Indication For Cardiac Resynchronization Therapy Research Articles

Fusion Cardiac Resynchronization Therapy in an LVAD Patient from Two Devices and Crossing Leads

<h3>Introduction</h3> Cardiac implanted electronic devices (CIEDs) have significantly improved the survival and quality of life in heart failure patients. The role of implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy (CRT) in patients with a left ventricular assist device (LVAD) has not been well defined. CIED procedures come at a price of venous access problems, lead malfunctions and pocket complications. This requires creative approaches to tackle CIED related issues in LVAD patients. <h3>Case Report</h3> Here we describe the clinical course of a 67 year old patient with an LVAD as destination therapy. The heart failure etiology was a non-ischemic cardiomyopathy due to sarcoidosis and he was pacing dependent due to a total atrioventricular block. The patient had an ICD due to recurrent monomorphic ventricular tachycardias and a CRT indication due to previous deterioration of (right sided) heart failure in the temporary absence of biventricular pacing. He recently had a pump thrombosis which was treated medically as he was deemed too frail to undergo a pump exchange. The anticoagulation regimen consisted of a vitamin K antagonist (INR 2.5-3.0) and clopidogrel 75mg o.d.. The patient was admitted for a pulse generator exchange due to low battery voltage. We were confronted with impeding right ventricular lead failure and bilateral venous access problems due to chronic subclavian vein occlusions in a patient with 5 transvenous leads, therapeutic anticoagulation and pronounced thoracic collaterals (Fig 1). Several strategies were considered - venous angioplasty, contralateral lead tunneling and epicardial lead implantation. We sought for a creative solution to deliver biventricular fusion pacing with the existing leads from two contralateral pulse generators. This provided the least invasive solution to deliver effective CRT. <h3>Summary</h3> This case illustrates the complexity of CIED related decision making in pacing dependent LVAD patients, particularly those with an ICD and CRT indication.

Use and Outcomes of Dual Chamber or Cardiac Resynchronization Therapy Defibrillators Among Older Patients Requiring Ventricular Pacing in the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry

Frequent right ventricular (RV) pacing can cause and exacerbate heart failure. Cardiac resynchronization therapy (CRT) has been shown to be associated with improved outcomes among patients with reduced left ventricular ejection fraction who need frequent RV pacing, but the patterns of use of CRT vs dual chamber (DC) devices and the associated outcomes among these patients in clinical practice is not known. To assess outcomes, variability in use of device type, and trends in use of device type over time among patients undergoing implantable cardioverter defibrillator (ICD) implantation who were likely to require frequent RV pacing but who did not have a class I indication for CRT. This retrospective cohort study used the National Cardiovascular Data Registry (NCDR) ICD Registry. A total of 3100 Medicare beneficiaries undergoing first-time implantation of CRT defibrillator (CRT-D) or DC-ICD from 2010 to 2016 who had a class I or II guideline ventricular bradycardia pacing indication but not a class I indication for CRT were included. Data were analyzed from August 2018 to October 2019. Implantation of a CRT-D or DC-ICD. All-cause mortality, heart failure hospitalization, and complications were ascertained from Medicare claims data. Multivariable Cox proportional hazards models and Fine-Gray models were used to evaluate 1-year mortality and heart failure hospitalization, respectively. Multivariable logistic regression was used to evaluate 30-day and 90-day complications. All models accounted for clustering. The median odds ratio (MOR) was used to assess variability and represents the odds that a randomly selected patient receiving CRT-D at a hospital with high implant rates would receive CRT-D if they had been treated at a hospital with low CRT-D implant rates. A total of 3100 individuals were included. The mean (SD) age was 76.3 (6.4) years, and 2500 (80.6%) were men. The 1698 patients (54.7%) receiving CRT-D were more likely than those receiving DC-ICD to have third-degree atrioventricular block (828 [48.8%] vs 432 [30.8%]; P < .001), nonischemic cardiomyopathy (508 [29.9%] vs 255 [18.2%]; P < .001), and prior heart failure hospitalizations (703 [41.4%] vs 421 [30.0%]; P < .001). Following adjustment, CRT-D was associated with lower 1-year mortality (hazard ratio [HR], 0.70; 95% CI, 0.57-0.87; P = .001) and heart failure hospitalization (subdistribution HR, 0.77; 95% CI, 0.61-0.97; P = .02) and no difference in complications compared with DC-ICD. Hospital variation in use of CRT was present (MOR, 2.00), and the use of CRT in this cohort was higher over time (654 of 1351 [48.4%] in 2010 vs 362 of 594 [60.9%] in 2016; P < .001). In this cohort study of older patients in contemporary practice undergoing ICD implantation with a bradycardia pacing indication but without a class I indication for CRT, CRT-D was associated with better outcomes compared with DC devices. Variability in use of device type was observed, and the rate of CRT implantation increased over time.

