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Aims: This study aims to investigate the long-term occurrence of the composite endpoint of heart failure (HF) hospitalization or all-cause death (primary endpoint) in patients randomized to cardiac resynchronization therapy (CRT) using individualized multimodality imaging-guided left ventricular (LV) lead placement compared with a routine fluoroscopic approach. Furthermore, this study aims to evaluate whether inter-lead electrical delay (IED) is associated with improved response rate of this endpoint.Methods and Results: We reviewed follow-up data until November 2020 for all 182 patients included in the ImagingCRT trial for the occurrence of HF hospitalization and all-cause death. During median (inter-quartile range) time to primary endpoint/censuring of 6.7 (3.3-7.9) years, the rate of the primary endpoint was 60% (n = 53) in the imaging group compared with 52% (n = 48) in the control group [hazard ratio (HR) 1.22, 95% confidence interval (CI) 0.83-1.81, P = 0.31]. Neither the risk of HF hospitalization (HR 1.11, 95% CI 0.62-1.99, P = 0.72) nor of all-cause death differed between treatment groups (HR 1.23, 95% CI 0.82-1.85, P = 0.32). The risk of the primary endpoint was significantly reduced among those with IED ≥100 ms when compared with those with IED <100 ms (HR 0.62, 95% CI 0.39-0.98, P = 0.04).Conclusions: In this study, an individualized multimodality imaging-guided strategy targeting LV lead placement towards the latest mechanically activated non-scarred myocardial segment during CRT implantation did not reduce HF hospitalization or all-cause death when compared with routine LV lead placement during long-term follow-up. Targeting the latest electrical activation should be studied as an alternative individualized strategy for optimizing LV lead placement in CRT recipients. [ABSTRACT FROM AUTHOR]

Aims: To test in a double-blinded, randomized trial whether the combination of electrically guided left ventricular (LV) lead placement and post-implant interventricular pacing delay (VVd) optimization results in superior increase in LV ejection fraction (LVEF) in cardiac resynchronization therapy (CRT) recipients.Methods and Results: Stratified according to presence of ischaemic heart disease, 122 patients were randomized 1:1 to LV lead placement targeted towards the latest electrically activated segment identified by systematic mapping of the coronary sinus tributaries during CRT implantation combined with post-implant VVd optimization (intervention group) or imaging-guided LV lead implantation by cardiac computed tomography venography, 82Rubidium myocardial perfusion imaging and speckle tracking echocardiography targeting the LV lead towards the latest mechanically activated non-scarred myocardial segment (control group). Follow-up was 6 months. Primary endpoint was absolute increase in LVEF. Additional outcome measures were changes in New York Heart Association class, 6-minute walk test, and quality of life, LV reverse remodelling, and device related complications. Analysis was intention-to-treat. A larger increase in LVEF was observed in the intervention group (11 ± 10 vs. 7 ± 11%; 95% confidence interval 0.4-7.9%, P = 0.03); when adjusting for pre-specified baseline covariates this difference did not maintain statistical significance (P = 0.09). Clinical response, LV reverse remodelling, and complication rates did not differ between treatment groups.Conclusion: Electrically guided CRT implantation appeared non-inferior to an imaging-guided strategy considering the outcomes of change in LVEF, LV reverse remodelling and clinical response. Larger long-term studies are warranted to investigate the effect of an electrically guided CRT strategy. [ABSTRACT FROM AUTHOR]

