An observational study in Left Bundle-Branch Block, Heart Failure and Cardiac Resynchronization Therapy, sponsored by Ashkan Eftekhari. Recruiting at 1 site in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-06-18.
Sponsored by Ashkan Eftekhari · Observational
Cardiac resynchronization therapy (CRT) is an effective therapeutic strategy in patients with symptomatic heart failure (HF) patients with LVEF of ≤35% and left bundle branch block (LBBB). However, approximately one-third of CRT-recipients do not improve after therapy (non-responders), despite meeting the required criteria.
Previous studies have documented that the positive respons to CRT is related to the delayed electrical activation of the left ventricle in patients with LBBB. It has also been illustrated that non-ischemic CRT-candidates with LBBB demonstrate lower regional myocardial blood flow and metabolism in the septum. Additionally, it has been suggested that LBBB can lead to impaired coronary blood flow in the left anterior descending artery (LAD). This observation is based on an echocardiography-based study, that showed that the percentage of diastolic flow duration (%DD) in LAD was shorter in patients with LBBB compared to the control-group and patients with right-ventricular pacing.
It has been demonstrated that CRT has positive effects on septal myocardial perfusion in patients with HF and LBBB. The dominant hypothesis explaining this phenomenon is built on improved septal myocardial work after CRT-implantation, which leads to increased myocardial energy and therefore increased myocardial perfusion. In contrast, it has been suggested that due to re-established synchronous left ventricular electrical activation, CRT reduces the septal intramyocardial pressure in early diastole, leading to a relatively longer antegrade flow duration in LAD. Therefore, the aim of the study is to evaluate the effect of CRT on coronary blood flow in LAD in patients with non-ischemic HF and LBBB.
The investigators hypothesize that increased LV-function after CRT not only is due to resynchronized LV ejection and filling, but also improved coronary flow.
The study aims to enroll 60 patients with heart failure due to non-ischemic dilated cardiomyopathy, LBBB, with or without CRT. All patients meeting the criteria will be recruited from the outpatient clinic at the Department of Cardiology, Aalborg University Hospital.
Invasive flow measurements in the LAD, including fractional flow reserve (FFR), absolute coronary flow and -reserve will be conducted with the CRT on and off, respectively.
94 studies on the registry are indexed under Bundle-Branch Block; 30 are open to participants now.
This study's planned enrollment of 60 is below the median of 162 across 33 observational studies indexed under Bundle-Branch Block.
Browse Bundle-Branch Block studies →This is the only study on the registry with Ashkan Eftekhari as lead sponsor.
Counted across the registry records on this site, refreshed daily.
The study will include patients with heart failure due to non ischemic dilated cardiomyopathy and LBBB, with or without excisting CRT.
Eligible patients who are admitted to the Department of Cardiology or at a visit to the outpatient clinic at the Dept. Cardiology Aalborg University Hospital will be enrolled in the study.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
Procedure: Intracoronary flow and pressure
Measurement of absolute coronary flow and resistance
Absolute coronary flow
Measurement of absolute coronary flow with/without CRT-function
Time frame: During procedure
Plan to share: Undecided
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.