Implantable Cardioverter-defibrillator Registry Research Articles

Survival Probability and Survival Benefit Associated With Primary Prevention Implantable Cardioverter-Defibrillator Generator Changes.

BackgroundAs patients derive variable benefit from generator changes (GCs) of implantable cardioverter‐defibrillators (ICDs) with an original primary prevention (PP) indication, better predictors of outcomes are needed.Methods and ResultsIn the National Cardiovascular Data Registry ICD Registry, patients undergoing GCs of initial non‐cardiac resynchronization therapy PP ICDs in 2012 to 2016, predictors of post‐GC survival and survival benefit versus control heart failure patients without ICDs were assessed. These included predicted annual mortality based on the Seattle Heart Failure Model, left ventricular ejection fraction (LVEF) >35%, and the probability that a patient's death would be arrhythmic (proportional risk of arrhythmic death [PRAD]). In 40 933 patients undergoing GCs of initial noncardiac resynchronization therapy PP ICDs (age 67.7±12.0 years, 24.5% women, 34.1% with LVEF >35%), Seattle Heart Failure Model–predicted annual mortality had the greatest effect size for decreased post‐GC survival (P<0.0001). Patients undergoing GCs of initial noncardiac resynchronization therapy PP ICDs with LVEF >35% had a lower Seattle Heart Failure Model–adjusted survival versus 23 472 control heart failure patients without ICDs (model interaction hazard ratio, 1.21 [95% CI, 1.11–1.31]). In patients undergoing GCs of initial noncardiac resynchonization therapy PP ICDs with LVEF ≤35%, the model indicated worse survival versus controls in the 21% of patients with a PRAD <43% and improved survival in the 10% with PRAD >65%. The association of the PRAD with survival benefit or harm was similar in patients with or without pre‐GC ICD therapies.ConclusionsPatients who received replacement of an ICD originally implanted for primary prevention and had at the time of GC either LVEF >35% alone or both LVEF ≤35% and PRAD <43% had worse survival versus controls without ICDs.

The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Report 2020

The Pacemaker (PM) and Implantable Cardioverter-Defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers. For the year 2020, the main data about national PM and ICD implantation activity were obtained on the basis of European Cards and subsequently analyzed to create a standard report. PM Registry: data about 22 080 PM implantations were collected (18 027 first implants and 3803 replacements). The number of collaborating centers was 142. Median age of treated patients was 82 years (75 quartile I; 87 quartile III). ECG indications included atrioventricular conduction disorders in 31.0% of first PM implants, sick sinus syndrome in 13.8%, atrial fibrillation plus bradycardia in 9.9%, other unspecified ECG and electrophysiological abnormalities in 36.6%. Use of single-chamber PMs was reported in 29.0% of first implants, of dual-chamber PMs in 68.2%, of PM with cardiac resynchronization therapy (CRT) in 2.7%. ICD Registry: data about 11 931 ICD implantations were obtained (8266 first implants and 3665 replacements). The number of collaborating centers was 330. Median age of treated patients was 72 years [63 quartile I; 79 quartile III]. Primary prevention indication was reported in 85.0% of first implants, secondary prevention in 15.0% (cardiac arrest in 4.2%). A single-chamber ICD was used in 30.2% of first implants, dual-chamber ICD in 31.2% and biventricular ICD in 38.6%. In the calendar year 2020, the Italian PM Registry showed stable ECG and symptom indications, with an important prevalence of dual-chamber pacing. The ICD Registry documented a large use of prophylactic and biventricular ICDs, reflecting a favorable adherence in clinical practice to trials and guidelines. The ICD longevity and the number of recalls demonstrated a favorable trend. In order to increase and optimize the cooperation of Italian PM and ICD implanting centers, the online data entry (https://www.aiac.it/riprid) should be adopted at large scale.

Trends in Use of Single- vs Dual-Chamber Implantable Cardioverter-Defibrillators Among Patients Without a Pacing Indication, 2010-2018

Use of dual-chamber implantable cardioverter-defibrillator (ICD) systems among patients without a pacing indication is an example of low-value care given higher procedural risks, higher costs, and little evidence for benefit from an atrial lead. However, variation in the use of dual-chamber systems was present among patients without a pacing indication. To examine the temporal trends and hospital variation in use of single- and dual-chamber ICD implantation among patients without a pacing indication undergoing first-time ICD implantation. A multicenter cross-sectional study was conducted using the US National Cardiovascular Data Registry ICD Registry. A total of 266 182 patients undergoing initial implantation of a single- or dual-chamber transvenous ICD without a bradycardia pacing indication, class I or II cardiac resynchronization therapy indication, or history of atrial fibrillation or atrial flutter were included. The study was conducted from April 1, 2010, to December 31, 2018; data analysis was performed from October 19, 2020, to January 5, 2022. Implantation of a single- or dual-chamber ICD. Temporal trends among patients undergoing single- vs dual-chamber ICDs were determined using the Cochran-Armitage trend test, and hospital-level variation using adjusted hospital median odds ratios was examined. A total of 266 182 patients (single-chamber ICD, 134 925; dual-chamber ICD, 131 257) were included in this analysis; mean (SD) age was 58.0 (14.0) years and 91 990 patients (68.2%) were men. The use of dual-chamber ICDs decreased from 64.7% (n = 15 694) in 2010 to 42.2% (n = 9762) in 2018 (P < .001). Adjusted for patient characteristics, the median hospital-level proportion of single-chamber ICDs increased from 42.9% (95% CI, 42.6%-45.0%) in 2010 to 50.0% (95% CI, 47.8%-51.0%) in 2018. The median odds ratio for the use of dual-chamber ICDs, adjusted for patient characteristics, was 1.6 (95% CI, 1.6-1.8) in 2010 and 1.5 (95% CI, 1.5-1.8) in 2018, indicating decreasing but persistent variation in use. In this national study of US patients undergoing first-time ICD implantation without a clinical indication for an atrial lead, the use of dual-chamber devices decreased. However, institutional variability in the use of atrial leads persists, suggesting differences in individual or institutional cultures of real-world practice and opportunity to reduce this low-value practice.

Familial risk of atrioventricular block in first-degree relatives

ObjectiveRare cases of genetically inherited atrioventricular block (AVB) have been reported; however, the heredity of AVB remains unknown. We aimed to assess the heredity of AVB.Design, setting and participantsUsing data...

Longitudinal Outcomes of Subcutaneous or Transvenous Implantable Cardioverter-Defibrillators in Older Patients

BackgroundThe subcutaneous (S-) implantable cardioverter-defibrillator (ICD) is an alternative to the transvenous (TV-) ICD that is increasingly implanted in younger patients; data on the safety and effectiveness of the S-ICD in older patients are lacking. ObjectivesThe purpose of this study was to compare outcomes among older patients who received an S- or TV-ICD. MethodsThe authors compared S-ICD and single-chamber TV-ICD implants in Fee-For-Service Medicare beneficiaries using the National Cardiovascular Data Registry ICD Registry. Outcomes were ascertained from Medicare claims data. Cox regression or competing-risk models (with TV-ICD as reference) with overlap weights were used to compare death and nonfatal outcomes (device reoperation, device removal for infection, device reoperation without infection, and cardiovascular admission), respectively. Recurrent all-cause readmissions were compared using Anderson-Gill models. ResultsA total of 16,063 patients were studied (age 72.6 ± 5.9 years, 28.4% women, ejection fraction 28.3 ± 8.9%). Compared with TV-ICD patients (n = 15,072), S-ICD patients (n = 991, 6.2% overall) were more often Black, younger, and dialysis dependent and less likely to have history of atrial fibrillation or flutter. In adjusted analyses, there were no differences between device type and risk of all-cause mortality (HR: 1.020; 95% CI: 0.819-1.270), device reoperation (subdistribution [s] HR: 0.976; 95% CI: 0.645-1.479), device removal for infection (sHR: 0.614; 95% CI: 0.138-2.736), device reoperation without infection (sHR: 0.975; 95% CI: 0.632-1.506), cardiovascular readmission (sHR: 1.087; 95% CI: 0.912-1.295), or recurrent all-cause readmission (HR: 1.072; 95% CI: 0.990-1.161). ConclusionsIn a large representative national cohort of older patients undergoing ICD implantation, risk of death, device reoperation, device removal for infection, device reoperation without infection, and cardiovascular and all-cause readmission were similar among S- and TV-ICD recipients.

Hospital Characteristics and Early Enrollment Trends in the American College of Cardiology Voluntary Public Reporting Program

Limited data exist regarding the characteristics of hospitals that do and do not participate in voluntary public reporting programs. To describe hospital characteristics and trends associated with early participation in the American College of Cardiology (ACC) voluntary reporting program for cardiac catheterization-percutaneous coronary intervention (CathPCI) and implantable cardioverter-defibrillator (ICD) registries. This cross-sectional study analyzed enrollment trends and characteristics of hospitals that did and did not participate in the ACC voluntary public reporting program. All hospitals reporting procedure data to the National Cardiovascular Data Registry (NCDR) CathPCI or ICD registries that were eligible for the public reporting program from July 2014 (ie, program launch date) to May 2017 were included. Stepwise logistic regression was used to identify hospital characteristics associated with voluntary participation. Enrollment trends were evaluated considering the date US News & World Report (USNWR) announced that it would credit participating hospitals. Data analysis was performed from March 2017 to January 2018. Hospital characteristics and participation in the public reporting program. By May 2017, 561 of 1747 eligible hospitals (32.1%) had opted to participate in the program. Enrollment increased from 240 to 376 hospitals (56.7%) 1 month after the USNWR announcement that program participation would be considered as a component of national hospital rankings. Compared with hospitals that did not enroll, program participants had increased median (IQR) procedural volumes for PCI (481 [280-764] procedures vs 332 [186-569] procedures; P < .001) and ICD (114 [56-220] procedures vs 62 [25-124] procedures; P < .001). Compared with nonparticipating hospitals, an increased mean (SD) proportion of participating hospitals adhered to composite discharge medications after PCI (0.96 [0.03] vs 0.92 [0.07]; P < .001) and ICD (0.88 [0.10] vs 0.81 [0.12]; P < .001). Hospital factors associated with enrollment included participation in 5 or more NCDR registries (odds ratio [OR],1.98; 95% CI, 1.24-3.19; P = .005), membership in a larger hospital system (ie, 3-20 hospitals vs ≤2 hospitals in the system: OR, 2.29; 95% CI, 1.65-3.17; P = .001), participation in an NCDR pilot public reporting program of PCI 30-day readmissions (OR, 2.93; 95% CI, 2.19-3.91; P < .001), university affiliation (vs government affiliation: OR, 3.85, 95% CI, 1.03-14.29; P = .045; vs private affiliation: OR, 2.22; 95% CI, 1.35-3.57; P < .001), Midwest location (vs South: OR, 1.47; 95% CI, 1.06-2.08; P = .02), and increased comprehensive quality ranking (4 vs 1-2 performance stars in CathPCI: OR, 8.08; 95% CI, 5.07-12.87; P < .001; 4 vs 1 performance star in ICD: OR, 2.26; 95% CI, 1.48-3.44; P < .001) (C statistic = 0.829). This study found that one-third of eligible hospitals participated in the ACC voluntary public reporting program and that enrollment increased after the announcement that program participation would be considered by USNWR for hospital rankings. Several hospital characteristics, experience with public reporting, and quality of care were associated with increased odds of participation.

Risk and predictors of mortality after implantable cardioverter-defibrillator implantation in patients with sarcoid cardiomyopathy

Implantable cardioverter-defibrillators (ICDs) are recommended for patients with cardiac sarcoidosis (CS) with an indication for pacing, prior ventricular arrhythmias, cardiac arrest, or left ventricular ejection fraction <35%, but data on outcomes are limited. Using data from the National Cardiovascular Data Registry ICD Registry between April 1, 2010 and December 31, 2015, we evaluated a propensity matched cohort of CS patients implanted with ICDs versus non-ischemic cardiomyopathies (NICM). We compared mortality using Kaplan-Meier survival curves and Cox proportional hazards models. We identified 1,638 patients with CS and 8,190 propensity matched patients with NICM. The rate of death at 1 and 2 years was similar in patients with CS and patients with NICM (5.2% vs 5.4%, P = 0.75 and 9.0% vs 9.3%, P = 0.72, respectively). After adjusting for other covariates, patients with CS had similar mortality at 2 years after ICD implantations compared with NICM patients (RR 1.03, 95% CI 0.87-1.23). Among patients with CS, multivariable logistic regression identified 6 factors significantly associated with increased 2-year mortality: presence of heart failure (HR 1.92, 95% CI 1.44-3.22), New York Heart Association (NYHA) Class III heart failure (HR 1.68, 95% CI 1.16-2.45), NYHA Class IV heart failure (HR 3.08, 95% CI 1.49-6.39), atrial fibrillation/flutter (HR 1.66, 95% CI 1.17-2.35), chronic lung disease (HR 1.64, 95% CI 1.17-2.29), creatinine >2.0 mg/dL (HR 4.07, 95% CI 2.63-6.30), and paced rhythm (HR 2.66, 95% CI 1.07-6.59). Mortality following ICD implantation was similar in CS patients compared with propensity matched NICM patients. Presence of heart failure, NYHA class, atrial fibrillation/flutter, chronic lung disease, renal dysfunction, and paced rhythm at time of implantation were all predictors of increased 2-year mortality among CS patients with ICDs.

Secondary prevention implantable cardioverter-defibrillator (ICD) therapy in octogenarians: effective and safe

Abstract Aims Implantable cardioverter-defibrillator is well established for secondary prevention, but there is a lack of studies showing efficacy and safety in the elderly. The current study compared the outcome of octogenarians after ICD implantation to other age groups. Methods Data was achieved from a local ICD registry. Patients who received ICD implantation for secondary prevention were included. All-cause mortality, appropriate ICD therapy and acute adverse events requiring surgical intervention were compared between different age groups. Results 519 patients were enrolled. 34 patients were ≥80 years. Over a median follow-up of 35 months after ICD implantation 129 patients (annual mortality rate 5.0%) died, including 16 patients in the age group ≥80 years (annual mortality rate 9.4%). Mortality rate in the age group ≥80 years was significantly higher than in the age groups ≤69 years (p&amp;lt;0.001) but no difference could be seen compared to age groups 70–79 y. Age at the time of ICD implantation was an independent predictor of all-cause mortality (p&amp;lt;0.001). 29.7% of patients had appropriate ICD therapy with no difference between age groups. Acute adverse events leading to surgical intervention were low (n=13) and not age-related. Conclusion Age is an independent predictor of mortality after ICD implantation for secondary prevention. No difference in mortality rate could be seen between octogenarians and other elderly from 70 – 79 years. Appropriate ICD therapy and acute adverse events leading to surgical intervention were not age-related. Implantable cardioverter-defibrillator for secondary prevention seems to be an effective and safe therapy in octogenarians. Funding Acknowledgement Type of funding sources: None.

Spanish Implantable Cardioverter-defibrillator Registry. 17th Official Report of the Heart Rhythm Association of the Spanish Society of Cardiology (2020)

Introduction and objectivesWe present the data corresponding to implantable cardioverter-defibrillator (ICD) implants in Spain in 2020. MethodsThe data in this registry were drawn from implantation centers, which voluntarily completed a data collection sheet. ResultsIn 2020, 7056 implant sheets were received compared with 7106 reported by Eucomed (European Confederation of Medical Suppliers Associations), indicating that data were collected from 99% of the devices implanted in Spain. Completion of the implant sheet ranged from 99.8% for the field “name of the implanting hospital” to 2.6% for the variable “referral hospital”. A total of 173 hospitals performed ICD implants and participated in the registry, which is a similar figure to that in 2019 (n=172). The total rate of registered implants was 149/million inhabitants (150 according to Eucomed), revealing a slight reduction in implants in Spain in 2020 as a result of the impact of the COVID-19 pandemic. This reduction was uneven among the autonomous communities. ConclusionsThe Spanish Implantable Cardioverter Defibrillator Registry for 2020 shows an improvement in the rate of implants reported and a reduction in the number of ICD implants, which likely reflects the decrease in hospital activity not related to the treatment of COVID-19 infection. Similar to previous years, the total number of implants in Spain is still much lower than the average for the European Union, with an increase in the differences between Spanish autonomous communities.

Defibrillation Safety Margin Testing in Patients With Congenital Heart Disease: ResultsFromthe NCDR.

This study analyzed the predictors of defibrillation safety margin (DSM) testing at the time of implantable cardioverter-defibrillator (ICD) insertion and factors associated with inadequate DSM in patients with congenital heart disease (CHD). There are few data about the prevalence and safety of DSM testing in those with CHD. A retrospective analysis was performed of all patients with atrial or ventricular septal defect, tetralogy of Fallot, transposition of the great vessels, Ebstein anomaly, or common ventricle undergoing a transvenous ICD procedure in the National Cardiovascular Data Registry (NCDR) ICD Registry from April 2010 to March 2016, and DSM testing was assessed. Inadequate DSM was defined as a lowest successful energy tested<10J than the maximum output of the ICD generator. Of all ICD recipients (N=7,024), DSM testing was performed in 52.0% (n=3,654). The mean lowest successful energy tested was 20.7 ± 7.3 J. Of those with DSM adequacy data available (n=3,623), an inadequate DSM occurred in 13.8% (n=501). After multivariable adjustment, DSM testing was not associated with in-hospital complications or death (odds ratio [OR]: 1.00; 95% confidence interval [CI]: 0.79 to 1.28) but was associated with lower odds of prolonged hospital stay (>3days) (OR: 0.71; 95%CI: 0.60 to 0.84; p<0.0001). An inadequate DSM was not associated with in-hospital death or complications (OR: 1.27; 95%CI: 0.79 to 2.04) or prolonged hospital stay (OR: 1.34; 95%CI: 0.995 to 1.81). DSM testing is being performed less frequently over time and seems safe in those with CHD. An inadequate DSM was not associated with worse in-hospital outcomes.

Registro Español de Desfibrilador Automático Implantable. XVII Informe Oficial de la Asociación del Ritmo Cardiaco de la Sociedad Española de Cardiología (2020)

Introduction and objectivesWe present the data corresponding to implantable cardioverter-defibrillator (ICD) implants in Spain in 2020. MethodsThe data in this registry were drawn from implantation centers, which voluntarily completed a data collection sheet. ResultsIn 2020, 7056 implant sheets were received compared with 7106 reported by Eucomed (European Confederation of Medical Suppliers Associations), indicating that data were collected from 99% of the devices implanted in Spain. Completion of the implant sheet ranged from 99.8% for the field “name of the implanting hospital” to 2.6% for the variable “referral hospital”. A total of 173 hospitals performed ICD implants and participated in the registry, which is a similar figure to that in 2019 (n=172). The total rate of registered implants was 149/million inhabitants (150 according to Eucomed), revealing a slight reduction in implants in Spain in 2020 as a result of the impact of the COVID-19 pandemic. This reduction was uneven among the autonomous communities. ConclusionsThe Spanish Implantable Cardioverter Defibrillator Registry for 2020 shows an improvement in the rate of implants reported and a reduction in the number of ICD implants, which likely reflects the decrease in hospital activity not related to the treatment of COVID-19 infection. Similar to previous years, the total number of implants in Spain is still much lower than the average for the European Union, with an increase in the differences between Spanish autonomous communities.Full English text available from:www.revespcardiol.org/en

Longitudinal Outcomes Associated With Non-Evidence-Based Implantable Cardioverter-Defibrillators Among Medicare Beneficiaries (From the National Cardiovascular Data Registry)

Primary prevention implantable cardioverter-defibrillators (ICDs) in patients with recent myocardial infarction or coronary revascularization and those with newly diagnosed or severe heart failure (HF) are considered non-evidence-based, as defined by pivotal randomized clinical trials. Although non-evidence-based ICDs have been associated previously with greater risk of in-hospital adverse events, longitudinal outcomes are not known. We used Medicare-linked data from the National Cardiovascular Data Registry's ICD Registry to identify patients discharged alive following first-time primary prevention ICD implantations performed between 2010 and 2013. We compared longitudinal outcomes, including all-cause mortality and all-cause hospital readmission among patients receiving non-evidence-based versus evidence-based ICDs, up to 4.75 years after implantation, using multivariable time-to-event analyses. Of 71,666 ICD implantations, 9,609 (13.4%) were classified as non-evidence-based. Compared to patients receiving evidence-based ICDs, non-evidence-based ICD recipients had greater mortality risk at 90 days (HR=1.44, CI: 1.37 - 1.52, p <0.0001) and at 1 year (HR=1.19, CI: 1.15 - 1.24, p <0.0001), but similar mortality risk at 3 years (HR=1.03, CI: 0.98 - 1.08, p=0.2630). Risk of all-cause hospitalization was higher in patients with non-evidence-based ICDs at 90 days (HR=1.17, CI: 1.14 - 1.20, p <0.0001), but the difference diminished at 1 year (HR=1.04, CI 1.00 - 1.07, p=0.0272) and at 3 years (HR=0.94, CI: 0.90 - 0.99, p=0.0105). In conclusion, among patients undergoing primary prevention ICD implantations between 2010 and 2013, those with non-evidence-based ICDs were at increased risk of mortality and readmission during longitudinal follow-up. Differences in the risk of mortality and hospitalization were highest in the first year following device implantation.

The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual report 2019

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2019 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers. The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards. PM Registry: data about 22 889 PM implantations were collected (19 621 first implants and 3268 replacements). The number of collaborating centers was 173. Median age of treated patients was 81 years (75 quartile I; 87 quartile III). ECG indications included atrioventricular conduction disorders in 33.3% of first PM implants, sick sinus syndrome in 16.4%, atrial fibrillation plus bradycardia in 11.6%, other in 38.7%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (18.3% of first implants). Use of single-chamber PMs was reported in 25.5% of first implants, of dual-chamber PMs in 67.1%, of PMs with cardiac resynchronization therapy (CRT) in 1.5%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 5.8%. ICD Registry: data about 17 328 ICD implantations were collected (12 129 first implants and 5199 replacements). The number of collaborating centers was 425. Median age of treated patients was 71 years (62 quartile I; 77 quartile III). Primary prevention indication was reported in 83.1% of first implants, secondary prevention in 16.9% (cardiac arrest in 5.9%). A single-chamber ICD was used in 26.1% of first implants, dual-chamber ICD in 28.0% and biventricular ICD in 45.9%. The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a large use of prophylactic and biventricular ICD, reflecting a favorable adherence to trials and guidelines in clinical practice. In order to increase and optimize the cooperation of Italian implanting centers, online data entry (https://www.aiac.it/riprid) should be adopted at large scale.

Mortality, appropriate and inappropriate shocks - observations from an institutional implantable cardioverter defibrillator registry

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Implantable cardioverter defibrillator (ICD) is an effective therapy for primary (PP) and secondary prevention (SP) of sudden cardiac death (SCD). ICD adverse events include inappropriate shocks (IS), device infection and failure. Methods We analysed the data concerning all newly implanted ICDs in our institution from 2011 to 2017. Follow-up data was collected until the end of 2019. Results In total, 507 ICDs were implanted (85.4% male, 57.6 ± 14.0 years-old), 375 (74.0%) for PP and 132 (26.0%) for SP. The mean follow-up was 34.3 ± 23.8 months. ICD delivered therapy in 42.4% of SP and in 28.8% of PP patients (p = 0.15). In PP, shocks were delivered in 25.7% of non-ischaemic heart disease (NIHD) and in 17.6% ischaemic heart disease (IHD) patients (p = 0.81). IS were significantly more common in NIHD patients (13.8% vs 2.4% in IHD group, p &amp;lt; 0.0001). PP patients with NIHD also had a higher shock burden (average of 8.0 ± 17.4 shocks compared to 2.7 ± 3.0 in the IHD group). However, it failed to reach the level of statistical significance (p = 0.052). In SP, the rate of ICD activation and that of IS were similar in both groups (IHD and NIHD). In total, 32.6% of SP patients received appropriate shock (AS) and 5.3% of them received at least one IS (average number of AS and IS being 8.7 ± 11.5 and 1.1 ± 0.4 respectively). Mortality was significantly higher in SP than in PP (34.8% vs 13.9%, p &amp;lt; 0.001). In PP, significantly more deaths occurred among IHD than NIHD patients (18.8% vs 10.0%, p &amp;lt; 0.001). Conclusion The prevalence of AS and IS was relatively higher than reported elsewhere. Same was true for mortality. Interestingly, the rate of IS was somewhat higher in NIHD than in IHD, which was unexpected. ICD outcomes Primary prevention Secondary prevention Total IHD NIHD Total IHD NIHD Patients, n 375 165 210 132 88 44 Patients with ICD activation, n (%) 108 (28.8) 46 (27.9) 62 (29.5) 56 (42.4) 33 (37.5) 22 (50.0) Patientns with AS, n (%) 60 (16.0) 27 (16.4) 33 (15.7) 43 (32.6) 29 (33.0) 14 (31.8) Patientns with IS, n (%) 33 (8.8) 4 (2.4) 29 (13.8) 7 (5.3) 5 (5.7) 2 (4.5) AS delivered (mean ± SD) 5.6 ± 13.3 2.7 ± 3.0 8.0 ± 17.4 8.7 ± 11.5 9.9 ± 12.2 9.7 ± 17.6 IS delivered (mean ± SD) 3.2 ± 5.1 1.2 ± 0.5 3.5 ± 5.4 1.1 ± 0.4 1.0 ± 0 3.2 ± 5.2 Deaths, n (%) 52 (13.9) 31 (18.8) 21 (10.0) 46 (34.8) 32 (36.4) 14 (31.8) Time to death (months, mean ± SD) 20.3 ± 13.9 19.9 ± 12.6 21.1 ± 16.5 27.1 ± 25.7 28.9 ± 24.9 22.6 ± 28.1 ICD, implantable cardioverter defibrillator; IHD, ischemic heart disease; NIHD, non-ischemic heart disease; AS, appropriate shock; IS, inappropriate shock

Cardioverter-related complications: observations from an institutional implantable cardioverter defibrillator registry

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Implantable cardioverter defibrillator (ICD) is gold standard therapy for primary and secondary prevention of sudden cardiac death (SCD) and ventricular tachyarrhythmias. While reducing arrhythmic mortality in patients with left ventricular dysfunction of various causes, inherited primary arrhythmia syndromes and after aborted SCD, these devices can have serious adverse effects including inappropriate shocks and device-related infection. Purpose The aim of this study was to create an institutional ICD registry and to examine the major complications after ICD implantation. Methods We analysed the data concerning all newly implanted ICDs in our institution from 2011 to 2017. All patients received periprocedural antibiotic prophylaxis according to relevant guidelines. Follow-up data was collected from hospital electronic medical records. Results Total number of implanted ICDs was 507 (85.4% male, 57.6 ± 14.0 years-old) and mean follow-up was 34.3 ± 23.8 months. Major complications (infection, large haematoma/hemorrhage, lead displacement/dysfunction) occurred in 18 (3.6%) patients. In 9 (1.8%) cases patients were diagnosed with ICD infection (8 surgical wound/pocket infections and 1 confirmed endocarditis of the lead). Device was explanted in 5 cases (1.0%) while the rest were treated only with antibiotic therapy (empirically or according to swab/blood culture results). All of the infections were successfully resolved and no relapses were noted. Eventually, 3 of 5 devices were reimplanted. One death was recorded 5 month after the explanation. Second most common complication was lead displacement/dysfunction which occurred in 5 (1.0%) patients and was successfully repaired in all cases. Large haematoma and/or hemorrhage at the implantation site were present in 5 (0.8%) patients (2 required surgical revision and transfusion while 2 were managed by needle aspiration). Pneumothorax (2 cases, 0.4%) had to be drained in one patient. There was one case of subclavian vein thrombosis which was treated by anticoagulation. Conclusion Despite appropriate antibiotic prophylaxis, the rate of ICD infections in our institution was relatively higher than the one reported in similar registries. The prevalence of other major complications, including lead dysfunction was quite low. Institutional registries could help monitor and plan actions to resolve ICD-related complications to improve patient outcomes.

Reassessment of clinical variables in cardiac resynchronization defibrillator patients at the time of first replacement:Death after replacement of CRT (DARC) score.

