How many patients with heart failure are eligible for cardiac resynchronization? Insights from two prospective cohorts

Sex Differences in Implantation and Outcomes of Cardiac Resynchronization Therapy in Real-World Settings: A Systematic Review of Cohort Studies

Background

Evidence from randomized trials is conflicting on the effects of cardiac resynchronization therapy (CRT) by sex, and differences in access are unknown. We examined sex differences in the implantation rates and outcomes in patients treated with CRT using cohort studies.

Methods

We followed a pre-specified protocol (International Prospective Register of Systematic Reviews [PROSPERO]: CRD42020204804). MEDLINE, Embase, and Web of Science were searched for cohort studies from January 2000 to June 2020 that evaluated the response to CRT in patients ≥ 18 years old and reported sex-specific information in any language.

Results

We included 97 studies (1,172,654 men and 486,553 women). Men received CRT more frequently than women (median ratio, 3.16; 25th to 75th interquartile range, 2.48-3.62). In the unadjusted analysis, men had a greater long-term all-cause mortality rate after CRT, compared with women (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.38-1.63; P < 0.001). Adjustment for confounders did not affect the strength or direction of association (HR, 1.45; 95% CI, 1.32-1.59; P < 0.001). Women achieved a greater rate of improvement in left ejection fraction compared with men (HR, 4.66; 95% CI, 4.23-5.13; P < 0.001). Men had a lower risk of a pneumothorax (relative risk, 0.21; 95% CI, 0.13-0.34; P < 0.001]); otherwise, there were no differences in complications.

Conclusions

We found in this large meta-analysis that men were more often implanted with CRT than women, yet men had a higher long-term all-cause mortality following CRT, compared with women, and smaller improvement in left ventricular ejection fraction. Reasons for this difference in implantation rates of CRT in real-world practice need to be investigated.

Autonomic Testing Optimizes Therapy for Heart Failure and Related Cardiovascular Disorders

PURPOSE OF REVIEW

Cardiovascular autonomic control is an intricately balanced dynamic process. Autonomic dysfunction, regardless of origin, promotes and sustains the disease processes, including in patients with heart failure (HF). Autonomic control is mediated through the two autonomic branches: parasympathetic and sympathetic (P&S). HF is arguably the disease that stands to most benefit from P&S manipulation to reduce mortality risk. This review article briefly summarizes some of the more common types of autonomic dysfunction (AD) that are found in heart failure, suggests a mechanism by which AD may contribute to HF, reviews AD involvement in common HF co-morbidities (e.g., ventricular arrhythmias, AFib, hypertension, and Cardiovascular Autonomic Neuropathy), and summarizes possible therapy options for treating AD in HF.

RECENT FINDINGS

Autonomic assessment is important in diagnosing and treating CHF, and its possible co-morbidities. Autonomic assessment may also have importance in predicting which patients may be susceptible to sudden cardiac death. This is important since most CHF patients with sudden cardiac death have preserved left ventricular ejection fraction and better discriminators are needed. Many life-threatening cardiovascular disorders will require invasive testing for precise diagnoses and therapy planning when modulating the ANS is important. In cases of non-life-threatening disorders, non-invasive ANS testing techniques, especially those that individually assess both ANS branches simultaneously and independently, are sufficient to diagnose and treat serially.

Response by Sex in Patient-Centered Outcomes With Baroreflex Activation Therapy in Systolic Heart Failure

OBJECTIVES

The aim of this study was to assess sex differences in the efficacy and safety of baroreflex activation therapy (BAT) in the BeAT-HF (Baroreflex Activation Therapy for Heart Failure) trial.

BACKGROUND

Patients were randomized 1:1 to receive guideline-directed medical therapy (GDMT) alone (control group) or BAT plus GDMT.

METHODS

Pre-specified subgroup analyses including change from baseline to 6 months in 6-min walk distance (6MWD), quality of life (QoL) assessed using the Minnesota Living With Heart Failure Questionnaire (MLWHQ), New York Heart Association (NYHA) functional class, and N-terminal pro–B-type natriuretic peptide (NT-proBNP) were conducted in men versus women.

