Efficacy Of Implantable Cardioverter-defibrillator Research Articles

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.

Primary prevention implantable cardioverter-defibrillator and opportunities for sudden cardiac death risk assessment in non-ischaemic cardiomyopathy.

Sudden cardiac death (SCD) accounts for approximately one-third of all deaths among patients with non-ischaemic cardiomyopathy (NICM). Implantable cardioverter-defibrillator (ICD) therapy has been the primary intervention for managing individuals at high risk for SCD. However, individual ICD trials in the NICM population have failed to demonstrate a mortality benefit with prophylactic ICD implantation. Current guidelines recommend ICD implantation in NICM patients with symptomatic heart failure and a left ventricular ≤35% and are based on meta-analyses of multiple trials that span three decades and include the recent Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischaemic Heart Failure on Mortality (DANISH) trial. These pooled analyses report a significant reduction in all-cause mortality with ICD implantation compared with medical therapy alone. In addition, each of these trials has demonstrated consistently a reduction in the risk of SCD compared with medical therapy alone. As a result, a refined approach of risk stratification that selects patients at the highest risk for SCD may lead to a significant improvement in ICD efficacy. In this clinical review, we first discuss the evolution of clinical trials that have evaluated ICDs in the NICM population. We then highlight some key markers of arrhythmia risk that hold promise in personalizing risk stratification for SCD.

Implantable cardioverter-defibrillator in Chagas heart disease: A systematic review and meta-analysis of observational studies

BackgroundIn patients with Chagas cardiomyopathy (ChCM), sudden cardiac death (SCD) is the leading cause of mortality. Implantable cardioverter-defibrillator (ICD) is a well-established therapy for secondary prevention in patients with structural heart disease, but there are conflicting opinions regarding its efficacy and safety in patients with ChCM. The aim of this meta-analysis was to assess the efficacy of the ICD for secondary prevention in patients with ChCM, comparing mortality as the primary outcome of patients treated with ICD with those treated with amiodarone. MethodsWe systematically searched five databases for studies assessing mortality outcomes in patients with ChCM and sustained ventricular tachycardia (VT) treated with ICD implantation or with amiodarone. The results of studies were pooled using random-effects modeling. ResultsThere was no randomized clinical trial comparing efficacy of ICD versus medical treatment in patients with ChCM. Six observational studies were included, totalizing 115 patients in amiodarone group and 483 patients in ICD group. The mortality outcome in the ICD population was 9.7 per 100 patient-years of follow-up (95%CI 5.7–13.7) and 9.6 per 100 patient-years in the amiodarone group (95%CI 6.7–12.4) (p = 0.95). Meta-regression did not show any association with LV ejection fraction (p = 0.32), age (p = 0.44), beta-blocker (p = 0.33) or angiotensin-converting enzyme inhibitors (p = 0.096) usage. ConclusionThe best available evidence derived from small observational studies suggests that ICD therapy in secondary prevention of sudden death (VT or resuscitated SCD) is not associated with lower rate of all-cause mortality in patients with ChCM. Randomized controlled trials are needed to answer this question.

Long-term follow-up of Chagas heart disease patients receiving an implantable cardioverter-defibrillator for secondary prevention.

Chagas heart disease (CHD) is a dilated cardiomyopathy characterized by malignant ventricular arrhythmias and increased risk of sudden cardiac death (SCD). Much controversy exists concerning the efficacy of implantable cardioverter-defibrillator (ICDs) in CHD because of mixed results observed. We report our long-term experience with ICDs for secondary prevention in CHD, with the specific aim of assessing the results in groups with preserved or depressed global left ventricular function. 111 patients (75 males; 60 ± 12 years) were followed for 1,948 ± 1,275 days after ICD. Time to death was the primary outcome; LVEF ≤ 45% the exposure; and age, gender, and ICD therapy delivery the potential confounders. We used time-to-event methods and Cox proportional models for analysis, censoring observations at time of death or at 5-year follow-up in survivors. Seventy-two percent of the patients presented at least one sustained ventricular arrhythmia requiring appropriate therapy, and only three patients received inappropriate therapy. Death occurred in 50 (45%) patients, with an annual mortality rate of 8.4%, mostly due to refractory heart failure or noncardiac causes. Unadjusted survival rates were significantly distinct between patients with left ventricular ejection fraction (LVEF)≤45% (26 deaths), 50.5% (95% confidence interval [CI]: 36.2%-63.2%) when compared to patients with LVEF>45% (10 deaths), 77.6% (95% CI: 62.3%-87.3%, P<0.01). After adjusting for confounders, low LVEF (hazard ratio [HR]: 5.2, 95% CI: 2.3-11.6), age (HR: 1.04, 95% CI: 1.01-1.07), and female gender (HR: 3.97, 95% CI: 1.85-8.54) were independently associated with the outcome. ICDs successfully aborted life-threatening arrhythmias in CHD patients. Impaired left ventricular function predicted higher mortality in CHD patients with an ICD for secondary prevention of SCD.

Important Parameters for Implantable Cardioverter Defibrillator Selection.

The efficacy of implantable cardioverter defibrillators in reducing the risk of sudden cardiac death has been well established by several clinical trials. Several factors relating to device characteristics, patient attributes, and comorbidities should be considered when selecting the appropriate implantable cardioverter defibrillators for each patient. This review examines some of these issues.

Implantable Cardioverter Defibrillator Implantation with or Without Defibrillation Testing.

Defibrillation testing (DFT) during implantable cardioverter-defibrillator (ICD) implantation is still considered standard of care in some, but in increasingly fewer centers. The goal is to ensure that the device system functions as intended by testing in the controlled laboratory setting. Although safe, complications can occur and DFT is associated with an increased procedural time and cost. DFT is useful in assessing device function when programming changes or patient characteristics raise concerns regarding ICD efficacy. DFT remains standard of practice following implantation of subcutaneous ICDs and other specific circumstances. Implanting physicians should remain familiar with the process of DFT and situations where it is useful for individual patients.

Implantable cardioverter defibrillator in nonischemic cardiomyopathy: A systematic review and meta-analysis.

The evidence to support implantable cardioverter defibrillator (ICD) in subjects with nonischemic cardiomyopathy (NICM) for primary prevention of sudden cardiac death (SCD) is not robust. This meta‐analysis intends to assess the impact of routine ICD implantation for primary prevention of mortality due to SCD in NICM based on all the published randomized clinical trials (RCTs). Six RCTs were selected using PubMed/Medline, EMBASE, and CENTRAL from inception to December 2016. Outcomes were calculated as random‐effects relative risk (RR) and risk difference (RD) with 95% confidence interval (CI). Patients were randomized to ICD arm and control arm (usual care, medical treatment, and anti‐arrhythmic drugs). ICD significantly reduced all‐cause mortality in NICM patients (RR, 0.74, 95% CI, 0.56‐0.97, P = .03, I2 = 40). Mortality benefit was achieved due to a significant reduction in sudden cardiac death (SCD) (RR, 0.47, 95% CI, 0.30‐0.73, P < .001, I2 = 0). There were no statistical differences between two groups with regard to risk of noncardiac mortality, non‐SCD, cardiac arrest, cardiac transplant, sustained ventricular tachycardia (VT), and VT requiring medical treatment. Our results support efficacy of ICDs at reducing all‐cause mortality due to a reduction in SCD.

Association of Implantable Cardioverter Defibrillators With Survival in Patients With and Without Improved Ejection Fraction

Improvement in left ventricular ejection fraction (EF) to >35% occurs in many patients with reduced EF at baseline. To our knowledge, whether implantable cardioverter defibrillator (ICD) therapy improves survival for these patients is unknown. To examine the efficacy of ICD therapy in reducing risk of all-cause mortality and sudden cardiac death among patients with an EF ≤35% at baseline, with or without an improvement in EF to >35% during follow-up. This retrospective analysis examined data collected in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), which randomly assigned 2521 patients to placebo, amiodarone, or ICD between 1997 and 2001. A subset of 1902 participants (75.4%) of the SCD-HeFT had a repeated assessment of EF a mean (SD) of 13.5 (6) months after randomization. We stratified these patients by EF ≤35% and >35% based on the first repeated EF measurement after randomization and compared all-cause mortality in 649 patients randomized to placebo vs 624 patients randomized to ICD. Follow-up started with the repeated EF assessment. Analysis was performed between January 2016 and July 2016. Implantable cardioverter-defibrillator therapy. All-cause mortality and sudden cardiac death. Of the included 1273 patients, the mean (SD) age was 59 (12) years, and 977 (76.7%) were male and 1009 (79.3%) were white. Repeated EF was >35% in 186 participants (29.8%) randomized to ICD and 185 participants (28.5%) randomized to placebo. During a median follow-up of 30 months, the all-cause mortality rate was lower in the ICD vs placebo group, both in patients whose EF remained ≤35% (7.7 vs 10.7 per 100 person-year follow-up) and in those whose EF improved to >35% (2.6 vs 4.5 per 100 person-year follow-up). Compared with placebo, the adjusted hazard ratio for the effect of ICD on mortality was 0.64 (95% CI, 0.48-0.85) in patients with a repeated EF of ≤35% and 0.62 (95% CI, 0.29-1.30) in those with a repeated EF >35%. There was no interaction between treatment assignment and repeated EF for predicting mortality. Among participants in the SCD-HeFT who had a repeated EF assessment during the course of follow-up, those who had an improvement in EF to >35% accrued a similar relative reduction in mortality with ICD therapy as those whose EF remained ≤35%. Prospective randomized clinical trials are needed to test ICD efficacy in patients with an EF >35%. clinicaltrials.gov Identifier: NCT01114269.

Implantable cardioverter defibrillator use for primary prevention in ischaemic and non-ischaemic heart disease-indications in the post-DANISH trial era: results of the European Heart Rhythm Association survey.

Implantable cardioverter-defibrillator (ICD) is the standard of care for prevention of sudden cardiac death (SCD) in high-risk patients. For primary prevention of SCD, in patients with ischaemic heart disease, there is more robust data on the effect of ICD therapy compared with patients with non-ischaemic heart disease, but current real-life practice may differ substantially. The aim of this European Heart Rhythm Association survey was to evaluate the clinical practice regarding implantation of ICD for primary prevention among European countries in patients with non-ischaemic and ischaemic heart disease. Furthermore, we wanted to investigate the impact of the results of the recently published DANISH trial on clinical practice among European countries. In total, 48 centres from 17 different countries responded to the questionnaire. The majority did not implant ICD for primary prevention on a regular basis in patients with non-ischaemic heart disease despite current guidelines. Also, centres have changed their indications after the recent report on the efficacy of ICD in these patients. In patients with ischaemic heart disease, the guidelines for primary prevention ICD were followed on a regular basis, and no relevant change in indications were reported.

Response by Hess et al to Letter Regarding Article, “Sex and Race/Ethnicity Differences in Implantable Cardioverter-Defibrillator Counseling and Use Among Patients Hospitalized With Heart Failure: Findings From the Get With The Guidelines-Heart Failure Program”

We appreciate Drs Dhruva and Redberg’s thoughtful letter regarding our finding that counseled women were as likely as men to proceed with primary prevention implantable cardioverter-defibrillator (ICD) placement (adjusted odds ratio, 1.13; 95% confidence interval, 0.99–1.29).1 Women were indeed underrepresented in the landmark clinical trials establishing the efficacy of primary prevention ICDs. Post hoc meta-analyses of the randomized data as well as observational studies have reached divergent conclusions regarding the survival benefit of primary prevention ICDs among women compared with men, yet no significant heterogeneity in ICD benefit by sex has been demonstrated to date.2,3 Definitive randomized data likely are not forthcoming given the ethical and cost considerations surrounding a primary prevention ICD trial among women. In this setting, professional societies and especially guideline writing committees have deliberated the body of evidence and determined …

Increasing sex differences in the use of cardiac resynchronization therapy with or without implantable cardioverter-defibrillator

Previous studies have identified sex disparities in the use of cardiac resynchronization therapy (CRT) and implantable cardioverter defibrillators (ICD), although the basis of underutilization in women remains poorly understood. The aim of this study was to assess sex differences in patterns of CRT use with our without ICD. In this cross-sectional study using the National Inpatient Sample database we identified 311 009 patients undergoing CRT implantation in the United States between 2006 and 2012. Demographic and clinical characteristics were compared between men and women undergoing CRT implantation, with special attention to clinical predictors of left ventricular reverse remodelling (CRT response, score range: 0-4) and reduced ICD efficacy (score range: 0-7). When compared to men, women undergoing CRT implantation were significantly more likely to have ≥ 3 predictors of CRT response (47.3 vs. 33.2%, P < 0.001) and less likely to have ≥3 predictors of reduced ICD efficacy (27.0 vs. 37.3%, P < 0.001). Despite this, men were significantly more likely to undergo CRT with ICD (CRT-D) as the type of CRT (88.6 vs. 80.1% of all CRT implants). Compared to those with the greatest likelihood of CRT response (score ≥ 3), those with the least likelihood of CRT response had a significant decreased odds of CRT-D implant (adj odds ratio 0.27 [0.24-0.31], P < 0.001), with a greater decreased odds in women compared to men (P, for sex interaction <0.001). The difference in the % of CRT-D implant in men vs. women increased over the study period (P, sex Δ time trend = 0.012). In this large, contemporary cohort, sex differences in CRT-D implantation were inversely related to predicted CRT efficacy and have increased over time. Future efforts to narrow the gap in CRT-D implantation in men and women may help better align device selection with those most likely to benefit.

Long-Term Efficacy of Implantable Cardioverter Defibrillator in Repaired Tetralogy of Fallot - Role of Anti-tachycardia Pacing.

Tetralogy of Fallot (TOF) is one of the common congenital heart diseases (CHD) in implantable cardioverter defibrillator (ICD) recipients, but few studies have reported the long-term outcomes of and the anti-tachycardia pacing (ATP) efficacy in repaired TOF.Methods and Results:Twenty-one repaired TOF patients with an ICD implanted between April 2003 and March 2015 were investigated retrospectively. ICD therapy and clinical outcome were analyzed. Mean patient age was 39±11 years; 62% were male; and mean age at repair surgery was 9.4±6.8 years. During a median follow-up of 5.6 years (range, 2.6-8.4 years), no patients died. Appropriate ATP were delivered in 11 patients (52%), with appropriate shocks in 5 patients (24%) and inappropriate shocks in 5 patients (24%). The success rate of ATP was 98% for fast ventricular tachycardia (VT; cycle length ≤320 ms) and 98% for slow VT (cycle length >320 ms). ATP effectiveness increased from 81.5% with the first ATP attempt to 93.7% with the second ATP attempt, to 97.5% with the third ATP attempt, and to 98.6% with the fourth or successive ATP attempt (P<0.0001, Cochran-Armitage trend test). ATP was highly effective in repaired TOF regardless of VT cycle length. Multiple ATP attempts could have an important role in VT termination, and the novel subcutaneous ICD without ATP capability should be used carefully.

Abstract 13142: Implantable Cardioverter Defibrillators Continue to Offer Mortality Benefit After Improvement in Ejection Fraction to Above 35%: Results From the Sudden Cardiac Death in Heart Failure Trial

Introduction: Patients (pts) discovered to have low ejection fraction (EF ≤ 35%) frequently show increase in EF to &gt; 35% over time. The efficacy of implantable cardioverter defibrillators (ICD) to improve survival is unknown in these pts. Hypothesis: Mortality benefit with ICD therapy is less in pts whose EF improves to &gt; 35% than those whose EF remains ≤ 35%. Methods: A total of 1875 (74%) participants of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) had a repeat assessment of EF 13.5 ± 6 months after randomization. We stratified them by EF ≤ 35% and &gt; 35% based on the 1 st repeat EF after randomization and compared all-cause mortality of 649 pts randomized to placebo vs. 624 pts randomized to ICD (602 pts randomized to amiodarone were not analyzed). Follow-up started at the time of 1 st repeat EF assessment. Results: Repeat EF was &gt; 35% in 186 (30%) pts in the ICD group and 185 (29%) pts in the placebo group (mean EF increased from 26±7% to 46±8%). The all-cause mortality rate was lower in the ICD group vs. placebo group, both in pts whose EF remained ≤ 35% and in those whose EF improved to &gt; 35% (Table). Compared to placebo, the unadjusted hazard ratio for ICD effect on mortality was 0.72 (95% CI 0.55-0.95) in pts with repeat EF ≤ 35% and 0.58 (95% CI 0.29-1.17) in those with repeat EF &gt; 35%. After adjustment for potential confounders, the estimated effect of ICD was 0.64 (95% CI 0.48-0.85) and 0.62 (95% CI 0.29-1.30) in patients with repeat EF ≤ 35% or &gt; 35%, respectively (Table). We found no evidence of an interaction between treatment assignment and repeat EF for prediction of mortality (p=0.93), suggesting that the ICD effect was similar in patients with EF ≤ 35% or &gt; 35%. Conclusions: Pts with an improvement in EF to &gt; 35% accrued a similar relative reduction in mortality with ICD therapy as those whose EF remained ≤ 35%. However, the absolute benefit of ICD therapy was less in pts with repeat EF &gt; 35% due to the lower mortality risk in this group.

Outcome of Primary Prevention Implantable Cardioverter Defibrillator Therapy According to New York Heart Association Functional Classification

We aimed to assess if the outcome of primary prevention implantable cardioverter defibrillators (ICDs) without cardiac resynchronization therapy is dependent on New York Heart Association (NYHA) class. Among the participants of Défibrillateur Automatique Implantable-Prévention Primaire (DAI-PP; NCT01992458) multicenter cohort study, 155patients in NYHA class I, 504 in NYHA class II, and 188 in NYHA class III had a QRSwidth <120ms and were implanted with an ICD without cardiac resynchronization therapy and, thus, were eligible for the purpose of this analysis. Total and specific mortalities and the incidence of appropriate therapies were assessed for every NYHA. During 2,606 patient-years (3.1 ± 2.1years), 104 (12.3%) subjects died and 188 (22.2%) experienced appropriate therapies. After adjustment, overall mortality increased with NYHA class (adjusted hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.11 to 2.41, p= 0.014), driven by an increase in cardiovascular death. Conversely, incidence of appropriate ICDintervention was comparable among the 3 NYHA groups (NYHA class I 7.43, NYHA class II 7.91, and NYHA class III 12.10 per 100 patient-years; HR 1.19, 95% CI 0.89 to 1.59, p= 0.231). Incidence of ICD-unresponsive sudden death was very low and also comparable (NYHA class I 0.22, NYHA class II 0.36, and NYHA class III 0.83 per 100 patient-years (HR 6.34, 95% CI 0.32 to 124.49, p= 0.224). No significant differences were observed in the other specific modes of death. In conclusion, although patients in NYHA class III have higher overall mortality, they experience a comparable incidence of appropriate ICD therapies. The low incidence of ICD-unresponsive sudden death in all assessed NYHA classes also supports the efficacy of ICDs, irrespective of NYHA class.

Rationale, design, and baseline characteristics of the DANish randomized, controlled, multicenter study to assess the efficacy of Implantable cardioverter defibrillators in patients with non-ischemic Systolic Heart failure on mortality (DANISH)

The effect of an implantable cardioverter defibrillator (ICD) in patients with symptomatic systolic heart failure (HF) caused by coronary artery disease is well documented. However, the effect of primary prophylactic ICDs in patients with systolic HF not due to coronary artery disease is much weaker. In addition, HF management has improved, since the landmark ICD trials and a large proportion of patients now receive cardiac resynchronization therapy (CRT) where the effect of ICD treatment is unknown. In the DANISH study, 1,116 patients with symptomatic systolic HF not caused by coronary artery disease have been randomized to receive an ICD or not, in addition to contemporary standard therapy. The primary outcome of the trial is time to all-cause death. Follow-up will continue until June 2016 with a median follow-up period of 5 years. Baseline characteristics show that enrolled patients are treated according to current guidelines. At baseline, 97% of patients received an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, 92% received a β-blocker, 58% a mineralocorticoid receptor antagonist, and 58% were scheduled to receive CRT. Median age was 63 years (range, 21-84 years) at baseline, and 28% were women. DANISH will provide pertinent information about the effect on all-cause mortality of a primary prophylactic ICD in patients with symptomatic systolic HF not caused by coronary artery disease on contemporary standard therapy including CRT.

