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Completed

NCT Number: NCT06113133

Assessment of Maximal Oxygen Uptake in Cardiac Rehabilitation

To advance the methodology for evaluating persons with heart disease and their maximal oxygen uptake, the primary aim of this study is to investigate the occurrence of a plateau in oxygen uptake. This plateau will be examined for the purpose of assessing VO2 max in persons enrolled in exercise-based cardiac rehabilitation. Furthermore, this study aims to investigate the age-related respiratory exchange ratio, and rating of perceived exertion, and describe their association with the presence of a plateau.

Heart disease and characteristics for all participants are obtained. Participants underwent a maximal exercise test on an ergometer cycle with direct measurement of oxygen uptake to assess oxygen plateau attainment. This included measurement of the maximal oxygen uptake, respiratory exchange ratio, heart rate and the ratio of perceived exertion (BORG6-20).

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Key information

Conditions

Oxygen Consumption Cardiovascular Diseases Heart Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Claus Sevel

Aarhus N, 8200, Denmark

About this study

Oxygen uptake is measured breath-by-breath by a cardiopulmonary exercise test (CPET), and oxygen and carbon dioxide sensors were calibrated before each test along with the flow sensor, there was calibrated with a 3-litre syringe.

To examine the primary aim, the incidence of a plateau in oxygen uptake was examined by comparing the moving average of the last 15 consecutive breaths with the penultimate 15 breaths and cut-offs at <50 ml and <100 ml of oxygen.

Secondary criteria; Respiratory exchange ratio (RER max), Rating of perceived exertion (BORG RPE max) and heart rate (HR max) are examined to determine if the participant performs the exercise test with a maximal effort to exertion. The respiratory exchange ratio (VCO2/VO2) using age-depending RER cut-offs; 1.10 for ages 40-59 years, 1.06 for ages 60-69 years and +70 years to determine if a maximal effort is provided. There are no recommendations for RER cut-off when participants are aged above 69 years. Therefore, they must reach the RER cut-off 1.06 to be evaluated as maximal effort.

The rating of perceived exertion using the BORG RPE 6-20 scale evaluation > 17 is considered maximal effort. The test was supervised by experienced physiotherapists, an in-house nurse supported if necessary, and a physician was available upon request. Participants and physiotherapists were blinded for VO2 max results from CPET. CPET gas exchange system was operated by an experienced researcher.

Maximal heart rate is rated as a maximal effort by cut-offs calculated as 208 - (0.7 x age in years) according to age group. Using respectively, > 92% and > 89% of the calculated HR max for the age group 40-59 years and the age groups 60-69 years and +70 years to consider maximal effort.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • participants with heart disease referred to exercise-based cardiac rehabilitation in primary healthcare settings were included

Exclusion criteria

  • heart-related symptoms according to clinical guidelines that prevent participants from performing a maximal exercise test.

Treatment and study plan

measurement of oxygen uptake

Diagnostic Test

oxygen uptake is obtained during a maximal exercise test

Primary outcomes

  1. Maximal oxygen uptake

    Time frame: Pretest is conducted at the first day in rehabilitation. Posttest is conducted when a participant finish rehabilitation or maximal 1 week after the end of the rehabilitation after 12-weeks

    Cardiopulmonary exercise test by Metalyzer 3B to determine maximal oxygen uptake measured in millimetre oxygen

Secondary outcomes

  1. Respiratory exchange ratio

    Time frame: Respiratory exchange ratio is measured during CPET at pretest the first day in rehabilitation. Posttest is conducted the last week of rehabilitation or maximal 1 week after ending the 12-week program.

    Respiratory exchange ratio is according to the production of carbon dioxide divided by oxygen uptake and is expressed numerically for example 1,05. The highest RER value in the last 1 minute of the test is considered the result

  2. Ratio of perceived exertion

    Time frame: The participants rate their perceived exertion immediately after CPET is finished at pretest the first day in rehabilitation. Posttest is conducted the last week of rehabilitation or maximal 1 week after ending the 12-week program.

    Ratio of perceived exertion is assessed using the BORG scale 6-20, where 20 is the highest score

  3. Maximal heart rate

    Time frame: Heart rate is measured during CPET at pretest the first day in rehabilitation. Posttest is conducted the last week of rehabilitation or maximal 1 week after ending the 12-week program.

    Measurement of the heart rate expressed by beats per minute. The highest HR within the last 1 minute of the test is considered the result.

Sponsors and collaborators

Lead sponsor

VIA University College

Other

Registry information

Official study title

Assessment of Maximal Oxygen Uptake in Persons Enrolled in Exercise-based Cardiac Rehabilitation

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Nov 2, 2023
Registry last updated
Nov 2, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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