RESULTS

Fifty-three women and 211 men were evaluated. Women had similar baseline NT-proBNP levels, 6MWDs, and percentage of subjects with NYHA functional class III symptoms but poorer MLWHQ scores (mean 62 ± 22 vs. 50 ± 24; p = 0.01) compared with men. Women experienced significant improvement from baseline to 6 months with BAT plus GDMT relative to GDMT alone in MLWHQ score (—34 ± 27 vs. —9 ± 23, respectively; p < 0.01), 6MWD (44 ± 45 m vs. —32 118 m; p < 0.01), and improvement in NYHA functional class (70% vs. 27%; p < 0.01), similar to the responses seen in men, with no significant difference in safety. Women receiving BAT plus GDMT had a significant decrease in NT-proBNP (—43% vs. 7% with GDMT alone; difference —48%; p < 0.01), while in men this decrease was —15% versus 2%, respectively (difference —17%; p = 0.08), with an interaction p value of 0.05.

CONCLUSIONS

Women in BeAT-HF had poorer baseline QoL than men but demonstrated similar improvements with BAT in 6MWD, QoL, and NYHA functional class. Women had a significant improvement in NT-proBNP, whereas men did not. (Baroreflex Activation Therapy for Heart Failure [BeAT-HF]; NCT02627196) (J Am Coll Cardiol HF 2021;9:430–8)

CRT Optimization: What Is New? What Is Necessary?

Cardiac resynchronization therapy (CRT) has proven to improve quality of life, reduce heart failure hospitalization, and prolong life in selected heart failure patients with reduced ejection fraction, on optimal medical therapy and with electrical dyssynchrony. To ensure maximal benefit for CRT patients, optimization of care should be implemented. This begins with appropriate referring as well as selecting patients, knowing that the presence of left bundle branch block and QRS ≥ 150 ms is associated with the greatest reverse remodeling. The LV lead, preferably quadripolar, is best targeted in a postero-lateral position. After implantation, optimal device programming should aim for maximal biventricular pacing and in selected cases further electrical delay optimization might be of use. Even as important, is the implementation of thorough multidisciplinary heart failure care with medication uptitration, remote monitoring, rehabilitation, and patient education. The role of newer pacing strategies as endocardial or His-bundle pacing remains the subject of ongoing investigation.

First granted example of novel FDA trial design under Expedited Access Pathway for premarket approval: BeAT-HF

BACKGROUND

The Food and Drug Administration (FDA) initiated the Expedited Access Pathway (EAP) to accelerate approval of novel therapies targeting unmet needs for life-threatening conditions. EAP allows for the possibility of initial FDA approval using intermediate end points with postapproval demonstration of improved outcomes.

OBJECTIVE

Describe the EAP process using the BeAT-HF trial as a case study.

METHODS

BeAT-HF will examine the safety and effectiveness of baroreflex activation therapy (BAT) in heart failure patients with reduced ejection fraction using an Expedited and Extended Phase design. In the Expedited Phase, BAT plus guideline-directed medical therapy (GDMT) will be compared at 6 months postimplant to GDMT alone using 3 intermediate end points: 6-minute hall walk distance, Minnesota Living with Heart Failure Questionnaire, and N-terminal pro-B-type natriuretic peptide. The rate of heart failure morbidity and cardiovascular mortality will be compared between the arms to evaluate early trending using predictive probability modeling. Sample size of 264 patients randomized 1:1 to BAT + GDMT versus GDMT alone provides 81% power for the Expedited Phase intermediate end points. For the Extended Phase, the heart failure morbidity and cardiovascular mortality end point is based on an expected event rate of 0.4 events/patient/year in the GDMT arm. With an adaptive sample size selection design for robustness to inaccurate assumptions, a sample size of 480-960 randomized patients followed ≥2 years allows detecting a 30% reduction in the primary end point with a power of 97.5%.

CONCLUSION

Through a unique collaboration with FDA under the EAP, the BeAT-HF trial design allows for the possibility of approval of BAT, initially for symptom relief and subsequently for outcomes improvement.

Eligibility for cardiac resynchronization therapy in patients hospitalized with heart failure

Aims

Recent guidelines recommend cardiac resynchronization therapy (CRT) in mildly symptomatic heart failure (HF) but favour left bundle branch block (LBBB) morphology in patients with moderate QRS prolongation (120–150 ms). We defined how many patients hospitalized with HF fulfil these criteria.

