Implantable Cardioverter-defibrillator Registry Research Articles

A call for re-evaluation of the guidelines for prophylactic ICD implantation.

A call for re-evaluation of the guidelines for prophylactic ICD implantation.

Survival after primary prevention implantable cardioverter-defibrillator placement among patients with chronic kidney disease.

Guidelines recommend that implantable cardioverter-defibrillator (ICD) candidates have an estimated longevity of ≥1 year. Longevity can be affected by chronic kidney disease (CKD). Using the National Cardiovascular Data Registry ICD registry linked with the Social Security Death Master File, we assessed the rate of death after primary prevention ICD placement between January 1, 2006, and December 31, 2007, according to CKD stage. Using Cox models, we identified factors associated with death among patients with CKD. Compared with patients without CKD (n=26,056), those with CKD (n=21,226) were older, less commonly men, more often white, and more frequently had comorbid illness. Compared with patients without CKD, patients with a glomerular filtration rate 30 to 60, glomerular filtration rate <30, and end-stage renal disease on dialysis had a higher risk of death after ICD placement (hazard ratio, 2.08; 95% confidence interval, 1.99-2.18; P<0.0001; hazard ratio, 4.20; 95% confidence interval, 3.92-4.50; P<0.0001; and hazard ratio, 4.80; 95% confidence interval, 4.46-5.17; P<0.0001, respectively). Corresponding 1-year death rates were 4.4%, 9.1%, 20.2%, and 22.4%. Among patients with CKD, factors associated with increased risk of death included CKD severity, age >65 years, heart failure symptoms, diabetes mellitus, lung disease, serum sodium <140 mEq/L, atrial fibrillation or flutter, and a lower ejection fraction. The risk of death after primary prevention ICD placement is proportional to CKD severity. Among patients with CKD, several factors are prognostically significant and could inform clinical decision making on primary prevention ICD candidacy.

Abstract 317: Outcomes after Primary Prevention Implantable Cardioverter Defibrillator Placement: Results of the Cardiovascular Research Network Longitudinal Study of Implantable Cardioverter Defibrillators

Background: Implantable cardioverter defibrillators (ICDs) are commonly used for the primary prevention of sudden cardiac death. Controversies persist, however, about outcomes in representative cohorts and in clinically important patient subgroups. Observational studies of outcomes following primary prevention ICD implantation are typically limited to relatively restricted cohorts (e.g. Medicare) or with short follow up. Methods: In the Cardiovascular Research Network (CVRN), we conducted a study in 7 integrated health care delivery systems to identify patients undergoing primary prevention ICD implantation for left ventricular systolic dysfunction between 2006-2010. Baseline procedural and clinical data were obtained from the NCDR ICD Registry; longitudinal data to ascertain outcomes after implantation were obtained through clinical health system data from the CVRN Virtual Data Warehouse. We assessed the occurrence of complications at 90 days and mortality, all-cause hospitalization, and heart failure hospitalization up to 5 years after implantation in clinical strata designated a priori. Multivariable models accounting for clustering of patients within site were used to assess the relationship between clinical variables and each outcome. Clinical variables of interest (Table) were included in all models; additional variables were assessed with forward selection to account for possible confounders. Results: Among 2953 eligible patients, median age was 69 years and 26% were women Coexisting conditions, including hypertension (74%), atrial fibrillation (32%), COPD (20%), and diabetes (42%), were common. Overall event rates (per 1000 patient years) were 110 for death, 438 for any hospitalization, and 58 for heart failure hospitalization. The association between clinically important variables and outcomes are shown in the Table. Conclusions: In a diverse population of patients undergoing ICD implantation in contemporary practice we identified specific clinical variables associated with adverse outcomes. These data can inform prognosis in clinical care and guide the design of future trials of this therapy.

Predictors of an Inadequate Defibrillation Safety Margin at ICD Implantation: Insights From the National Cardiovascular Data Registry

BackgroundDefibrillation testing is often performed to establish effective arrhythmia termination, but predictors and consequences of an inadequate defibrillation safety margin (DSM) remain largely unknown. ObjectivesThe aims of this study were to develop a simple risk score predictive of an inadequate DSM at implantable cardioverter-defibrillator (ICD) implantation and to examine the association of an inadequate DSM with adverse events. MethodsA total of 132,477 ICD Registry implantations between 2010 and 2012 were analyzed. Using logistic regression models, factors most predictive of an inadequate DSM (defined as the lowest successful energy tested <10 J from maximal device output) were identified, and the association of an inadequate DSM with adverse events was evaluated. ResultsInadequate DSMs occurred in 12,397 patients (9.4%). A simple risk score composed of 8 easily identifiable variables characterized patients at high and low risk for an inadequate DSM, including (with assigned points) age <70 years (1 point); male sex (1 point); race: black (4 points), Hispanic (2 points), or other (1 point); New York Heart Association functional class III (1 point) or IV (3 points); no ischemic heart disease (2 points); renal dialysis (3 points); secondary prevention indication (1 point); and ICD type: single-chamber (2 points) or biventricular (1 point) device. An inadequate DSM was associated with greater odds of complications (odds ratio: 1.22; 95% confidence interval: 1.09 to 1.37; p = 0.0006), hospital stay >3 days (odds ratio: 1.24; 95% confidence interval: 1.19 to 1.30; p < 0.0001), and in-hospital mortality (odds ratio: 1.96; 95% confidence interval: 1.63 to 2.36; p < 0.0001). ConclusionsA simple risk score identified ICD recipients at risk for an inadequate DSM. An inadequate DSM was associated with an increased risk for in-hospital adverse events.

Renal dysfunction and clinical outcomes of patients undergoing ICD and CRTD implantation: data from the Israeli ICD registry.

Implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality in patients with heart failure (HF) and left ventricular dysfunction. However, their efficacy in patients with chronic kidney disease (CKD) is controversial. We examined the association between renal dysfunction and clinical outcomes in patients undergoing ICD and CRT defibrillator (CRTD) implantation. Data were collected from the Israeli ICD registry. Estimated glomerular filtration rate (eGFR) at implantation was assessed using the modification of diet in renal disease formula. Primary outcome was all-cause mortality. Secondary outcomes included the composite endpoints of death or HF and death or ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]); any hospitalizations; first appropriate and inappropriate ICD therapy. During the study period (July 2010-November 2012), 2,811 patients were implanted with ICD or CRTD. One-year follow-up data were available for 730 ICD patients and 453 CRTD patients. Patients with eGFR < 30 mL/minute/1.73 m(2) (n = 54, 4.6%) were older, had a higher prevalence of diabetes, hypertension, or ischemic heart disease. eGFR <30 mL/minute/1.73 m(2) was associated with increased mortality risk in ICD (HR 5.4; 95% CI 1.5-19.2), but not in CRTD patients (HR 0.9; 95% CI 0.1-7.5). Renal dysfunction was associated with the composite endpoints of death or HF and death or VT/VF in ICD, but not in CRTD patients. Mean eGFR during follow-up decreased by 8.0 ± 4.3 mL/minute/1.73 m(2) in ICD patients (P = 0.06) and by 1.8 ± 1.3 mL/minute/1.73 m(2) in patients with CRTD (P = 0.2). Based on this retrospective analysis, CKD is associated with adverse prognosis after ICD implantation, but not after CRTD implantation. GFR decreased in patients with ICD, but not in CRTD patients.

Association between prophylactic implantable cardioverter-defibrillators and survival in patients with left ventricular ejection fraction between 30% and 35%.

Clinical trials of prophylactic implantable cardioverter-defibrillators (ICDs) have included a minority of patients with a left ventricular ejection fraction (LVEF) between 30% and 35%. Because a large number of ICDs in the United States are implanted in such patients, it is important to study survival associated with this therapy. To characterize patients with LVEF between 30% and 35% and compare the survival of those with and without ICDs. Retrospective cohort study of Medicare beneficiaries in the National Cardiovascular Data Registry ICD registry (January 1, 2006, through December 31, 2007) with an LVEF between 30% and 35% who received an ICD during a heart failure hospitalization and similar patients in the Get With The Guidelines-Heart Failure (GWTG-HF) database (January 1, 2005, through December 31, 2009) with no ICD. The analysis was repeated in patients with an LVEF less than 30%. There were 3120 patients with an LVEF between 30% and 35% (816 in matched cohorts) and 4578 with an LVEF less than 30% (2176 in matched cohorts). Propensity score matching and Cox models were applied. The primary outcome was all-cause mortality; data were obtained from Medicare claims through December 31, 2011. There were no significant differences in the baseline characteristics of the matched groups (n = 408 for both groups). Among patients with an LVEF between 30% and 35%, there were 248 deaths in the ICD Registry group, within a median follow-up of 4.4 years (interquartile range, 2.7-4.9) and 249 deaths in the GWTG HF group, within a median follow-up of 2.9 years (interquartile range, 2.1-4.4). The risk of all-cause mortality in patients with an LVEF between 30% and 35% and an ICD was significantly lower than that in matched patients without an ICD (3-year mortality rates: 51.4% vs 55.0%; hazard ratio, 0.83 [95% CI, 0.69-0.99]; P = .04). Presence of an ICD also was associated with better survival in patients with an LVEF less than 30% (3-year mortality rates: 45.0% vs 57.6%; 634 and 660 total deaths; hazard ratio, 0.72 [95% CI, 0.65-0.81]; P < .001) (P = .20 for interaction). Among Medicare beneficiaries hospitalized for heart failure and with an LVEF between 30% and 35% and less than 30%, survival at 3 years was better in patients who received a prophylactic ICD than in comparable patients with no ICD. These findings support guideline recommendations to implant prophylactic ICDs in eligible patients with an LVEF of 35% or less.

Evaluation of the need of elective implantable cardioverter-defibrillator generator replacement in primary prevention patients without prior appropriate ICD therapy

ObjectiveIt is not clear whether patients who received an implantable cardioverter-defibrillator (ICD) for primary prevention should undergo device replacement if they never experienced an appropriate ICD therapy during the first...

In-Hospital Complications Associated With Reoperations of Implantable Cardioverter Defibrillators

Repeat implantable cardioverter defibrillator (ICD) procedures are increasing and may be associated with higher risks for complications. To provide more information for clinical decision making, especially in light of recent defibrillator advisories, we examined a large national cohort to characterize repeat ICD procedural outcomes. Using data from the National Cardiovascular Data Registry (ICD Registry), we compared patient characteristics, reasons for ICD implantation, and associated in-hospital adverse events among 92,751 patients receiving their first device and 81,748 patients who underwent repeat procedures with (n= 31,057) and without (n= 50,691) lead involvement. Hierarchical multivariable logistic regression was used to determine the predictors of in-hospital complications. Complication rates were higher in those who underwent repeat ICD procedures with lead involvement (lead implantation or revision), compared with patients who underwent initial implants (3.2% vs 2.6%, p <0.001) or versus those with pocket-only (e.g., generator change only) procedures (3.2% vs 0.6%, p <0.001). There were significantly more in-hospital deaths, lead dislodgements, and infections requiring antibiotics in the lead involvement cohort. Compared with those who had a pocket-only procedure, the multivariable adjusted odds ratio of any complication were increased at 4.20 (95% confidence interval: 3.66 to 4.82, p <0.001) in patients who underwent repeat procedures with lead involvement excluding lead extraction or 7.11 (95% confidence interval: 5.96 to 8.48, p <0.001) in procedures involving lead extractions. Inconclusion, repeat ICD procedures, when involving the addition or revision of a lead with or without concurrent lead extraction, are associated with higher complication ratescompared with initial implants and with those who underwent pocket-only procedures.

Cardiac resynchronisation therapy in populations underrepresented in randomised controlled trials

### Learning objectives The benefits of cardiac resynchronisation therapy (CRT) on long term survival and left ventricular (LV) function of patients with heart failure symptoms have been demonstrated in several...

Influence of healthy candidate bias in assessing clinical effectiveness for implantable cardioverter-defibrillators: cohort study of older patients with heart failure

Objective To assess the potential contribution of unmeasured general health status to patient selection in assessments of the clinical effectiveness of implantable cardioverter-defibrillator (ICD) therapy.Design Retrospective cohort study.Setting Linked data...

Comparative Effectiveness of Cardiac Resynchronization Therapy With an Implantable Cardioverter-Defibrillator Versus Defibrillator Therapy Alone

Trials comparing implantable cardioverter-defibrillator (ICD) therapy with cardiac resynchronization therapy with a defibrillator (CRT-D) are limited to selected patients treated at centers with extensive experience. To compare outcomes after CRT-D versus ICD therapy in contemporary practice. Retrospective cohort study using the National Cardiovascular Data Registry's ICD Registry linked with Medicare claims. 780 U.S. hospitals implanting both CRT-D and ICD devices. 7090 propensity-matched patients older than 65 years with reduced left ventricular ejection fraction (&lt;0.35) and prolonged QRS duration on electrocardiography (≥120 ms) having CRT-D or ICD implantation between 1 April 2006 and 31 December 2009. Risks for death, readmission, and device-related complications over 3 years. Compared with ICD therapy, CRT-D was associated with lower risks for mortality (cumulative incidence, 25.7% vs. 29.8%; adjusted hazard ratio [HR], 0.82 [99% CI, 0.73 to 0.93]), all-cause readmission (cumulative incidence, 68.6% vs. 72.8%; adjusted HR, 0.86 [CI, 0.81 to 0.93]), cardiovascular readmission (cumulative incidence, 45.0% vs. 52.4%; adjusted HR, 0.80 [CI, 0.73 to 0.88]), and heart failure readmission (cumulative incidence, 24.3% vs. 29.4%; adjusted HR, 0.78 [CI, 0.69 to 0.88]). It was also associated with greater risks for device-related infection (cumulative incidence, 1.9% vs. 1.0%; adjusted HR, 1.90 [CI, 1.07 to 3.37]). The lower risks for heart failure readmission associated with CRT-D compared with ICD therapy were most pronounced among patients with left bundle branch block or a QRS duration at least 150 ms and in women. Patients were not randomly assigned to treatment groups, and few patients could be propensity-matched. The findings may not extend to younger patients or those outside of fee-for-service Medicare. In older patients with reduced left ventricular ejection fraction and prolonged QRS duration, CRT-D was associated with lower risks for death and readmission than ICD therapy alone. Agency for Healthcare Research and Quality.

Prevalence of Guideline-Directed Medical Therapy Among Patients Receiving Cardiac Resynchronization Therapy Defibrillator Implantation in the National Cardiovascular Data Registry During the Years 2006 to 2008

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality among selected patients with left ventricular systolic dysfunction and severe heart failure symptoms despite guideline-directed medical therapy (GDMT). Contemporaneous guidelines provided clear recommendations regarding selection of patients for CRT, including that all patients should first receive GDMT with β blockers and renin-angiotensin axis antagonists. Prevalence of GDMT among real-world patients receiving CRT defibrillators (CRT-D) has not been well studied. We identified 45,392 patients in the National Cardiovascular Data Registry Implantable Cardioverter-Defibrillator Registry who underwent first CRT-D implantation for primary prevention of sudden death from January 2006 to June 2008. We calculated the proportion of patients with contemporaneous class I guideline indications for CRT-D, the proportion receiving GDMT for heart failure, and the proportion receiving GDMT who had class I guideline indications for CRT-D. Among patients without contraindications, 87% were prescribed β blockers, 78% an angiotensin-converting enzyme inhibitor or an angiotensin II receptor inhibitor, and 70% both a β blocker and an angiotensin-converting enzyme or angiotensin II receptor inhibitor at discharge. Finally, 50% of patients met class I guideline indications and were prescribed GDMT at discharge; 9% neither met class I indications nor were prescribed GDMT at discharge. The major limitation of this study is the lack of dosage information in the Implantable Cardioverter-Defibrillator Registry and lack of prescribing information at times other than discharge. In conclusion, many patients receiving CRT-D are not receiving GDMT at discharge. Ensuring that all patients receiving CRT-D are also receiving GDMT appears to be a quality improvement target.

Sex differences in implantable cardioverter-defibrillator implantation indications and outcomes: lessons from the Nationwide Israeli-ICD Registry

Implantable cardioverter-defibrillators (ICDs) improve survival in certain high arrhythmic risk populations. However, there are sex differences regarding both the utilization and the benefit of these devices. Using a prospective national ICD registry, we aim to compare the indications for ICD implantation as well as outcomes in implanted women vs. men. All subjects implanted with an ICD or cardiac resynchronization therapy with a defibrillator (CRTD) in Israel between July 2010 and February 2013 were included. A total of 3544 subjects constructed the baseline cohort, of whom 615 (17%) were women. Women had the same age (64 years) and rate of secondary prevention indication (26%) as men. However, women were more likely than men to have significant heart failure symptoms (52 vs. 45%), QRS > 120 ms (41 vs. 36%), and a higher rate of non-ischaemic cardiomyopathy (54 vs. 21%, all P values <0.05). Using multivariate analysis, women were more likely to undergo CRTD implantation (odds ratio = 1.8, P < 0.01). Follow-up data were available for 1518 subjects with a mean follow-up of 12 months. During follow-up, there were no significant differences among genders in the rate of any single or the combined outcomes of appropriate device therapies, heart failure admissions, or death. First-year re-intervention rate was double among women (5.6 vs. 3.0%, P < 0.01). In real-world setting, women implanted with an ICD differ significantly from men in their baseline characteristics and in the use of CRTD devices. These, however, did not translate into outcome differences.

Circulation : Clinical Summaries

<i>Circulation</i> : Clinical Summaries

Temporal trends in quality of care among recipients of implantable cardioverter-defibrillators: insights from the National Cardiovascular Data Registry.

The ICD Registry was established in 2006 in part to measure quality of care in patients undergoing implantation of implantable cardioverter-defibrillators (ICDs); however, whether outcomes have improved since initiation of the registry is unknown. Our objective was to examine changes over time in 3 quality metrics available from the registry. We performed an observational study of 367 153 patients who received new ICD implants from April 2006 to March 2010. Three quality metrics were selected: Adverse events (in-hospital complications or mortality), optimal medical therapy (OMT), and cardiac resynchronization therapy (CRT). OMT was defined as prescription of β-blocker and either angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in eligible patients. CRT eligibility was determined by QRS ≥120 ms, left ventricular ejection fraction ≤35%, and New York Heart Association class III/IV. Observation periods were divided into four 12-month intervals. We analyzed changes over time and used hierarchical logistic regression to adjust for potential confounders. Adverse events decreased over time (3.7% to 2.8%, P<0.001). Among eligible patients, rates of OMT and CRT increased over time (OMT: 69.0% to 74.3%, P<0.001; CRT: 80.5% to 84.2%, P<0.001). After adjustment for potential confounders, patients were significantly less likely to experience adverse events in year 4 than in year 1 (odds ratio, 0.75; 95% confidence interval, 0.71-0.79) and significantly more likely to receive OMT (odds ratio, 1.29; 95% confidence interval, 1.26-1.32) and CRT (odds ratio, 1.42; 95% confidence interval, 1.35-1.49). Since initiation of the ICD Registry, adverse events have been decreasing, and rates of OMT and CRT among eligible patients have been increasing, although there is still significant room for improvement.

ICD Recipients’ Understanding of Ethical Issues, ICD Function, and Practical Consequences of Withdrawing the ICD in the End‐of‐Life

The current international expert consensus statements recommend that clinicians should discuss elective implantable cardioverter defibrillator (ICD) deactivation before implantation of the device, and then consistently during the illness trajectory. However, no previous studies have investigated predictors of ICD patients' knowledge about end-of-life issues or whether knowledge influences patients' attitudes about deactivation. This nationwide survey study (n = 3,067) had a cross-sectional correlational design of self-reported data. Participants were recruited from the Swedish ICD and Pacemaker Registry and asked to complete a questionnaire about knowledge in relation to the ICD and end-of-life. Only 79 respondents (3%) scored correctly on all 11 questions. The mean sample score was 6.6 ± 2.7 out of a maximum score of 11. A total of 835 participants (29%) had an insufficient knowledge when using the 25th percentile as a cutoff. Younger ICD recipients, those cohabiting, male participants, and those who had received shocks, had a generator replacement, or who had discussed illness trajectory with their physician were more likely to have sufficient knowledge on the end-of-life issues. Insufficient knowledge was associated with indecisiveness to make decisions about ICD deactivation in the end-of-life situations, and with favorable attitudes about replacing the ICD even if seriously ill or have reached an advanced age, and keeping the shock therapy of the ICD even in a terminal phase of life when dying from cancer or other serious chronic illnesses. Insufficient knowledge is common among ICD recipients and is associated with attitudes and decisions that may result in a stressful and potentially painful end-of-life situation.

Role of defibrillation threshold testing during implantable cardioverter-defibrillator placement: Data from the Israeli ICD Registry

Defibrillation threshold (DFT) testing during placement of an implantable cardioverter-defibrillator (ICD) has been considered mandatory. Accumulating data suggest a more limited role for DFT. The purpose of this study was to compare the outcome of ICD recipients who underwent DFT testing compared with those who did not. In this prospective cohort analysis of patients who received an ICD between July 2010 and March 2013, we compared patients who underwent DFT testing and those who did not. Primary end-points were death and malignant ventricular arrhythmias. Secondary end-points included the composite end-points and inappropriate ICD discharges. Of the 3596 patients in the registry, 614 patients (17%) underwent DFT testing during ICD placement vs 2982 (83%) who did not. Variables associated with ICD testing were implantation for secondary prevention (relative risk [RR] 1.87), prior ventricular arrhythmias (RR 1.81), use of antiarrhythmic medication (RR 1.59), and sinus rhythm (RR 2.05). Factors predisposing against testing were cardiac resynchronization therapy defibrillator implantation (RR 0.56) and concomitant diuretic use (RR 0.71). ICD testing was not associated with 1-year mortality (5.3% vs 5.1%, P = .74), delivery of appropriate shocks (8.6% vs 5.6%, P = .16), combined outcomes of ventricular arrhythmias and death (12.9% vs 11.3%, P = .45), or inappropriate ICD discharges (3.9% vs 2.1%, P = .2) compared to no DFT testing. No significant differences in the incidence of mortality, malignant ventricular arrhythmias, or inappropriate ICD discharges were observed between patients who underwent DFT testing compared to those who did not. Our results may support avoiding DFT testing during ICD placement, but this requires confirmation by additional prospective studies.

Do patients with a left ventricular ejection fraction between 30% and 35% benefit from a primary prevention implantable cardioverter defibrillator?

Several randomized clinical trials have shown that the implantable cardioverter defibrillator (ICD) improves the survival of patients with systolic heart failure due to ischemic or non-ischemic cardiomyopathy [1–5]. Although most of these trials required a left ventricular ejection fraction (LVEF) of ≤35%, the median LVEF of enrolled patients was well below 30% [1–5]. This is why when the United States' government mandated a national ICD registry to collect data on primary prevention ICDs in patients ≥65years of age, they designated patients with LVEF between 30% and 35% as an important subgroup in need of more data on ICD effectiveness [6,7].

The pacemaker and implantable cardioverter-defibrillator registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual Report 2012

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 2012 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 25 611 PM implantations were collected (18 870 first implant and 6741 replacements). The number of collaborating centers was 245. Median age of treated patients was 80 years (74 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 41.9% of first PM implants, sick sinus syndrome in 26.0%, atrial fibrillation plus bradycardia in 13.7%, other in 18.4%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (21.7% of first implants). Use of single-chamber PMs was reported in 29.0% of first implants, of dual-chamber PMs in 61.3%, of PMs with cardiac resynchronization therapy (CRT) in 1.7%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 8.0%. ICD REGISTRY: data about 16 606 ICD implantations were collected (11 393 first implants and 5213 replacements). The number of collaborating centers was 427. Median age of treated patients was 71 years (62 quartile I; 77 quartile III). Primary prevention indication was reported in 68.6% of first implants, secondary prevention in 31.4% (cardiac arrest in 9.0%). A single-chamber ICD was used in 29.4% of first implants, dual-chamber in 37.6% and biventricular in 32.9%. 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 constant increase in prophylactic and biventricular ICD use, reflecting a favorable adherence to trials and guidelines in clinical practice.

Mortality risk following replacement implantable cardioverter-defibrillator implantation at end of battery life: Results from the NCDR®

Implantable cardioverter-defibrillator (ICD) generator replacement at the end of expected battery life accounts for a substantial proportion of all ICD implant procedures. However, little is known about the predictors of mortality following ICD generator replacement. The purpose of this study was to identify clinical and procedural factors associated with death following ICD generator replacement. Patients from the National Cardiovascular Data Registry (NCDR) ICD Registry receiving ICD generator replacements at the end of device battery life between January 1, 2005, and March 30, 2010, were eligible. Predictors of mortality were determined using multivariable Cox regression. Analysis of 111,826 patients (mean age 70.7 ± 12.4, 75.5% male) revealed 1-, 3-, and 5-year mortality of 9.8%, 27.0%, and 41.2%, respectively. After adjustment, atrial fibrillation (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.20-1.27) and congestive heart failure (HR 1.21, 95% CI 1.16-1.27) predicted worse survival. In addition to older age (HR 1.43, 95% CI 1.41-1.45), several noncardiac conditions were also associated with poorer survival, including chronic lung disease (HR 1.53, 95% CI 1.49-1.57), cerebrovascular disease (HR 1.28, 95% CI 1.24-1.32), diabetes (HR 1.27, 95% CI 1.23-1.30), and lower glomerular filtration rate (HR 1.15 for each 10-unit increment decline, 95% CI 1.14-1.16). In the absence of a non-ICD control group, risk reduction provided by ICD therapy in this cohort is not known. In addition to age, atrial fibrillation, and congestive heart failure, noncardiac comorbidities are associated with higher mortality following ICD replacement, which should be considered in the decision to undergo this procedure.