Clinical and prognostic implications of phenomapping in patients with heart failure receiving cardiac resynchronization therapy

Despite having an indication for cardiac resynchronization therapy according to current guidelines, patients with heart failure with reduced ejection fraction who receive cardiac resynchronization therapy do not consistently derive benefit from it. To determine whether unsupervised clustering analysis (phenomapping) can identify distinct phenogroups of patients with differential outcomes among cardiac resynchronization therapy recipients from routine clinical practice. We used unsupervised hierarchical cluster analysis of phenotypic data after data reduction (55 clinical, biological and echocardiographic variables) to define new phenogroups among 328 patients with heart failure with reduced ejection fraction from routine clinical practice enrolled before cardiac resynchronization therapy. Clinical outcomes and cardiac resynchronization therapy response rate were studied according to phenogroups. Although all patients met the recommended criteria for cardiac resynchronization therapy implantation, phenomapping analysis classified study participants into four phenogroups that differed distinctively in clinical, biological, electrocardiographic and echocardiographic characteristics and outcomes. Patients from phenogroups 1 and 2 had the most improved outcome in terms of mortality, associated with cardiac resynchronization therapy response rates of 81% and 78%, respectively. In contrast, patients from phenogroups 3 and 4 had cardiac resynchronization therapy response rates of 39% and 59%, respectively, and the worst outcome, with a considerably increased risk of mortality compared with patients from phenogroup 1 (hazard ratio 3.23, 95% confidence interval 1.9-5.5 and hazard ratio 2.49, 95% confidence interval 1.38-4.50, respectively). Among patients with heart failure with reduced ejection fraction with an indication for cardiac resynchronization therapy from routine clinical practice, phenomapping identifies subgroups of patients with differential clinical, biological and echocardiographic features strongly linked to divergent outcomes and responses to cardiac resynchronization therapy. This approach may help to identify patients who will derive most benefit from cardiac resynchronization therapy in "individualized" clinical practice.

Abstract 15815: Left Atrial Strain Characterizes the Atrio-ventricular Substrate Responsive to Cardiac Resynchronization Therapy in Patients With Intermediate Electrocardiographic Criteria

Introduction: Guidelines favor patient selection by left bundle branch block (LBBB) with QRS width ≥150 ms for cardiac resynchronization therapy (CRT). Predicting CRT response in patients with QRS width 120 to 149 ms or non-LBBB remains difficult. Left ventricular (LV) global longitudinal strain (GLS) and systolic stretch index (SSI) have shown to characterize the ventricular substrate responsive to CRT. However, the potential application of longitudinal left atrial (LA) strain remains unclear. Hypothesis: Baseline LA strain has prognostic value in CRT patients with intermediate ECG criteria. Methods: We studied 195 patients who underwent CRT based on routine indications: ejection fraction ≤35% and QRS width ≥120 ms. GLS was assessed using the 3 standard apical views. Radial SSI was derived from the mid LV short axis view. Peak longitudinal LA strain was derived from the 2 and 4-chamber apical view. The predefined combined clinical endpoint was death, heart transplant or left ventricular assist device over 4 years after CRT. Results: LA strain was feasible in 162 (83%) of the CRT candidates: QRS duration 156 ± 26 ms, 39.5% had LBBB with QRS ≥ 150ms, 60.5% had intermediate ECG criteria. High peak longitudinal strain (&gt;median, 10.1%) was associated with favorable event-free survival (p&lt;0.001). Patients with intermediate ECG criteria for CRT and both high peak longitudinal LA strain and high GLS (&gt;median, 8.4%) had similar outcome to those with Class I indications for CRT. Multivariable analysis revealed that LA strain had independent prognostic value (hazard ratio 0.9 per LA strain %, p &lt; 0.001) even after adjusted for other clinical, electrophysiological and echocardiographic covariates including QRS morphology and duration, GLS and SSI. Conclusions: Peak LA strain had important prognostic value in candidates for CRT. Prognostic value of LA strain was additive to LV strain characteristics and most significant in CRT patients with intermediate ECG criteria for CRT.

Baseline left atrial strain is associated with clinical outcomes following cardiac resynchronization therapy in patients with intermediate electrocardiographic criteria

Abstract Background Guidelines favor patient selection by left bundle branch block (LBBB) with QRS width ≥150 ms for cardiac resynchronization therapy (CRT). However, predicting response to CRT patients with QRS width 120 to 149 ms or non-LBBB remains difficult. Speckle tracking left atrial (LA) strain is a novel means to assess cardiac function, however its applications to CRT patients remains unclear. Purpose To test the hypothesis that baseline LA strain has prognostic value in CRT patients with intermediate ECG criteria. Methods We studied 195 patients with heart failure (HF) who underwent CRT based on routine indications: ejection fraction ≤35% and QRS width ≥120 ms. GLS was assessed using the 3 standard apical views. LA longitudinal strain was based on 12 segments from the 2 and 4-chamber apical view. Peak LA strain, a measure associated with the reservoir function of the LA, was defined as the average of peak longitudinal strain from all segments. The predefined combined clinical endpoint was death, heart transplant or left ventricular assist device (LVAD) over 4 years after CRT. Results LA strain was feasible in 162 (83%) of the candidates for CRT: age 64±11 years, 72% male, QRS duration 156±26 ms, 39.5% had LBBB with QRS ≥150ms, 60.5% had intermediate ECG criteria. Median LA strain was 11.0% [1.3% - 36.8%]. High LA peak strain was associated with more favorable event-free survival and Low LA Peak strain was associated with worse clinical outcome following CRT (FIGURE, p&amp;lt;0.001). Patients with intermediate ECG criteria for CRT (non-LBBB or QRS width 120 to 149 ms) and high peak LA strain had similar outcome to those with Class I indications for CRT (LBBB and QRS≥150 ms). Multivariable analysis revealed that LA strain had independent prognostic value (hazard ratio 0.98 per LA strain %, p&amp;lt;0.01) even after adjusted for other clinical, electrophysiological and echocardiographic covariates including QRS morphology and duration, ischemic cardiomyopathy, LVEF and global longitudinal strain. Conclusions Baseline peak LA strain had important prognostic value in HF patients who are candidates for CRT. Prognostic value of LA strain was most significant in CRT patients with intermediate ECG criteria (QRS 120 to 149ms or non-LBBB) and has promise for clinical applications. LA strain and clinical outcome after CRT Funding Acknowledgement Type of funding source: None

Quality of life response to BAROSTIM Therapy

Abstract Background Patients with heart failure with reduced ejection fraction (HFrEF) have poor quality of life as measured by both physical and emotional dimensions. Purpose Evaluate the quality of life in subjects with and without baroreflex activation therapy (BAT) at six months. Methods In a multicenter randomized trial conducted in subjects with NYHA class II (recently III) or III HFrEF, left ventricular ejection fraction ≤35%, stable optimal guideline directed medical HF therapy (GDMT), no Class 1 indication for cardiac resynchronization therapy (CRT), and NT-proBNP&amp;lt;1600 pg/ml, a total of 264 subjects were randomized to BAROSTIM therapy plus GDMT (BAT group) or GDMT alone (Control group). Quality of life was measured at baseline and six months using the Minnesota Living with HF Questionnaire (MLWHF) and the EuroQol 5-Dimension Long (EQ-5D) tool. From the MLWHF questionnaire, both a physical and an emotional dimension was analyzed using subsets of the 21 questions. From the EQ-5D, the five individual dimensions and the overall health status (0–100, where 100 is best) was analyzed. Results Of the 264 randomized subjects, 120 BAT and 125 Control subjects had 6-month quality of life data. As shown in the table, treatment with BAT resulted in significant improvements in quality of life overall, as well as in the specific dimensions of the quality of life questionnaires, compared to the Control subjects. Conclusion Among subjects with symptomatic HFrEF, treatment with BAT resulted in significant improvement in quality of life at six months. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): CVRx, Inc.

Symptomatic endpoint responder rates to BAROSTIM Therapy

Abstract Background Patients with heart failure with reduced ejection fraction (HFrEF) have varying responses to symptomatic endpoints with device-based HF therapies. Purpose Evaluate the symptomatic response to baroreflex activation therapy (BAT) at six months. Methods In a trial of subjects with NYHA Class II (recently III) or III HFrEF, left ventricular EF≤35%, guideline directed medical HF therapy (GDMT), no indication for cardiac resynchronization therapy, and NT-proBNP&amp;lt;1600 pg/ml, 264 subjects were randomized to BAROSTIM therapy plus GDMT (BAT group) or GDMT alone (Control group). Six-minute hall walk (6MHW), Minnesota Living with HF (QOL) and NYHA Class were analyzed. Clinically relevant responders were defined by 6-month improvement in 6MHW&amp;gt;10%, QOL&amp;gt;5 points or improvement in at least one NYHA class; super responders were defined by 6-month improvement in 6MHW&amp;gt;20%, QOL&amp;gt;10 points or improvement to NYHA class I. Results Both clinically relevant and super responders were significantly higher in BAT versus Control subjects for all symptomatic endpoints. In BAT subjects, 72% had clinically relevant improvements in ≥2 endpoints compared to 29% of Control subjects (p&amp;lt;0.001), and 28% of BAT subjects had super responder improvements in ≥2 endpoints versus 10% of Control subjects (p&amp;lt;0.001). Conclusion Among subjects with symptomatic HFrEF, treatment with BAT resulted in clinically relevant and super responder rates. The BAT clinically relevant and super responder rates are similar to those seen with CRT, in CRT-indicated patients. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): CVRx, Inc.

Left Bundle Branch Area Pacing for Cardiac Resynchronization Therapy: Results From the International LBBAP Collaborative StudyGroup.

