Outcome Of Cardiac Resynchronization Therapy Research Articles

Segment Length in Cine Strain Analysis Predicts Cardiac Resynchronization Therapy Outcome Beyond Current Guidelines.

Patients with a class I recommendation for cardiac resynchronization therapy (CRT) are likely to benefit, but the effect of CRT in class II patients is more heterogeneous and additional selection parameters are needed in this group. The recently validated segment length in cine strain analysis of the septum (SLICE-ESSsep) measurement on cardiac magnetic resonance cine imaging predicts left ventricular functional recovery after CRT but its prognostic value is unknown. This study sought to evaluate the prognostic value of SLICE-ESSsep for clinical outcome after CRT. Two hundred eighteen patients with a left bundle branch block or intraventricular conduction delay and a class I or class II indication for CRT who underwent preimplantation cardiovascular magnetic resonance examination were enrolled. SLICE-ESSsep was manually measured on standard cardiovascular magnetic resonance cine imaging. The primary combined end point was all-cause mortality, left ventricular assist device, or heart transplantation. Secondary end points were (1) appropriate implantable cardioverter defibrillator therapy and (2) heart failure hospitalization. Two-thirds (65%) of patients had a positive SLICE-ESSsep ≥0.9% (ie, systolic septal stretching). During a median follow-up of 3.8 years, 66 (30%) patients reached the primary end point. Patients with positive SLICE-ESSsep were at lower risk to reach the primary end point (hazard ratio 0.36; P<0.001) and heart failure hospitalization (hazard ratio 0.41; P=0.019), but not for implantable cardioverter defibrillator therapy (hazard ratio, 0.66; P=0.272). Clinical outcome of class II patients with a positive ESSsep was similar to those of class I patients (hazard ratio, 1.38 [95% CI, 0.66-2.88]; P=0.396). Strain assessment of the septum (SLICE-ESSsep) provides a prognostic measure for clinical outcome after CRT. Detection of a positive SLICE-ESSsep in patients with a class II indication predicts improved CRT outcome similar to those with a class I indication whereas SLICE-ESSsep negative patients have poor prognosis after CRT implantation.

Heart Failure Etiology in Patients Undergoing Cardiac Resynchronization Therapy: Is It Relevant?

Background: Cardiac resynchronization therapy (CRT) is an established treatment for heart failure with reduced ejection fraction (HfrEF). Etiology may influence the outcome of patients undergoing CRT. Objective: to evaluate whether etiology (ischemic vs non-ischemic) influences the response to CRT and overall outcome. Methods: Our study included HFrEF patients undergoing CRT between January 2017-November 2019. We assessed right ventricle (RV) and left ventricle (LV) function using transthoracic echocardiography at baseline and one year after CRT. The response to CRT was defined by a decrease of more than 15% of left ventricle systolic volume. Patients were divided in two groups: ischemic and non-ischemic based on personal history. Adverse events (HF related hospitalizations and deaths) were tracked for 33± 12.8 months. Results: 52 patients undergoing CRT were included (64±13.5 years, 55.7% male, 70% non-ischemic etiology) The two groups were similar considering LV systolic baseline parameters and volumes. Ischemic etiology was associated with non-LBBB morphology on ECG (p=0.03), a more severe LV diastolic dysfunction using E/e ratio (p&lt;0.05), and a more severe RV dysfunction using TAPSE (p=0.008) and RV fractional area change (FAC) (p&lt;0.05). There was no significant difference in CRT response between ischemic and non-ischemic etiology. 14 (26.9%) patients had events (10 hospitalizations and 4 deaths) with a higher prevalence in the ischemic group (58.33% vs 25%, p=0.01). Univariate Cox regression analysis reported a higher risk of cardiovascular events for ischemic etiology (HR 2.4, 95% CI [0.8-8.1], p &lt;0.05). In our cohort there was no significant difference in use of an implantable cardioverter-defibrillator in addition to CRT between ischemic and non-ischemic group (64.2% respectively 63.3%, p =0.3). Conclusion: Our study shows that ischemic and nonischemic HF patients had similar response to CRT. However, ischemic etiology was associated with a higher risk ofadverse cardiovascular events and a worse RV systolic dysfunction at baseline.

