Clinical trial NCT06113133: Assessment of Maximal Oxygen Uptake in Cardiac Rehabilitation
Official title: Assessment of Maximal Oxygen Uptake in Persons Enrolled in Exercise-based Cardiac Rehabilitation
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Oxygen Consumption
Keywords: Physical fitness
heart disease
oxygen consumption
Lead sponsor: VIA University College
Sponsor class: OTHER
First posted: 2023-11-02
Enrollment: 97
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: OTHER
Sampling method: PROBABILITY_SAMPLE
Study population: Participants are adults with heart diseases such as ischemia, heart failure and after heart valve surgery

Brief summary: 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).

Detailed description: 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.

Eligibility criteria: 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.

Primary outcomes:
measure: Maximal oxygen uptake
timeFrame: 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
Secondary outcomes:
measure: Respiratory exchange ratio
timeFrame: 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.
measure: Ratio of perceived exertion
timeFrame: 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.
measure: Maximal heart rate
timeFrame: 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.
Other outcomes:
Locations:
city: Aarhus N
country: Denmark
facility: Claus Sevel
Study officials:
affiliation: University of Aarhus
name: Maribo, Professor
role: STUDY_CHAIR
References: