Implantable Cardioverter-defibrillator Registry Research Articles

Cardiac Resynchronization Defibrillator Therapy for Nonspecific Intraventricular Conduction Delay Versus Right Bundle Branch Block

BackgroundThe benefits of cardiac resynchronization therapy (CRT) in patients with non-left bundle branch block (LBBB) conduction abnormality have not been fully explored. ObjectivesThis study sought to evaluate clinical outcomes among Medicare-aged patients with nonspecific intraventricular conduction delay (NICD) versus right bundle branch block (RBBB) in patients eligible for implantation with a CRT with defibrillator (CRT-D). MethodsUsing the National Cardiovascular Data Registry implantable cardioverter-defibrillator (ICD) registry data between 2010 and 2013, the authors compared outcomes in CRT-eligible patients implanted with CRT-D versus ICD-only therapy among patients with NICD and RBBB. Also, among all CRT-D–implanted patients, the authors compared outcomes in those with NICD versus RBBB. Survival curves and multivariable adjusted hazard ratios (HRs) were used to assess outcomes including hospitalization and death. ResultsIn 11,505 non-LBBB CRT-eligible patients, after multivariable adjustment, among patients with RBBB, CRT-D was not associated with better outcomes, compared with ICD alone, regardless of QRS duration. Among patients with NICD and a QRS ≥150 ms, CRT-D was associated with decreased mortality at 3 years compared with ICD alone (HR: 0.602; 95% confidence interval [CI]: 0.416 to 0.871; p = 0.0071). Among 5,954 CRT-D–implanted patients, after multivariable adjustment NICD compared with RBBB was associated with lower mortality at 3 years in those with a QRS duration of ≥150 ms (HR: 0.757; 95% CI: 0.625 to 0.917; p = 0.0044). ConclusionsAmong non-LBBB CRT-D–eligible patients, CRT-D implantation was associated with better outcomes compared with ICD alone specifically in NICD patients with a QRS duration of ≥150 ms. Careful patient selection should be considered for CRT-D implantation in patients with non-LBBB conduction.

Arrhythmic burden among asymptomatic patients with ischemic cardiomyopathy and an implantable cardioverter-defibrillator

The clinical benefit of primary prevention implantable cardioverter-defibrillator (ICD) therapy in asymptomatic patients (New York Heart Association [NYHA] functional class I) with ischemic cardiomyopathy and left ventricular dysfunction is continually disputed. The purpose of this study was to evaluate the incidence of ventricular arrhythmias, mortality rates, and appropriate device therapies by NYHA class in a prospective national ICD registry. The study comprised 1670 consecutive patients with ischemic cardiomyopathy who were implanted with a primary prevention ICD and enrolled in the prospective national Israeli ICD Registry from 2010. The risk for clinical and arrhythmic events was assessed by NYHA class. Asymptomatic patients (NYHA I) composed 19% of the study cohort. Comparison according to NYHA class showed that the highest mortality rate was in the NYHA III-IV group vs NYHA I and NYHA II (10.5% vs 5.4% and 5.8%, respectively; log rank P= .003). Conversely, cumulative incidence of appropriate ICD therapies, corrected for death as a competing risk, were higher among patients with NYHA I (11% vs 7%; P = .021). In a multivariate model, NYHA I vs ≥II remained independently associated with a significant 2-fold risk for appropriate ICD therapy (hazard ratio 2.03; 95% confidence interval 1.28-3.24). Our findings indicate that patients with ischemic cardiomyopathy without heart failure symptoms have a higher risk of appropriate ICD therapy compared with symptomatic patients after adjustment for the competing risk of death, suggesting possible incremental benefit of primary ICD implantation in this population.

Association of body mass index with cardiac resynchronization therapy intention and left ventricular lead implantation failure: insights from the NCDR implantable cardioverter-defibrillator registry.

Cardiac resynchronization therapy with defibrillator (CRT-D) implantation involves left ventricular (LV) lead placement for biventricular pacing and is more complex than implantable cardioverter-defibrillator (ICD)-only implantation. Differences in the prescription of CRT-D versus ICD may result from clinician biases based on patient body habitus, and body habitus may be associated with LV lead implantation failure. We sought to evaluate whether patient body mass index (BMI) was associated with planned use and implantation failure of CRT-D therapy. We studied all patients enrolled in the National Cardiovascular Data Registry ICD Registry who met standard CRT-D criteria and received either an ICD or CRT-D between 2010 and 2012. BMI was categorized based on World Health Organization classification. Using hierarchical logistic regression, two multivariate models adjusted for patient demographic and clinical characteristics were fit based on the following outcome variables: (1) planned implantation with CRT-D versus ICD and (2) failed versus successful LV lead placement. Of 337,547 patients, 41,872 met inclusion criteria for the first analysis and 35,186 met criteria for the second analysis. After multivariable adjustment, patients with extreme (BMI > 40kg/m2) obesity were less likely to receive guideline-concordant CRT-D compared with patients with normal weight (adjusted odds ratio (AOR), 0.86; 95% confidence interval (CI), 0.75-0.99; p = 0.04). Extreme (BMI > 40kg/m2) obesity was associated with higher odds of failed LV lead placement (AOR, 1.35; 95% CI, 1.07-1.72, p = 0.01). Compared with normal weight patients, extremely obese (BMI > 40kg/m2) CRT-D eligible patients were less likely to be prescribed CRT-D and were at higher odds for failed LV lead placement.

Multi-morbidity burden, psychological distress, and quality of life in implantable cardioverter defibrillator recipients: Results from a nationwide study

BackgroundThe prevalence of multi-morbidity in implantable cardioverter defibrillator (ICD) recipients is approximately 25%. Multi-morbidity is associated with poor health and psychological outcomes in this population and may affect ICD recipients' quality-of-life (QOL). The purpose of this study was to determine the prevalence of psychological distress (anxiety, depressive symptoms, and Type-D personality) in ICD recipients with varying levels of comorbidities, and to examine the association between multi-morbidity burden and QOL in this population. MethodsAll adults listed in the Swedish ICD and Pacemaker Registry in 2012 with an ICD implanted for at least one year were invited to participate in this study. Binary logistic regression was used to predict QOL using the EQ-5D mean index dichotomized based on median QOL scores. Multi-morbidity burden scores were based on quartile groupings. ResultsA total of 2658 ICD recipients participated in the study (with a mean age of 65, 20.6% female, mean implant duration of 4.7 years, with 35.4% implanted for primary prevention of sudden cardiac arrest). Greater multi-morbidity burden, female sex, not working outside the home, history of ICD shock, negative ICD experience, higher levels of ICD-related concerns, and the presence of anxiety, depression, or Type D personality were associated with worse QOL in ICD recipients. Predictors differed by multi-morbidity burden level. ConclusionsMulti-morbidity burden and psychological distress is an essential factor related to QOL. This issue should be discussed with potential ICD recipients prior to implant. Further exploration of increased recognition and treatment of psychological distress in ICD recipients is warranted.

The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual report 2017

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 2017 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 23 457 PM implantations were collected (19 378 first implant and 4079 replacements). The number of collaborating centers was 185. Median age of treated patients was 81 years (75 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 37.1% of first PM implants, sick sinus syndrome in 19.5%, atrial fibrillation plus bradycardia in 13.2%, other in 30.2%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (21.0% of first implants). Use of single-chamber PMs was reported in 25.6% of first implants, of dual-chamber PMs in 66.7%, of PMs with cardiac resynchronization therapy (CRT) in 1.4%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 6.3%. ICD Registry: data about 19 023 ICD implantations were collected (13 898 first implants and 5125 replacements). The number of collaborating centers was 437. Median age of treated patients was 71 years (63 quartile I; 78 quartile III). Primary prevention indication was reported in 81.8% of first implants, secondary prevention in 18.2% (cardiac arrest in 6.4%). A single-chamber ICD was used in 27.0% of first implants, dual-chamber in 33.6% and biventricular in 39.3%. 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 (http://www.aiac.it/riprid) should be adopted at large scale.

SURVIVAL FOLLOWING IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IMPLANTATION IN PATIENTS WITH CARDIAC SARCOIDOSIS

Implantable cardioverter-defibrillators (ICDs) are recommended for patients with cardiac sarcoidosis with complete heart block, prior ventricular arrhythmias, cardiac arrest, or left ventricular ejection fraction <35%, but data are limited on outcomes. Using data from the NCDR ICD Registry between

Risk of death without appropriate defibrillator shock in patients with advanced renal dysfunction.

Heart failure patients with advanced chronic kidney disease (CKD) may experience an increased rate of non-arrhythmic mortality due to associated comorbidities. We aimed to evaluate the risk of mortality without appropriate implantable cardioverter-defibrillator (ICD) shocks in this high-risk population. The study population comprised 3542 patients who received an ICD, were enrolled, and prospectively followed-up in the Israeli ICD registry. Study patients were categorized into two groups: those with advanced CKD [defined by a glomerular filtration rate of <30 mL/min/1.73 m2 or being on dialysis at time of implantation (n = 197)], and those without advanced CKD (n = 3344). The primary endpoint was the risk of death without receiving appropriate ICD shock. Kaplan-Meier survival analysis showed that at 5 years of follow-up the rates of death without prior ICD shock were significantly higher in the advanced kidney disease group (46%) compared with the non-advanced CKD group (19%; log-rank P-value <0.001). Consistently, multivariate analysis showed that the risk of death without receiving appropriate ICD shock therapy at 5 years was 2.5-fold (P < 0.001) higher among advanced CKD patients. In contrast, the rate of appropriate ICD shock therapy at 5 years among advanced CKD patients was only 9%, with a very high mortality rate (63%) within 3.5 years subsequent to shock therapy. Nearly one-half of ICD with advanced CKD die within 5 years without receiving an appropriate ICD shock. These findings stress the importance of appropriate patient selection for primary ICD implantation in this high-risk population.

Quality and Safety in Health Care, Part XLIII: Selected Outcome Studies From the Implantable Cardioverter Defibrillator Registry.

To compare outcome results from different institutions in a registry, it is necessary to have a way to take into account differences in the risk characteristics of the patients. This model has been constructed for the Implantable Cardioverter Defibrillator (ICD) Registry, and the most important variables have been identified. In another study, it has also been found that many of these patients have comorbidities, and the mortality rate 60 months after a replacement ICD was 41.2%. In a third study, it was determined that for individuals at least 65 years of age, 60 months after ICD placement, 50.9% of the recipients used hospice services or were dead.

Is Time From Last Hospitalization for Heart Failure to Placement of a Primary Prevention Implantable Cardioverter-Defibrillator Associated With Patient Outcomes?

Landmark studies have demonstrated the safety and efficacy of implantable cardioverter-defibrillators (ICDs) in selected stable ambulatory patients with heart failure (HF) with a reduced ejection fraction receiving optimal medical therapy. It is not known whether a recent hospitalization for HF before ICD placement is associated with subsequent outcomes. A post hoc analysis was performed of Medicare beneficiaries enrolled in the National Cardiovascular Data Registry's ICD Registry with a known diagnosis of HF and an ejection fraction ≤35% underdoing a new ICD placement for primary prevention. Patients were grouped based on the timing of ICD placement from the last hospitalization for HF. The association between timing of ICD placement and outcomes was assessed by using multivariable logistic regression models. The final analytic cohort included 81 180 patients undergoing initial ICD placement for primary prevention who were currently hospitalized for HF (n=11 563, 14%), hospitalized for HF within 3 months (n=6252, 8%), or hospitalized for HF >3 months previously or had no previous hospitalizations for HF (n=63 365, 78%). Patients currently or recently hospitalized for HF had a higher unadjusted composite periprocedural complication rate (2.60% versus 1.71% versus 1.25%, P<0.001). After adjusting for potential confounders, patients currently hospitalized for HF were at higher risk for death (odds ratio, 2.25; 95% CI, 2.02-2.52; P <0.001) and all-cause readmission (odds ratio, 1.89; 95% CI, 1.79-1.99; P <0.001) at 90 days. Older patients currently or recently hospitalized for HF undergoing initial ICD placement for primary prevention experienced a higher rate of periprocedural complications and were at increased risk of death in comparison with those receiving an ICD without recent HF hospitalization. Additional prospective, real-world, pragmatic, comparative effectiveness studies should be conducted to define the optimal timing of ICD placement.

Spanish Implantable Cardioverter-defibrillator Registry. 14th Official Report of the Spanish Society of Cardiology Electrophysiology and Arrhythmias Section (2017)

Introduction and objectivesThe Spanish Automatic Defibrillator Registry has provided activity data since 2002. MethodsThe data in this registry are submitted by implantation centers that voluntarily complete a data collection sheet. ResultsDuring 2017, a total of 6273 implant sheets were received, compared with 6429 reported by Eucomed (European Confederation of Medical Suppliers Associations). Therefore, the registry contains data on 97.6% of the devices implanted in Spain. Compliance ranged from 99.7% for the field “name of the implanting hospital” to 46.1% for the variable “New York Heart Association functional class”. A total of 181 hospitals reported data to the registry, representing an increase compared with the number of participating hospitals in 2016 (177) and in previous years (169 in 2015, 162 in 2014, 154 in 2013, and 153 in 2012). ConclusionsThe number of implants per million inhabitants in Spain increased for several years but decreased in 2017. As in previous years, the total number of implants in Spain is still much lower than the European Union average, and the gap continues to widen. There are still substantial differences between autonomous communities.

Outcomes following implantable cardioverter-defibrillator generator replacement in patients with recovered left ventricular systolic function: The National Cardiovascular Data Registry

Some patients with heart failure (HF) experience recovery of left ventricular (LV) systolic function by the end of their implantable cardioverter-defibrillator (ICD) generator battery life. Outcomes following generator replacement in this setting are poorly understood. We sought to describe outcomes following ICD generator replacement associated with recovery of LV systolic function. We evaluated 26,197 Medicare beneficiaries enrolled in the American College of Cardiology's National Cardiovascular Data Registry ICD Registry who underwent primary prevention ICD generator replacement between 2006 and 2009, stratified by LV ejection fraction (LVEF): reduced (LVEF ≤35%), partially recovered (LVEF >35% and ≤50%), and recovered (LVEF >50%). At the time of generator replacement, 1915 (7.3%) patients had recovered LVEF and 4576 (17.5%) had partially recovered LVEF. Periprocedural events were rare (<1%) in all patients. In patients with reduced LVEF, the incidence of HF readmission and mortality at 3 years was 27.5% and 32.7%, respectively. In comparison, the rates of HF readmission and mortality were lower for patients with partially recovered LVEF (readmission: 15.9%; hazard ratio [HR] 0.66; 95% confidence interval [CI] 0.61-0.72; mortality: 23.0%; HR 0.82; 95% CI 0.76-0.87) and those with recovered LVEF (readmission: 12.2%; HR 0.55; 95% CI 0.48-0.63; mortality: 18.2%; HR 0.72; 95% CI 0.64-0.80). Patients with partially recovered and recovered LVEF have lower risks of mid-term adverse outcomes than do those with reduced LVEF following ICD generator replacement. Approximately 3 in 4 patients continue to have reduced LVEF at the time of generator replacement and are at high risk of HF readmission and mortality. These data highlight the prognostic associations of LVEF in patients undergoing generator replacement as well as the clinical encounter for generator replacement as an opportunity to identify those at increased risk of adverse outcomes.

Quality and Safety in Health Care, Part XLII: Introduction to the Implantable Cardioverter Defibrillator Registry.

Implantable cardioverter defibrillators for both primary and secondary prevention have been successful in decreasing sudden cardiac death. The Implantable Cardioverter Defibrillator Registry was established partly for reimbursement for primary prevention. However, the registry also has been helpful in better understanding the risks and appropriate selection of patients to receive these devices, serving as an impetus for quality improvement by giving outcome information to the contributing institutions regarding their performance relative to the national results, and increasing research. It is also expected to be helpful to compare results from different devices and provide information to the public.

Perceived Social Support in Persons With Heart Failure Living With an Implantable Cardioverter Defibrillator: A Cross-sectional Explorative Study.

The links between chronic illness, psychological well-being, and social support have previously been established. Social isolation and loneliness have shown an increased mortality risk for those with heart failure (HF). Increasingly more people with HF are living with an implantable cardioverter defibrillator (ICD), but only a few small-scale studies have focused on social support in this population. The aim of this study was to explore factors related to perceived social support in a large cohort of individuals with HF living with an ICD. All eligible adult ICD recipients in the Swedish ICD registry were invited to participate in this cross-sectional study. For this analysis, those with HF and complete data on perceived social support were included (N = 1550; age, 67.3 (SD, 9.8) years; 19.5% female). Most reported a high level of social support, but 18% did not. In logistic regression, living alone was the greatest predictor of low/medium support. Lower social support for those living alone was associated with poorer perceived health status, having symptoms of depression, and experiencing low perceived control. For those living with someone, lower support was associated with female gender, symptoms of depression and anxiety, and less control. Heart failure status and perceived symptom severity were not related to the outcome. One in five participants reported low/medium social support. Our study underlines the complex relationships between perceived social support, psychological well-being and perceived control over the heart condition. Multiple aspects need to be taken into account when developing interventions to provide psychosocial support and optimize outcomes in this patient group.

Developing a risk score to predict mortality in the first year after implantable cardioverter defibrillator implantation: Data from the Israeli ICD Registry.

Life expectancy of less than 1 year is usually a contraindication for implantable cardioverter defibrillator (ICD) implantation. The aim was to identify patients at risk of death during the first year after implantation. Data were derived from a prospective Israeli ICD Registry. Two groups of patients were compared, those who died and those who were alive 1 year after ICD implantation. Factors associated with 1-year mortality were identified on a derivation cohort. A risk score was established and validated. A total of 2617 patients have completed 1 year of follow-up after ICD or cardiac resynchronization therapy defibrillator (CRT-D) implantation. Age greater than 75 years (hazard ratio [HR], 2.7; 95% confidence interval [95% CI], 1.6 to 4.4), atrial fibrillation (AF; HR, 1.9; 95% CI, 1.12 to 3.17), chronic lung disease (HR, 2.0; 95% CI, 1.1 to 3.76), anemia (HR, 2.3; 95% CI, 1.3 to 3.93) and chronic renal failure (CRF; HR, 3.4; 95% CI, 1.74 to 6.6) were independent risk factors for 1-year mortality. We propose a simple AAACC ("triple A double C") score for prediction of 1-year mortality after ICD implantation: Age greater than 75 years (3 points(pts)), anemia (2 pts), AF (1 pt), CRF (3 pts) and chronic lung disease (1 pt). Mortality risk increased with rising number of points (from 1% with 0 pts to 12.5% with >4 pts). The risk score was evaluated with receiver operating characteristic curve and the area under the curve of the validation curve is 0.71 (95% CI, 0.66 to 0.76). Age greater than 75, AF, chronic lung disease, anemia, and CRF were independent risk factors for 1-year mortality. AAACC risk score identifies patients at high risk of death during 1 year after ICD implantation.

Primary prevention with the implantable cardioverter-defibrillator in high-risk long-QT syndrome patients.

Prospective data regarding the role of implantable cardioverter-defibrillator (ICD) for the primary prevention of sudden cardiac death in patients with long QT syndrome (LQTS) is scarce. Herein, we explore the prospective Rochester LQTS ICD registry to assess the risk for appropriate shock in primary prevention in a real-world setting. We studied 212 LQTS patients that had ICD implantation for primary prevention. Best-subsets proportional-hazards regression analysis was used to identify clinical variables that were associated with the first appropriate shock. Conditional models of Prentice, Williams, and Peterson were utilized for the analysis of recurrent appropriate shocks. During a median follow-up of 9.2 ± 4.9 years, there were 42 patients who experienced at least one appropriate shock and the cumulative probability of appropriate shock at 8 years was 22%. QTc ≥ 550 ms [hazard ratio (HR) 3.94, confidence interval (CI) 2.08-7.46; P < 0.001) and prior syncope on β-blockers (HR 1.92, CI 1.01-3.65; P = 0.047) were associated with increased risk of appropriate shock. History of syncope while on β-blocker treatment (HR 1.87, CI 1.28-2.72; P = 0.001), QTc 500-549 ms (HR 1.68, CI 1.10-2.81; P = 0.048), and QTc ≥ 550 ms (HR 3.66, CI 2.34-5.72; P < 0.001) were associated with increased risk for recurrent appropriate shocks, while β-blockers were not protective (HR 1.03, CI 0.63-1.68, P = 0.917). LQT2 (HR 2.10, CI 1.22-3.61; P = 0.008) and multiple mutations (HR 2.87, CI 1.49-5.53; P = 0.002) were associated with higher risk for recurrent shocks as compared with LQT1. In this prospective ICD registry, we identified clinical and genetic variables that were associated appropriate shock risk. These data can be used for risk stratification in high-risk patients evaluated for primary prevention with ICD.

Highlights From the Circulation Family of Journals

Highlights From the <i>Circulation</i> Family of Journals

Cardiac implant registries 2006–2016: a systematic review and summary of global experiences

ObjectivesThe importance of Cardiac Implant Registry (CIR) for ensuring a long-term follow-up in postmarket surveillance has been recognised and approved, but there is lack of consensus standards on how to...

Device Therapies Among Patients Receiving Primary Prevention Implantable Cardioverter-Defibrillators in the Cardiovascular Research Network.

BackgroundPrimary prevention implantable cardioverter‐defibrillators (ICDs) reduce mortality in selected patients with left ventricular systolic dysfunction by delivering therapies (antitachycardia pacing or shocks) to terminate potentially lethal arrhythmias; inappropriate therapies also occur. We assessed device therapies among adults receiving primary prevention ICDs in 7 healthcare systems.Methods and ResultsWe linked medical record data, adjudicated device therapies, and the National Cardiovascular Data Registry ICD Registry. Survival analysis evaluated therapy probability and predictors after ICD implant from 2006 to 2009, with attention to Centers for Medicare and Medicaid Services Coverage With Evidence Development subgroups: left ventricular ejection fraction, 31% to 35%; nonischemic cardiomyopathy <9 months’ duration; and New York Heart Association class IV heart failure with cardiac resynchronization therapy defibrillator. Among 2540 patients, 35% were <65 years old, 26% were women, and 59% were white. During 27 (median) months, 738 (29%) received ≥1 therapy. Three‐year therapy risk was 36% (appropriate, 24%; inappropriate, 12%). Appropriate therapy was more common in men (adjusted hazard ratio [HR], 1.84; 95% confidence interval [CI], 1.43–2.35). Inappropriate therapy was more common in patients with atrial fibrillation (adjusted HR, 2.20; 95% CI, 1.68–2.87), but less common among patients ≥65 years old versus younger (adjusted HR, 0.72; 95% CI, 0.54–0.95) and in recent implants (eg, in 2009 versus 2006; adjusted HR, 0.66; 95% CI, 0.46–0.95). In Centers for Medicare and Medicaid Services Coverage With Evidence Development analysis, inappropriate therapy was less common with cardiac resynchronization therapy defibrillator versus single chamber (adjusted HR, 0.55; 95% CI, 0.36–0.84); therapy risk did not otherwise differ for Centers for Medicare and Medicaid Services Coverage With Evidence Development subgroups.ConclusionsIn this community cohort of primary prevention patients receiving ICD, therapy delivery varied across demographic and clinical characteristics, but did not differ meaningfully for Centers for Medicare and Medicaid Services Coverage With Evidence Development subgroups.

Atrio-ventricular junction ablation and pacemaker treatment: a comparison between men and women

Objectives. To explore sex differences regarding indication for atrio-ventricular junction ablation (AVJ), choice of pacing system, complications to pacemaker treatment, long-term outcome, and cause of death after AVJ ablation. Design. 700 patients who had undergone AVJ ablation between January 1990 and December 2010 were included. Data were retrieved from the patients´ medical records and the Swedish Pacemaker and Implantable Cardioverter-Defibrillator Registry. Information about admission to hospital and cause of death was retrieved from the National Board of Health and Welfare. Results. Mean follow-up was 90 ± 64 months. Indication for AVJ ablation, choice of pacing system, and outcome after AVJ ablation differed between the sexes. The men had more often permanent atrial fibrillation, p = .0001, and a VVIR pacemaker or cardiac resynchronization therapy (CRT) implanted prior to ablation, p = .0001. Heart failure was present in 44% of the men vs. 28% of the women, p = .0001. LVEF decreased slightly in the whole cohort after the AVJ ablation. There were no sex differences in complication rates due to the pacemaker/ICD treatment, p = .3 or mortality due to AVJ ablation. Conclusion. In this long-term follow-up in patients with atrial fibrillation treated with AVJ ablation and pacing, indication, choice of pacing system, and morbidity differed but there were no sex differences regarding survival or primary cause of death found. The main factor influencing survival was age at the time of ablation. Women less often received treatment with ICD and/or CRT when indication was present compared with men.

Ventricular Fibrillation Conversion Testing After Implantation of a Subcutaneous Implantable Cardioverter Defibrillator: Report From the National Cardiovascular Data Registry.

Compared with transvenous implantable cardioverter defibrillators (ICDs), subcutaneous (S)-ICDs require a higher energy for effective defibrillation. Although ventricular fibrillation conversion testing (CT) is recommended after S-ICD implantation to ensure an adequate margin between the defibrillation threshold and maximum device output (80J), prior work found that adherence to this recommendation is declining. We studied first-time recipients of S-ICDs (between September 28, 2012, and April 1, 2016) in the National Cardiovascular Database Registry ICD Registry to determine predictors of use of CT, predictors of an insufficient safety margin (ISM, defined as ventricular fibrillation conversion energy >65J) during testing, and inhospital outcomes associated with use of CT. Multivariable logistic regression analysis was used to predict use of CT and ISM. Inverse probability weighted logistic regression analysis was used to examine the association between use of CT and inhospital adverse events including death. CT testing was performed in 70.7% (n=5624) of 7960 patients with S-ICDs. Although deferral of CT was associated with several patient characteristics (including increased body mass index, increased body surface area, severely reduced ejection fraction, dialysis dependence, warfarin use, anemia, and hypertrophic cardiomyopathy), the facility effect was comparatively more important (area under the curve for patient level versus generalized linear mixed model: 0.619 versus 0.877). An ISM occurred in 6.9% (n=336) of 4864 patients without a prior ICD and was more common among white patients and those with ventricular pacing on the preimplant ECG, higher preimplant blood pressure, larger body surface area, higher body mass index, and lower ejection fraction. A risk score was able to identify patients at low (<5%), medium (5% to 10%), and high risk (>10%) for ISM. CT testing was not associated with a composite of inhospital complications including death. Use of CT testing after S-ICD implantation was driven by facility preference to a greater extent than patient factors and was not associated with a composite of inhospital complications or death. ISM was relatively uncommon and is associated with several widely available patient characteristics. These data may inform ICD system selection and a targeted approach to CT.