The Effect of Short-term Bed Rest on Cardiac Function Measured by Cardiac Magnetic Resonance Imaging (MRtime)

October 14, 2024 updated by: Bente Kiens, University of Copenhagen

The primary objective of this study is to investigate the effect of short-term bed rest (4 hours) on heart function, measured by cardiac magnetic resonance (CMR), in healthy participants. This aim will be addressed through a single-arm repeated study, assessing participants during three hours of bedrest.

The hypothesis is that short-term bed rest will decrease cardiac output measured by repeated CMR scans.

This study will also investigate the reproducibility of CMR within a narrow time frame. Limited data are available on these aspects, despite their critical importance for conducting consecutive examinations, both in clinical practice and research trials10-12. The study also aims to investigate the appliances of short-time measures of cardiac function.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The study will be conducted as a single-arm repeated measurement study in healthy participants (n=19). The participants will undergo a three and half-hour experimental day.

Initially, potential participants are invited to an information meeting and after informed consent, a control screening of MR contraindications is fulfilled. Following inclusion, the test day are conducted. The participants will arrive after a 4-hour period with no intake of food and drinks, except 250g of water, and by passive transportation (train, bus, or car). After arrival, a vein catheter is inserted into the antecubital vein. Then, a basal venous blood sample (-15 min) is drawn (4 ml in total) for analysis of plasma catecholamine and acetylcholine, and blood pressure is taken. Thereafter, the first basal CMRs will be performed with ECG monitoring.

During the test day, the participants will undergo five 15 min CMR imaging scans at 0, 30, 60, 120 and 180 mins. The first three are consecutive measurements with short breaks between, therefor the participants will lay in the scanner for the first 75 min and stay in bed in between the two sequential measurements. The participants will be in bedrest throughout the experimental day. Venous blood samples (4 ml) are obtained at 75, 110, and 170 min, where also blood pressure is taken. In total, up to 25 ml blood is obtained during the test day. The duration of the test day is 4.5 hour.

The time requirements for each participant are summarized:

  • Information meeting and screening, approximately 1.5 hour
  • 1 test day of approximately 4.5 hour.

Screening At the screening, height, and body weight will be measured, and a questionnaire on contraindications for CMR will be completed to ensure compliance to the scanner. The daily study leader will ask about previous illnesses, medication intake, alcohol, and smoking habits.

Statistical considerations Measures of myocardial function are highly reproducible when assessed using CMR, and interstudy and cohort coefficients of variation are in the range of 3%-5%10-12. In this study, the primary outcome is change in cardiac output after bed rest compared with the first CMR scanning before bed rest.

In an ongoing study, preliminary observations reveal a decrease of mean±SD -10±9% in CO and -4.1±5.9% in LVEF in both healthy participants and those with heart failure after two hours of bed rest, as evaluated by CMR.

For the upcoming study, the aim is to be able to detect a minimal effect difference of 10% and variation in the CMR data sampling as evident from unpublished observations described above. Sample size calculations were performed, considering a conservative approach with a power of 95% and a significance level of 0.05, utilizing paired Student's t-test for data evaluation. The calculations are as follows:

  • For changes in CO, 11 participants would be sufficient to detect a 10% change.
  • For changes in LVEF, 19 participants would be adequate to detect a 4% change. To account for potential dropouts or failed scans, the plan is to include, up to 29 participants, until 19 completed experimental days have been obtained .

In regard to the analysis plan, a t-test comparing the first (no bedrest) and the last CMR scan (4h bed rest) is the primary endpoint, further a mixed model will be performed to assess the difference in cardiac function throughout the day.

Participants Participants in this study consist of 19 healthy male and female participants.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
19

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Denmark
      • Copenhagen, Denmark, 2100
        • University of Copenhagen

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

Male or female.

  • Age between 18-80 years old.
  • No use of medications with influence on heart function.
  • For ethical reasons, we only include participants who are willing to be informed on new health information, as CMR may reveal relevant secondary health findings.

Exclusion Criteria:

  • Diabetes, kidney, or liver disease.
  • Contraindications to CMR, e.g., abdominal height exceed limitations of the MR-scanner, pacemaker, aortastent, neurostimulator, or other electronic device implanted, implanted metal devices, severe claustrophobia, or physiological diseases.
  • Pregnant, lactating, or planning to become pregnant within the study period.
  • In ongoing cancer treatment.
  • Blood donation during and < 1 month prior to study.
  • Simultaneous participation in other clinical trials potentially affecting the study outcome.
  • Inability, physically or mentally, to comply with the procedure required by the study protocol ad evaluated by the primary investigator, study manager or clinical responsible.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Cardiac magnetic resonance measurements
Healthy participants will undergo a three and half-hour experimental day including repeated measurements of cardiac magnetic resonance and blood sampling.
Other: Bedrest
Investigation of the effect of short-term bed rest (3 hours) on heart function, measured by cardiac magnetic resonance, in healthy participants ( males and females)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
cardiac output
Time Frame: 0-4 hours
Change in cardiac output will be measured assessed by repeated cardiac magnetic resonance measurement after shortterm bed rest compared with before bedrest.
0-4 hours

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Left ventricular ejection fraction
Time Frame: 0-4 hours
Left ventricular ejection fraction willl be measured by cardiac magnetic resonance before and after shortterm bedrest
0-4 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Copenhagen

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Bente Kiens, D.sci, PhD, University of Copenhagen

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 15, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 31, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 4, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 14, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 16, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 16, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 14, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2024

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • MRTIME

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

a decision has not jet been made

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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