Evidence of clinical practice heterogeneity in the use of implantable cardioverter-defibrillators in heart failure and post–myocardial infarction left ventricular dysfunction: Findings from IMPROVE HF

Use of Implantable Cardioverter-Defibrillators for Primary Prevention of Sudden Cardiac Death in Asia

The effectiveness of primary prevention implantable cardioverter-defibrillators (ICDs) is well established. However, there are several unsolved problems related to ICD use for primary prevention in Asia, including ICD underuse, population differences in underlying heart disease, and the rate of appropriate ICD therapy compared with Western countries. Although the prevalence of ischemic cardiomyopathy in Asia is lower than in Europe and the United States, the mortality rate of Asian patients with ischemic heart disease has been increasing recently. As for the use of ICDs for primary prevention, there have been no randomized clinical trials, and limited data are available in Asia. This review focuses on the unmet needs related to ICD use for primary prevention in Asia.

Influence of Social Determinants of Health on Heart Failure Outcomes: A Systematic Review

Background Prior research suggests an association between clinical outcomes in heart failure (HF) and social determinants of health (SDoH). Because providers should identify and address SDoH in care delivery, we evaluated how SDoH have been defined, measured, and evaluated in studies that examine HF outcomes. Methods and Results Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, databases were searched for observational or interventional studies published between 2009 and 2021 that assessed the influence of SDoH on outcomes. Selected articles were assessed for quality using a validated rating scheme. We identified 1373 unique articles for screening; 104 were selected for full-text review, and 59 met the inclusion criteria, including retrospective and prospective cohort, cross-sectional, and intervention studies. The majority examined readmissions and hospitalizations (k=33), mortality or survival (k=29), and success of medical devices and transplantation (k=8). SDoH examined most commonly included race, ethnicity, age, sex, socioeconomic status, and education or health literacy. Studies used a range of 1 to 9 SDoH as primary independent variables and 0 to 7 SDoH as controls. Multiple data sources were employed and frequently were electronic medical records linked with national surveys and disease registries. The effects of SDoH on HF outcomes were inconsistent because of the heterogeneity of data sources and SDoH constructs. Conclusions Our systematic review reveals shortcomings in measurement and deployment of SDoH variables in HF care. Validated measures need to be prospectively and intentionally collected to facilitate appropriate analysis, reporting, and replication of data across studies and inform the design of appropriate, evidence-based interventions that can ameliorate significant HF morbidity and societal costs.

Improve the Prevention of Sudden Cardiac Arrest in Patients With Post-Acute Myocardial Infarction

BACKGROUND

Implantable cardioverter-defibrillator (ICD) implantation to prevent sudden cardiac death (SCD) in post-myocardial infarction (MI) patients varies by geography but remains low in many regions despite guideline recommendations.

OBJECTIVES

This study aimed to characterize the care pathway of post-MI patients and understand barriers to referral for further SCD risk stratification and management in patients meeting referral criteria.

METHODS

This prospective, nonrandomized, multi-nation study included patients ≥18 years of age, with an acute MI ≤30 days and left ventricular ejection fraction <50% ≤14 days post-MI. The primary endpoint was defined as the physician's decision to refer a patient for SCD stratification and management.

RESULTS

In total, 1,491 post-MI patients were enrolled (60.2 ± 12.0 years of age, 82.4% male). During the study, 26.7% (n = 398) of patients met criteria for further SCD risk stratification; however, only 59.3% of those meeting criteria (n = 236; 95% CI: 54.4%-64.0%) were referred for a visit. Of patients referred for SCD risk stratification and management, 94.9% (n = 224) attended the visit of which 56.7% (n =127; 95% CI: 50.1%-63.0%) met ICD indication criteria. Of patients who met ICD indication criteria, 14.2% (n = 18) were implanted.