Clinical Significance of Global Wasted Work in Patients with Heart Failure Receiving Cardiac Resynchronization Therapy

The relationship between myocardial work assessment using pressure-strain loops by echocardiography before cardiac resynchronization therapy (CRT) and response to CRT has been recently revealed. Among myocardial work parameters, the impact of left ventricular myocardial global wasted work (GWW) on response to CRT and outcome following CRT has been seldom studied. Hence, the authors evaluated the relationship between preprocedural GWW and outcome in a large prospective cohort of patients with heart failure (HF) and reduced ejection fraction receiving CRT. The study included 249 patients with HF. Myocardial work indices including GWW were calculated using speckle-tracking strain two-dimensional echocardiography using pressure-strain loops. End points of the study were (1) response to CRT, defined as left ventricular reverse remodeling and/or absence of hospitalization for HF, and (2) all-cause death during follow-up. Median follow-up duration was 48months (interquartile range, 43-54months). Median preoperative GWW was 281mm Hg% (interquartile range, 184-388mm Hg%). Preoperative GWW was associated with CRT response (area under the curve, 0.74; P<.0001), and a 200mm Hg% threshold discriminated CRT nonresponders from responders with 85% specificity and 50% sensitivity, even after adjustment for known predictors of CRT response (adjusted odds ratio, 4.03; 95% CI, 1.91-8.68; P<.001). After adjustment for established predictors of outcome in patients with HF with reduced ejection fraction receiving CRT, GWW < 200mm Hg% remained associated with a relative increased risk for all-cause death compared with GWW ≥ 200mm Hg% (adjusted hazard ratio, 2.0; 95% CI, 1.1-3.9; P=.0245). Adding GWW to a baseline model including known predictors of outcome in CRT resulted in an improvement of this model (χ2 to improve 4.85, P=.028). The relationship between GWW and CRT response and outcome was stronger in terms of size effect and statistical significance than for other myocardial work indices. Low preoperative GWW (<200mm Hg%) is associated with absence of CRT response in CRT candidates and with a relative increased risk for all-cause death. GWW appears to be a promising parameter to improve selection for CRT of patients with HF with reduced ejection fraction.

Rhythm or rate control strategy in CRT recipients with long-standing persistent atrial fibrillation - preliminary results of the PilotCRAfT study

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Cardiology in Warsaw Statutory Grant Background The presence of atrial fibrillation (AF) in cardiac resynchronization therapy (CRT) recipients is common and AF is a marker of poorer CRT response. The negative influence of AF on CRT efficacy is mediated mainly by the drop of the effectively captured biventricular paced beats percentage (BiVp%) which should exceed 95-98% to warrant good CRT response. Sinus rhythm (SR) restoration may improve CRT efficacy which in turn may protect AF recurrence. However, there is lack of randomized studies comparing rhythm and rate control strategies in these patients. Purpose The purpose of the Pilot-CRAfT study (NCT01850277) was to compare the efficacy of rhythm vs rate control strategy in CRT patients with long-standing persistent or permanent atrial fibrillation. Methods The study included patients with CRT and permanent or persistent AF lasting for ≥6 months, resulting in BiVp% &amp;lt;95%, who were randomly assigned to rhythm or rate control strategy. The rhythm control strategy comprised of external electrical cardioversion (EEC). The rate control strategy included pharmacotherapy and atrioventricular node ablation (AVNA) as needed. Both of the study arms received amiodarone. The follow-up lasted 12 months. The primary endpoint was the 12-month BiVp%. The patients underwent ECHO, cardiopulmonary test, quality of live (QoL) and clinical outcomes assessment. Results The study included 43 CRT patients (97,7% males) aged 68,4 (SD: ±8,3) years with mean BiVp% 82,4% ±9,7% at baseline. The mean duration of AF paroxysm was 25 ±19 months. The mean baseline left ventricular ejection fraction (LVEF), left atrium area and maximal oxygen uptake (VO2max) were: 30 ±8%, 33 ±7 cm2, 14 ±5 mL/(kg*min), respectively. The EEC was performed in 19 out of 22 patients assigned to the rhythm control arm. The immediate success rate of EEC was 58%. 42% of the rhythm control arm patients remained in SR after 12 months. In the rate control group 1 person underwent AVNA and in 1 patient spontaneous SR resumption was observed. After 12 months there was significant BiVp% increase in both the rhythm and the rate control arms (98,1 ±2,3 vs 96,3 ±3,9%, respectively. The BiVp% differences between the groups were not significant (P = 0,093). However, in the per protocol analysis, the rhythm control group had greater LVEF after 12 months as opposed to the rate control arm (36,8% vs 29,9% respectively, P = 0,039). The LVEF raised significantly in the rhythm control group (ΔLVEF 5,0 (95%CI: 1,54; 8,46)). No significant differences between the groups in the VO2max, QoL, clinical and safety end-points were noticed. Conclusions Structured follow-up of CRT patients with long-standing persistent or permanent AF leads to significant BiVp% increase exceeding 95%. The rate control strategy did not improve CRT effectivness, irrespective of high BiVp%. However limited in the efficacy, the rhythm control strategy may improve CRT outcome in these patients, resulting in LVEF increase.