The aim of this study was to assess the feasibility and outcomes of left bundle branch area pacing (LBBAP) in patients eligible for cardiac resynchronization therapy (CRT) in an international, multicenter, collaborative study. CRT using biventricular pacing is effective in patients with heart failure and left bundle branch block (LBBB). LBBAP has been reported as an alternative option for CRT. LBBAP was attempted in patients with left ventricular ejection fraction (LVEF)<50% and indications for CRT or pacing. Procedural outcomes, left bundle branch capture, New York Heart Association functional class, heart failure hospitalization, echocardiographic data, and lead complications were recorded. Clinical (no heart failure hospitalization and improvement in New York Heart Association functional class) and echocardiographic responses (≥5% improvement in LVEF) were assessed. LBBAP was attempted in 325 patients, and CRT was successfully achieved in 277 (85%) (mean age 71 ± 12 years, 35% women, ischemic cardiomyopathy in 44%). QRS configuration at baseline was LBBB in 39% and non-LBBB in 46%. Procedure and fluoroscopy duration were 105 ± 54 and 19 ± 15min, respectively. LBBAP threshold and R-wave amplitudes were 0.6 ± 0.3V at 0.5ms and 10.6 ± 6mV at implantation and remained stable during mean follow-up of 6± 5months. LBBAP resulted in significant QRS narrowing from 152 ± 32 to 137 ± 22ms (p<0.01). LVEF improved from33 ± 10% to 44 ± 11% (p<0.01). Clinical and echocardiographic responses were observed in 72% and 73% ofpatients, respectively. Baseline LBBB (odds ratio: 3.96; 95% confidence interval: 1.64 to 9.26; p<0.01) and left ventricular end-diastolic diameter (odds ratio: 0.62; 95% confidence interval: 0.49 to 0.79; p<0.01) were independent predictors of echocardiographic response. LBBAP is feasible and safe and provides an alternative option for CRT. LBBAP provides remarkably low and stable pacing thresholds and was associated with improved clinical and echocardiographic outcomes.

Ventricular arrhythmia risk is associated with myocardial scar but not with response to cardiac resynchronization therapy.

Sudden cardiac death (SCD) risk estimation in patients referred for cardiac resynchronization therapy (CRT) remains a challenge. By CRT-mediated improvement of left ventricular ejection fraction (LVEF), many patients loose indication for primary prevention implantable cardioverter-defibrillator (ICD). Increasing evidence shows the importance of myocardial scar for risk prediction. The aim of this study was to investigate the prognostic impact of myocardial scar depending on the echocardiographic response in patients undergoing CRT. Patients with indication for CRT were prospectively enrolled. Decision about ICD or pacemaker implantation was based on clinical criteria. All patients underwent delayed-enhancement cardiac magnetic resonance imaging. Median follow-up duration was 45 (24-75) months. Primary outcome was a composite of sustained ventricular arrhythmia, appropriate ICD therapy, or SCD. A total of 218 patients with LVEF 25.5 ± 6.6% were analysed [158 (73%) male, 64.9 ± 10.7 years]. Myocardial scar was observed in 73 patients with ischaemic cardiomyopathy (ICM) (95% of ICM patients); in 62 with non-ischaemic cardiomyopathy (45% of these patients); and in all but 1 of 36 (17%) patients who reached the primary outcome. Myocardial scar was the only significant predictor of primary outcome [odds ratio 27.7 (3.8-202.7)], independent of echocardiographic CRT response. A total of 55 (25%) patients died from any cause or received heart transplant. For overall survival, only a combination of the absence of myocardial scar with CRT response was associated with favourable outcome. Malignant arrhythmic events and SCD depend on the presence of myocardial scar but not on CRT response. All-cause mortality improved only with the combined absence of myocardial scar and CRT response.

Minimalistic strategy for coronary sinus lead implant: A single tool capable of electrophysiological mapping, pressure measurement, and angiography.

Left ventricular (LV) lead implantation for cardiac resynchronization therapy (CRT) may be confounded by contrast load during attempted cannulation and lead dislodgement during guiding catheter splitting. An LV lead implant system with a steerable single catheter that completely avoids the use of guiding catheters when needed, acquires atrioventricular electrograms, measures intracardiac pressures, permits CS angiography, and has the ability to direct a coronary angioplasty wire that will lead the final delivery of LV lead into a CS tributary, may help limit contrast use and avoid lead dislodgement at CS guide sheath removal. In this article as a proof of concept, we describe the use of this minimalist technique as a first line approach in six patients who had standard indications for CRT. The LV lead was successfully implanted in a target vein in all patients without acute complications. Contrast was not used in half the group and the LV lead was successfully implanted without guiding catheter in four patients. The implantation technique evolved through the series and in the final patient, no guiding sheath or contrast was used. Postimplant lead positions on chest X-ray and lead parameters were stable in all patients at follow-up. In proof of concept paper, we describe a technique of LV lead implantation potentially without the use of contrast and standard CS guiding catheters. Once familiar, this approach may provide a less complicated strategy.

Cardiac Resynchronization Therapy Guided by Echocardiography, MRI, and CT Imaging: ARandomized Controlled Study.