CONCLUSIONS

We found that ∼40% of patients meeting criteria were not referred for further SCD risk stratification and management and ∼85% of patients who met ICD indications did not receive a guideline-directed ICD. Physician and patient reasons for refusing referral to SCD risk stratification and management or ICD implant varied by geography suggesting that improvement will require both physician- and patient-focused approaches. (Improve Sudden Cardiac Arrest [SCA] Bridge Study; NCT03715790).

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

BACKGROUND

Whether insurance status influences practice patterns in implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) defibrillators, when indicated, is not known.

METHODS AND RESULTS

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

CONCLUSIONS

In propensity-weighted analysis, uninsured patients are less likely to receive CRT when indicated but more likely to be receiving optimal medical therapy at discharge. Reasons for differences in device implantation practices based on insurance status require further study.

Predictors of adoption and impact of evidence-based programming on the incidence of implantable cardioverter-defibrillator therapies

INTRODUCTION AND OBJECTIVES

The ADVANCE III trial showed that a delayed-detection strategy reduces implantable cardioverter-defibrillator (ICD) therapies. Here, we describe the adherence to and predictors of ADVANCE adoption and compare ICD therapy rates between patients with and without ADVANCE programming.

METHODS

This observational retrospective study analyzed patients implanted with Medtronic ICDs included from 2005 to 2016 in a Spanish national multicenter registry (UMBRELLA database; ClinicalTrials.gov, NCT01561144). Changes in ADVANCE programming adoption were described in relation to a) publication of the ADVANCE trial, b) implementation of an "ADVANCE awareness" campaign, and c) publication of an expert consensus statement. Multivariate logistic regression identified predictors of adoption. Therapy incidence rates were compared between groups by estimating the adjusted incidence rate ratio (aIRR) using negative binomial regression.

RESULTS

A total of 3528 patients were included. An ADVANCE strategy was used in 20% overall and in 44% at the end of the study. ADVANCE III adoption increased after trial publication, with less growth after an "ADVANCE awareness" campaign and after expert consensus statement publication. Predictors of ADVANCE adoption were as follows: ICD device with a nominal number of intervals to detect 30/40 (aOR, 4.4; 95%CI, 3.5-5.4), implantation by an electrophysiologist (aOR, 1.7; 95%CI, 1.4-2.2), and secondary prevention (aOR, 3.2; 95%CI, 2.6-3.9). Dual-chamber ICDs (aOR, 0.6; 95%CI, 0.5-0.8) and cardiac resynchronization-defibrillators (aOR, 0.5; 95%CI, 0.4-0.7) were associated with lower adoption. ADVANCE programming was associated with reduced total therapy burden (aIRR, 0.77; 95%CI, 0.69-0.86) and fewer inappropriate shocks (aIRR, 0.66; 95%CI, 0.52-0.85).

CONCLUSIONS

ADVANCE adoption remains modest and can be improved through evidence-driven selection of nominal ICD settings. ADVANCE programming is associated with reduced therapy rates in real-world ICD recipients.

Complications of retained pacemaker hardware in heart transplant recipients: case series and review of the literature

Heart transplantation (HT) in patients with prior cardiovascular implantable electronic devices (CIEDs) is becoming more common, in parallel with the increased use of CIEDs for patients with advanced heart failure. Complete removal of CIED components during HT is not always feasible, and it is thus surprising that the literature addressing the implications of retained CIED components is limited. Indeed, there are neither guidelines nor consensus regarding the need for removal of these CIED fragments. This issue is nonetheless becoming important in light of the increase in the percentage of HT candidates having CIEDs, on the one hand, and newer therapeutic immunosuppressive protocols with higher bacterial infection potential, on the other. Thus, with the aim to study the implications of retained CIED fragments as a step towards establishing a therapeutic approach for the unique population of HT recipients with CIED remnants, we present here a case series of HT patients with retained CIED fragments who developed complications of infections together with a review of the available literature.

How Well Do Results From Randomized Clinical Trials and/or Recommendations for Implantable Cardioverter-Defibrillator Programming Diffuse Into Clinical Practice?Translation Assessed in a National Cohort of Patients With Implantable Cardioverter-Defibrillators ( ALTITUDE )

Background Inappropriate implantable cardioverter-defibrillator programming can be detrimental. Whether trials/recommendations informing best implantable cardioverter-defibrillator programming (high-rate cutoff and/or extended duration of detection) influence practice is unknown. Methods and Results We measured reaction to publication of MADIT-RIT (Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy; 2012) and the Consensus Statement (2015) providing generic programming parameters, in a national cohort of implantable cardioverter-defibrillator recipients, using the ALTITUDE database (Boston Scientific). Yearly changes in programmed parameters to either trial-specified or class 1 recommended parameters (≥185 beats per minute or delay ≥6 seconds) were assessed in parallel. From 2008 to 2017, 232 982 patients (aged 67±13 years; 28% women) were analyzed. Prevalence of MADIT- RIT -specific settings before publication was <1%, increasing to 13.6% in the year following. Thereafter, this increased by <6% over 5 years. Among preexisting implants (91 171), most patients (58 739 [64.4%]) underwent at least 1 in-person device reprogramming after trial publication, but <2% were reprogrammed to MADIT - RIT settings. Notably, prevalence of programming to ≥185 beats per minute or delay ≥6 seconds was increased by MADIT - RIT (57.4% in 2013 versus 40.2% at baseline), but the following publication of recommendations had minor incremental effect (73.2% in 2016 versus 70.8% in 2015). High-rate cutoff programming was favored almost 2-fold compared with extended duration throughout the test period. Practice changes demonstrated large interhospital and interstate variations. Conclusions Trial publication had an immediate effect during 1 year postpublication, but absolute penetration was low, and amplified little with time. Consensus recommendations had a negligible effect. However, generic programming was exercised more widely, and increased after trial publication, but not following recommendations.

Use of Cardiac Resynchronization Therapy Among Eligible Patients Receiving an Implantable Cardioverter Defibrillator: Insights From the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry

Importance

Cardiac resynchronization therapy (CRT) reduces the risk for mortality and heart failure-related events in select patients. Little is known about the use of CRT in combination with an implantable cardioverter defibrillator (ICD) in patients who are eligible for this therapy in clinical practice.

Objective

To (1) identify patient, clinician, and hospital characteristics associated with CRT defibrillator (CRT-D) use and (2) determine the extent of hospital-level variation in the use of CRT-D among guideline-eligible patients undergoing ICD placement.

Design, Setting, and Participants

Multicenter retrospective cohort from 1428 hospitals participating in the National Cardiovascular Data Registry ICD Registry between April 1, 2010, and June 30, 2014. Adult patients meeting class I or IIa guideline recommendations for CRT at the time of device implantation were included in this study.

Main Outcomes and Measures

Implantation of an ICD with or without CRT.

Results

A total of 63 506 eligible patients (88.6%) received CRT-D at the time of device implantation. The mean (SD) ages of those in the ICD and CRT-D groups were 67.9 (12.2) years and 68.4 (11.5) years, respectively. In hierarchical multivariable models, black race was independently associated with lower use of CRT-D (odds ratio [OR], 0.77; 95% CI, 0.71-0.83) as was nonprivate insurance (OR, 0.90; 95% CI, 0.85-0.95 for Medicare and OR, 0.73; 95% CI, 0.65-0.82 for Medicaid). Clinician factors associated with greater CRT-D use included clinician implantation volume (OR, 1.01 per 10 additional devices implanted; 95% CI, 1.01-1.01) and electrophysiology training (OR, 3.13 as compared with surgery-boarded clinicians; 95% CI, 2.50-3.85). At the hospital level, the overall median risk-standardized rate of CRT-D use was 79.9% (range, 26.7%-100%; median OR, 2.08; 95% CI, 1.99-2.18).

Conclusions and Relevance

In a national cohort of patients eligible for CRT-D at the time of device implantation, nearly 90% received a CRT-D device. However, use of CRT-D differed by race and implanting operator characteristics. After accounting for these factors, the use of CRT-D continued to vary widely by hospital. Addressing disparities and variation in CRT-D use among guideline-eligible patients may improve patient outcomes.

Consideration for primary prevention implantable cardioverter defibrillators differ between specialities

PURPOSE

Implantable cardioverter defibrillator (ICD) implantation rates remain variable despite established guideline recommendations. This study aims to assess whether being managed by a cardiologist has an impact on whether patients are considered for an ICD for primary prevention of sudden cardiac death.

DESIGN/METHODS

Single-centre, retrospective, observational study of patients identified to have severe left ventricular systolic dysfunction (LVSD) on echocardiography (n = 129) between 1 and 30 June 2016 with cross-sectional assessment at 1 year. An assessment of ICD consideration at 1 year following the echocardiogram was documented, in addition to the specialty of the managing physician (group 1-electrophysiologist/heart failure specialist; group 2-all other cardiologists; group 3-non-cardiologist).

RESULTS

129/1173 (11%) transthoracic echocardiographies (s) were identified to have severe LVSD. 52 (40%), 37 (29%) and 40 (31%) were managed by group 1, group 2 and group 3, respectively. Mean age was 74.7 (±12.6) years with a predominance of male gender (70.5%). An ICD was not considered in 47.3%. Those managed by a cardiologist were more likely to be considered for an ICD than a non-cardiologist (63.9% vs 30.0%; OR 4.0, 95% CI 1.8 to 8.8, p = 0.001) with a greater survival at 1 year (89.9% vs 52.5%, OR 8.1 95% CI 3.2 to 20.4, p < 0.001). Group 1 were more likely to consider ICD than group 2 cardiologists (75.0% vs 45.9%; OR 3.5; 95% CI 1.4 to 8.7, p = 0.005).

CONCLUSION

There is significant variation between cardiologists and non-cardiologists, as well as within different cardiology subspecialists, when considering the option of ICD therapy for primary prevention.

Temporal Trends of Cardiac Implantable Electronic Device Implantations: a Nationwide Population-based Study

Background and Objectives

Implantation of cardiac implantable electronic devices (CIED), including permanent pacemakers (PM), implantable cardioverter-defibrillators (ICD), and cardiac resynchronization therapy (CRT) devices, has increased significantly over the past several years. However, limited data exists regarding temporal trends of CIED implantations in Asian population. This study aimed to investigate temporal trends of CIED treatment in Korea.

Methods

Using the National Health Insurance Service database of the entire Korean adult population, temporal trends of CIED procedures between 2009 and 2016 were evaluated. Additionally, temporal changes in the prevalence of patients' comorbidities were evaluated.

Results

A total of 35,421 CIED procedures (new implantations: 27,771, replacements: 7,650) were performed during the study period. The mean age of new CIED recipients and the prevalence of comorbidities, including hypertension, diabetes mellitus, heart failure, stroke, and atrial fibrillation, increased substantially with time. Compared to 2009, the number of new implantations of PM, ICD, and CRT devices increased by 2.0 (1,977 to 3,910), 3.6 (230 to 822), and 4.9 (44 to 217) times in 2016, respectively. The annual new implantation rate of CIED also increased accordingly (5.1 to 9.3 for PM, 0.6 to 1.9 for ICD, and 0.1 to 0.5 for CRT devices, per 100,000 persons).

Conclusions

The number of CIED implantation increased substantially from 2009 to 2016 in Korea. Also, the patients with CIED have been changed to be older and have more comorbidities. Therefore, the burden of health care cost in patients with CIED would be expected to increase in the future.

Disparity Between Indications for and Utilization of Implantable Cardioverter Defibrillators in Asian Patients With Heart Failure

BACKGROUND

Implantable cardioverter defibrillators (ICDs) are lifesaving devices for patients with heart failure (HF) and reduced ejection fraction. However, utilization and determinants of ICD insertion in Asia are poorly defined. We determined the utilization, associations of ICD uptake, patient-perceived barriers to device therapy and, impact of ICDs on mortality in Asian patients with HF.

METHODS AND RESULTS

Using the prospective ASIAN-HF (Asian Sudden Cardiac Death in Heart Failure) registry, 5276 patients with symptomatic HF and reduced ejection fraction (HFrEF) from 11 Asian regions and across 3 income regions (high: Hong Kong, Japan, Korea, Singapore, and Taiwan; middle: China, Malaysia, and Thailand; and low: India, Indonesia, and Philippines) were studied. ICD utilization, clinical characteristics, as well as device perception and knowledge, were assessed at baseline among ICD-eligible patients (EF ≤35% and New York Heart Association Class II-III). Patients were followed for the primary outcome of all-cause mortality. Among 3240 ICD-eligible patients (mean age 58.9±12.9 years, 79.1% men), 389 (12%) were ICD recipients. Utilization varied across Asia (from 1.5% in Indonesia to 52.5% in Japan) with a trend toward greater uptake in regions with government reimbursement for ICDs and lower out-of-pocket healthcare expenditure. ICD (versus non-ICD) recipients were more likely to be older (63±11 versus 58±13 year; P<0.001), have tertiary (versus ≤primary) education (34.9% versus 18.1%; P<0.001) and be residing in a high (versus low) income region (64.5% versus 36.5%; P<0.001). Among 2000 ICD nonrecipients surveyed, 55% were either unaware of the benefits of, or needed more information on, device therapy. ICD implantation reduced risks of all-cause mortality (hazard ratio, 0.71; 95% confidence interval, 0.52-0.97) and sudden cardiac deaths (hazard ratio, 0.33; 95% confidence interval, 0.14-0.79) over a median follow-up of 417 days.

CONCLUSIONS

ICDs reduce mortality risk, yet utilization in Asia is low; with disparity across geographic regions and socioeconomic status. Better patient education and targeted healthcare reforms in extending ICD reimbursement may improve access.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov/ct2/show/NCT01633398. Unique identifier: NCT01633398.

Survival in Women Versus Men Following Implantation of Pacemakers, Defibrillators, and Cardiac Resynchronization Therapy Devices in a Large, Nationwide Cohort

Background

Whether outcomes differ between sexes following treatment with pacemakers (PM), implantable cardioverter defibrillators, and cardiac resynchronization therapy (CRT) devices is unclear.

Methods and Results

Consecutive US patients with newly implanted PM, implantable cardioverter defibrillators, and CRT devices from a large remote monitoring database between 2008 and 2011 were included in this observational cohort study. Sex‐specific all‐cause survival postimplant was compared within each device type using a multivariable Cox proportional hazards model, stratified on age and adjusted for remote monitoring utilization and ZIP‐based socioeconomic variables. A total of 269 471 patients were assessed over a median 2.9 [interquartile range, 2.2, 3.6] years. Unadjusted mortality rates (MR; deaths/100 000 patient‐years) were similar between women versus men receiving PMs (n=115 076, 55% male; MR 4193 versus MR 4256, respectively; adjusted hazard ratio, 0.87; 95% CI, 0.84–0.90; P<0.001) and implantable cardioverter defibrillators (n=85 014, 74% male; MR 4417 versus MR 4479, respectively; adjusted hazard ratio, 0.98; 95% CI, 0.93–1.02; P=0.244). In contrast, survival was superior in women receiving CRT defibrillators (n=61 475, 72% male; MR 5270 versus male MR 7175; adjusted hazard ratio, 0.73; 95% CI, 0.70–0.76; P<0.001) and also CRT pacemakers (n=7906, 57% male; MR 5383 versus male MR 7625, adjusted hazard ratio, 0.69; 95% CI, 0.61–0.78; P<0.001). This relative difference increased with time. These results were unaffected by age or remote monitoring utilization.

Conclusions

Women accounted for less than 30% of high‐voltage implants and fewer than half of low‐voltage implants in a large, nation‐wide cohort. Survival for women and men receiving implantable cardioverter defibrillators and PMs was similar, but dramatically greater for women receiving both defibrillator‐ and PM‐based CRT.

An analysis of patient-sharing physician networks and implantable cardioverter defibrillator therapy

The application of social network analysis to the organization of healthcare delivery is a relatively new area of research that may not be familiar to health services statisticians and other methodologists. We present a methodological introduction to social network analysis with a case study of physicians' adherence to clinical guidelines regarding use of implantable cardioverter defibrillators (ICDs) for the prevention of sudden cardiac death. We focus on two hospital referral regions (HRRs) in Indiana, Gary and South Bend, characterized by different rates of evidence-based ICD use (86% and 66%, respectively). Using Medicare Part B claims, we construct a network of physicians who care for cardiovascular disease patients based on patient-sharing relationships. Approaches for weighting physician dyads and aggregating physician dyads by hospital are discussed. Then, we obtain a set of weighted network statistics for the positions of hospitals in their referral region, global statistics for the physician network within each hospital, and of the network positions of individual physicians within hospitals, providing the mathematical specification and sociological intuition underlying each measure. We find that adjusting for network measures can reduce the observed differences between referral regions for evidence-based ICD therapy. This study supports previous reports on how variation in physician network structure relates to utilization of care, and motivates future work using physician network measures to examine variation in evidence-based medicine.

Cardiac resynchronization therapy: implant rates, temporal trends and relationships with heart failure epidemiology

BACKGROUND

Consensus guidelines define indications for cardiac resynchronization therapy (CRT), but the variability in implant rates in 'real world' clinical practice, as well as the relationship with the epidemiology of heart failure are not defined.

METHODS AND RESULTS

In Emilia-Romagna, an Italian region with around 4.4 million inhabitants, a registry was instituted to collect data on implanted devices for CRT, with (CRT-D) or without defibrillation (CRT-P) capabilities. Data from all consecutive patients resident in this region who underwent a first implant of a CRT device in years 2006-2010 were collected and standardized (considering each of the nine provinces of the region). The number of CRT implants increased progressively, with a 71% increase in 2010 compared to 2006. Between 84 and 90% of implants were with CRT-D devices. The variability in standardized implant rates among the provinces was substantial and the ratio between the provinces with the highest and the lowest implant rates was always greater than 2. Considering prevalent cases of heart failure in the period 2006-2010, the proportion of patients implanted with CRT per year ranged between 0.23 and 0.30%.

CONCLUSIONS

The application in 'real world' clinical practice of CRT in heart failure is quite heterogeneous, with substantial variability even among areas belonging to the same region, with the need to make the access to this treatment more equitable. Despite the increased use of CRT, its overall rate of adoption is low, if a population of prevalent heart failure patients is selected on the basis of administrative data on hospitalizations.

Outcomes in African Americans undergoing cardioverter-defibrillator implantation for primary prevention of sudden cardiac death: findings from the Prospective Observational Study of Implantable Cardioverter-Defibrillators (PROSE-ICD)

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) reduce the risk of death in patients with left ventricular dysfunction. Little is known regarding the benefit of this therapy in African Americans (AAs).

OBJECTIVE

The purpose of this study was to determine the association between AA race and outcomes in a cohort of primary prevention ICD patients.

METHODS

We conducted a prospective cohort study of patients with systolic heart failure who underwent ICD implantation for primary prevention of sudden cardiac death. The primary end-point was appropriate ICD shock defined as a shock for rapid ventricular tachyarrhythmias. The secondary end-point was all-cause mortality.

RESULTS

There were 1189 patients (447 AAs and 712 non-AAs) enrolled. Over a median follow-up of 5.1 years, a total of 137 patients experienced an appropriate ICD shock, and 343 died (294 of whom died without receiving an appropriate ICD shock). The multivariate adjusted hazard ratio (95% confidence interval) comparing AAs vs non-AAs were 1.24 (0.96-1.59) for all-cause mortality, 1.33 (1.02, 1.74) for all-cause mortality without receiving appropriate ICD shock, and 0.78 (0.51, 1.19) for appropriate ICD shock. Ejection fraction, diabetes, and hypertension appeared to explain 24.1% (10.1%-69.5%), 18.7% (5.3%-58.0%), and 13.6% (3.8%-53.6%) of the excess risk of mortality in AAs, with a large proportion of the mortality difference remaining unexplained.

CONCLUSION

In patients with primary prevention ICDs, AAs had an increased risk of dying without receiving an appropriate ICD shock compared to non-AAs.

Clinical reminders to providers of patients with reduced left ventricular ejection fraction increase defibrillator referral: a randomized trial

BACKGROUND

Many patients who are candidates for implantable cardioverter defibrillators (ICDs) are not referred for potential implantation. We sought to determine if a simple provider reminder would increase referrals.

METHODS AND RESULTS

We identified consecutive patients from January 2007 through July 2010 in the VA Palo Alto Health Care System with a left ventricular ejection fraction<35% on echocardiography. Patients were excluded using available administrative data only (no chart review) if they were known to have an ICD, if they were ≥80 years old, or if they did not have a current primary care or cardiology provider within the system. We randomized patients to no intervention or a clinical note to the provider in the medical record. The outcomes were referral for consideration of defibrillator implantation (primary) and documented discussion (secondary). Of 330 patients with left ventricular ejection fraction≤35%, 128 were known to have an ICD, 85 were no longer followed in the healthcare system, and 28 were ≥80 years old, leaving 89 patients to be randomized. Forty-six patients were randomized to intervention and 43 to control. Eleven of 46 (24%) intervention patients were referred for consideration of ICD implantation during the following 6 months versus 1 of 43 (2%) control patients (P=0.004). Overall, 31 of 46 (67%) intervention patients versus 19 of 43 (44%) control patients had documentation discussing potential candidacy for defibrillators (P=0.05).

CONCLUSIONS

In patients with low left ventricular ejection fraction, a simple electronic medical record-based intervention directed to their providers improved the rates of referral for ICD implantation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01217827.

Referring physicians' discordance with the primary prevention implantable cardioverter-defibrillator guidelines: a national survey

BACKGROUND

The American College of Cardiology, the American Heart Association, and the Heart Rhythm Society guidelines provide patient selection criteria for primary prevention implantable cardioverter-defibrillators (ICDs). For unknown reasons, guideline-discordant practice is common.

OBJECTIVE

To determine referring physicians' concordance with the primary prevention ICD guidelines.

METHODS

We mailed a survey regarding ICD guidelines and individual practice characteristics to a random national sample of 3000 physicians selected from the American Medical Association Masterfile-one-third each specializing in family medicine, internal medicine, and general cardiology.

RESULTS

Sixty-four percent with correct contact information responded. Three hundred ninety-five (28%; 95% confidence interval [CI] 25%-30%) respondents never refer patients with the intent of consideration for a primary prevention ICD, including 7% (95% CI 5%-10%) of cardiologists. Two hundred twelve (15%; 95% CI 13%-17%) believe ventricular arrhythmias are required before a primary prevention ICD is indicated; 525 (36%; 95% CI 34%-39%) believe that an ejection fraction of >40% warrants a primary prevention ICD; and 361 (25%; 95% CI 23%-27%) would refer a patient for a primary prevention ICD within 40 days of a myocardial infarction. In multivariate analyses, family practice physicians and physicians residing in the western United States most often provided guideline-discordant answers, while cardiologists and those who refer to an electrophysiologist most often provided guideline-concordant answers. Primary care physicians who manage heart failure patients without referral to a subspecialist were not more likely to provide guideline-concordant answers.