IntroductionCardiac resynchronization defibrillator (CRT‐D) as primary prevention is known to reduce mortality. At the time of replacement, higher age and comorbidities may attenuate the benefit of implantable cardioverter‐defibrillator (ICD) therapy. The purpose of this study was to evaluate the progression of comorbidities after implantation and their association with mortality following CRT‐D generator replacement. In addition, a risk score was developed to identify patients at high risk for mortality after replacement.Methods and ResultsWe identified patients implanted with a primary prevention CRT‐D (n = 648) who subsequently underwent elective generator replacement (n = 218) from two prospective ICD registries. The cohort consisted of 218 patients (median age: 70 years, male gender: 73%, mean left ventricular ejection fraction [LVEF]: 36 ± 11% at replacement). Median follow‐up after the replacement was 4.2 years during which 64 patients (29%) died and 11 patients (5%) received appropriate ICD shocks. An increase in comorbidities was observed in 77 patients (35%). The 5‐year mortality rate was 41% in patients with ≥2 comorbidities at the time of replacement. A risk score incorporating age, gender, LVEF, atrial fibrillation, anemia, chronic kidney disease, and history of appropriate ICD shocks at time of replacement accurately predicted 5‐year mortality (C‐statistic 0.829). Patients with a risk score of greater than 2.5 had excess mortality at 5‐year postreplacement compared with patients with a risk score less than 1.5 (57% vs. 6%; p < .001).ConclusionA simple risk score accurately predicts 5‐year mortality after replacement in CRT‐D patients, as patients with a risk score of greater than 2.5 are at high risk of dying despite ICD protection.

Use and Outcomes of Dual Chamber or Cardiac Resynchronization Therapy Defibrillators Among Older Patients Requiring Ventricular Pacing in the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry

Frequent right ventricular (RV) pacing can cause and exacerbate heart failure. Cardiac resynchronization therapy (CRT) has been shown to be associated with improved outcomes among patients with reduced left ventricular ejection fraction who need frequent RV pacing, but the patterns of use of CRT vs dual chamber (DC) devices and the associated outcomes among these patients in clinical practice is not known. To assess outcomes, variability in use of device type, and trends in use of device type over time among patients undergoing implantable cardioverter defibrillator (ICD) implantation who were likely to require frequent RV pacing but who did not have a class I indication for CRT. This retrospective cohort study used the National Cardiovascular Data Registry (NCDR) ICD Registry. A total of 3100 Medicare beneficiaries undergoing first-time implantation of CRT defibrillator (CRT-D) or DC-ICD from 2010 to 2016 who had a class I or II guideline ventricular bradycardia pacing indication but not a class I indication for CRT were included. Data were analyzed from August 2018 to October 2019. Implantation of a CRT-D or DC-ICD. All-cause mortality, heart failure hospitalization, and complications were ascertained from Medicare claims data. Multivariable Cox proportional hazards models and Fine-Gray models were used to evaluate 1-year mortality and heart failure hospitalization, respectively. Multivariable logistic regression was used to evaluate 30-day and 90-day complications. All models accounted for clustering. The median odds ratio (MOR) was used to assess variability and represents the odds that a randomly selected patient receiving CRT-D at a hospital with high implant rates would receive CRT-D if they had been treated at a hospital with low CRT-D implant rates. A total of 3100 individuals were included. The mean (SD) age was 76.3 (6.4) years, and 2500 (80.6%) were men. The 1698 patients (54.7%) receiving CRT-D were more likely than those receiving DC-ICD to have third-degree atrioventricular block (828 [48.8%] vs 432 [30.8%]; P < .001), nonischemic cardiomyopathy (508 [29.9%] vs 255 [18.2%]; P < .001), and prior heart failure hospitalizations (703 [41.4%] vs 421 [30.0%]; P < .001). Following adjustment, CRT-D was associated with lower 1-year mortality (hazard ratio [HR], 0.70; 95% CI, 0.57-0.87; P = .001) and heart failure hospitalization (subdistribution HR, 0.77; 95% CI, 0.61-0.97; P = .02) and no difference in complications compared with DC-ICD. Hospital variation in use of CRT was present (MOR, 2.00), and the use of CRT in this cohort was higher over time (654 of 1351 [48.4%] in 2010 vs 362 of 594 [60.9%] in 2016; P < .001). In this cohort study of older patients in contemporary practice undergoing ICD implantation with a bradycardia pacing indication but without a class I indication for CRT, CRT-D was associated with better outcomes compared with DC devices. Variability in use of device type was observed, and the rate of CRT implantation increased over time.

Impact of insurance status on ICD implantation practice patterns: Insights from the NCDR ICD registry

Whether insurance status influences practice patterns in implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) defibrillators, when indicated, is not known. We analyzed the NCDR ICD Registry to evaluate associations of insurance status with guidelines-based receipt of CRT, as well as device-type, complication rates, and use of optimal medical therapy defined by guidelines. Among 798,028 patients with de novo ICD implants, we included only patients < 65 years (those older have Medicare) and excluded those admitted before 2006 (n=1,835) or with insurance coverage other than Medicare, Medicaid or private insurance (n=25,695) leaving 286,556 for analysis. Inverse probability of treatment weighting was used to control for imbalances between groups. Mean age was 53 years, 29% were female. Patients with private insuranceand Medicare were more likely to receive CRT-D when indicated (79.6%, OR 1.19 95% CI 1.09-1.28, P <.001 and 78.5%, OR 1.11 95% CI 1.01-1.21 P = .03, respectively) compared to the uninsured (76.7%). The uninsured were also more likely than other groups to receive a single-chamber device. Complication rates did not differ. Uninsured patients were, however, more likely to receive optimal medical therapy, particularly in the subgroup receiving the implant for primary prevention. In propensity-weighted analysis, uninsured patients are less likely to receive CRT when indicated but more likely to be receiving optimal medical therapy at discharge. Reasons for differences in device implantation practices based on insurance status require further study.

Incidence and Predictors of Out-of-Hospital Cardiac Arrest Within 90 Days After Myocardial Infarction

BackgroundThe risk of sudden cardiac death (SCD) is high early after myocardial infarction (MI). Current knowledge and guidelines mainly rely on results from older clinical trials and registry studies. Left ventricular ejection fraction (LVEF) alone has not been proven a reliable predictor of SCD. ObjectivesThis study sought to identify the incidence and additional predictors of SCD early after MI in a contemporary nationwide setting. MethodsThe authors used data from SWEDEHEART, the Swedish Cardiopulmonary Resuscitation Registry, and the Swedish Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Registry. Cases of MI, which had undergone coronary angiography and were discharged alive between 2009 to 2017 without a prior ICD, were followed up to 90 days. Cox regression models were used to assess associations between clinical parameters and out-of-hospital cardiac arrest (OHCA). ResultsAmong 121,379 cases, OHCA occurred in 349 (0.29%) and non-OHCA death in 2,194 (1.8%). A total of 6 variables (male sex, diabetes, estimated glomerular filtration rate <30 ml/min/1.73 m2, Killip class ≥II, new-onset atrial fibrillation/flutter, and impaired LVEF [reference ≥50%] categorized as 40% to 49%, 30% to 39%, and <30%) were identified as independent predictors, were assigned points, and were grouped into 3 categories, where the incidence of OHCA ranged from 0.12% to 2.0% and non-OHCA death from 0.76% to 11.7%. Stratified by LVEF <40% alone, the incidence of OHCA was 0.20% and 0.76% and for non-OHCA death 1.1% and 4.9%. ConclusionsIn this nationwide study, the incidence of OHCA within 90 days after MI was <0.3%. A total of 5 clinical parameters in addition to LVEF predicted OHCA and non-OHCA death better than LVEF alone.

Abstract 16496: Longitudinal Outcomes After Implantation of a Subcutaneous or Transvenous Implantable Cardioverter Defibrillator in Older Patients: A Report From the National Cardiovascular Data Registry

Introduction: The subcutaneous (S-) implantable cardioverter defibrillator (ICD) is an alternative to the transvenous (TV-) ICD that is increasingly implanted in younger patients. However, data on the safety and effectiveness of the S-ICD in older patients are lacking. Methods: We compared S-ICD and single chamber TV-ICD implants in Medicare beneficiaries (≥65yrs) using National Cardiovascular Data Registry ICD Registry data from 9/28/2012 through 12/31/2017. We excluded patients with prior pacemaker or ICD, an indication for pacing or resynchronization, and those undergoing implant in an acute setting. Mortality status was determined using the Medicare master summary beneficiary file. Cox regression analyses with overlap weights were used to compare all-cause mortality. Mean cumulative counts of all-cause readmissions were compared among for Fee for Service beneficiaries. Results: A total of 23,717 patients met inclusion criteria [mean age 72.7±5.8 years, 29% female, 69% ischemic heart disease, 33% atrial arrhythmias, 49% NYHA II, 31.7% NYHA III, ejection fraction (EF) 28±9%, 3% dialysis dependent, 20% with prior ventricular tachycardia]. Compared to TV-ICD patients (n=22,264), S-ICD patients (n=1,453, 6% overall) were more often male, black, diabetic, dialysis dependent and were less likely to have atrial or ventricular arrhythmias or ischemic heart disease. There was no difference in age or EF between the 2 groups. In adjusted analyses, during a median follow-up of 2.3 years (IQR: 1.2 - 3.5), there was no difference between the 2 groups in all-cause mortality (HR 1.04, CI 0.91-1.17, Figure A ) or readmissions (based on overlap of confidence intervals, Figure B ). Conclusions: In a large representative cohort of older patients undergoing ICD implant, all-cause mortality and readmission were similar among S-ICD and TV-ICD recipients. These findings support use of the S-ICD for the prevention of sudden cardiac death in appropriately selected older patients.