Primary Prevention ICD Research Articles

Programming of implantable cardioverter defibrillators for primary prevention: outcomes at centers with high vs. low concordance with guidelines.

While ICD therapy reduction programming strategies are recommended in current multi-society guidelines, concerns remain about a possible trade-off between the benefits of ICD therapy reduction and failure to treat episodes of ventricular arrhythmias. The study is to evaluate the outcomes of primary prevention patients followed in centers with high and low concordance with the 2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement and 2019 focused update on optimal ICD programming and testing guidelines. Consecutive patients with primary prevention ICD implantation from two centers between 2014 and 2016 were included. One center was classified as high guideline concordance center (HGC) with 47% (146/310) of patients with initial ICD concordant with the guidelines, and the other center was classified as low guideline concordance center (LGC) with only 1% (2/178) of patients with guideline-concordant initial ICD programming. Cox proportional hazard models were used to assess risk of first ICD therapy (ATP or shock), first ICD shock, and mortality. A total of 488 patients were included (mean age, 66 ± 13years). During a mean follow-up of 1.9 ± 0.9years, patients followed at HGC were 63% less likely to receive any ICD therapy (adjusted HR [aHR] 0.37, 95% CI 0.42-0.99). There were no significant differences in the rate of first ICD shock (aHR 0.72, 95% CI 0.34-1.52) or mortality (aHR 1.19, 95% CI, 0.47-3.05). Compared to primary prevention patients followed at LGC, primary prevention ICD patients followed at HGC received a significantly lower rate of ICD therapy, mainly from ATP reduction, without a difference in mortality during follow-up.

Abstract 13435: Utilization of Primary Prevention Implantable Cardioverter Defibrillator (ICD) Among Older Patients With Hypertrophic Cardiomyopathy (HCM): A Real World Analysis

Introduction: Guidelines differ for the use of primary prevention ICDs among patients with HCM, with particular ambiguity among older patients (age > 65). This analysis examined the utilization of primary prevention ICDs among older patients with HCM. Methods: NCDR ICD was queried to identify patients with HCM who received a primary prevention ICD between 2010-2016. Patient characteristics were reported overall and by age category. Trends in ICD utilization and relevant patient characteristics were assessed over time. Results: Of 5571 patients with HCM who were included, 1511 (27.1%) were > 65 years old. In comparison with younger HCM patients, those > 65 had higher NYHA class (III-IV 18.9% vs 12.3%, p<0.001), and more frequently had cardiovascular and non-cardiovascular co-morbidities (atrial fibrillation (40.6% vs 19.8%, p<0.001), ischemic heart disease (24.3% vs 8.3%, p<0.001), valvular disease (12.5% vs 7.2%, p<0.001), hypertension (79.2% vs 49.5%, p<0.001), cerebrovascular disease (12.3% vs 6.5%, p<0.001), chronic lung disease (15.0% vs 7.6%, p<0.001) and diabetes mellitus (23.2% vs 12.5%, p<0.001). Analyzing risk factors for sudden cardiac death (SCD), older patients had a lower prevalence of family history of SCD (20.3% vs. 30.1%), but a higher prevalence of syncope (34.3% vs 31%, p=0.019), NSVT (50.7% vs. 38.6%) and reduced LVEF (23.1% vs. 15.3%) (p<0.001 for all). ICD utilization increased over time in all age groups, but represented a similar percentage of the overall HCM cohort irrespective of age. There were no changes in the prevalence of risk factors for SCD over time (Figure). Conclusions: Older patients who received a primary prevention ICD had more cardiovascular and non-cardiovascular comorbidities and higher rates of certain SCD risk factors compared with younger patients with HCM. ICD utilization among older patients with HCM increased over time at a similar rate as observed among younger patients despite stable a prevalence of SCD risk factors.

Abstract 13443: Clinical Outcomes Following Primary Prevention Implantable Cardioverter Defibrillator (ICD) Implantation Among Older Patients With Hypertrophic Cardiomyopathy (HCM)

