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

Heart Failure Clinical Trial

— FLOW-LBBB  

Official title:

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05564689
• Other study ID #: N-20220040
• Status: Recruiting
• Start date: September 29, 2022
• Est. completion date: September 30, 2024

Study information

• Verified date: May 2023
• Source: Aalborg University Hospital
• Contact: Ashkan Eftekhari
• Phone: 004528973764
• Email: asef[@]rn.dk
• Is FDA regulated: No
• Study type: Observational

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 60
• Est. completion date: September 30, 2024
• Est. primary completion date: September 30, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Age > 18

• QRS = 150 ms before implantation

• Heart failure because of dilated cardiomypathy

• Sinus rhythm

• Stable medical therapy

• LBBB

• CRT device

Exclusion Criteria:

• eGFR < 30 ml/min

• Severe valvular heart disease

• Permanent atrial fibrillation or atrial flutter

• Prior PCI or CABG

• Prior myocardial infarction

• Heart failure due to ischemic heart disease

• Other type of device (pacemaker, ICD)

• Not able to give informed consent

• Does not understand Danish

Related Conditions & MeSH terms

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

Intervention

Procedure:
• Intracoronary flow and pressure
Measurement of absolute coronary flow and resistance

Locations

Country	Name	City	State
Denmark	Aalborg Universityhospital	Aalborg

Sponsors (1)

Lead Sponsor	Collaborator
Ashkan Eftekhari

Country where clinical trial is conducted

Denmark, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Absolute coronary flow	Measurement of absolute coronary flow with/without CRT-function	During procedure