Implantable Cardioverter-Defibrillators for Primary Prevention of Sudden Cardiac Death

Implantable cardioverter-defibrillators (ICDs) are an effective treatment strategy for patients with aborted sudden cardiac death (SCD) and ventricular tachyarrhythmias. rimary prevention of SCD is a strategy involving the use of ICDs in patients who are at high risk for, but have not had, any previous events of ventricular arrhythmias or cardiac arrest. Several randomized clinical trials have demonstrated the efficacy of ICDs in the primary prevention of SCD. Therefore, ICD implantation is recommended as a standard of care by the guidelines in patients who have ischemic or nonischemic cardiomyopathy and a low left ventricular ejection fraction. However, the rates of ICD implantation as a primary prevention in Korea is quite low compared to western countries. In this review, we will summarize the results and efficacy of ICDs in the clinical trials about primary prevention of SCD, the current treatment guidelines, and the reimbursement policy of Korean health insurance. We hope that this review will help broaden the recognition of importance of ICD implantation for the primary prevention of SCD. Keywords: Implantable cardioverter-defibrillator; Sudden cardiac death; Primary prevention 중심 단어: ì‚½ìž í˜• ì œì„¸ë™ê¸°; 돌연사; ì¼ì°¨ì  예방

Abstract 18639: Implantable Cardioverter-defibrillator Use is Associated With Improved Survival on the Waitlist for Heart Transplantation: A UNOS/ OPTN Registry Analysis of 36,397 Patients

Background: Current guidelines do not support routine use of implantable cardioverter-defibrillators (ICDs) in patients (pts) with end-stage heart failure (HF), unless these pts are awaiting advanced HF therapies such as left ventricular assist devices (LVADs) or a heart transplantation (HT). Whether ICDs improve survival in end-stage HF pts awaiting HT has not been previously examined in a large, multicenter cohort. Hypothesis: Presence of ICDs at time of listing for HT is associated with lower waitlist mortality. Methods: The United Network for Organ Sharing registry was used to identify adults (≥18 years) listed for HT between January 4, 1999 &amp; September 30, 2014. Pts with congenital heart disease, total artificial heart, restrictive cardiomyopathy, prior HT, or missing covariates were excluded. Cox regression analysis was used to assess the impact of an ICD at the time of listing on waitlist mortality. Results: The analysis included 36,397 pts (mean age 53±12; 77% males) listed for HT. The prevalence of ICDs at listing has steadily increased over time before reaching a plateau in 2006 (27% in 1999, and range 76-82% between 2006-2014). In the unadjusted model, ICD use was associated with a 36% reduction in waitlist mortality (HR 0.64, 95% CI 0.60-0.68, p&lt;0.001). After adjustment for covariates such as age, sex, race, creatinine, ischemic cardiomyopathy, and listing status, this association was nearly unchanged (HR 0.67, 95% CI 0.62-0.72, p&lt;0.001). Test for interaction by listing era (pre- and post-2006) was non-significant (p=0.28). In the final adjusted model, that included listing era and LVAD status in addition to the above listed covariates, ICD use continued to remain associated with a mortality benefit on the waitlist for HT (HR 0.84, 95% CI 0.78-0.91, p&lt;0.001). Conclusion: ICDs are increasingly prevalent in pts listed for HT; however many pts are still listed for HT without these devices. The presence of an ICD at the time of listing is associated with lower mortality on the waitlist. Although the magnitude of ICD efficacy diminishes slightly, its benefit continues to remain significant even after adjustment for listing era and LVAD use. Further analyses are required to identify specific sub-groups of pts where ICD use is most beneficial and appropriate.