Introduction: The clinical benefit of primary prevention ICDs among older patients (age > 65) with HCM is unclear. This analysis examined procedural complications and post-discharge outcomes among older patients with HCM following initial placement of a primary prevention ICD. Methods: The NCDR ICD Registry was queried to identify patients with HCM who received a primary prevention ICD between 2010-2016. Procedure-related adverse event rates were examined. Direct identifiers were used to link patients > 65 years to CMS claims data. Cox proportional hazard models were used to assess clinical factors associated with post-discharge mortality and hospitalization for cardiac arrest/ventricular arrhythmia (VA). Kaplan Meier curves were generated to depict 5-year outcomes. Results: Of 5571 patients with HCM who were included, 1511 (27.1%) were > 65 years old. Compared with patients < 65 years of age, older patients with HCM were more likely to experience a procedure-related event (2.3% vs 1.5%, p=0.038) and procedure-related death (0.3% vs 0.1%, p=0.024). The variables most strongly associated with post-discharge mortality were older age (aHR 1.8, 95% CI 1.47-2.21), NYHA class (III/IV vs I/II aHR 2.17, 95% CI 1.57-2.98), and LVEF (LVEF < 35% vs >50% aHR 2.34, 95% CI 1.58-3.48; LVEF 36-50% vs >50% aHR 2.98, 95% CI 2.02-4.4). For the endpoint of hospitalization for cardiac arrest/VA, history of NSVT at the time of device implantation (aHR 2.38, 95% CI 1.62-3.51) and NYHA class (NYHA class III/IV vs I/II aHR 1.84, 95% CI 1.22-2.78) were the strongest predictors. The event-free survival rates are shown ( Figure). Conclusions: Procedure-related complication and mortality rates were low, but they occurred more frequently among older patients. Further prospective investigation should focus on whether clinical factors, such as NYHA class and history of NSVT, may be useful in identifying older patients with HCM who are most likely to benefit from a primary prevention ICD.

Abstract 10951: Temporal and Global Trends of the Incidence of Sudden Cardiac Death in Hypertrophic Cardiomyopathy: A Meta-Analysis

Introduction: Since hypertrophic cardiomyopathy(HCM) initial description, sudden cardiac death (SCD) has been the most feared complication of HCM. Hypothesis: Temporal, geographical, and age-related trends of SCD rates in HCM have drastically decreased over time. Methods: Databases were systematically searched to Nov 2021 for studies reporting on SCD event rates in HCM. Patients with SCD equivalents (appropriate ICD shocks and non-fatal SCD) were excluded. Random-effects model was utilized to pool study estimates calculating the overall incidence rates(IR) for each time-era, geographical region, and age-group. We analyzed 2 eras (before vs. after 2000, following implementation of ICD in HCM). Following 2000, 5-year intervals were used to reflect the temporal change in SCD. Results: 98 studies (N=70,510patients and 431,407patient-years) met inclusion criteria. Overall rate of HCM SCD was 0.43%/year (95% CI: 0.37-0.50%; I 2 =75%; SCD events:1,938; person-years of follow-up: 408,715), with young patients(<18 years) demonstrating a>2-fold-risk for SCD vs. adults(18-60years) (IR:1.09%; 95% CI: 0.69-1.73% vs. IR: 0.43%; 95% CI: 0.37-0.50%)(P-value for subgroup differences:<0.01). Contemporary SCD rates from 2015-present were 0.32%/year; significantly lower compared to 2000 or earlier (IR: 0.32%; 95% CI:0.20-0.52%, vs. IR: 0.73%; 95% CI:0.53-1.02%,respectively). Reported HCM-SCD rates were lowest in North America (IR: 0.28%;95% CI:0.18-0.43%) and highest in Asia(IR: 0.67%; 95% CI:0.54-0.84%). Conclusions: Contemporary HCM-related SCD are low (0.32%/year) representing a 2-fold decrease compared to prior treatment eras, with young HCM patients at the highest risk. SCD risk stratification maturation and primary prevention ICD application are likely responsible for the notable decline in SCD trends. Moreover, worldwide geographical disparities in SCD was evident, underscoring the need to increase access to SCD prevention for all HCM patients.

Clinical outcomes of subcutaneous vs. transvenous implantable defibrillator therapy in a polymorbid patient cohort.