Aim: Left ventricular (LV) lead position at the latest mechanically activated non-scarred myocardial LV region confers improved response to cardiac resynchronization therapy (CRT). We conducted a double-blind, randomized controlled trial to evaluate the clinical benefit of multimodality imaging-guided LV lead placement in CRT.Methods and Results: Patients were allocated (1:1) to imaging-guided LV lead placement using cardiac computed tomography (CT) venography, 99m Technetium myocardial perfusion imaging, and speckle-tracking echocardiography radial strain to target the optimal coronary sinus (CS) branch closest to the non-scarred myocardial segment with latest mechanical activation (imaging group, n = 89) or to routine LV lead implantation in a posterolateral region with late electrical activation (control group, n = 93). The primary endpoint was clinical non-response to CRT [≥1 of the following after 6 months: (1) death, (2) heart failure hospitalization, or (3) no improvement in New York Heart Association class and <10% increase in 6-min walk distance]. Secondary outcomes included LV remodelling and the combination of all-cause mortality and hospitalization owing to heart failure during 1.8 ± 0.9 years. Analysis was intention-to-treat. In the imaging group, fewer patients reached the primary endpoint (26% vs. 42%, P = 0.02). More patients in the imaging group had the LV lead placed in the optimal CS branch (83% vs. 65%, P = 0.01). There were no between-group differences in reverse LV remodelling or the combined endpoint of death or hospitalizations for heart failure.Conclusions: Multimodality imaging-guided LV lead placement towards the CS branch closest to latest mechanically activated non-scarred myocardial LV segment reduces the proportion of clinical non-responders to CRT. Larger long-term multicentre studies are needed. [ABSTRACT FROM AUTHOR]

Background: Biventricular (BiV) pacing has been found to improve systolic function and exercise tolerance in patients with severe congestive heart failure and bundle branch block. The mechanisms behind this beneficial effect is still not sufficiently clarified. Aim: To evaluate the regional myocardial perfusion (MP) during BiV pacing and after acute change of the pacing mode to conventional dual chamber (DDD) pacing, and single chamber atrial (AAI) pacing in patients with severe congestive heart failure and prolonged QRS width treated with chronic BiV pacing. Methods and Results: Fourteen patients (age 63±7 years, 13 male) were evaluated 13±7 months after implantation of a triple-chamber biventricular pacemaker. MP was quantified with 13N-labeled ammonia positron emission tomography during BiV pacing, DDD pacing, and AAI pacing. MP was assessed in the anterior, lateral, inferior, and septal regions, and the global mean MP was calculated. Clinical assessment was performed before pacemaker implantation and after at least 3 months of BiV pacing including a 6-min walk test (WT), New York Heart Association (NYHA) class functional score and echocardiography. Global mean MP (BiV: 0.65±0.20 vs. DDD: 0.65±0.21 vs. AAI: 0.65±0.18 ml g−1 min−1) and MP in each of the four regions did not differ between the three pacing modes. The patients improved clinically during BiV pacing; 6 min WT increased (338±59 vs. 415±73 m, P<0.001), NYHA class score improved (class I/II/III/IV: 0/0/11/3 vs. 1/9/2/0, P<0.001), and left ventricular ejection fraction increased (21±5 vs. 29±8%, P=0.004). Conclusion: No differences in regional MP are detectable after chronic BiV pacing when the pacing mode is changed acutely in patients with severe congestive heart failure and bundle branch block. This finding indicates, that the clinical improvement caused by BiV pacing is not associated with any increase in the MP and thereby oxygen demand. [Copyright &y& Elsevier]

Aims: Cardiac resynchronization therapy (CRT) improves symptoms, left ventricular function, and survival in patients with heart failure (HF) and wide QRS. The benefit of adding implantable cardioverter-defibrillator (ICD) backup is debated. We analysed the long-term outcome of patients with HF due to ischaemic cardiomyopathy (ICM) or non-ischaemic cardiomyopathy (NICM) treated with a CRT device with or without defibrillator backup.Methods and Results: In this observational study, consecutive patients with an ejection fraction ≤35% and QRS width ≥120 ms receiving a CRT device at Aarhus University Hospital, Denmark from 2000 to 2010 were included. Baseline characteristics were retrieved from patient files and survival data were obtained from the Danish Civil Registration System. The primary outcome was all-cause mortality. The effect of ICD backup was estimated using Cox proportional hazards model, and the multivariate analyses were adjusted for a priori selected variables. We included 917 HF patients, 427 with NICM, and 490 with ICM. Median follow-up was 4.0 years. Adjusted hazard ratio (aHR) for all-cause mortality was 0.76 [95% confidence interval (95% CI), 0.60-0.97; P = 0.03] in all patients; 0.96 (95% CI, 0.60-1.51; P = 0.85) in patients with NICM, and 0.74 (95% CI, 0.56-0.97; P = 0.03) in patients with ICM. In patients with NICM, ICD backup seemed to be associated with improved survival among non-responders to CRT (P = 0.08), but not among responders (P = 0.61).Conclusion: Adding an ICD backup is associated with better survival in CRT recipients. This effect was evident among patients with ICM, but not in patients with NICM. [ABSTRACT FROM AUTHOR]

ALBERTSEN, A.E.,et al.: Left Ventricular Lead Performance in Cardiac Resynchronization Therapy: Impact of Lead Localization and Complications. Introduction:Cardiac resynchronization therapy (CRT) using left ventricular (LV) pacing from the coronary sinus tributary is increasingly and frequently used in patients with severe congestive heart failure. The present study investigates LV lead performance in different anatomic locations.Methods:The LV pacing site was defined by bi-plane fluoroscopy. In the left anterior oblique view, the coronary sinus is encircling the mitral ring with the tributaries radiating out like the hands of a watch. Using this clockwise method, Group A had an LV pacing site before 3 o'clock and Group B at or after 3 o'clock. In right anterior oblique view, the LV was divided into three segments: basal, mid-ventricular, and apical.Results:LV lead implantation was successful in all of 120 consecutive patients. Mean follow-up was 16.7 months. Implantation time decreased from mean 190 to 80 minutes during the period (P= 0.01). The mean LV lead stimulation threshold increased initially and stabilized afterwards. The threshold measured at last follow-up was higher than at implantation (2.3 vs 2.7μJ, P= 0.04). Useful venograms were obtained in 94 patients. No significant difference in thresholds was observed between Groups A and B. Phrenic nerve stimulation was most commonly seen in Group B (8/70 vs 1/24, P= 0.001).Conclusion:Implantation of an LV lead for CRT is possible in patients with congestive heart failure and associated with an acceptable low complication rate. LV lead implantation is associated with a learning curve. At mid-term follow-up, LV lead performance is stable and unrelated to the LV implantation site.(PACE 2005; 28:483–488) [ABSTRACT FROM AUTHOR]

Objectives: We used tissue velocity imaging (TVI) and three-dimensional echocardiography to evaluate the effect of acute biventricular pacing on left ventricular (LV) performance and volumes in patients with severe heart failure and bundle branch block. Background: Biventricular pacing causes acute hemodynamic improvement in patients with severe heart failure, and QRS duration has been used as a predictor of improved resynchronization. Tissue velocity has the potential of demonstrating the degree of LV resynchronization and three-dimensional echocardiography enables accurate quantitation of LV volumes and function. Methods: TVI and three-dimensional echocardiography were performed during sinus rhythm and biventricular pacing in 25 consecutive patients with severe heart failure. Results: Biventricular pacing significantly improved the extent of contracting myocardium in synchrony by 15.4% and the duration of contraction synchrony by 17% (p < 0.05 for both). Furthermore, end-diastolic and end-systolic volumes decreased by 7 ± 4.5% and 13 ± 6% (p < 0.01) and ejection fraction increased by 22.8 ± 9% (p < 0.01). Baseline duration of QRS and the preejection period as well as the extent of myocardium with asynchronous contraction measured by TVI predicted pacing efficacy. In multivariate analysis, only the extent of myocardium with asynchronous contraction at the LV base predicted biventricular pacing efficacy. Conclusion: Biventricular pacing improves LV systolic performance and reduces LV volumes during short-term treatment. TVI provides important pathophysiological information on the degree of LV resynchronization and may contribute to improved patient selection.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]