Clinical Management and Prevention of Sudden Cardiac Death

Despite the revolutionary advancements in the past 3 decades in the treatment of ventricular tachyarrhythmias with device-based therapy, sudden cardiac death (SCD) remains an enormous public health burden. Survivors of SCD are generally at high risk for recurrent events. The clinical management of such patients requires a multidisciplinary approach from postresuscitative care to a thorough cardiovascular investigation in an attempt to identify the underlying substrate, with potential to eliminate or modify the triggers through catheter ablation and ultimately an implantable cardioverter-defibrillator (ICD) for prompt treatment of recurrences in those at risk. Early recognition of low left ventricular ejection fraction as a strong predictor of death and association of ventricular arrhythmias with sudden death led to significant investigation with antiarrhythmic drugs. The lack of efficacy and the proarrhythmic effects of drugs catalyzed the development and investigation of the ICD through several major clinical trials that proved the efficacy of ICD as a bedrock tool to detect and promptly treat life-threatening arrhythmias. The ICD therapy is routinely used for primary prevention of SCD in patients with cardiomyopathy and high risk inherited arrhythmic conditions and secondary prevention in survivors of sudden cardiac arrest. This compendium will review the clinical management of those surviving SCD and discuss landmark studies of antiarrhythmic drugs, ICD, and cardiac resynchronization therapy in the primary and secondary prevention of SCD.

Defibrillator implantations for primary prevention in the United States: Inappropriate care or inadequate documentation: Insights from the National Cardiovascular Data ICD Registry

Prior studies have reported that more than 20% of implantable cardioverter-defibrillator (ICD) implantations in the United States do not adhere to trial-based criteria. We sought to investigate the patient characteristics associated with not meeting the inclusion criteria of the clinical trials that have demonstrated the efficacy of primary prevention ICDs. Using data from the National Cardiovascular Data Registry's ICD Registry, we identified patients who received ICDs for primary prevention from January 2006 to December 2008. We determined whether patients met the inclusion criteria of at least 1 of the 4 ICD primary prevention trials: Multicenter Automatic Defibrillator Implantation Trial (MADIT), MADIT-II, Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), and the Multicenter Unsustained Tachycardia Trial (MUSTT). Among 150,264 patients, 86% met criteria for an ICD implantation based on trial data. The proportion of patients who did not meet trial-based criteria increased as age decreased. In multivariate analysis, the significant predictors for not meeting trial criteria included prior cardiac transplantation (odds ratio [OR] 2.1), pediatric electrophysiology operator (OR 2.0), and high-grade atrioventricular conduction disease (OR 1.4). Among National Cardiovascular Data Registry registrants receiving first-time ICDs for primary prevention, the majority met trial-based criteria. Multivariate analyses suggested that many patients who did not meet the trial-based criteria may have had clinical circumstances that warranted ICD implantation. These findings caution against the use of trial-based indications to determine site quality metrics that could penalize sites that care for younger patients. The planned incorporation of appropriate use criteria into the ICD registry may better characterize patient- and site-level quality and performance.

Abstract 223: Outcomes of Older Patients Receiving Secondary Prevention Implantable Cardioverter Defibrillators: An Analysis From the NCDR ICD Registry

Background: The clinical trials establishing the efficacy of implantable cardioverter defibrillators (ICDs) for secondary prevention of sudden cardiac death enrolled limited numbers of older patients. We sought to assess the morbidity and mortality of older patients receiving ICDs for secondary prevention in contemporary clinical practice. Methods: Using the NCDR ICD Registry, we identified 20,751 Medicare beneficiaries &gt; 65 years old who underwent secondary prevention ICD implantation between 2006 and 2010 in 1027 US hospitals. Using a probabilistic method, eligible subjects were matched to Medicare claims to assess longitudinal outcomes, including death, hospitalization, and skilled nursing facility (SNF) admission over 1 year. Outcomes were evaluated in strata according to age (&lt;70, 70-74, 75-79, and &gt;80 years). Results: The mean age of the cohort was 75 years at the time of implantation; 24.1% were&lt;70 and 26.8% &gt; 80 (Table). Overall 1-year survival was 87%, with 91% and 82% in ages &lt;70 and &gt;=80 respectively. Regardless of age, hospitalizations at one year were frequent, ranging from 47% in &lt;70 to 57% in &gt; 80. Early admission to a SNF was much higher for &gt; 80 (12%) than for &lt;70 (4%) (p &lt;0.01). Conclusions: In older patients receiving secondary prevention ICDs, 1-year survival was high in all age strata including age &gt; 80. However, rates of hospitalization and SNF admission indicate substantial care needs after device implantation. Figure: