Cardiac Resynchronization Therapy Eligibility Research Articles

The relation between cardiac 123I-mIBG scintigraphy and functional response 1 year after CRT implantation.

Aims Cardiac resynchronization therapy (CRT) is a disease-modifying therapy in patients with chronic heart failure (CHF). Current guidelines ascribe CRT eligibility on three parameters only: left ventricular ejection fraction (LVEF), QRS duration, and New York Heart Association (NYHA) functional class. However, one-third of CHF patients does not benefit from CRT. This study evaluated whether 123I-meta-iodobenzylguanidine (123I-mIBG) assessed cardiac sympathetic activity could optimize CRT patient selection.Methods and results A total of 78 stable CHF subjects (age 66.8 ± 9.6 years, 73% male, LVEF 25.2 ± 6.7%, QRS duration 153 ± 23 ms, NYHA 2.2 ± 0.7) referred for CRT implantation were enrolled. Subjects underwent 123I-mIBG scintigraphy prior to implantation. Early and late heart-to-mediastinum (H/M) ratio and 123I-mIBG washout were calculated. CRT response was defined as either an increase of LVEF to >35%, any improvement in LVEF of >10%, QRS shortening to <150 ms, or improvement in NYHA class of >1 class. In 33 patients LVEF increased to >35%, QRS decreased <150 ms in 36 patients, and NYHA class decreased in 33 patients. Late H/M ratio and hypertension were independent predictors of LVEF improvement to >35% (P = 0.0014 and P = 0.0149, respectively). In addition, early H/M ratio, LVEF, and absence of diabetes mellitus (DM) were independent predictors for LVEF improvement by >10%. No independent predictors were found for QRS shortening to <150 ms or improvement in NYHA class.Conclusion Early and late H/M ratio were independent predictors of CRT response when improvement of LVEF was used as measure of response. Therefore, cardiac 123I-mIBG scintigraphy may be used as a tool to optimize selection of subjects that might benefit from CRT.

Abstract 108: Identifying and Addressing Gaps in Utilization of Cardiac Resynchronization Therapy

Objective: Prior registry studies have reported potential underutilization of cardiac resynchronization therapy (CRT) in clinical practice. We sought to identify and address gaps in the use of CRT among eligible patients in a large healthcare system. Methods: From the Allina Health enterprise data warehouse, we identified potentially eligible patients for CRT and refined eligibility assessment through detailed chart review. Following this eligibility assessment, patient lists were provided to cardiology providers who had last seen the patient in clinical care delivery to further review and refer for CRT as appropriate. Results: We identified 13,897 patients with a left ventricular ejection fraction of ≤ 35% by echocardiography performed between January 1, 2013 and November 13, 2018 (see Figure). We excluded 5,943 (42.8%) patients with QRS duration &lt;120 ms on the first available ECG within one year of the index echocardiogram and 3,160 (22.7%) patients with no ECG during that time interval. We also excluded 917 (6.6%) patients with recovery of systolic function to &gt;35% on a repeat echocardiogram performed ≥ 3 months after the index assessment and 1,772 (12.8%) patients without a follow-up echocardiogram at ≥ 3 months. Of the remaining 2,105 patients, 671 (31.9%) patients died in follow-up, 742 patients (35.2%) subsequently underwent CRT-D, 141 (6.7%) underwent CRT-P, 108 (5.1%) had further improvement in EF to &gt;35% on the most recent echocardiogram, 46 (2.2%) had a most recent QRS duration &lt;120 ms, and 20 (1.0%) underwent left ventricular assist device implantation or transplant, resulting in 377 (17.9%) patients potentially eligible for CRT. Following detailed chart review of 183 patients identified in this process, 73 (39.9%) patients remained eligible for CRT. These 73 patients were attributed to 41 different cardiology providers who further reviewed their clinical situation and referred 17 (9.3%) of these patients for CRT. Conclusion: Filtering a data repository on elements that determine CRT eligibility facilitated targeted chart review to address potential quality gaps in the use of this therapy. Only 9% of potentially eligible patients identified prior to chart review were ultimately referred for CRT, suggesting gaps in use of CRT may be smaller than suggested from prior registry studies.

Eligibility for cardiac resynchronization therapy in patients hospitalized with heart failure.

AimsRecent 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 resultsA 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).ConclusionsTwenty‐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.

Indications for Cardiac Resynchronization Therapy: A Comparison of the Major International Guidelines

ObjectivesThis study compares and contrasts the recommended indications for cardiac resynchronization therapy (CRT) according to the most recent guidelines from international cardiology societies. BackgroundCRT has been shown to reduce morbidity and mortality in selected patients with systolic heart failure. Cardiology societies provide guidelines regarding the indications for CRT. As evidence evolves, it is challenging for the guideline committees to review the impact of newer evidence in a timely fashion. MethodsSix of the most recent international guidelines providing recommendation concerning CRT implantation ranging from 2011 to 2017 were reviewed. These included guidelines from 2 European, 1 North American, 1 Canadian, and 1 Australian/New Zealand societies and the National Institute for Health and Care Excellence guidelines, specific to the United Kingdom. ResultsAlthough international societies provide consistent recommendations for most CRT indications, differences are found in recommendations for several important patient populations. Specifically, divergent recommendations exist regarding QRS duration, bundle branch morphology, patients in atrial fibrillation, choice of device type (CRT pacemakers vs. CRT defibrillators), and selected patients who are likely to be dependent on right ventricular pacing. The timing of publication of specific guidelines appears to play an essential role in explaining these disparities. ConclusionsDespite general consistency in international guideline recommendations, there remain certain patient populations for whom there are variations in recommendations concerning eligibility for CRT and selection of the most appropriate device in the individual patient.

Pediatric Dilated Cardiomyopathy Patients Do Not Meet Traditional Cardiac Resynchronization Criteria

Cardiac resynchronization therapy (CRT) is an effective device-based intervention for adults with heart failure (HF) with specific indications, based on large, multicenter randomized clinical trials. The criteria for CRT in adult HF include significant symptoms, ventricular systolic dysfunction, prolonged QRS duration, and left bundle branch block (LBBB) pattern on electrocardiogram (ECG). Despite having less data, CRT is also being widely utilized in children with HF. The shortage of evidence-based CRT criteria in pediatrics prompted us to review a cohort of children with dilated cardiomyopathy and evaluate their potential eligibility for CRT using the traditional adult criteria. Single-center data of all pediatric patients with dilated cardiomyopathy were extracted from the heart failure registry and retrospectively reviewed. Patients who had at least 2 separate visits that included HF scoring, electrocardiogram, and echocardiogram were included. Patients who were ventricular paced were excluded. Data for 52 patients meeting inclusion criteria were analyzed. The mean ejection fraction was 25% on the first clinical evaluation and 27% on the second visit. No patient and 2 patients met the adult criteria for prolonged QRS on the first and second encounters, respectively. No patients had an LBBB pattern on ECG. None of the pediatric HF patients in our study met the published Class I criteria for CRT device therapy in adults. These findings suggest that extrapolation of adult HF data to pediatrics is not sufficient for CRT criteria. Specific guidelines for device implantation in children must be based on scientific investigation including pediatric clinical trials.

(890) - Eligibility for Cardiac Resynchronization Therapy for Systolic Heart Failure in Children With Cardiomyopathy

Cardiac resynchronization therapy (CRT) for systolic heart failure (HF) has been well established in adults but data in children are limited. We sought to identify the prevalence of children with cardiomyopathy (CM) and HF who would be eligible for CRT based on adult guidelines.

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

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

Selection of Patient for Cardiac Resynchronization Therapy: Role of QT Corrected Dispersion

About 30 to 50% of patients undergoing cardiac resynchronization therapy (CRT) may not show clinical or echocardiographic improvement, despite fulfilling guidelines recommendations for CRT. For this reason, we need a more accurate method to assess CRT eligibility. The aims of this study were to verify, on a 12-month follow-up, the usefulness of QT corrected dispersion (QTcD) in a patient's selection for CRT. We stratified 53 patients who underwent CRT, into two groups based on the estimation of QTcD, that is, QTcD > 60 ms and QTcD ≤ 60 ms. In all patients were performed New York Heart Association (NYHA) class determination, six-minute walking test, QtcD, and QRS measurements, and complete echocardiographic assessment at 1, 3, 6, and 12 months after implantation. At baseline, there were no significant differences in clinical, echocardiographic, and electrocardiographic parameters duration between two groups. At 12-month follow-up between the two groups, there were significant differences in NYHA (1.2 ± 0.4 vs 2 ± 0.6; P < 0.01), six-minute walking distance (422 ± 68 vs 364 ± 68; P < 0.01), left ventricular (LV) ejection fraction (34 ± 7% vs 28 ± 6%; P < 0.01), LV end-diastolic diameter (57 ± 7 vs 63 ± 8; P < 0.01), and LV intraventricular dyssynchrony (24 ± 14 vs 39 ± 23; P < 0.01). This study suggests that QTc dispersion in addition to QRS duration could improve the sensitivity of electrocardiogram in a patient's selection for CRT.

Comentário a «Definir bloqueio completo do ramo esquerdo na era da terapêutica de ressincronização cardíaca»

Cardiac resynchronization therapy (CRT) has emerged as an attractive intervention to improve left ventricular mechanical function by changing the sequence of electrical activation. Unfortunately, many patients receiving CRT do not benefit but are subjected to device complications and costs. Thus, there is a need for better selection criteria. Current criteria for CRT eligibility include a QRS duration >120 ms. However, QRS morphology is not considered, although it can indicate the cause of delayed conduction. Recent studies have suggested that only patients with left bundle branch block (LBBB) benefit from CRT, and not patients with right bundle branch block or nonspecific intraventricular conduction delay. The authors review the pathophysiologic and clinical evidence supporting why only patients with complete LBBB benefit from CRT. Furthermore, they review how the threshold of 120 ms to define LBBB was derived subjectively at a time when criteria for LBBB and right bundle branch block were mistakenly reversed. Three key studies over the past 65 years have suggested that 1/3 of patients diagnosed with LBBB by conventional electrocardiographic criteria may not have true complete LBBB, but likely have a combination of left ventricular hypertrophy and left anterior fascicular block. On the basis of additional insights from computer simulations, the investigators propose stricter criteria for complete LBBB that include a QRS duration >140 ms for men and >130 ms for women, along with mid-QRS notching or slurring in >2 contiguous leads. Further studies are needed to reinvestigate the electrocardiographic criteria for complete LBBB and the implications of these criteria for selecting patients for CRT.

Comment on “Defining left bundle branch block in the era of cardiac resynchronization therapy”

Cardiac resynchronization therapy (CRT) has emerged as an attractive intervention to improve left ventricular mechanical function by changing the sequence of electrical activation.Unfortunately, many patients receiving CRT do not benefit but are subjected to device complications and costs. Thus, there is a need for better selection criteria. Current criteria for CRT eligibility include a QRS duration >120ms. However, QRS morphology is not considered, although it can indicate the cause of delayed conduction. Recent studies have suggested that only patients with left bundle branch block (LBBB) benefit from CRT, and not patients with right bundle branch block or nonspecific intraventricular conduction delay. The authors review the pathophysiologic and clinical evidence supporting why only patients with complete LBBB benefit from CRT. Furthermore, they review how the threshold of 120ms to define LBBB was derived subjectively at a time when criteria for LBBB and right bundle branch block were mistakenly reversed. Three key studies over the past 65 years have suggested that 1/3 of patients diagnosed with LBBB by conventional electrocardiographic criteria may not have true complete LBBB, but likely have a combination of left ventricular hypertrophy and left anterior fascicular block. On the basis of additional insights from computer simulations, the investigators propose stricter criteria for complete LBBB that include a QRS duration >140ms for men and >130ms for women, along with mid-QRS notching or slurring in >2 contiguous leads. Further studies are needed to reinvestigate the electrocardiographic criteria for complete LBBB and the implications of these criteria for selecting patients for CRT.

Functional and clinical implications of cardiac resynchronization therapy on outcomes of diabetic patients with heart failure

To compare functional and structural changes of the left ventricle and long-term clinical outcomes in diabetic and nondiabetic patients with heart failure undergoing cardiac resynchronization therapy (CRT). Sixty-eight patients with heart failure undergoing CRT were included: 18 were diabetic patients and 50 nondiabetic patients. The CRT eligibility was established by echocardiographic assessments. CRT improved ventricular geometry and dyssynchrony in both diabetic and nondiabetic patients, with no significant difference in the magnitude of the effects on the left ventricular function. Over a median follow-up of 30.6 ± 6.2 months, there were no significant differences in the rates of any cause death (16.7 vs. 14.0%, P = 0.72), cardiac death (11.1 vs. 8.0%, P = 0.65) and heart rehospitalization (5.6 vs. 6.0%, P = 1.0), between diabetic and nondiabetic patients, respectively. Diabetes was not found to be an independent factor associated with worse clinical outcome. Resynchronization therapy provided significant functional and hemodynamic improvements in both diabetic and nondiabetic patients. Long-term prognosis in heart failure patients with diabetes was comparable with that in those without diabetes.

Assessment of Systolic Dyssynchrony for Cardiac Resynchronization Therapy Is Not Clinically Useful

Cardiac resynchronization therapy (CRT) is an effective treatment in patients with medically refractory heart failure. Several clinical trials have shown improvement in both left ventricular (LV) function and symptoms with CRT compared with controls,1,–,4 with the 2 largest trials showing a reduction in rates of hospitalization and death.5,6 On the basis of data from these studies, most international guidelines agree on the standard indications for CRT: impaired functional status with New York Heart Association functional class III or IV, LV ejection fraction (LVEF) ≤35%, and prolonged QRS duration ≥120 ms in the setting of optimal medical therapy.7,–,9 However, not all patients experienced improvement in symptoms or LV function, and numerous studies have focused on improving the selection criteria for CRT in the hopes of excluding these “nonresponders.”1,–,4 One of the most frequently studied modalities for patient selection is echocardiographic measurement of LV systolic dyssynchrony based on the supposition that there is a threshold for mechanical dyssynchrony below which there is no therapeutic benefit. Despite these studies, we argue that current echocardiographic methods of measuring dyssynchrony should not be used to exclude patients who are otherwise candidates for CRT. Conversely, in patients with narrow QRS, echocardiographic evidence of dyssynchrony is insufficient to warrant CRT on the basis of current data. Response by Delgado and Bax on p 663 There are important unresolved issues regarding the use of mechanical dyssynchrony measurements for determining CRT eligibility in an individual patient. Let us examine the case of a 60-year-old man with ischemic cardiomyopathy, recurrent hospitalizations, and New York Heart Association functional class III despite an excellent heart failure drug regimen. He inquires about additional therapy to help improve his symptoms and keep him out of the …

Sleep apnea in patients with heart failure: Could cardiac resynchronization therapy be the first line treatment?

Adaptive servo-ventilation as well as continuous and bi-level positive airway pressure seems to effectively treat sleep apnea syndrome (SAS) in patients with chronic heart failure (CHF), and to improve left ventricular function. However, no randomized data show a significant impact of ventilation on survival in patients with CHF. By contrast, there is overwhelming evidence that cardiac resynchronization therapy (CRT) improves outcomes in patients with CHF. CRT also provides a clinically significant decrease in SAS severity in patients with CHF. Consequently, CRT eligibility criteria should always be searched for in patients with severe CHF having SAS.

Phase Analysis of Gated Myocardial Perfusion Single-Photon Emission Computed Tomography Compared With Tissue Doppler Imaging for the Assessment of Left Ventricular Dyssynchrony

The purpose of this study was to compare left ventricular (LV) dyssynchrony assessment by gated myocardial perfusion single-photon emission computed tomography (SPECT) (GMPS) and tissue Doppler imaging (TDI). Recently, it has been suggested that LV dyssynchrony is an important predictor of response to cardiac resynchronization therapy (CRT); dyssynchrony is predominantly assessed by TDI with echocardiography. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle, which tracks the onset of LV thickening. In 75 patients with heart failure, depressed LV function, and wide QRS complex, GMPS and 2-dimensional echocardiography, including TDI, were performed as part of clinical screening for eligibility for CRT. Clinical status was evaluated with New York Heart Association functional classification, 6-min walk distance, and quality-of-life score. Different parameters (histogram bandwidth, phase SD, histogram skewness, and histogram kurtosis) of LV dyssynchrony were assessed from GMPS and compared with LV dyssynchrony on TDI with Pearson's correlation analyses. Histogram bandwidth and phase SD correlated well with LV dyssynchrony assessed with TDI (r = 0.89, p < 0.0001 and r = 0.80, p < 0.0001, respectively). Histogram skewness and kurtosis correlated less well with LV dyssynchrony on TDI (r = -0.52, p < 0.0001 and r = -0.45, p < 0.0001, respectively). The LV dyssynchrony assessed from GMPS correlated well with dyssynchrony assessed by TDI; histogram bandwidth and phase SD showed the best correlation with LV dyssynchrony on TDI. These parameters seem most optimal for assessment of LV dyssynchrony with gated SPECT. Outcome studies after CRT are needed to further validate the use of GMPS for assessment of LV dyssynchrony.

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

To determine what proportion of patients with heart failure are eligible for cardiac resynchronization therapy (CRT). Eligibility criteria from the trials establishing the efficacy of CRT were applied to two prospective cohorts: the first enrolled patients with newly diagnosed heart failure discharged from 103 hospitals between April 1999 and March 2001 ('the hospital discharge cohort'); the second enrolled patients seen in a specialized clinic between August 2003 and January 2004 ('the specialty clinic cohort'). In the hospital discharge cohort, 73 patients (3% of the 2640 patients with ischaemic or dilated cardiomyopathy and 1% of all 9096 patients with heart failure discharged alive) met trial eligibility criteria: LVEF< or =0.35, QRS > or =120 ms, sinus rhythm, and NYHA class III or IV symptoms despite the treatment with ACE-inhibitor/angiotensin receptor blocker and beta-blocker. In the specialty clinic cohort, 54 patients (21% of the 263 patients with ischaemic or dilated cardiomyopathy and 17% of all 309 patients with heart failure) met these criteria. If persistent symptoms despite taking spironolactone were required for CRT eligibility, then the proportions qualifying dropped to 1% in the hospital discharge cohort and 18% in the specialty clinic cohort. Few heart failure patients meet trial eligibility criteria for CRT.

Implications of cardiac resynchronization therapy and prophylactic defibrillator implantation among patients eligible for heart transplantation

This study analyzed the relations and time-related changes in eligibility for cardiac resynchronization therapy and prophylactic defibrillator implantation in 161 potential candidates for heart transplantation. Although up to 62% of patients who fulfilled the severity criteria for heart transplantation were eligible for either device, this percentage increased as clinical/instrumental parameters of heart failure severity worsened.

Eligibility for Cardiac Resynchronization Therapy in Geriatric Patients in a Community Hospital

Eligibility for Cardiac Resynchronization Therapy in Geriatric Patients in a Community Hospital