The CHA2DS2-VASc Score and Its Association with Long-Term Outcome in a Cardiac Resynchronization Therapy Population

Background: Cardiac resynchronization therapy (CRT) is commonly used in patients with heart failure and left ventricular dyssynchrony. Several scoring systems have been tested in order to predict long-term outcome. Although intended for use in patients with atrial fibrillation, we sought to assess the performance of the CHA₂DS₂-VASc score in a CRT population. Methods: Data on 796 consecutive CRT patients were retrospectively gathered from hospital records and healthcare registries. CHA₂DS₂-VASc scores were calculated, as well as other stratification scores for comparison. The outcomes were crude mortality, time to first heart failure hospitalization, and a composite of the 2. CHA₂DS₂-VASc score was evaluated against the end points with survival analyses and compared to other risk stratification scores. Results: The CHA₂DS₂-VASc score was significantly correlated with both outcomes in univariable and multivariable analysis adjusting for other known predictors of CRT outcome (unadjusted HR 1.28, 95% CI 1.21–1.36 and HR 1.19, 95% CI 1.13–1.25 for the mortality and heart failure hospitalization end points, respectively). Its performance compared well to other validated scores for the mortality end point (Harrell’s C: 0.61, range for other scoring systems: 0.57–0.65), as well as the heart failure hospitalization end point (Harrell’s C: 0.57, range of other scoring systems: 0.58–0.62). It correlated to 5- and 10-year survival with an area under the curve of 0.63 and 0.73, respectively. Conclusion: When tested for association with outcome in a CRT population, the CHA₂DS₂-VASc score correlates to increased mortality and risk of heart failure hospitalization. It performs similarly to CRT-specific scores. However, the results of this study indicate that all tested scores should be used with caution in CRT patients.

Does the Age Affect the Outcomes of Cardiac Resynchronization Therapy in Elderly Patients?

Background: More and more heart failure (HF) patients aged ≥ 75 years undergo cardiac resynchronization therapy (CRT) device implantation, however the data regarding the outcomes and their predictors are scant. We investigated the mid- to long-term outcomes and their predictors in CRT patients aged ≥ 75 years. Methods: Patients in the Cardiac Resynchronization Therapy Modular (CRT MORE) Registry were divided into three age-groups: <65 (group A), 65–74 (group B) and ≥75 years (group C). Mortality, hospitalization, and composite event rate were evaluated at 1 year and during long-term follow-up. Results: Patients (n = 934) were distributed as follows: group A 242; group B 347; group C 345. On 12-month follow-up examination, 63% of patients ≥ 75 years displayed a positive clinical response. Mortality was significantly higher in patients ≥ 75 years than in the other two groups, although the rate of hospitalizations for HF worsening was similar to that of patients aged 65–74 (7 vs. 9.5%, respectively; p = 0.15). Independent predictors of death and of negative clinical response were age >80 years, chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD). Over long-term follow-up (1020 days (IQR 680-1362)) mortality was higher in patients ≥ 75 years than in the other two groups. Hospitalization and composite event rates were similar in patients ≥ 75 years and those aged 65–74 (9 vs. 11.8%; p = 0.26, and 26.7 vs. 20.5%; p = 0.06). Conclusion: Positive clinical response and hospitalization rates do not differ between CRT recipients ≥ 75 years and those aged 65–74. However, age > 80 years, COPD and CKD are predictors of worse outcomes.

Comparison between cardiac magnetic resonance and speckle-tracking echocardiography in prediction of cardiac resynchronization therapy outcomes

Background Cardiac resynchronization therapy (CRT) improves quality of life, exercise tolerance, and myocardial function in a considerable number of patients with heart failure (HF) and left bundle branch block. In addition, CRT decreases HF hospitalizations and overall mortality. However, structural, morbidity, and mortality improvements after CRT rate between 40 and 60%. Objective To compare the role of the cardiac magnetic resonance (CMR) and speckle-tracking echocardiography (STE) in expectation of response to CRT. Patients and methods We investigated the predictors of CRT response using CMR measurement of left ventricular (LV) volumes and function, CMR-derived mechanical dyssynchrony, scar percentage, and its relation to the site of LV lead implantation, in comparison with STE in prediction of CRT outcomes. Results A total of 35 patients with HF planned for CRT were included. Echocardiography was used to define the response to CRT (15% reduction in LV end-systolic volume 6 months after implantation). At follow-up, 18 (51.43%) patients were categorized as responders. Echocardiographic speckle-tracking radial strain analysis showed a significant LV dyssynchrony in responders versus nonresponders (radial mid-anteroseptal and posterior wall delays were 245.1 ms and 80.7 ms, respectively) (P&lt;0.0001). LV radial dyssynchrony, as measured by CMR-feature tracking, was significantly higher in responders versus nonresponders (mean of SDt-16 of radial strain were 232.7 ms vs. 180.4 ms, P&lt;0.0001), and median of radial mid-anteroseptal-to-inferolateral wall delay was 375 vs. 125.4 ms, P&lt;0.0001). Late contrast-enhanced CMR was performed for scar assessment. It was noticed that scar percentage of LV mass was much higher in nonresponders (median 6.2 vs. 0%) (P=0.005). Conclusion CMR imaging offers the unique opportunity to predict the CRT outcomes by measurement of LV volumes, LV mechanical dyssynchrony (that well correlated with that of STE), and the total scar percentage and distribution in a single examination.

Outcomes of cardiac resynchronization therapy in patients with chemotherapy-induced cardiomyopathy.

Several chemotherapy agents are associated with the development of non-ischemic cardiomyopathy (NIC). When chemotherapy-induced cardiomyopathy (CHIC) is associated with left bundle branch block (LBBB) and a left ventricular ejection fraction (LVEF) 35% or lower, cardiac resynchronization therapy (CRT) is often utilized to improve cardiac function and relieve symptoms. To determine the echocardiographic and clinical outcomes of CRT in patients with CHIC. The study included 29 patients with CHIC (CHIC group) and 58 patients with other types of NIC (control group) who underwent CRT implantation between 2004 and 2017. The primary endpoints were changes in LVEF, left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD) at 6-18 months after CRT. The secondary outcomes included changes in left ventricular global longitudinal strain (GLS), systolic strain rate (SRS), early diastolic strain rate (SRE), and overall survival. Out of 29 patients with CHIC, 62.1% received chemotherapy for lymphoma, 13.7% for breast cancer, and 24.1% for sarcoma. The agent implicated in 93.1% of the patients was an anthracycline. Half of the patients had LBBB. The mean baseline LVEF was 28% ± 8%. The mean baseline QRS duration was 146 ± 26ms. Twenty-eight patients had post-CRT follow-up data. CRT was associated with improvement in echocardiographic outcomes in the CHIC group and the control group. There was no difference in overall survival between the two groups (log-rank p=.148). CRT improves left ventricular function and reverses remodeling in patients with CHIC.

Outcomes of Cardiac Resynchronization Therapy in Heart Failure Patients and Effect of MAGGIC-HF Score on Prognosis

Outcomes of Cardiac Resynchronization Therapy in Heart Failure Patients and Effect of MAGGIC-HF Score on Prognosis

Importance of systematic right ventricular assessment in cardiac resynchronization therapy candidates: a machine-learning approach

Abstract Funding Acknowledgements Type of funding sources: None. Background Despite having all a systolic heart failure and broad QRS, patients proposed for cardiac resynchronization therapy (CRT) are highly heterogeneous and it remains extremely complicated to predict the impact of the device on left ventricular (LV) function and outcomes. Objectives We sought to evaluate the relative impact of clinical, electrocardiographic, and echocardiographic data on the left ventricular (LV) remodeling and prognosis of CRT-candidates by the application of machine learning (ML) approaches. Methods 193 patients with systolic heart failure undergoing CRT according to current recommendations were prospectively included in this multicentre study. We used a combination of the Boruta algorithm and random forest methods to identify features predicting both CRT volumetric response and prognosis (Figure 1). The model performance was tested by the area under the receiver operating curve (AUC). We also applied the K-medoid method to identify clusters of phenotypically-similar patients. Results From 28 clinical, electrocardiographic, and echocardiographic-derived variables, 16 features were predictive of CRT-response; 11 features were predictive of prognosis. Among the predictors of CRT-response, 7 variables (44%) pertained to right ventricular (RV) size or function. Tricuspid annular plane systolic excursion was the main feature associated with prognosis. The selected features were associated with a very good prediction of both CRT response (AUC 0.81, 95% CI: 0.74-0.87) and outcomes (AUC 0.84, 95% CI: 0.75-0.93) (Figure 1, Supervised Machine Learning Panel). An unsupervised ML approach allowed the identifications of two phenogroups of patients who differed significantly in clinical and parameters, biventricular size and RV function. The two phenogroups had significant different prognosis (HR 4.70, 95% CI: 2.1-10.0, p &amp;lt; 0.0001; log –rank p &amp;lt; 0.0001; Figure 1, Unsupervised Machine Learning Panel). Conclusions Machine learning can reliably identify clinical and echocardiographic features associated with CRT-response and prognosis. The evaluation of both RV-size and function parameters has pivotal importance for the risk stratification of CRT-candidates and should be systematically assessed in patients undergoing CRT. Abstract Figure 1

A multicenter prospective randomized controlled trial of cardiac resynchronization therapy guided by invasive dP/dt.

BackgroundNo periprocedural metric has demonstrated improved cardiac resynchronization therapy (CRT) outcomes in a multicenter setting.ObjectiveWe sought to determine if left ventricular (LV) lead placement targeted to the coronary sinus (CS) branch generating the best acute hemodynamic response (AHR) results in improved outcomes at 6 months.MethodsIn this multicenter randomized controlled trial, patients were randomized to guided CRT or conventional CRT. Patients in the guided arm had LV dP/dtmax measured during biventricular (BIV) pacing. Target CS branches were identified and the final LV lead position was the branch with the best AHR and acceptable threshold values. The primary endpoint was the proportion of patients with a reduction in LV end-systolic volume (LVESV) of ≥15% at 6 months.ResultsA total of 281 patients were recruited across 12 centers. Mean age was 70.8 ± 10.9 years and 54% had ischemic etiology. Seventy-three percent of patients in the guided arm demonstrated a reduction in LVESV of ≥15% at 6 months vs 60% in the conventional arm (P = .02). Patients with AHR ≥ 10% were more likely to demonstrate a reduction of ESV ≥ 15% (84% of patients with an AHR ≥10% vs 28% with an AHR <10%; P < 0.001). Procedure duration and fluoroscopy times were longer in the pressure wire–guided arm (104 ± 39 minutes vs 142 ± 39 minutes; P < .001 and 20 ±16 minutes vs 28 ± 15 minutes; P = .002).ConclusionsAHR determined by invasively measuring LV dP/dtmax during BIV pacing predicts reverse remodeling 6 months after CRT. Patients in whom LV dP/dtmax was used to guide LV lead placement demonstrated better rates of reverse remodeling.

Clinical outcome of cardiac resynchronization therapy in patients randomized to an active fixation bipolar left ventricular lead versus a passive quadripolar lead

Objectives: To compare the clinical outcome of cardiac resynchronization therapy (CRT) in patients receiving a bipolar left ventricular (LV) lead with a side helix for active fixation to the outcome in patients receiving a quadripolar passive fixation LV lead. Design: Sixty-two patients (mean age 72 ± 11 years) were blindly and randomly assigned to the active fixation bipolar lead group (n = 31) or to the quadripolar lead group (n= 31). The LV leads were targeted to the basal LV segment in a vein concordant to the LV segment with the latest mechanical contraction chosen on the basis of preoperative radial strain (RS) echocardiography. Results: At the 6-month follow-up (FU), the reduction in LV end-systolic volume and LV reverse remodelling responder rate, defined as LV end-systolic volume reduction >15%, was 77% in the active fixation group and 83% in the quadripolar group, which was not significantly different. At the 12-month FU, the LV ejection fraction (LVEF) did not differ between the groups. There were no significant differences between the two groups in changes in New York Heart Association (NYHA) functional class or Minnesota Living with Heart Failure Questionnaire score. The occurrence of phrenic nerve stimulation (PNS) was 19% in the active fixation group versus 10% in the quadripolar group (p=.30), and all cases were resolved by reprogramming the device. All patients were alive at the 12-month FU. There was no device infection. Conclusions: There were no significant differences between the active fixation group of patients and the quadripolar group of patients concerning improvement in echocardiographic parameters or clinical symptoms. ClinicalTrials.gov number, NCT04632472

Importance of Systematic Right Ventricular Assessment in Cardiac Resynchronization Therapy Candidates: A Machine Learning Approach

Despite all having systolic heart failure and broad QRS intervals, patients screened for cardiac resynchronization therapy (CRT) are highly heterogeneous, and it remains extremely challenging to predict the impact of CRT devices on left ventricular function and outcomes. The aim of this study was to evaluate the relative impact of clinical, electrocardiographic, and echocardiographic data on the left ventricular remodeling and prognosis of CRT candidates by the application of machine learning approaches. One hundred ninety-three patients with systolic heart failure receiving CRT according to current recommendations were prospectively included in this multicenter study. A combination of the Boruta algorithm and random forest methods was used to identify features predicting both CRT volumetric response and prognosis. Model performance was tested using the area under the receiver operating characteristic curve. The k-medoid method was also applied to identify clusters of phenotypically similar patients. From 28 clinical, electrocardiographic, and echocardiographic variables, 16 features were predictive of CRT response, and 11 features were predictive of prognosis. Among the predictors of CRT response, eight variables (50%) pertained to right ventricular size or function. Tricuspid annular plane systolic excursion was the main feature associated with prognosis. The selected features were associated with particularly good prediction of both CRT response (area under the curve, 0.81; 95% CI, 0.74-0.87) and outcomes (area under the curve, 0.84; 95% CI, 0.75-0.93). An unsupervised machine learning approach allowed the identification of two phenogroups of patients who differed significantly in clinical variables and parameters of biventricular size and right ventricular function. The two phenogroups had significantly different prognosis (hazard ratio, 4.70; 95% CI, 2.1-10.0; P<.0001; log-rank P<.0001). Machine learning can reliably identify clinical and echocardiographic features associated with CRT response and prognosis. The evaluation of both right ventricular size and functional parameters has pivotal importance for the risk stratification of CRT candidates and should be systematically performed in patients undergoing CRT.