Methods and results

A single‐centre retrospective cohort study of 363 consecutive patients hospitalized with HF (438 admissions) was performed. Electronic imaging, electrocardiograms, and records were reviewed. Overall, 153 patients (42%) had left ventricular ejection fraction (LVEF) ≤ 35%, and 34% of patients had QRS prolongation. Eighty patients (22%) were potentially eligible with LVEF ≤ 35% and QRS ≥ 120 ms or existing CRT. The majority (68 of 80) had a Class I or IIa recommendation according to international guidelines (LBBB or non‐LBBB QRS ≥ 150 ms or right ventricular pacing). Only a minority (12 of 80) had moderate QRS prolongation of non‐LBBB morphology. One‐quarter (n = 22) of patients fulfilling criteria were ineligible for reasons including dementia, co‐morbidities, or palliative care. A further eight patients required optimization of medical therapy. CRT was therefore immediately indicated in 50 patients. Of these, 29 were implanted or had existing CRT systems. Twenty‐one of the 80 patients eligible for CRT were not identified or treated (6% of the total hospitalized cohort).

Conclusions

Twenty‐two per cent of elderly real‐life patients hospitalized with HF fulfil LVEF and QRS criteria for CRT, most having a Class I or IIa indication. However, a large proportion is ineligible owing to co‐morbidities or requires medical optimization. Although uptake of CRT was reasonable, there remain opportunities for improvement.

Effect of expanding evidence and evolving clinical guidelines on the prevalence of indication for cardiac resynchronization therapy in patients with heart failure

AIMS

To assess the prevalence of indication for cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and reduced ejection fraction (EF) when recommendations from evolving European Society of Cardiology (ESC) guidelines are considered.

METHODS AND RESULTS

Unique patients (n=17 193) with EF ≤39% and key data available for evaluation of CRT indication from the Swedish HF Registry were included. Indication for CRT was defined as either CRT implanted or CRT device absent but fulfilling criteria for class I-IIa recommendations in ESC guidelines published between 2005/2007 and 2016. Prevalence was calculated as the ratio of patients with CRT indication to the study population. The prevalence of CRT indication increased from 24.5% when the 2005/2007 ESC guidelines were considered to a peak of 30.0% when the 2013 ESC guidelines were considered (P<0.001, 22.4% relative increase). Compared to the 2013 ESC guidelines, the prevalence declined significantly when the 2016 ESC guidelines were used as determinant for CRT indication (26.8%, 10.7% relative reduction, P<0.001). Actual CRT utilization was 6.8%.

CONCLUSION

Among patients with HF and reduced EF, the prevalence of CRT indication increased significantly comparing recommendations from ESC guidelines published between 2005/2007 and 2013, but then declined when the 2016 ESC guidelines were considered. The 2005-2013 increase may reflect the expansion of documented CRT efficacy to New York Heart Association class II, whereas the subsequent drop likely results from the more stringent criteria for QRS duration in the 2016 ESC guidelines. Actual CRT utilization is lower than indicated, regardless of which guidelines are considered.

Review of eligibility for cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is underused. Recent guidelines have expanded indications for CRT to include less severe symptoms but now favor left bundle branch block morphology in patients with moderate QRS prolongation. The prevalence of CRT eligibility according to historical and current guidelines is uncertain. The aim of this review was to identify and synthesize all existing published research reporting the prevalence of CRT eligibility. A systematic review of electronic databases including MEDLINE, Embase, and the Cochrane Library was performed. The primary outcome was the proportion of patients eligible for CRT according to historical and current criteria. Secondary outcomes included the individual components of eligibility (the ejection fraction, symptoms, and QRS duration and morphology). Eligibility estimates were pooled using random-effects models because of marked heterogeneity in between-study variance. Thirty studies were identified. No study used current guideline criteria. On the basis of historical criteria, 11 ± 3% of ambulatory and 9 ± 3% of hospitalized patients are eligible for CRT. However, New York Heart Association class II in current guidelines is at least as frequent as New York Heart Association III or IV. Approximately 1/3 of patients have QRS prolongation, 2/3 of whom have left bundle branch block. Only a few patients have non-left bundle branch block with QRS duration <150 ms. Medical contraindication or ineligibility was rarely assessed. In conclusion, current estimates of need are outdated. Inclusion of milder symptoms potentially doubles the eligible population. Studies in unselected cohorts are needed to accurately define the individual components of eligibility, together with the prevalence and reasons for ineligibility.

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.

Rates and reasons for device-based guideline eligibility in patients with heart failure

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) are recommended by guidelines for patients with heart failure (HF) meeting specific criteria. Uncertainty exists regarding estimates of device eligibility, related in part to the method of assessing for guideline nonadherence.