This study evaluated if selecting the left ventricular (LV) target segment by echocardiography-derived late mechanical activation, with access to multimodality imaging for scar and venous anatomy, could help to increase responder rates to cardiac resynchronization therapy (CRT). LV lead placement is important for clinical outcome, but the optimal strategy for LV lead placement in CRT is still debated. This study conducted a prospective, blinded randomized controlled trial on 102 patients with indication for CRT (27% women, 46% with ischemic cardiomyopathy, 63% in New York Heart Association functional class III, 74% with left bundle branch block, and with mean ejection fraction of 23%). Optimal LV lead location was defined as the latest mechanically activated available segment (free of transmural scar), determined by radial strain echocardiography, cardiac computed tomography, and cardiac magnetic resonance (n=70). The primary endpoint was reduction of LV end-systolic volume by≥15% at 6months post-implantation. Patients were followed for 47 ± 21months. Based on imaging, optimal or adjacent lead placement was feasible in 96% of all cases and was obtained in 83% of the intervention group versus 80% of the control group. Fifty-six percent of the patients were LV end-systolic volume responders compared with the control group (55%) (p=0.96), and 71% improved≥1 New York Heart Association functional class (74% vs. 67%; p=0.43). Death or heart failure hospitalization within 2 years occurred in 6% (2% of the intervention group vs. 10% of the control group; p=0.07). Radial strain-guided LV lead placement, in combination with multimodality imaging, did not result in increased clinical or echocardiographic response, nor in a significant reduction of death or heart failure hospitalization. (Combining Myocardial Strain and Cardiac CT to Optimize Left Ventricular Lead Placement in CRT Treatment [CRT Clinic]; NCT01426321).

Electrocardiographic patterns predictive of left bundle branch block correction with His bundle pacing.

Permanent His bundle pacing (p-HBP) could be an alternative for traditional cardiac resynchronization therapy (CRT), but an important limitation is that p-HBP cannot always correct the left bundle branch block (LBBB). The purpose of this article is to assess electrocardiographic patterns of LBBB that can predict electrocardiographic response (QRS narrowing) to His bundle pacing. We designed a prospective descriptive study of patients with LBBB and CRT indication proposed for CRT by p-HBP. We analyzed the correlation between the different electrocardiographic patterns and the correction of conduction disturbance (LBBB). We included 70 patients. Pacing at the location where His bundle electrogram was recorded narrowed the QRS in 81.4% (n=57). Basically, we identified two electrocardiographic patterns in lead V1: QS or rS. The QS pattern was a sensitivity of 56%, a specificity of 84.6%, and a positive predictive value (PPV) of 94.1% to predict the correction of the LBBB (area under the curve [AUC] = .70). In patients with rS pattern, a ratio between the descending and the ascending S wave component duration ≥0.64 was a very good predictor of the correction of the LBBB (AUC = .968); with a value ≥0.64, the sensitivity, specificity, and PPV was 92%, 100%, and 100%, respectively. In patients with LBBB and CRT indication, the QS pattern in lead V1 predicts the correction of the QRS with HBP. In the case of rS pattern in lead V1, the ratio descending/ascending S wave component duration has a strong correlation with the LBBB correction.

Sequential His bundle and left ventricular pacing for cardiac resynchronization.

Fusion of left ventricular pacing with intrinsic conduction provides superior resynchronization compared to biventricular pacing. His bundle pacing (HBP) preserves intrinsic conduction and allows for constant fusion with left ventricular pacing. This study evaluated sequential His bundle and left ventricular pacing for cardiac resynchronization therapy (CRT). In patients referred for CRT, sequential His bundle and left ventricular pacing was performed when HBP did not correct the QRS. At implant, QRS duration and area were compared between biventricular pacing and His bundle and left ventricular pacing. Devices were programmed for His and left ventricular pacing. Functional status and echocardiography were evaluated in follow up. Twenty-one patients, seven female, 70.7 ± 9.9 years, 57% with nonischemic cardiomyopathy were included. Baseline QRS duration was 170 ± 21 ms and was 157 ± 16 ms with HBP. Biventricular pacing resulted in a QRS duration of 141 ± 15 ms and decreased to 110 ± 14 ms with His bundle and left ventricular pacing (p < .0005). His bundle and left ventricular pacing resulted in a smaller paced QRS area (38.5 ± 22.6 µVs) compared to biventricular pacing (67.5 ± 24.0 µVs) and baseline (78.1 ± 28.1 µVs; p < .0005). Left ventricular ejection fraction increased from 27.6 ± 6.4% to 41.1 ± 12.5 (at 25 mean months, p = .001) and functional class improved from 3.1 ± 0.5 to 2.1 ± 0.8 (at mean 32 months, p < .001). Sequential His bundle and left ventricular pacing results in superior electrical synchrony in patients with indication for CRT when HBP does not correct the QRS and resulted in promising clinical and echocardiographic response rates.

Cardiac Resynchronization Therapy in Patients With Nonischemic Cardiomyopathy Using LeftBundleBranch Pacing.