Abstract 14768: Echocardiographic Strain Outcomes of Cardiac Resynchronization Therapy in Patients With Chemotherapy Induced Cardiomyopathy

Introduction: Several chemotherapy agents, especially anthracyclines, are associated with the development of non-ischemic cardiomyopathy. When chemotherapy-induced cardiomyopathy (CHIC) is associated with left bundle branch block (QRS &gt;150 ms) and a left ventricular ejection fraction (LVEF) of 35% or lower, cardiac resynchronization therapy (CRT) is often utilized to improve cardiac function and relieve symptoms. Hypothesis: CRT is associated with improvement in left ventricular strain in patients with CHIC. Methods: The study included 22 patients with CHIC and 44 age- and gender-matched controls with other types of NIC who underwent CRT implantation between 2004 and 2017. LVEF, left ventricular global longitudinal strain (GLS), systolic strain rate (SRS), and early diastolic strain rate (SRE) were assessed at baseline and 6-18 months after CRT. CRT response was defined as LVEF improvement by &gt;5% after CRT. Results: CRT responders had a significant improvement in left ventricular GLS as compared to CRT non-responders in the control group, but not in the CHIC group (Table 1). The mean change in LVEF after CRT was similar between the CHIC and control groups (10 ± 10% versus 11 ± 11%, p= 0.67). The mean change in GLS after CRT was also similar between the two groups (-2.15 ± 4.32 versus -3.57 ± 4.02, p= 0.19). The proportion of patients whose LVEF increased by more than 5% was similar between the two groups (59% in the CHIC group versus 68% in the control group, p= 0.46). The mean changes in LV myocardial systolic and early diastolic strain rates were similar between the CHIC and control groups. Mean SRS decreased by 0.13 ± 0.14 in the CHIC group and by 0.34 ± 1.28 in the control group (p=0.45). Mean SRE increased by 0.06 ± 0.18 in the CHIC group and by 0.07 ± 0.22 in the control group (p=0.86). Conclusions: CRT is associated with improvement in left ventricular strain in patients with CHIC. Prospective studies are needed to further evaluate the echocardiographic strain outcomes of CRT in CHIC.

Exercise rehabilitation in cardiac resynchronization: systematic review and a meta-analysis.

The benefit of exercise training in cardiac resynchronization therapy (CRT) recipients is not well established. We conducted a systematic review and meta-analysis to determine the effect of exercise training on clinical outcomes in CRT recipients.A comprehensive search until 2019 was conducted of MEDLINE, Epub, Embase, CINAHL and Cochrane databases as well as a bibliographic hand search to identify additional studies. We included all studies that compared aerobic exercise interventions in adults treated with CRT devices with adults treated with usual CRT care. These studies evaluated patient clinical characteristics, exercise testing measures, hemodynamic measures, echocardiography parameters, biomarkers and adverse events. Independent reviewers evaluated study eligibility, abstracted data and assessed risk of bias in duplicate. We used random-effect meta-analysis methods to estimate mean differences and odds ratios. Grades of Recommendation, Assessment, Development and Evaluation system were used to quantify absolute effects and quality of evidence. I2 was used to evaluate heterogeneity.We identified seven studies, six randomized control trials and one observational study, totaling 332 CRT patients in the exercise intervention and 534 patients receiving usual care. Peak VO2 was 2.4ml/kg/min higher in the exercise group in comparison with the control group (pooled mean difference 2.26, 95% CI 1.38-3.13, I2=53%, high quality). AT-VO2 improved with exercise rehabilitation, and heterogeneity was considered low (pooled mean difference 3.96, 95% CI 2.68-5.24, I2=0.0%, moderate quality).Peak VO2 and AT-VO2 are increased with aerobic exercise in CRT recipients, demonstrating a significant improvement in functional capacity.