OBJECTIVE

The aim of this study was to identify the rates of guideline eligibility and device utilization after accounting for reasons for not receiving an ICD or CRT.

METHODS

Patients were identified from 2006 to 2011 in a tertiary Heart Function Clinic in Canada. The chart-level data were collected that would indicate guideline eligibility and nonadherence.

RESULTS

A total of 762 patients with HF were included (mean age 66 years; 527 (69%) were males; median left ventricular ejection fraction 33%). Over follow-up, 331 patients (43%) were never guideline eligible whereas 431 (57%) were guideline eligible for a device. Yearly rates for ICD and CRT adherence in "guideline-eligible" patients ranged from 59% to 68% and from 66% to 81%, respectively. "Patient preference" was the most commonly documented reason for guideline nonadherence in eligible patients. After removal of patients with reasons for nonadherence, rates of ICD and CRT adherence in the "truly eligible" patients were found to be higher (70%-81% and 71%-88%, respectively) than those in guideline-eligible patients. Independent predictors of device nonadherence in truly eligible patients were age >75 years, QRS duration <120 ms, left ventricular ejection fraction <30%, and female sex.

CONCLUSION

Based on chart-level data, utilization rates of device-based therapies in patients with HF appear much higher than those of prior registry-based estimates. Given the importance of patient preferences for lack of device use, future quality-of-care metrics based on guideline adherence should capture detailed chart-level data and patient preferences.

Canadian Cardiovascular Society guidelines on the use of cardiac resynchronization therapy: implementation

Recent studies have provided the impetus to update the recommendations for cardiac resynchronization therapy (CRT). This article provides guidance on the implementation of CRT and is intended to serve as a framework for the implementation of CRT within the Canadian health care system and beyond. These guidelines were developed through a critical evaluation of the existing literature, and expert consensus. The panel unanimously adopted each recommendation. The 9 recommendations relate to patient selection in the presence of comorbidities, delivery and optimization of CRT, and resources required to deliver this therapy. The strength of evidence was weighed, taking full consideration of any risk of bias, and any imprecision, inconsistency, and indirectness of the available data. The strength of each recommendation and the quality of evidence were adjudicated. Trade-offs between desirable and undesirable consequences of alternative management strategies were considered, as were values, preferences, and resource availability. These guidelines were externally reviewed by experts, modified based on those reviews, and will be updated as new knowledge is acquired.

Impact of chronic atrial fibrillation in patients with severe heart failure and indication for CRT: data of two registries with 711 patients (1999-2006 and 2007-6/2008)

AIMS

Atrial fibrillation (AF) is a relevant comorbidity in heart failure (HF) patients. In milestone cardiac resynchronization therapy (CRT) studies, patients with AF were excluded. We sought to investigate the influence of chronic atrial fibrillation (AF) on patients with CRT. AV node (AVN) ablation is frequently recommended. Converting AF to sinus rhythm (SR) is not a standard concept.

METHODS

A total of 584 consecutive patients with CRT devices were included in a single-center registry from 1999-2006 (retrospective registry) and 127/324 patients from 2007-06/2008 (prospective registry). The impact of persistent AF (group 1) on clinical and echocardiographic improvement compared with patients in SR (group 2) after 12 (6) months follow-up were analyzed. Re-establishing SR after initial cardioversion or need for AVN ablation was examined.

RESULTS

In the retrospective registry, 139 (24%) patients presented with AF (group 1) and 445 with SR (group 2). The groups differed in age, gender, and left atrium (LA) size but not in NYHA class, ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD), B-type natriuretic peptide (BNP) levels, QRS width, and underlying disease. After 1 year, CRT improvement of NYHA class and EF was similar with higher mortality in group 1 (12% vs. 7%; OR 1.80; 95% confidence interval 0.95-3.4). The AF group presented with SR in 33/82 (40%) patients and 11% needed AVN ablation. The prospective data showed 27 (21%) patients in AF with conversion to SR in 41% after 6 months.

CONCLUSION

Patients with severe HF and chronic AF had a comparable improvement with CRT as those in SR. CRT is a successful treatment option in patients with chronic AF offering the potential to restore SR in a significant number of patients.

Cardiac resynchronization therapy in the elderly: a realistic option for an increasing population?

