Effects of Isolated LBBB on Maximal Functional Capacity

Effects of Isolated Left Bundle Branch Block on Maximal Functional Capacity

Left bundle branch block (LBBB) has been commonly associated with adverse cardiovascular (CV) events, but the effect of an isolated LBBB on maximal functional capacity is not well characterized.

The study's main objective is to evaluate the effect of LBBB on maximum functional capacity.

Study Overview

• Status: Recruiting
• Conditions: Left Bundle-Branch Block
• Intervention / Treatment: Diagnostic test: Cardiopulmonary exercise testing; Diagnostic test: Echocardioghaphy

Detailed Description

Left bundle branch block (LBBB) has been commonly associated with adverse cardiovascular (CV) events, but the effect of an isolated LBBB on maximal functional capacity is not well characterized.

The main objective of the study is to evaluate the effect of LBBB on maximum functional capacity (objectively evaluated by the maximum oxygen consumption -VO2max- at peak exercise in a cardiopulmonary stress test -CPET-) in subjects with LBBB without known cardiovascular disease and compare these data with controls without LBBB.

This is a prospective study that will be carried out in a single centre. All patients with a diagnosis of LBBB and without evidence of structural heart disease in imaging tests will be enrolled. For each candidate with LBBB, one control without LBBB and matched for age, sex, body surface area, and daily physical activity will be selected. All included subjects will undergo a CPET and echocardiography. A sample size estimation [alpha: 0.05, power: 80%, and a clinically significant VO2max difference between groups of at least 10%] of 148 subjects (74 subjects with LBBB + 74 controls) would be necessary to test our hypothesis.

• Study Type: Observational
• Enrollment (Estimated): 148

Contacts and Locations

• Study Contact: Name: Marta Peiró, PhD; Phone Number: +0034 961973536; Email: mpeiro@incliva.es

Study Locations

• Spain
  • Valencia, Spain, 46010
    • Recruiting
    • Marta Peiro
    • Contact: M Peiró, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

A total of 74 consecutive adults with a previous diagnosis of isolated left bundle branch block recruited from general practitioner outpatient clinics will be included.

For each candidate with an isolated left bundle branch block, one control without a left bundle branch block and matched for age, sex, body surface area, and daily physical activity will be selected from general practitioner outpatient clinics

Description

Inclusion Criteria:

• Adult >18 years old
• ECG criteria of left bundle branch block (for controls without left bundle branch block )
• Provide informed consent

Exclusion Criteria:

• Inability to perform a maximal baseline exercise test;
• Structural heart disease, valve heart disease or diastolic dysfunction estimated by two-dimensional echocardiography;
• Previous ischemic heart disease, heart failure, myocardiopathy or myocarditis
• Effort angina during cardiopulmonary exercise testing (CPET);
• Any moderate pulmonary disease;
• Anaemia
• Left ventricular ejection fraction < 55%.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Isolated LBBB; Subjects with left bundle branch block in the absence of clinically detectable heart disease	Diagnostic test: Cardiopulmonary exercise testing; Maximal functional capacity will be evaluated using incremental and symptom-limited cardiopulmonary exercise testing (CPET) on a bicycle ergometer, beginning with a workload of 10 W and increasing gradually in a ramp protocol at 10-W increments every 1 minute. We will define maximal functional capacity as when the patient stops pedalling because of symptoms, and the respiratory exchange ratio (RER) is ≥1.1. During exercise, patients were monitored with 12-lead electrocardiogram and blood pressure measurements every 2 minutes. Gas exchange data and cardiopulmonary variables were averages of values taken every 10 seconds. Peak oxygen consumption (PeakVO2) will be defined as the highest value of oxygen consumption during the last 20 seconds of exercise.; Diagnostic test: Echocardioghaphy; Doppler echocardiogram examinations were performed under resting conditions using 2-dimensional echocardiography. Left ventricular end-diastolic volume and left ventricular ejection fraction will be measured according to the European Society of Echocardiography
Matched controls without LBBB; Subjects without left bundle branch block and in the absence of clinically detectable heart disease	Diagnostic test: Cardiopulmonary exercise testing; Maximal functional capacity will be evaluated using incremental and symptom-limited cardiopulmonary exercise testing (CPET) on a bicycle ergometer, beginning with a workload of 10 W and increasing gradually in a ramp protocol at 10-W increments every 1 minute. We will define maximal functional capacity as when the patient stops pedalling because of symptoms, and the respiratory exchange ratio (RER) is ≥1.1. During exercise, patients were monitored with 12-lead electrocardiogram and blood pressure measurements every 2 minutes. Gas exchange data and cardiopulmonary variables were averages of values taken every 10 seconds. Peak oxygen consumption (PeakVO2) will be defined as the highest value of oxygen consumption during the last 20 seconds of exercise.; Diagnostic test: Echocardioghaphy; Doppler echocardiogram examinations were performed under resting conditions using 2-dimensional echocardiography. Left ventricular end-diastolic volume and left ventricular ejection fraction will be measured according to the European Society of Echocardiography

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak oxygen consumption	Peak oxygen consumption at peak exercise of a maximal symptom-limited cardiopulmonary exercise testing. Units peak oxygen consumption : mL/kg/min	Eligible patients will perform only one cardiopulmonary exercise testing on the first visit. Peak oxygen consumption will be evaluated during the procedure and compared to control patients.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Left ventricular end-diastolic volume	Evaluate left ventricular end-diastolic indexed volume by echocardiography at rest. Unit: ml/m2	Eligible patients will perform only one echocardiography on the first visit. Left ventricular end-diastolic volume will be assessed during the procedure and compared to control patients.
Left ventricular ejection fraction	Evaluate left ventricular ejection fraction by echocardiography at rest. Unit: %	Eligible patients will perform only one echocardiography on the first visit. Left ventricular ejection fraction will be assessed during the procedure and compared to control patients.

Collaborators and Investigators

• Sponsor: Fundación para la Investigación del Hospital Clínico de Valencia
• Investigators: Principal Investigator: Patricia Palau, MD, PhD, INCLIVA

Study record dates

Study Major Dates

• Study Start (Actual): December 22, 2022
• Primary Completion (Estimated): January 22, 2024
• Study Completion (Estimated): December 31, 2024

Study Registration Dates

• First Submitted: November 22, 2022
• First Submitted That Met QC Criteria: December 7, 2022
• First Posted (Actual): December 8, 2022

Study Record Updates

• Last Update Posted (Actual): September 8, 2023
• Last Update Submitted That Met QC Criteria: September 5, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: Functional capacity; Cardiac dyssynchrony; Myocardial deformation
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Heart Block; Bundle-Branch Block
• Other Study ID Numbers: 2021/061

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No