The subcutaneous implantable cardioverter-defibrillator (S-ICD) has been designed to overcome lead-related complications and device endocarditis. Lacking the ability for pacing or resynchronization therapy its usage is limited to selected patients at risk for sudden cardiac death (SCD). The aim of this single-center study was to assess clinical outcomes of S-ICD and single-chamber transvenous (TV)-ICD in an all-comers population. The study cohort comprised a total of 119 ICD patients who underwent either S-ICD (n = 35) or TV-ICD (n = 84) implantation at the University Hospital Frankfurt from 2009 to 2017. By applying an inverse probability-weighting (IPW) analysis based on the propensity score including the Charlson Comorbidity Index (CCI) to adjust for potential extracardiac comorbidities, we aimed for head-to-head comparison on the study composite endpoint: overall survival, hospitalization, and device-associated events (including appropriate and inappropriate shocks or system-related complications). The median age of the study population was 66.0 years, 22.7% of the patients were female. The underlying heart disease was ischemic cardiomyopathy (61.4%) with a median LVEF of 30%. Only 52.9% had received an ICD for primary prevention, most of the patients (67.3%) had advanced heart failure (NYHA class II-III) and 16.8% were in atrial fibrillation. CCI was 5 points in TV-ICD patients vs. 4 points for patients with S-ICD (p = 0.209) indicating increased morbidity. The composite endpoint occurred in 38 patients (31.9 %), revealing no significant difference between patients implanted with an S-ICD or TV-ICD (unweighted HR 1.50, 95 % confidence interval (CI) 0.78-2.90; p = 0.229, weighted HR 0.94, 95% CI, 0.61-1.50, p = 0.777). Furthermore, we observed no difference in any single clinical endpoint or device-associated outcome, neither in the unweighted cohort nor following inverse probability-weighting. Clinical outcomes of the S-ICD and TV-ICD revealed no differences in the composite endpoint including survival, freedom of hospitalization and device-associated events, even after careful adjustment for potential confounders. Moreover, the CCI was evaluated in a S-ICD cohort demonstrating higher survival rates than predicted by the CCI in young, polymorbid (S-)ICD patients.

Use of Sacubitril/Valsartan Prior to Primary Prevention Implantable Cardioverter Defibrillator Implantation

BackgroundImplantable cardioverter defibrillators (ICDs) are an adjunct to guideline-directed medical therapy for heart failure with reduced ejection fraction. The uptake of sacubitril/valsartan in this population is not well described. We report the uptake and factors associated with sacubitril/valsartan use in patients with left ventricular dysfunction undergoing ICD implantation. MethodsA retrospective chart review was performed on all patients with left ventricular dysfunction who underwent de novo primary prevention ICD implantation between October 2015 and December 2021 (n = 422) at Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. Pre-procedure sacubitril/valsartan use was determined. Logistic regression analysis was performed to examine factors associated with sacubitril/valsartan use. A Bayesian estimator of abrupt change was employed to determine a time period in which a change in the rate of sacubitril/valsartan use occurred. ResultsLoop diuretic use (odds ratio [OR] = 2.20) and higher severity of New York Heart Association class symptoms (OR = 1.62) were associated with sacubitril/valsartan use. Sacubitril/valsartan use increased during the study period, to 59% in December 2021. This increase was larger among those aged ≥ 65 years (OR = 1.09). A change in the rate of sacubitril/valsartan use occurred 3 years after drug approval, 1 year after provincial drug coverage became available, and 6 months after being strongly recommended in clinical guidelines. ConclusionsIn a contemporary cohort of ICD patients, sacubitril/valsartan use increased between 2015 and 2021, notably in those aged ≥ 65 years and after government drug coverage became available. Understanding barriers to sacubitril/valsartan use in ICD patients is recommended to improve clinical outcomes and survival in this population.

Preventive substrate ablation in chronic post-myocardial infarction patients with high-risk scar characteristics for ventricular arrhythmias: rationale and design of PREVENT-VT study.

Recent studies showed that an early strategy for ventricular tachycardia (VT) ablation resulted in reduction of VT episodes or mortality. Cardiac magnetic resonance (CMR)-derived border zone channel (BZC) mass has proved to be a strong non-invasive predictor of VT in post-myocardial infarction (MI). CMR-guided VT substrate ablation proved to be safe and effective for reducing sudden cardiac death (SCD) and VA occurrence. PREVENT-VT is a prospective, randomized, multicenter, and controlled trial designed to evaluate the safety and efficacy of prophylactic CMR-guided VT substrate ablation in chronic post-MI patients with CMR-derived arrhythmogenic scar characteristics. Chronic post-MI patients with late gadolinium enhancement (LGE) CMR will be evaluated. CMR images will be post-processed and the BZC mass measured: patients with a BZC mass > 5.15g will be eligible. Consecutive patients will be enrolled at 3 centers and randomized on a 1:1 basis to undergo a VT substrate ablation (ABLATE arm) or optimal medical treatment (OMT arm). Primary prevention ICD will be implanted following guideline recommendations, while non-ICD candidates will be implanted with an implantable cardiac monitor (ICM). The primary endpoint is a composite outcome of sudden cardiac death (SCD) or sustained monomorphic VT, either treated by an ICD or documented with ICM. Secondary endpoints are procedural safety and efficiency outcomes of CMR-guided ablation. In some patients, the first VA episode causes SCD or severe neurological damage. The aim of the PREVENT-VT is to evaluate whether primary preventive substrate ablation may be a safe and effective prophylactic therapy for reducing SCD and VA occurrence in patients with previous MI and high-risk scar characteristics based on CMR. ClinicalTrials.gov, NCT04675073, registered on January 1, 2021.