The aim of this study was to assess the feasibility and efficacy of left bundle branch pacing (LBBP) using a novel intraseptal technique to deliver cardiac resynchronization therapy (CRT) in patients with left bundle branch block (LBBB) and nonischemic cardiomyopathy. His bundle pacing to correct LBBB is a viable alternative approach to achieve CRT but is limited by suboptimal lead delivery and high thresholds. This was a prospective, multicenter study performed between June 2017 and August 2018 at 6 centers. Patients with nonischemic cardiomyopathy, complete LBBB, and left ventricular ejection fractions (LVEFs)≤50% who had indications for CRT and/or ventricular pacing in whom LBBP was attempted were included. Success rates, QRS duration, LVEF, left ventricular end-systolic volume, and improvement in functional class were assessed. LBBP was successful in 61 of 63 patients (97%, mean age 68 ± 11 years, 52.4% men). During LBBP, QRS duration narrowed from 169 ± 16 to 118 ± 12ms (p<0.001). Pacing threshold and R-wave amplitude remained stable at 1-year follow-up compared with implantation values (0.5 ± 0.15 V/0.5ms vs. 0.58 ± 0.14 V/0.5ms and 11.1 ± 4.9mV vs. 13.3 ± 5.3mV, respectively). LVEF increased significantly (33 ± 8% vs. 55 ± 10%; p<0.001), with a reduction in left ventricular end-systolic volume (123 ± 61ml vs. 67 ± 39ml; p<0.001). LVEF had normalized (≥50%) in 75% of patients at 1 year. New York Heart Association functional class improved significantly from 2.8 ± 0.6 at baseline to 1.4±0.6 at 1 year. No deaths or heart failure hospitalizations were observed during follow-up. LBBP is a feasible and effective method for achieving electric resynchronization of LBBB, with resultant improvements in left ventricular structure and function. Low and stable pacing thresholds may be advantageous over His bundle pacing for CRT in patients with LBBB and nonischemic cardiomyopathy.

Baroreflex Activation Therapy in Patients With Heart Failure With Reduced Ejection Fraction

BackgroundThis study demonstrated the safety and effectiveness of baroreflex activation therapy (BAT) in patients with heart failure with reduced ejection fraction (HFrEF). ObjectivesThe BeAT-HF (Baroreflex Activation Therapy for Heart Failure) trial was a multicenter, prospective, randomized, controlled trial; subjects were randomized 1:1 to receive either BAT plus optimal medical management (BAT group) or optimal medical management alone (control group). MethodsFour patient cohorts were created from 408 randomized patients with HFrEF using the following enrollment criteria: current New York Heart Association (NYHA) functional class III or functional class II (patients who had a recent history of NYHA functional class III); ejection fraction ≤35%; stable medical management for ≥4 weeks; and no Class I indication for cardiac resynchronization therapy. Effectiveness endpoints were the change from baseline to 6 months in 6-min hall walk distance (6MHW), Minnesota Living with HF Questionnaire quality-of-life (QOL) score, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. The safety endpoint included the major adverse neurological or cardiovascular system or procedure-related event rate (MANCE). ResultsResults from, timeline and rationale for, cohorts A, B, and C are presented in detail in the text. Cohort D, which represented the intended use population that reflected the U.S. Food and Drug Administration−approved instructions for use (enrollment criteria plus NT-proBNP <1,600 pg/ml), consisted of 245 patients followed-up for 6 months (120 in the BAT group and 125 in the control group). BAT was safe and significantly improved QOL, 6MHW, and NT-proBNP. In the BAT group versus the control group, QOL score decreased (Δ = −14.1; 95% confidence interval [CI]: −19 to −9; p < 0.001), 6MHW distance increased (Δ = 60 m; 95% CI: 40 to 80 m; p < 0.001), NT-proBNP decreased (Δ = −25%; 95% CI: −38% to −9%; p = 0.004), and the MANCE free rate was 97% (95% CI: 93% to 100%; p < 0.001). ConclusionsBAT was safe and significantly improved QOL, exercise capacity, and NT-proBNP. (Baroreflex Activation Therapy for Heart Failure [BeAT-HF]; NCT02627196)

P1487Cardiac resynchronization through His bundle pacing in patients with heart failure

Abstract Introduction and purpose Permanent His bundle pacing (p-HBP) can correct intraventricular conduction disorders and could be a physiological alternative for traditional cardiac resynchronization therapy (CRT) via the coronary sinus: our aim was to describe our results in patients with heart failure and ventricular dysfunction who were resynchronized by p-HBP. Methods Prospective descriptive study of patients with CRT indication and who were resynchronized by p-HBP, using the specific tools. The correction of bundle branch block (BBB) by His bundle pacing (HBP) has been previously checked. We analyzed: the global success of the implant, the His thresholds, and the improvement in left ventricular ejection fraction (LVEF) at one month of follow-up. Results We included 54 patients (median age 66 (56-72)) with an indication for CRT: 89% (n = 48) with heart failure (HF), left bundle block branch (LBBB) and LVEF &amp;lt;35%; 3% (n = 2) with HF, right bundle block branch (RBBB) and LVEF &amp;lt;35%; 2% (n = 1) with permanent pacemaker, ventricular dysfunction and ventricular pacing &amp;gt;40%; and 6 % (n = 3) with complete AV block, LBBB and ventricular dysfunction. With HBP we corrected the BBB in 83% of patients (n = 45), and we achieved cardiac resynchronization through p-HBP in 93% of this patients (n = 42), with a global success (including those in whom HBP did not correct the BBB) of 78% (n = 42). The basal QRS was 160 ms (151-162) and the paced QRS was 132 ms (125-145). The median of His acute threshold was 1.6 volts (0.9-1.9), stable at one month of follow-up, excluding one patient whose His threshold progressively increased to 5.5 volts. There was no dislocation of leads in the follow-up. LVEF improved in all patients: basal 30% (27-35) and at one month follow-up 52% (48-64). Median fluoroscopy times of device implantation including the time taken for temporary HBP were 8.1 minutes (range 6.1-9.9). There were no relevant complications during the implant or follow-up; all patients showed clinical subjective improvement. Conclusions CRT by p-HBP is feasible and safe in a high percentage of patients, with reasonable times of fluoroscopy, acceptable capture thresholds, and an early improvement in LVEF in patients with HF and an indication for CRT.

P320Prevalence of QRS 120 to 150 ms and QRS more than or equal to 150 ms from patients with left ventricular ejection fraction less than or equal to 35% in sinus rhythm and left bundle branch block

Abstract Introduction To date, no study in published literature has investigated the prevalence of patients with QRS ≥120 ms (ESC/EHRA Guidelines) and QRS ≥150 ms (ACC/AHA/HRS Guidelines) from patients with left ventricular ejection fraction (LVEF) ≤35% in sinus rhythm (SR) with left bundle branch block (LBBB) morphology, both said QRS durations were included in the criteria of Class I indication for cardiac resynchronization therapy (CRT) implantation. Purpose To determine the prevalence of patients with QRS 120-150 ms and QRS ≥150 ms from patients with LVEF ≤35% in SR and LBBB, to classify these patients to ischaemic cardiomyopathy (ICM) and nonischaemic cardiomyopathy (NICM), and to determine their demographics in terms of age, sex, and comorbidities Methods This is a cross-sectional study performed from January to September 2016. Data collection was performed which consists of 2-D echocardiogram with LVEF ≤35% in SR and LBBB, from which 2 groups of QRS 120-150 ms and ≥150 ms with their demographic profiles such as age, sex, and comorbidities will be identified and analyzed using percentage or proportion. Results The sample size in the study period was composed of 10,113 patients, of whom 1% (135) had LVEF ≤35% in SR. From 135 patients, 11% (15) had LBBB with QRS ≥120 ms. From 135 patients, 7% (9) had QRS 120-150 ms and also 7% (9) had QRS ≥150 ms. All patients who had QRS 120-150 ms were ICM while those with QRS ≥150 ms, 56% (5) were ICM and 44% (4) were NICM. Among patients with QRS 120-150 ms, youngest age was 50, median age was 67, and oldest age was 84, while among patients with QRS ≥150 ms, youngest age was 50, median age was 66, and oldest age was 82. Among those with QRS 120-150 ms, 67% (6) were males and 33% (3) were females whereas those with QRS ≥150 ms, 78% (7) were males and 22% (2) were females. Both groups of QRS 120-150 ms and ≥150 ms had the same identified comorbidities: coronary artery disease (CAD), hypertension (HTN), diabetes mellitus (DM), dyslipidemia and end stage renal disease (ESRD). Those with QRS 120-150 ms, 67% (6) had both CAD and DM, 56% (5) had HTN, 22% (2) had dyslipidemia and 11% (1) had ESRD, whereas those with QRS ≥150 ms, 78% (7) had CAD, 56% (5) had HTN, 44% (4) had DM, and 11% (1) had both dyslipidemia and ESRD. Conclusions There was both 7% prevalence of patients with QRS 120-150 ms and QRS ≥150 ms from patients with LVEF ≤35% in SR and LBBB. All patients with QRS 120-150 ms were ICM while majority of those with QRS ≥150 ms were ICM. In both groups of QRS duration, youngest age was 50; median age of QRS 120-150 ms was 67 whereas QRS ≥150 ms was 66; and with QRS 120-150 ms, patients who were affected were older (84 years old vs 82 years old). Both QRS 120-150 ms and ≥150 ms were predominantly males with CAD, HTN, and DM as identified important risk factors.

47CRT-D versus CRT-P: are we on the right track?

Abstract Introduction Implantable cardioverter defibrillators (ICD) and cardiac resynchronisation therapy (CRT) have both proven to reduce mortality in patients with heart failure (HF). However, randomised trials comparing CRT-pacemaker (CRT-P) vs CRT-defibrillator (CRT-D) are lacking. Understanding a patient’s primary mode of death is therefore important as this may guide the proper use of CRT systems and avoid risks that are associated with under -or overtreatment with an ICD. Purpose This study aims to analyse the mode of death and the occurrence of life-threatening ventricular arrhythmias (VAs) in patients who received a CRT-P or CRT-D. This may help in the future selection for an appropriate cardiac device in patients with HF. Methods Patients with HF undergoing CRT-P or CRT-D implantation in a tertiary hospital between January 2008 and December 2018 were retrospectively evaluated. CRT indications were in compliance with the ESC guidelines. The decision to implant CRT-D or CRT-P in primary prevention was left at the discretion of the treating physician but was based on ESC clinical guidance. Life threatening VAs (sustained ventricular tachycardia &amp;gt; 30s not requiring therapy or appropriate therapy for VAs) and mode of death were analysed. Results 511 patients were implanted with a CRT (CRT-D/CRT-P; n = 311/200) of which 410 (CRT-D/CRT-P; n= 245/165) were followed in our centre for 63,5 ± 38,1 months. Patients with CRT-P were older (77,6 ± 8,1 vs 66,8 ± 9,5 years; p &amp;lt;0,001), more often female (39,4 vs 26,9%; p 0,006), had more a non-ischaemic cause (61,2 vs 44,9%; p 0,001) and a significant higher comorbidity burden. They also received less treatment with neurohumoral blockers. Baseline LVEF was higher in the CRT-P group (33,1 ± 8,9 vs 28,0 ± 7,6%, p &amp;lt;0,001). 6 months follow-up showed a similar increase in LVEF in the CRT-P vs CRT-D group (+10,3 ± 9,6 vs +11,4 ± 10,8%, p 0,38). Main reasons to choose for CRT-P were RV-pacing induced cardiomyopathy (CMP) (26,1%), multiple comorbidities (18,8%), HF complicated by high degree AV block or AV junction ablation (18,2%), non-ischaemic CMP with suspected good CRT response (10,3%), age (7,3%), other (19,3%). 6/165 patients with CRT-P (3,6%), of which 5 were detected by remoted telemonitoring, vs 51/245 with CRT-D (20,8%) experienced episodes of life-threatening arrhythmias (p &amp;lt;0,001). All-cause mortality was higher in the CRT-P vs CRT-D group (36,4 vs 25,3%, p 0,005). However, the CRT-P group had a predominant non-cardiac mode of death (70,9 vs 43,3%, p &amp;lt;0,001). Death secondary to a tachyarrhythmic event was present in only 1 patient (1,7%) in the CRT-P group. Conclusions Guided by clinical parameters and presence of competitive non-cardiac causes of death, adequate decision between CRT-P or CRT-D implantation can be made. In our cohort, sudden cardiac death in the CRT-P group occurred only once. Remote monitoring is able to identify a subgroup of patients potentially benefiting from an upgrade from CRT-P to CRT-D.

Impact of different selection policies on subcutaneous ICD implants and therapies

Patients with existing or anticipated indications for cardiac resynchronisation therapy (CRT), bradycardia, or anti-tachycardia pacing should not be offered subcutaneous defibrillators (SQIDs) but it remains unclear how clinicians should predict future need for these therapies. We applied three SQID selection policies to data collected retrospectively from transvenous implantable cardioverter defibrillator (TV-ICD) implants: (a) approach A, SQID used in inherited channelopathies and idiopathic ventricular fibrillation only; (b) approach B, as above, plus all hypertrophic cardiomyopathy and grown-up congenital heart disease patients; (c) approach C, as above, plus primary and secondary prevention (for ventricular fibrillation only) of SCD in patients with QRS<150ms. Approach C reflects current ESC and AHA/ACC/HRS guidelines. 338 of 951 patients with TV-ICD were considered for SQID after excluding 613 patients with contraindications. Approaches A, B, and C yielded 45 (4.7%), 89 (9.4%), and 338 (35.5%) patients suitable for SQID, respectively. Use of SQID resulted in more frequent ICD shocks compared to TV-ICD with approach C only (0.43vs 0.23 per 1000 patient-days; P=.03). Rates of CRT upgrade were comparable across selection criteria (0, 0.03, and 0.07 per 1000 patient-days for approaches A, B, and C, respectively; P=NS). Risk of early mortality was higher when more liberal inclusion criteria were used (P=.003). One in three patients receiving ICDs may be suitable for SQID under current ESC and AHA/ACC/HRS guidelines. This proportion is influenced significantly by the selection criteria used, and the criteria used by a physician should be informed by the estimated survival of the patient, risk of shocks for MVT, future pacing, and CRT requirements.

Short-term and intermediate-term performance and safety of left bundle branch pacing.

IntroductionLeft bundle branch pacing (LBBP) is a promising new method for patients with pacing indications. This study aims to evaluate the safety and feasibility of LBBP in a relatively longer time span.Methods and ResultsA total of 164 patients were recruited for LBBP in this study. Among these patients, 148 patients had pacing indications due to symptomatic bradycardia while the other 16 patients had indications for cardiac resynchronization therapy (CRT). LBBP was successful in 89.0% (146/164) of all recruited patients. Intracardiac and surface electrographic parameters and image data were documented during the LBBP procedure. The mean paced QRS duration (pQRSD) and the mean stimulus to left ventricular activation time (stim‐LVAT) was 106.0 ± 12.9 ms and 64.4 ± 13.7 ms respectively. Left bundle branch (LBB) potentials were recorded in 89 patients. Forty‐three of whom had sick sinus syndrome (SSS), and 46 had atrioventricular block (AVB). The presence of LBB potential was more common in patients with SSS (82.7% vs 57.5%, P = .002). No significant differences in pQRSD, stim‐LVAT, or capture threshold were detected between patient groups with or without LBB potential. Patients were followed up at 1 month, 3 months, 6 months, and 1 year after the procedure. Pacing parameters and the echocardiographic data remained stable within a mean follow‐up period of 8.6 ± 4.3 months. No serious complication caused by this procedure was found in this study.ConclusionsSuccessful LBBP carried an aspect of short pQRSD and stim‐LVAT while the LBB potential was not the prerequisite and necessary feature. The LBBP procedure had a high success rate with satisfied and stable lead parameters during short and intermediate‐term observations.