Cardiac resynchronization therapy (CRT) has become a mainstay of heart failure treatment. Since heart failure is a disease primarily affecting older patients it is important to evaluate the performance of CRT in this population. Elderly has been suggested as a subgroup less likely to benefit from CRT. This is an important issue that should be clarified, because most patients with heart failure are old. The present review discusses the available data concerning cardiac resynchronization therapy in the elderly, focusing on efficacy, indication, safety, and impact of co-morbidities.

Trends in heart failure care: has the incident diagnosis of heart failure shifted from the hospital to the emergency department and outpatient clinics?

AIMS

Studies of heart failure (HF) incidence and prevalence frequently rely on hospitalization to identify patients. Our objective was to describe the incidence, prevalence, or outcomes for HF patients diagnosed in the outpatient or emergency department (ED) setting.

METHODS AND RESULTS

In a population-based study of 82,323 HF patients in a single-payer health-care system in Alberta, Canada from 1999 to 2007, we examined trends over time and clinical outcomes. Heart failure patients were first diagnosed in a general outpatient clinic (45.7%), a specialty outpatient clinic (4.0%), the ED (13.7%), or in hospital (36.6%). From years 2000 to 2006, the age-standardized incidence (per 100 000 population) decreased from 538 to 403, whereas the overall prevalence increased from 1585 to 2510. One-year mortality was significantly different among patients first diagnosed in a general outpatient clinic (6.6%), a specialty outpatient clinic (7.5%), ED (19.1%), and hospital (29.8%). Patients initially diagnosed at the time of hospitalization had the fewest median days alive and out of hospital [347, inter-quartile range (IQR): 136-363] over the next year compared with patients in the ED (354, IQR 313-365), specialty outpatient clinic (365, IQR 355-365), and general outpatient clinics (365, IQR: 359-365, P < 0.0001). Patients in the ED had the highest rate of subsequent ED visits, and all-cause, cardiovascular, or HF hospitalization.

CONCLUSIONS

Over time, more patients were diagnosed as outpatients compared with a hospital setting. The trends observed in incidence, prevalence, and outcomes for patients with HF differ substantially depending on the location of initial diagnosis. Additionally, efforts to study patients with HF in the ED should be a priority.

Morbidity and mortality in heart failure patients treated with cardiac resynchronization therapy: influence of pre-implantation characteristics on long-term outcome

AIMS

Cardiac resynchronization therapy (CRT) improves cardiac function, heart failure symptoms, and prognosis in selected patients. Many baseline characteristics associated with heart failure may influence prognosis after CRT. The objective of this study was to evaluate the effect of several baseline characteristics in relation to long-term prognosis in heart failure patients treated with CRT.

METHODS AND RESULTS

A total of 716 consecutive heart failure patients treated with CRT were included in an observational registry. All available data, including clinical and echocardiographic measurements, were analysed in relation to two endpoints: all-cause mortality and a combined endpoint of all-cause mortality or major cardiovascular event. Outcome data were collected by chart review, device interrogation, and telephone contact. Mean follow-up was 25 ± 19 months. During follow-up, 141 patients (20%) died (primary endpoint). Most of these patients (61%) died due to worsening heart failure. A total of 214 patients (30%) reached the secondary endpoint. Larger left ventricular end-systolic volume, less distance covered in the 6 min walking test, poor renal function, more severe heart failure, male gender, presence of atrial fibrillation, no posterolateral left ventricular (LV) lead, and no LV dyssynchrony were associated with poor prognosis after CRT.

CONCLUSION

In this large single-centre registry, several baseline clinical and echocardiographic characteristics were associated with prognosis after CRT. Worsening heart failure was the main cause of death in heart failure patients treated with CRT.

Trial-generated profiles for implantation of electrical devices in outpatients with heart failure: real-world prevalence and 1-year outcome

BACKGROUND

Randomized controlled trials have generated strong evidence on the efficacy of electrical device therapy in selected patients with heart failure (HF). The enrolment criteria of these three trials generated patient profiles that helped to shape current guidelines on chronic heart failure (CHF) treatment and sudden cardiac death (SCD) prevention. We investigated the prevalence of trial-generated profiles for implantable defibrillator or cardiac resynchronization therapy candidacy among HF outpatients; we explored differences between real-world and trial populations and we evaluated 1-year survival without device treatment.

METHODS

We reviewed Italian Network on Congestive Heart Failure (IN-CHF) registry patients (n = 4977) enrolled in a period (1995-2000) roughly concurrent with the MADIT-II and SCD-HeFT trials.

