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Absolute Coronary Flow in Patients With Heart Failure With Reduced Ejection Fraction and Left Bundle Branch Block With Cardiac Resynchronization Therapy

NCT05564689 · Status: RECRUITING · Type: OBSERVATIONAL · Enrollment: 60

Last updated 2025-06-18

No results posted yet for this study

Summary

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.

Conditions

  • Left Bundle-Branch Block
  • Heart Failure
  • Cardiac Resynchronization Therapy
  • Dilated Cardiomyopathy

Interventions

PROCEDURE

Intracoronary flow and pressure

Measurement of absolute coronary flow and resistance

Sponsors & Collaborators

  • Ashkan Eftekhari

    lead OTHER

Principal Investigators

  • Ashkan Eftekhari · Department of Cardiology, Aalborg University Hospital

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2022-09-29
Primary Completion
2026-09-30
Completion
2026-09-30

Countries

  • Denmark

Study Locations

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT05564689 on ClinicalTrials.gov