Clinical outcome and mortality in patients with ICD for primary prevention

Abstract Background ICD (Implantable Cardiac Defibrilator) for primary prevention is indicated in patients with EF ≤35% and NYHA class II–III heart failure despite at least 3 months of optimal medical therapy.However, the studies that form the basis of this recommendation belong to more than 20 years ago. These studies may not reflect the characteristics and treatment of current heart failure patients. Therefore, the effect of ICD for primary prevention on prognosis may have been changed. Recent studies have called into question the effectiveness of the ICD in primary prevention. Aim The aim of our study is to evaluate the patients who had ICD for primary prevention implanted retrospectively. Method The primary outcomes of all-cause death and sudden death were compared in patients who underwent ICD for primary prevention at our clinic between 01.01.2015 and 01.03.2020 and patients with ICD indication but who did not accept this treatment. Results Of the 228 patients who had ICD for primary prevention implanted, 175 (76.8%) were male.The mean age of the patients was 65.63±11.94 years. The mean follow-up period of the patients was 39.45±18.89 months. The mean left ventricular ejection fraction of the patients was found to be 24.30±6.19%. Procedural complications developed in 36 (15.8%) of 228 patients. When these complications were analyzed according to the gender of the patients, complications developed in 21 (12%) of 175 male patients and 15 (28.3%) of 53 female patients (p: 0.004). When the ICD implanted group and the control group were compared in terms of all cause mortality, 67 (29.4%) of 228 patients in the ICD arm and 39 (26%) of 150 patients in the control group died due to all causes mortality (p: 0.473) (Figure 1). When the ICD implanted group and the control group were compared in terms of sudden death, 2 patients in the ICD arm and 8 patients in the control group had sudden death (p: 0.017). Age, left ventricular ejection fraction, BNP value, and previous hospitalization due to decompensation heart failure were found to be independent predictors of all-cause mortality by multiple logistic regression method. Mortality was 3.4 times higher in patients who were hospitalized with decompensated heart failure before the procedure. In the ICD implanted group, the all-cause mortality of patients with a BNP value above 508.5, LVEF value below 24.5%, and age greater than 68.5 was 25 times higher than in other patients (Wald: 9.938 OR (95% Cl): 0.039 (0.005–0.293) p: 0.002) (Table 1). It was found that the presence of coronary artery disease was not an independent risk factor. Conclusion Our patient population and our findings are compatible with current life data. We think that the recommendations for ICD for primary prevention implantation in the guidelines may be downgraded in the future with current treatment options. It will be important to determine which patient population will most benefit from the ICD treatment for primary prevention. Funding Acknowledgement Type of funding sources: None.

Utilization and in-hospital complications associated with implantation of dual versus single chamber implantable cardioverter defibrillator for primary prevention of sudden cardiac death

Abstract Introduction Multiple studies showed no clinical benefit in implantation of a dual compared to a single chamber implantable cardioverter defibrillator (dICD vs. sICD) for primary prevention of sudden cardiac death (SCD), in patients with no pacing indication. We aimed to investigate the extent of utilization and complications in sICD vs. dICD implantations in the US, using the National In-Patient Sample (NIS) database. Methods Using the NIS database, we identified patients who underwent an elective ICD implantation in the US between 2015 (last quarter)-2019. Patients who had concurrent conduction disorders or indication for atrial pacing were excluded. Baseline demographics, clinical characteristics, cardiomyopathy etiologies as well as outcomes including in-hospital complications, length of stay and mortality were collected. Multivariable logistic regression models were used to identify predictors of complications. Results and discussion An estimated total of 15940 patients, who underwent elective ICD implantation for primary prevention of SCD were identified, 8860 (55.6%) of them received a dICD. Forty percent of patients had ischemic cardiomyopathy. The mean age was 64 years and 66% were males. The complication rates documented in the dICD and sICD groups were 13% and 11%, respectively (p<0.001),driven by increased rate of pneumothorax (4.8% vs 3.2%, p<0.001) and lead dislodgement (3.6% vs 2.3%, p<0.001, Table 1). Multivariate analysis confirmed adding an atrial lead as an independent risk factor for “any complication” during ICD implantation [OR 1.13 (1.02–1.25), p=0.022] as well as for pneumo/hemothorax [OR 1.21 (1.03–1.44), p=0.025] and lead dislodgement [OR 1.41 (1.16–1.72), p<0.001]. Conclusion Despite significant evidence for lack of clinical benefit in adding an atrial lead to a primary prevention ICD implantation, significant proportion of the patients in the US are implanted with a dICD. We show increased risk for complications for dICD compared with sICD implantation in the US in recent years, driven by higher incidence of pneumo/hemothorax and lead dislodgement. Funding Acknowledgement Type of funding sources: None.