Abstract 15900: Incidence of Mortality and Morbidity in a Cohort of Congenital Complete Heart Block Patients Followed for Over 40 Years

Introduction: Congenital complete heart block (CCHB) is rare, 1:15,000 - 1:20,000 live births. The most important risk factors for mortality and cardiac morbidities in this population are not clear. Our CCHB population with structurally normal hearts is uniquely suited to evaluate natural history, impact of chronic pacing, and associated morbidities. Methods: We performed a retrospective cohort study of all identifiable subjects at the Children’s Hospital of Philadelphia from 1/1/1970-4/3/2018 with a CCHB ICD-9 or 10 code and confirmed CCHB by medical record review. We excluded those with structural congenital heart disease, genetic, or acquired cardiac conditions. The primary outcome was a composite of death, cardiomyopathy (CM), heart failure (HF), echocardiographic systolic dysfunction (SD), or cardiac resynchronization therapy (CRT). We applied univariate analysis using chi-square, ANOVA, and determined relative risk. Results: The cohort includes 114 subjects, 58% female, 68% white, 65% diagnosed in the first year of life, with 1571 person-years of follow-up. Maternal antibody testing was positive in 49 subjects (42%). Sixteen (14%) were paced on first day of life and 88 (77%) had at least one permanent pacemaker implanted. Median age at first implant was 1.9 years (IQR 0.1-7.9) and median paced duration 11.8 years (IQR 5.8-16.2). Of those born before 2000, 92% received a pacemaker; 66% born since 2000 have a pacemaker. Pacemaker lead fracture or dislodgement occurred in 28 (32% of paced subjects, 28 per 1000 pacemaker-years). Twenty-five (22%, 16 per 1000 person-years) reached the composite outcome, 23 with cardiac dysfunction (HF, CM or SD); 5 received CRT. Seven of the 25 subjects died. Pacing on first day of life and male sex had relative risks of 3.6 (95% CI 1.9-6.8) and 2.6 (95% CI 1.3-5.2), respectively, of reaching the primary outcome. Maternal antibody positivity, in utero diagnosis, age at diagnosis, birth decade, and duration of pacing were not associated with a higher risk of the primary outcome. Conclusions: The rate of a composite outcome of death, cardiac dysfunction, or CRT was 16 per 1000 person-years in a cohort of 114 subjects with CCHB. Pacing on first day of life and male sex were associated with a higher risk of the composite outcome.

Outcomes of cardiac resynchronization therapy with or without a defibrillator in patients with nonischemic cardiomyopathy in Korea: a nationwide cohort study

Abstract Background Randomized control trials comparing the effectiveness of cardiac resynchronization therapy devices, with (CRT-D) or without (CRT-P) a defibrillator, are scarce in heart failure patients. Patients with nonischemic dilated cardiomyopathy (NICM) may be at lower risk for ventricular arrhythmias compared with those with ischemic cardiomyopathy. In addition, NICM has been identified as a predictor of positive response to CRT. The aim of this study was to investigate the impact of an additional implantable cardioverter-defibrillator over CRT in Korean patients with NICM. Methods During the period from January 1, 2008 to December 31, 2017, 533 NICM patients (mean age, 65.7±12.2 years, male 53.6%) with newly-implanted CRT-P (n=71) or CRT-D (n=462) who were aged 19 years or older were identified by 50-percents random sampling from the Korean National Health Insurance Service database. Results Compared with patients receiving CRT-P, those receiving CRT-D were younger (65.3±12.3 vs. 68.3±11.6 years, p=0.038), more likely to be male (56.1% vs. 38.0%, p=0.005), and have an admission history of congestive heart failure (93.9% vs. 87.3%, p=0.041). Over the mean follow-up period of 21 months,114 cases in the CRT-D group and 24 cases in the CRT-P group died, with annualized mortality rates of 14.9 and 17.2 per 100 person-years, respectively. Kaplan-Meier estimates of event-free survival showed that there was no difference in mortality between CRT-D and CRT-P groups (p=0.343). In multivariate analysis, factors associated with mortality were chronic kidney disease, atrial fibrillation, and older age. With regard to death or heart failure hospitalization, heart failure death, and non-cardiac death, there were no difference between the two groups. Conclusions Among Asian patients with NICM with indications for CRT, death, death or heart failure hospitalization, heart failure death, and non-cardiac death were not different between CRT-D and CRT-P groups. Funding Acknowledgement Type of funding source: None

First-phase ejection fraction predicts response to cardiac resynchronization therapy and adverse outcomes

