prescribed low-dose statins, whereas Group 2 consisted of 56 patients who were prescribed high-dose statins. Univariate and multivariate analyses showed that left ventricular ejection fraction and use of low-dose statins were independent predictors of arrhythmic events. Conclusion: The study cohort exhibited comparable clinical and laboratory characteristics, suggesting that statin dosage is associated with malignant arrhythmic events in a homogeneous patient population.

Implantable cardioverter defibrillator for primary prevention in patients with non-ischemic cardiomyopathy in the era of novel therapeutic agents- meta-analysis.

Evidence regarding the mortality benefit of implantable cardioverter defibrillator (ICD) non-ischemic dilated cardiomyopathy (NIDCM) is inconsistent. The most recent randomized study, the DANISH trial, did not find improved outcomes with ICD. However, based on previous studies and meta-analyses, current guidelines still highly recommend ICD implantation in NIDCM patients. The introduction of novel medications for heart failure improved the clinical outcome dramatically. We aimed in this study to evaluate the effect of Angiotensin Receptor-Neprilysin Inhibitors (ARNi) and sodium-glucose transport protein 2 inhibitors (SGLT2i) on the mortality benefit of ICD in NIDCM. We used a previous metanalysis algorithm and added an updated comprehensive literature search in PubMed for randomized control trials that examined the mortality benefit of ICD in NIDCM vs. optimal medical treatment. The primary outcome included death from any cause. We did a meta-regression analysis to search for a single independent factor affecting mortality. Using previous data, we evaluated the theoretical effect of ICD implementation on patients treated with SGLT2 inhibitors and ARNi. No new articles were added to the results of the previous meta-analysis. 2,622 patients with NIDCM from 5 cohort studies published between 2002 and 2016 were included in the analysis. 50% of them underwent ICD implantation for primary prevention of sudden cardiac death, and 50% did not. ICD was associated with a significantly decreased risk for death from any cause compared to control (OR = 0.79, 95%CI: 0.66-0.95, p = 0.01, I2 = 0%). The theoretical addition of ARNi and the SGLT2 inhibitor dapagliflozin did not change the significant mortality effect of ICD (OR = 0.82, 95%CI: 0.7-0.9, p = 0.001, I2 = 0%) and (OR = 0.82, 95%CI: 0.7-0.9, p = 0.001, I2 = 0%). A meta-regression revealed no association between death from any cause and left bundle branch block (LBBB), use of amiodarone, use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers, year initiated enrollment, and the year ended enrollment (R2 = 0.0). In patients with NIDCM, the addition of ARNi and SGLT2i did not affect the mortality advantages of ICD for primary prevention. https://www.crd.york.ac.uk/prospero/, identifier: CRD42023403210.

MP-453086-1 THE USEFULNESS OF EPS TO PREDICT APPROPRIATE THERAPIES IN PRIMARY PREVENTION ICD PATIENTS

Current guidelines recommend ICD implantation for primary prevention in patients with LVEF ≤35% of both ischemic and nonischemic etiology, regardless of the results of the electrophysiological study. Some studies recently questioned this policy. We aimed to access the value of the EP study in long term prediction of the arrhythmic events in patients with reduced EF (≤35%) who underwent EPS and ICD implantation. We compared the risk for all-cause mortality in patients with negative EPS with and without ICD implantation and compared the risk for appropriate therapy according to the results of the EP study of patients who underwent ICD implantation in our institution. The median follow-up was 84 months. Of 293 patients, who underwent EPS, 159 had negative result (noninducible to VT). These patients were more likely to be female and have nonischemic etiology than patients with positive EPS. Patients did not differ in presence of diabetes, atrial fibrillation or ejection fraction. Kaplan-Meier survival analysis showed that there was no difference in mortality between the 2 groups (44.9% vs 42.0%, p=0.672). This was also true in both ischemic (53.2% vs 49.6%, p=0.554) and nonischemic (27.3% vs 27.3%, p=0.974) patients. Of 212 patients who underwent ICD implantation, 90 had negative EPS. Kaplan-Meier survival analysis showed that these patients were significantly less likely to receive appropriate therapy (5.7% vs 23.9%, p<0.0001) and appropriate shock (0% vs 9.7%, p=0.002), all appropriate shocks happened in the ischemic subgroup (0% vs 10.9%, p=0.004). The time to first appropriate ICD therapy was significantly longer in EPS negative patients (111 vs 92 months, p=0.001). The incidence of inappropriate therapies was similar in both groups (6.7% vs 5.8%, p=0.792). Age, gender, ischemic etiology, coronary disease risk factors, EF and NYHA class were not significantly associated with appropriate ICD therapy. ICD implantation did not reduce mortality in patients with reduced EF and negative EPS. Patients with negative EPS and implanted ICD had much lower incidence of appropriate ICD therapies and no appropriate shocks. EP study is useful to guide decisions about ICD implantation in patients with EF≤35%.

PO-04-075 TRANSVENOUS CARDIAC DEFIBRILLATOR WITHOUT INTERACTION WITH THE MAGNETIC TITANIUM BEADS SYSTEM FOR GASTROESOPHAGEAL REFLUX DISEASE

Gastroesophageal reflux is increasingly treated with LINX®, a flexible bracelet of magnetic titanium beads (not MRI compatible) that is laparoscopically implanted to wrap around the gastroesophageal junction for providing tone/support aiding passive relaxation of a weak lower esophageal sphincter with peristalsis. The FDA currently cautions against concurrent use of the LINX® system with cardiac implantable electronic devices (CIEDs) given that the risk of electromagnetic interference (EMI) is unknown, and safety has not been established. We assessed the safety of a transvenous ICD in a patient with the LINX® system. Case Report 59 year old male who previously had the LINX® system implanted after hiatal hernia repair for refractory reflux. Shortly after, he was then diagnosed with apical hypertrophic cardiomyopathy with obstruction (NYHA Class I, genetic testing revealed VUS in CSRP3). Given non-sustained VT on cardiac event monitoring, family history of sudden cardiac death (SCD) and late gadolinium enhancement on cardiac magnetic resonance imaging with a calculated 5-year SCD risk 4.1%, he was recommended ICD implantation for primary prevention. Patient underwent an uneventful transvenous dual chamber defibrillator implantation. Although we do not routinely perform (DFT) testing at our institution, given the coexisting LINX® system in close proximity to the RV lead, we elected to proceed with DFT Testing, which was successful (1 induction: T-wave shock from sinus to VF, 30J delivered successfully to sinus with 7s charge time, no ATP, 70 ohms impedance). Patient underwent routine remote device interrogations and at 1-year follow up (which included an in-person device interrogation), continues to have normal lead parameters (sensing, impedance, threshold), minimal atrial or ventricular pacing, and no recurrent arrhythmias including NSVT (was started on verapamil). Specifically, patient received no inappropriate shocks, and no high frequency noise episodes were detected. We present the first case report of a patient who had a concomitant dual chamber ICD that was implanted shortly after a LINX device placement. We demonstrate normal DFTs at implant and no device interaction at 1 year follow-up, suggesting that ICD implantation without removal of the LINX device might be reasonable. Decision-making for cardiac device implantation decisions in such patients should consider additional theoretical risks until additional data with more patients is available.