An interventional study of Resynchronization with conduction system pacing and Cardiac resynchronization therapy with biventricular stimulation in Dilated Cardiomyopathy with Conduction Defect, Left Bundle-Branch Block and Heart Failure, sponsored by University Medical Centre Ljubljana. Completed at 1 site in Slovenia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2024-11-01.
Sponsored by University Medical Centre Ljubljana · Not applicable, Interventional, and Treatment
Cardiac resynchronization therapy (CRT) with biventricular pacing (BiV) is the cornerstone treatment for heart failure patients with ventricular dyssynchrony. Recently, a new concept, conduction system pacing (CSP) with permanent pacing, including His bundle pacing and left bundle branch pacing, has been proposed as a potential alternative to conventional BiV-CRT. The prospective, randomized trial will compare echocardiographic, electrocardiographic, and clinical effects of CSP versus conventional BiV pacing in heart failure patients with reduced ejection fraction (LVEF ≤ 35%), sinus rhythm, and left bundle branch block. Patients will be randomized to either CSP or biventricular pacing study group and followed up for at least 6 months. The study will explore whether CSP is non-inferior to BiV pacing in echocardiographic, electrocardiographic, and clinical outcomes.
Cardiac resynchronization therapy (CRT) with biventricular pacing is an integral part of heart failure therapy in patients with reduced ejection fraction and wide QRS. Previous studies have demonstrated improved quality of life, reduced heart failure hospitalization, and decreased all-cause mortality. However, approx. 30% of patients still do not benefit from this therapy. High pacing thresholds and phrenic nerve stimulation are also common problems with BiV stimulation. Newer CRT systems with improved programmability and algorithms in conjunction with quadripolar left ventricular leads have solved some challenges of BiV pacing. However, BiV stimulation with non-physiological epicardial activation has shown a possible pro-arrhythmic effect which is more pronounced in the non-responder population.
On the other hand, CSP provides synchronous physiological ventricular activation with possible superior electrical and mechanical resynchronization compared to BiV pacing. Electrical activation maps obtained during CSP showed normalization of left bundle branch block with more homogeneous electrical resynchronization than in biventricular pacing. Additionally, BiV CRT effectively corrects mechanical dyssnchrony, demonstrated with homogenization of myocardial work. This has already been proven as the underlying pathophysiological mechanism for successful CRT response. However, the effect of CSP on echocardiographic parameters of mechanical dyssynchrony is not known.
Previous studies of CSP focused on feasibility and its benefits over right ventricular pacing in patients with refractory atrial fibrillation who underwent atrioventricular node ablation and pacemaker implantation. Promising results were followed by the acknowledgment of this physiological mode of pacing by the recent guidelines of European Society of Cardiology. However, studies evaluating the value of CSP as an alternative approach to BiV CRT in heart failure patients are limited. The purpose of this study is to compare the effects of CSP and conventional BiV pacing on electrocardiographic and echocardiographic parameters as well as on clinical outcomes in patients with heart failure with reduced ejection fraction (LVEF ≤35%), sinus rhythm, and left bundle branch block. In this single-center study, 60 patients will be randomized into one of two arms: a BiV pacing arm with BiV CRT implantation based on clinical guidelines or an experimental CSP arm with the implantation of a CSP device. Device with a defibrillator (ICD) will be selected at the discretion of the implanting physician. Baseline and follow up assessments will include clinical evaluation (New York Heart Association class, 6-minute walking distance), evaluation of quality of life (EQ-5D index), laboratory tests (N-terminal pro-B-type natriuretic peptide), electrocardiographic recordings (standard 12-leads ECG and high-resolution-ECG), and echocardiographic evaluation (standard echocardiographic parameters of LV reverse remodeling and non-invasive myocardial work assessment). Intra-operative and procedural parameters will also be recorded.
Investigators hypothesize that CSP could represent a feasible and safe alternative to conventional BiV pacing in terms of clinical, electrocardiographic, and echocardiographic outcomes.
94 studies on the registry are indexed under Bundle-Branch Block; 30 are open to participants now.
This study's enrollment of 62 is close to the median of 60 across 59 interventional studies indexed under Bundle-Branch Block.
Browse Bundle-Branch Block studies →University Medical Centre Ljubljana is the lead sponsor of 296 studies on the registry; 72 are open to participants now.
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The proposed inclusion criteria represent the minimum recommendations for CRT implantation according to the ESC 2021 guidelines. In addition:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Implantation of permanent pacemaker with conduction system pacing (preferably left bundle branch) with or without defibrillator lead placement. Optimal guidelines-based heart failure treatment and antiarrhythmic drugs.
Device: Resynchronization with conduction system pacing
Implantation of cardiac resynchronization therapy with biventricular stimulation with or without defibrillator lead placement. Optimal guidelines-based heart failure treatment and antiarrhythmic drugs.
Device: Cardiac resynchronization therapy with biventricular stimulation
Implantation of permanent pacemaker with conduction system pacing (preferably left bundle branch) with or without defibrillator lead placement
Implantation of cardiac resynchronization therapy with biventricular stimulation with or without defibrillator lead placement
Change in left ventricular volume
Effect on reverse left ventricular remodeling measured as changes in left ventricular volume in both arms
Time frame: acute after the procedure, 1 month, 6 months, 12 months
Change in left ventricular ejection fraction
Effect on reverse left ventricular remodeling measured as changes in left ventricular ejection fraction in both arms
Time frame: acute procedure, 1 month, 6 months, 12 months
Difference in Heart Failure Class
From class 1 to 4
Time frame: 6 months
Difference in pro-BNP value
pg/mL
Time frame: 6 months
Difference in 6-minute walk test distance
meters
Time frame: 6 months
Difference in the EQ-5D index
score
Time frame: 6 months
Difference in myocardial work redistribution
Echo measurement
Time frame: acute after the procedure, 1 month, 6 months, 12 months
Difference in QRS complex width
ms
Time frame: acute after the procedure, 1 month, 6 months, 12 months
Difference in filtered QRS duration on high-resolution electrocardiogram
ms
Time frame: acute after procedure, 1 month, 6 months, 12 months
Difference in sum absolute QRST integral
ms
Time frame: acute after the procedure, 1 month, 6 months, 12 months
Difference in arrhythmia occurrence
Descriptive
Time frame: at least 12 months after enrollment
Rate of procedural complications
Descriptive
Time frame: at least 12 months after enrollment
Tpeak-end duration
ms
Time frame: acute after the procedure, 1 month, 6 months, 12 months
Plan to share: Yes
This study is completed, as verified in Oct 2024. You cannot join it, but the record below documents what was studied.
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