Abstract Background Cardiac Resynchronization Therapy (CRT) is an important therapeutic treatment for chronic heart failure. However, even in carefully selected cases up to 40% of patient fail to respond. First-phase ejection fraction (EF1), the ejection fraction up to the time of maximal ventricular contraction, is a novel and more sensitive echocardiographic measure of early systolic function. Purpose We examined the value of EF1, to predict response to CRT and clinical outcomes after CRT. Methods We analysed echocardiograms from 197 patients who underwent CRT between 2009 and 2018 and were followed to determine clinical outcomes. Results Volumetric response rate (reduction in end-systolic volume ≥15%) was 92.3% vs. 12.1%, for those with EF1 in the highest vs. lowest tertiles (p&amp;lt;0.001). A cut-off value of 11.9% for EF1 had &amp;gt;85% sensitivity and specificity for prediction of response to CRT; on multivariate logistic regression analysis incorporating previously defined predictors, EF1 was the strongest predictor of response (OR: 1.563, 95% CI: 1.371–1.782, p&amp;lt;0.001) (table 1). EF1 was also the strongest predictor of a clinical composite score (OR: 1.115, 95% CI: 1.044–1.191, p=0.001). Improvement in EF1 at 6 months after CRT implantation (6.5±5.8% vs 1.8±4.3% in responders vs. non-responders, p&amp;lt;0.001) was the best predictor of heart failure re-hospitalization and death after median follow-up of 29.2 months (HR: 0.819, 95% CI:0.765–0.876, p&amp;lt;0.001). Conclusion EF1 is a promising marker to identify patients likely to respond to CRT and most likely provides a measure of myocardial viability that determines response. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation, Wellcome/EPSRC Centre for Medical Engineering

Outcomes of Cardiac Resynchronization Therapy in Patients with Hypothyroidism and Heart Failure

BackgroundHypothyroidism is known to be associated with adverse clinical outcomes in heart failure. The association between hypothyroidism and cardiac resynchronization therapy outcomes in patients with severe heart failure is not clear.MethodsThe study included 1316 patients who received cardiac resynchronization therapy between 2002 and 2015. Baseline demographics and cardiac resynchronization therapy outcomes, including left ventricular ejection fraction, New York Heart Association class, appropriate implantable cardioverter-defibrillator therapy, and all-cause mortality, were collected from the electronic health record.ResultsOf the study cohort, 350 patients (26.6%) were classified as the hypothyroidism group. The median duration of follow-up was 3.6 years (interquartile range, 1.7–6.2 years). Hypothyroidism was not associated with a higher risk of all-cause mortality in patients receiving CRT for heart failure. The risk of appropriate implantable cardioverter-defibrillator therapy significantly increased in association with increased baseline thyroid-stimulating hormone level in the entire cohort (hazard ratio, 1.23 per 5mIU/L increase; 95% CI, 1.01–1.5; P = 0.04) as well as in the hypothyroid group (hazard ratio, 1.44 per 5mIU/L increase; 95% CI, 1.13–1.84; P = 0.004).ConclusionsCRT improves cardiac function in hypothyroid patients. The ventricular arrhythmic events requiring ICD therapies are associated with baseline TSH level, which might be considered as an important biomarker to stratify the risk of sudden death for patients with heart failure and hypothyroidism.

Association of ECG characteristics with clinical and echocardiographic outcome to CRT in a non-LBBB patient population.

Effectiveness of cardiac resynchronization therapy (CRT) in patients without left bundle branch block (non-LBBB) QRS morphology is limited. Additional selection criteria are needed to identify these patients. Seven hundred ninety consecutive patients with non-LBBB morphology, who received a CRT-device in 3 university centers in the Netherlands, were selected. Pre-implantation 12-lead ECGs were evaluated on morphology, duration, and area of the QRS complex, as well as on PR interval, left ventricular activation time (LVAT), and the presence of fragmented QRS (fQRS). Association of these ECG features with the primary endpoint: a combination of left ventricular assist device (LVAD) implantation, cardiac transplantation and all-cause mortality, and secondary endpoint-echocardiographic reduction of left ventricular end-systolic volume (LVESV)-were evaluated. The primary endpoint occurred more often in non-LBBB patients with with PR interval ≥ 230ms, QRS area < 109μVs, and with fQRS. Multivariable regression analysis showed independent associations of QRS area (HR 2.33 [1.44, 3.77], p = 0.001) and PR interval (HR 2.03 [1.51, 2.74], p < 0.001) only. Mean LVESV reduction was significantly lower in patients with baseline RBBB, QRS duration < 150 ms, PR interval ≥ 230 ms, and in QRS area < 109 μVs. Multivariable regression analyses only showed significant associations between QRS area ≥ 109 μVs (OR 2.00 [1.09, 3.66] p = 0.025) and probability of echocardiographic response to CRT. In the heterogeneous non-LBBB patient population, QRS area and PR prolongation rather than traditional QRS duration and morphology are associated to both clinical and echocardiographic outcomes of CRT.