RESULTS

Regarding device eligibility, 14.5% IN-CHF patients at entry satisfied MADIT-II criteria, 6.8% satisfied CARE-HF criteria and as many as 47.9% fulfilled SCD-HeFT criteria. One-year overall mortality among non-implanted patients was 1.5 to 2-fold higher in each of these subgroups than in control arms of the corresponding trials. Among registry patients, different trial-profile combinations were associated with a wide range of 1-year outcomes (mortality, 8-35%; SCD/total mortality ratio, 0.35-0.57). Despite clear differences between registry and trial patients in pharmacological therapy (and clinical characteristics), none of the main drug classes independently predicted 1-year mortality in any of the IN-CHF subgroups.

CONCLUSIONS

As many as half the IN-CHF outpatients fulfilled current criteria for device implantation. Various subgroups had higher 1-year mortality than patients in trial control arms - a finding that may not be entirely attributable to differences in drug therapy (especially beta blockers).

Ethnic and racial disparities in cardiac resynchronization therapy

BACKGROUND

Racial/ethnic differences in the use of cardiac resynchronization therapy with defibrillator (CRT-D) may result from underprovision or overprovision relative to published guidelines.

OBJECTIVE

The purpose of this study was to examine the National Cardiovascular Data Registry (NCDR) ICD Registry for ethnic/racial differences in use of CRT-D.

METHODS

We studied white, black, and Hispanic patients who received either an implantable cardioverter-defibrillator (ICD) or CRT-D between January 2005 and April 2007. Two multivariate logistic regression models were fit with the following outcome variables: (1) receipt of either ICD or CRT-D and (2) receipt of CRT-D outside of published guidelines.

RESULTS

Of 108,341 registry participants, 22,205 met inclusion criteria for the first analysis and 27,165 met criteria for the second analysis. Multivariate analysis indicated CRT-eligible black (odds ratio [OR] 0.84; 95% confidence interval [CI], 0.75-0.95; P <.004) and Hispanic (OR 0.83; 95% CI, 0.71-0.99; P <.033) patients were less likely to receive CRT-D than were white patients. A substantial proportion of patients received CRT-D outside of published guidelines, although black (OR 1.18; 95% CI, 1.02-1.36; P = .001) and Hispanic (OR 1.17; 95% CI, 1.02-1.36; P = .03) patients were more likely to meet all three eligibility criteria.

CONCLUSION

Black and Hispanic patients who were eligible for CRT-D were less likely to receive therapy compared with white patients. Conversely, in the context of widespread out-of-guideline use of CRT-D, black and Hispanic patients were more likely to meet established criteria. Our findings suggest systematic racial/ethnic differences in the treatment of patients with advanced heart failure.

Device therapy in heart failure

Whether combined cardiac resynchronisation and implantable cardioverter defibrillator therapy offers benefit above either device alone remains uncertain

Inequitable distribution of implantable cardioverter defibrillators in Ontario

Objectives:Implantable cardioverter defibrillator (ICD) therapy reduces the risk of sudden death in patients with ischemic cardiomyopathy, but their novelty and cost may represent barriers to utilization. The objective of this study was to examine the influence of age, gender, place of residence, and socioeconomic status on rates of ICD implantation for the primary prevention of death.

Methods:We conducted a population-based retrospective cohort study involving the entire province of Ontario, Canada. Patients were eligible if they had survived following hospitalization for heart failure from 1 January 1993, to 31 March 2004, and previously sustained an acute coronary syndrome within 5 years. Patients with an existing ICD or a documented history of cardiac arrest were excluded, as were patients who died in the hospital. Primary outcome was ICD implantation.

Results:We identified 48,426 patients hospitalized for heart failure who survived to hospital discharge. Of these, 440 received an ICD, with a gradual 30-fold increase in implantation rates over the study period (.12–3.9 percent). ICD recipients were more likely to be men (odds ratio [OR] = 4.14; 95 percent confidence interval [CI], 3.24–5.30), younger than 75 years of age (OR = 3.19; 95 percent CI, 2.57–3.96), reside in a metropolitan area (OR = 1.42; 95 percent CI, 1.04–1.9), and live in a higher socioeconomic neighborhood (OR = 1.32; 95 percent CI, 1.08–1.61).

Conclusions:Among patients with heart failure and a previous myocardial infarction, ICD use is increasing in Ontario. However, the application of this technology is characterized by major sociodemographic inequities. The causes and consequences of the pronounced age and gender discrepancies, in particular, warrant further investigation.