Sudden cardiac death in children cardiomyopathy – a French study

Cardiomyopathies in children are rare and heterogeneous diseases whose rhythmic risk is difficult to stratify. We set up a retrospective and multicenter observational cohort in the Nord-Pas-de-Calais region in France from 2009 to 2019 in 11 medical centers. We included 224 pediatric patients (diagnosis ≤ 18 years) followed for cardiomyopathy including 72 hypertrophic cardiomyopathies (HCM). The objectives of our study were to describe patients who presented with severe arrhythmias in HCM, to highlight risk factors, to calculate the HCM Risk-Kids in our HCM patients. In our HCM cohort, event-free survival was 82% at 5 years. Of the 77 HCM, 11 presented with sudden death. The HCM Risk-Kids was calculated at 6.2% on average. Age at diagnosis > 9 years increased by 5.3 times the rhythmic risk ( P = 0.023). The presence of a genetic mutation also seemed to be associated with an increased risk, but this result was not significant ( P = 0.059). An HCM Risk-kids ≥ 6% was significantly associated with rhythmic risk ( P = 0.015). For a threshold of 6%, the Positive Predictive Value of the HCM Risk-Kids was only 27% and the Negative Predictive Value of 95%. Among the 21 patients implanted with an ICD for primary prevention in whom the HCM Risk-Kids could be calculated: 4 had a score < 4% when the ICD was fitted, 7 had a score between 4 and 6% and 9 a score ≥ 6%. The only patient who used his ICD had a score of 9.4% ( Fig. 1 ). Regarding the calculation of the HCM Risk Kids in the HCM population, even if this score has the merit of existing, it is not sufficient on its own to predict the risk of sudden death at 5 years in this population and should probably be coupled with the patient's genetic and MRI data to better stratify the rhythmic risk.

Implantable cardioverter-defibrillator placement among patients with left ventricular ejection fraction ≤35 % at least 40 days after acute myocardial infarction

BackgroundImplantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death among patients with persistently reduced (≤35 %) left ventricular ejection fraction (LVEF) at least 40 days following acute myocardial infarction (AMI). Few prior studies have used LVEF measured after the 40-day waiting period to examine primary prevention ICD placement. MethodsWe sought to determine factors associated with ICD placement among patients who met LVEF criteria post-MI within a large integrated health care system in the U.S by conducting a retrospective cohort study of Veteran patients hospitalized for AMI from 2004 to 2017 who had documented LVEF ≤35 % from echocardiograms performed between 40 and 455 (90 days +1 year) days post-MI. We used multivariable logistic regression to examine factors associated with ICD placement. ResultsOf 12,893 patients with LVEF ≤35 % at least 40 days post-MI, 2176 (16.9 %) received an ICD between 91- and 455-days post-MI. Younger age, fewer comorbidities, revascularization with PCI, and greater use of GDMT were associated with increased odds of receiving an ICD. However, half of patients treated with a beta-blocker, ACE inhibitor or angiotensin receptor blocker, and mineralocorticoid receptor antagonist prior to LVEF assessment did not receive an ICD. Eligible Black patients were less likely (odds ratio 0.80, 95 % confidence interval 0.69–0.92) to receive an ICD than White patients. ConclusionMany factors affect ICD placement among Veteran patients with a confirmed LVEF ≤35 % at least 40 days post-MI. Greater understanding of factors influencing ICD placement would help clinicians ensure guideline-concordant care.

Impact of coronary anatomy and residual syntax score on arrhythmic events in patients with ischemic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background ICD implantation is a cornerstone for primary prevention in patients with ischemic cardiomyopathy and impaired left ventricular function; reduced ejection fraction alone, however, doesn’t seem enough to discriminate which patients will really experience arrhythmic events in the follow up. Purpose We hypothesized that coronary anatomy and the extent of residual coronary lesions, measured with syntax score, could be a better predictor of the outcome in this setting. Materials and method Data of all patients implanted with single or dual chamber ICD in primary prevention for ischemic cardiomyopathy from 2011 to 2020 were retrospectively collected, together with follow up data obtained from clinical visits and ICD remote monitoring. Residual syntax score (RSS) was calculated for each patient, taking into consideration the last coronary angiography performed before ICD implantation. Results 110 patients were included in our registry. 90.1% were male, mean age was 66±7 years. 23.6% ICD were dual chamber devices. 96 (87.2%), 8 (7.3%) and 6 (5.5%) patients presented respectively with low (0-22), intermediate (23-32) or high (≥33) RSS. After a mean follow up of 4.4±2.9 years, 31 patients (28.2%) died; 20 patients (18.2%) and 27 patients (24.5%) received any appropriate ICD therapy, either shock or ATP. 12 patients (10.9%) experienced inappropriate shock. The composite outcome of death or any appropriate therapy (MACE) was observed in 47 patients (42.7%); left main or left descending artery stenosis were predictors of MACE (p = 0.026 and p = 0.040, respectively). Intermediate or high RSS was the only predictor of appropriate shock (p = 0.046). Conclusions Coronary anatomy and residual coronary stenosis quantified with syntax score are promising predictors of arrhytmic events during the follow up in patients with ischaemic cardiomyopathy and ICD implanted in primary prevention.

Discussions on implantable cardioverter defibrillator deactivation in patients receiving radiation therapy

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): University of Toronto Background Established guidelines discuss ICD deactivation and end of life care in ICD patients. A previous study has suggested that 45% of patients with an ICD and do not resuscitate order have not discussed ICD deactivation. In patients receiving radiation therapy for cancer ICD deactivation should be discussed given the life limiting nature of cancer, however it is unclear how frequently this topic is discussed in clinical practice. Objectives To report on the frequency of discussions of ICD deactivation in a population of patients receiving radiation therapy for cancer. Methods Our hospital is a large regional cancer and cardiac center in Canada. Consecutive patients of our institution presenting to our ICD clinic for ICD checks prior and during receipt of radiation therapy between 2005 and 2019 were included (n=43). Electronic medical records were reviewed to determine demographics, clinical characteristics, documentation of discussions on ICD deactivation, and survival at 1-year. Results The cohort was predominantly male (84%), with a primary prevention ICD (65%) without resynchronization capacity (74%). Discussions on ICD deactivation with subsequent deactivations occurred in 12 (28%) patients. During a median follow-up of 4 years 25 patients died, with 28% of these patients dying within 2 years of the ICD clinic encounter. Discussions on ICD deactivation were more frequent in patients who received a palliative care consultation. Conclusions End of life conversations regarding ICD deactivation in patients undergoing radiation therapy for cancer are rare. Collaboration with palliative care teams may facilitate conversations on ICD deactivation during this opportune time.

C30 IMPACT OF CORONARY ANATOMY AND RESIDUAL SYNTAX SCORE ON ARRHYTHMIC EVENTS IN PATIENTS WITH ISCHEMIC CARDIOMYOPATHY

Abstract Background ICD implantation is a cornerstone for primary prevention in patients with ischemic cardiomyopathy and impaired left ventricular function; reduced ejection fraction alone, however, doesn’t seem enough to discriminate which patients will really experience arrhythmic events in the follow up. We hypothesized that coronary anatomy and the extent of residual coronary lesions, measured with syntax score, could be a better predictor of the outcome in this setting. Materials and Methods Data of all patients implanted with single or dual chamber ICD in primary prevention for ischemic cardiomyopathy from 2011 to 2020 were retrospectively collected, together with follow up data obtained from clinical visits and ICD remote monitoring. Residual syntax score (RSS) was calculated for each patient, taking into consideration the last coronary angiography performed before ICD implantation. Results 110 patients were included in our registry. 90.1% were male, mean age was 66±7 years. 23.6% ICD were dual chamber devices. 96 (87.2%), 8 (7.3%) and 6 (5.5%) presented respectively with low (0–22), intermediate (23–32) or high (≥33) RSS. After a mean follow up of 4.4±2.9 years, 31 patients (28.2%) died; 20 patients (18.2%) and 27 patients (24.5%) received any appropriate ICD therapy, either shock or ATP. 12 patients (10.9%) experienced inappropriate shock. The composite outcome of death or any appropriate therapy (MACE) was observed in 47 patients (42.7%); left main or left descending artery stenosis were predictors of MACE (p = 0.026 and p = 0.040 respectively). Intermediate or high RSS was the only predictor of appropriate shock (p = 0.046). Conclusions Coronary anatomy and residual coronary stenosis quantified with syntax score are promising predictors of arrhythmic events during the follow up in patients with ischaemic cardiomyopathy and ICD implanted in primary prevention.

P23 TIMING OF EJECTION FRACTION REASSESSMENT AFTER SACUBITRIL–VALSARTAN INITIATION FOR INDICATION TO DEFIBRILLATOR IMPLANTATION. A SINGLE CENTER EXPERIENCE

Abstract Background Sacubitril/Valsartan (SV) has been validated for heart failure (HF) with reduced ejection fraction (EF) treatment. SV is effective on hard end–points as well as symptoms and heart remodeling. Present guidelines reccomend at least 3 month of optimized medical therapy (OMT). However, the best timing of EF assessment after SV initiation in order to proceed with defibrillator (ICD) implantation, is still unknown. Purpose Evaluate timing of improvement of EF after SV initiation in patients (pts) with systolic HF, candidates to primary prevention ICD implantation. Methods From 1 of february 2018, we evaluated retrospectively clinical and echocardiographic data of all consecutive pts with EF &amp;lt; 35% treated with SV and candidates to primary prevention ICD implantation. We evaluated clinical and echo follow up (Fup). Results have been analyzed with paired T–test. Results The study involved 95 pts (mean age 67±10 years, 70% male, ischaemic etiology 48%). Mean EF at enrollment was 30 ± 5% (ED vol 90 ±23 ml/m2; ES vol 62 ± 19 ml/m2, severe MR 23%) and NYHA III–IV 50%. In 58% pts reached the target dose of SV (97/103 mg bid). After a mean Fup of 6 months, mean EF of the study population increased to 37±7% (ED vol 80±19 ml/m2, ES vol 51±17 ml/m2, severe MR 5%, p &amp;lt; 0.001), and NYHA III–IV decreased to 8% (p = 0.01). Interestingly, thirty–one pts (32%) had their first Fup within 3 months and showed already an improvement [meanEF 28±5% to 35±6%; ΔEF 7±6%; NYHA III–IV 10 %]. Moreover, 49 pts (51%) had last Fup echo after 1 year (mean 13±6 months) and showed a further EF improvement (meanEF 41±8%; ΔEF 12±9%; p &amp;lt; 0.001).Sixteen pt (16%) underwent ICD (62%) or CRT–D (38%) implantation after 3±2 months of treatment and excluded from further FUP analysis. More favorable effects of treatment with SV were more evident in patient with non–ischaemic etiology of heart failure. Conclusions After SV initiation in systolic HF, favourable heart remodeling is clearly evident at 6 months FUP, but could be already observed after 3 months . These findings need to be validated from larger trials but suggest that the best timing of EF reassessment to decide for primary prevention ICD is likely between 3 and 6 months after SV initiation. However decision must be taken following close and individualized FUP for every patient, based on clinical characteristics and response to OMT.

CI-524-04 RISK OF VENTRICULAR ARRHYTHMIAS FOLLOWING IMPLANTABLE CARDIOVERTER DEFIBRILLATOR GENERATOR CHANGE IN PATIENTS WITH RECOVERED EJECTION FRACTION: IMPLICATIONS FOR SHARED DECISION MAKING

Primary-prevention ICDs are indicated for most patients with LVEF ≤35%. Some patients improve their LVEF to >35% during the life of their first ICD. In present practice, when the battery is depleted, ICDs most often are replaced regardless of LVEF. In patients with recovered LVEF who have never received appropriate ICD therapy, the utility of ICD generator replacement remains unclear.

Sex differences in ICDs for primary prevention: Time to include women in ICD trials!

Sex differences in ICDs for primary prevention: Time to include women in ICD trials!

Longitudinal Arrhythmic Risk Assessment Based on Ejection Fraction in Patients with Recent-Onset Nonischemic Dilated Cardiomyopathy

Practice guidelines suggest the use of implantable cardioverter-defibrillators in patients with left ventricular ejection fractions (LVEF)≤35% despite 3 to 6months of guideline-directed medical therapy (GDMT). It remains unclear whether this strategy is appropriate for patients with dilated cardiomyopathy (DCM), who can experience reverse ventricular remodeling for up to 24months after the initiation of GDMT. The aim of this study was to assess the longitudinal dynamic relationship between LVEF ≤ 35% and arrhythmic risk in patients with recent-onset nonischemic DCM on GDMT. A retrospective analysis was conducted among patients with recent-onset DCM (≤6months) and recent initiation of GDMT (≤3months) consecutively enrolled in a longitudinal registry. Risk for major ventricular arrhythmic events or sudden cardiac death was assessed in relationship to LVEF ≤ 35% at enrollment and 6 and 24months after initiation of GDMT. Five hundred forty-four patients met the inclusion criteria. LVEF ≤ 35% identified patients with increased risk for major ventricular arrhythmic events or sudden cardiac death starting from 24months after initiation of GDMT (hazard ratio, 2.126; 95% CI, 1.065-4.245; P=.03). However, LVEF ≤ 35% at presentation or 6months after enrollment did not have prognostic significance. Sixty-seven percent of 131 patients with LVEF ≤ 35% at 6months after initiation of GDMT had improved LVEFs (to >35%) by 24months. This late LVEF improvement correlated with lower arrhythmic risk (P=.012) and was preceded by a reduction of LV dimensions in the first 6months of GDMT. In patients with DCM, the present findings suggest that risk stratification for major ventricular arrhythmic events or sudden cardiac death on the basis of LVEF ≤ 35% is effective after 2years of GDMT, but not after 6months. In selected patients with DCM, it would be appropriate to wait 24months before primary prevention ICD implantation.

Sudden Cardiac Death Risk over Time in HCM Patients with Implantable Cardioverter-Defibrillator.

Background: In patients with HCM at high risk of SCD, an ICD should be considered as a standard of care. Current risk approximation algorithms recommended by ESC 2014 criteria indicate that SCD risk is not stable. The aim of the study was to investigate how the calculated SCD risk in HCM patients with an ICD implanted in the past changed over time. Methods: We analyzed 64 HCM patients with ICD for primary prevention, referred for ICD re-implantation, and 32 HCM patients referred for a first-time ICD placement during the same period. The 5-year-SCD risk was assessed for suitable patients using the recommended ESC calculator. Results: The first-time group had a higher 5-year-SCD risk than those referred for ICD re-implantation: 7.50 (IQR 5.98–10.46) vs. 4.88 (IQR 3.42–7.25), p < 0.05. Out of the patients with an initial calculated risk below 4%, the risk increased in 22% of cases, reaching the 4–6% range. In 78% of patients, the risk remained stable and low. In 31% of patients with an initial calculated SCD risk ≥ 6%, the risk decreased over time to below 6%, and in 14% of the cases, below 4%. Conclusions: SCD risk in HCM patients is usually stable or gets lower. Our data suggest it is important to re-evaluate the risk profile for patients with HCM when ICD re-implantation is considered.

The year in cardiovascular medicine 2021: arrhythmias.

Randomized trials reported on food supplements to prevent atrial fibrillation (AF),1 screening for AF,22 and left atrial appendage occlusion41 to prevent stroke and novel pacing strategies to prevent death in heart failure patients33 or syncope recurrence.35 In RATE-AF, digoxin was superior to bisoprolol,27 illustrating an old drug can be effective if wisely applied with a patient-oriented endpoint. To improve the impact of primary prevention ICD, the MADIT-ICD benefit score balances the risk of sudden cardiac death and the competing risk of non-arrhythmic death50 (calculator at https://redcap.urmc.rochester.edu/redcap/surveys/index.php?s=3H888TJ8N7). The worldwide differences in ICD usage56 further support a unified approach focusing on ICD benefits. Contrary to current guidelines, the EAST-AFNET4 substudy suggests that (early) rhythm control benefits asymptomatic and symptomatic patients alike concerning cardiovascular endpoints.57 Alcohol does not protect from AF no matter dose or type of alcohol (Csengeri study),3 although the latter is at variance with another recent BIOBANK study.7 Stopping consuming alcohol after detection of AF may reduce stroke;5 it may also reduce the recurrence of AF after ablation.6 Less AF24,25 and stroke25 was also seen with higher levels of physical activity (PA) as measured by modern day monitoring technology (#) in LOOP trial24 and UK Biobank.25 Also from the UK Biobank: long-term night shift work may cause AF.8