CONCLUSIONS

Answers discordant with the primary prevention ICD guidelines were common, suggesting that referring physician beliefs are an important barrier to appropriate patient referrals for primary prevention ICD implantation.

Quality of care for sudden cardiac arrest: Proposed steps to improve the translation of evidence into practice

Sudden cardiac arrest (SCA) is the most common cause of death in the United States. Despite national guidelines, patients at risk for SCA often fail to receive evidence-based therapies. Racial and ethnic minorities and women are at particularly high risk for undertreatment. To address the persistent challenges in improving the quality of care for SCA, the Duke Center for the Prevention of Sudden Cardiac Death at the Duke Clinical Research Institute (Durham, NC) reconvened the Sudden Cardiac Arrest Thought Leadership Alliance. Experts from clinical cardiology, cardiac electrophysiology, health policy and economics, the US Food and Drug Administration, the Centers for Medicare and Medicaid Services, the Agency for Health Care Research and Quality, and device and pharmaceutical manufacturers discussed the development of SCA educational tools for patients and providers, mechanisms of implementing successful tools to help providers identify patients in their practice at risk for SCA, disparities in SCA prevention, and performance measures related to SCA care. This article summarizes the discussions held at this meeting.

Indications for implantable cardioverter-defibrillator placement in ischemic cardiomyopathy and after myocardial infarction

Dramatic reductions in the rate of sudden cardiac death due to use of implantable cardioverter-defibrillators (ICDs) have been well-established in several large randomized clinical trials including patients with left ventricular dysfunction after myocardial infarction. This article reviews the literature regarding ICD utilization in the postinfarction population, with a strong emphasis on recent clinical trials. The most current indications for, and timing of, ICD implantation postinfarction also are summarized.

Secondary prevention in heart failure

Although most recent investigations into sudden cardiac death prevention in heart failure patients have been focused on primary prevention, secondary indications for defibrillators and medical therapy remain vitally important in this complex patient group. Antiarrhythmic therapy is currently used primarily as adjuvant therapy to implantable defibrillators. Secondary prophylaxis defibrillator trials have shown clear benefit in preventing recurrent sudden cardiac death, despite concern over inappropriate shocks and the potential detrimental effects of appropriate shocks. Device programming for secondary prophylaxis can help ameliorate these issues. This article discusses these issues as well as the continued underuse of defibrillators in specific populations.

Addressing disparities in sudden cardiac arrest care and the underutilization of effective therapies

Sudden cardiac arrest (SCA) is the most common cause of death in the Unites States. Despite its major impact on public health, significant challenges exist at the patient, provider, public, and policy levels with respect to raising more widespread awareness and understanding of SCA risks, identifying patients at risk for SCA, addressing barriers to SCA care, and eliminating disparities in SCA care and outcomes. To address many of these challenges, the Duke Center for the Prevention of Sudden Cardiac Death at the Duke Clinical Research Institute (Durham, NC) held a think tank meeting on December 7, 2009, convening experts on this issue from clinical cardiology, cardiac electrophysiology, health policy and economics, the US Food and Drug Administration, the Centers for Medicare and Medicaid Services, the Agency for Health Care Research and Quality, and device and pharmaceutical manufacturers. The specific goals of the meeting were to examine existing educational tools on SCA for patients, health care providers, and the public and explore ways to enhance and disseminate these tools; to propose a framework for improved identification of patients at risk of SCA; and to review the latest data on disparities in SCA care and explore ways to reduce these disparities. This article summarizes the discussions that occurred at the meeting.