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Completed

NCT Number: NCT05012878

Cardiac Rehab and Cerebral Blood Flow Study

This study is being done to better understand the influence of cardiovascular disease on brain blood flow regulation and cognitive function, determine whether exercise-based cardiac rehabilitation can lead to better regulation of brain blood flow that may help to improve or maintain cognitive function, and determine whether exercise intensity influences changes in brain blood flow regulation and cognitive function.

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Key information

Age range

40 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Mayo Clinic in Rochester

Rochester, Minnesota, 55905, United States

About this study

This study will investigate the influence of exercise training and intensity (as part of cardiac rehabilitation) on improving cerebral blood flow regulation and cognitive function following a cardiac event. This will be a randomized control trial, recruiting adults in mid-life (years 40-65) with coronary artery disease, enrolling in cardiac rehabilitation following a cardiac-related hospital admission. Patients that enroll in the Mayo Clinic cardiac rehabilitation will be randomized 1:1 to high intensity interval training (HIIT) or moderate intensity continuous training (MICT), with stratification for sex and coronary artery bypass graft surgery. Patients that decline enrollment in cardiac rehabilitation will be recruited as an observational control group, which will be matched to the intervention groups by age decade, sex, BMI category, and surgical status. Patients that enroll in cardiac rehabilitation but decline randomization will be recruited as an observational cardiac rehabilitation group. A healthy control group without cardiovascular disease will also be recruited for baseline comparison of outcome measures.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

for Patients with Cardiovascular Disease:

  • Aged 40-years and older.
  • Eligible for cardiac rehabilitation following a cardiac-related hospital admission, coronary artery disease (including angina, myocardial infarction, percutaneous coronary intervention, or coronary artery bypass graft surgery).

Inclusion criteria

for Healthy controls:

  • Aged 40-years and older.
  • Never been diagnosed with cardiovascular disease or coronary artery disease.
  • No history of cardiovascular disease risk factors including hypertension, hyperlipidemia, diabetes, obesity (body mass index > 30) or smoking.
  • Current body mass index < 30kg/m2

Exclusion criteria

for participants in randomized cardiac rehabilitation groups (HIIT & MICT) :

  • Known cerebrovascular or neurological disease
  • Known moderate-severe respiratory disease, pregnancy,
  • Orthopedic limitations affecting exercise capability
  • Unable to read and speak English
  • Unable to complete study-related activities
  • Contraindications to hypercapnia
  • Contraindications to maximal exercise testing
  • MRI incompatible devices
  • Unwillingness to undergo MRI scan (e.g. due to anxiety or claustrophobia).

Exclusion criteria

for participants in the observational control group and observational cardiac rehabilitation group:

  • Known cerebrovascular or neurological disease
  • Known moderate-severe respiratory disease, pregnancy,
  • Unable to read and speak English
  • Unable to complete study-related activities
  • Contraindications to hypercapnia
  • MRI incompatible devices
  • Unwillingness to undergo MRI scan (e.g. due to anxiety or claustrophobia)

Treatment and study plan

Cardiac rehabilitation - high intensity interval training (HIIT)

Behavioral

During cardiac rehabilitation (12-weeks, 3 sessions/week), exercise training will comprise of 4x4-min high intensity aerobic intervals at a rating of perceived exertion 15-17 (hard to very hard), interspersed by a 3-min active recovery at a rating of perceived exertion 11-13 (fairly light to somewhat hard). Warm-up (4-min) and cool-down (3-min) at a light intensity.

Other names: CR-HIIT

Cardiac rehabilitation - moderate intensity continuous training (MICT)

Behavioral

During cardiac rehabilitation (12-weeks, 3 sessions/week), exercise training will comprise of 34-min of continuous aerobic exercise at a rating of perceived exertion 11-13 (fairly light to somewhat hard). Warm-up (3-min) and cool-down (3-min) at a light intensity.

Other names: CR-MICT

Cardiac rehabilitation - control

Behavioral

Participants will receive exercise advice in line with usual hospital discharge procedures. This involves exercise physiologists providing verbal and written information on achieving the national physical activity guidelines (150min/week of moderate intensity exercise) 60 and range of movement exercises for surgical patients with sternotomy. However, no structured or supervised exercise training program or other contact with participants will be provided after hospital discharge, to reflect the usual care process for patients that decline cardiac rehabilitation.

Other names: CR-Control

Cardiac rehabilitation - observational

Behavioral

During cardiac rehabilitation (12-weeks), program frequency and exercise training protocol will align with clinical care decisions and/or patient choice rather than random assignment.

Other names: CR-Observational

Primary outcomes

  1. Cerebral blood flow regulation (as cerebrovascular reactivity)

    Time frame: Baseline and follow-up at 3-months

    Measured as the change in cerebral blood flow during a stepped protocol of increases in inhaled carbon dioxide concentrations. Reactivity will be measured as the regression slope of cerebral blood flow velocity (cm per second) per mmHg increase in end-tidal carbon dioxide.

Secondary outcomes

  1. Cognitive function

    Time frame: Baseline and follow-up at 3-months

    The main domains of cognitive function assessed using a neuropsychometric testing battery will be executive function, processing speed, and memory. Scores from these domains will be combined as the NIH Toolbox Fluid composite score, and assessed for change from baseline to follow-up. Analyses will also be completed for each separate cognitive domain.

Other outcomes

  1. Cerebral blood flow regulation (as neurovascular coupling)

    Time frame: Baseline and follow-up at 3-months

    Measured as the change in cerebral blood flow during a visual stimulus

  2. Cerebral blood flow regulation (as autoregulation)

    Time frame: Baseline and follow-up at 3-months

    Measured as the change in cerebral blood flow from seated position to standing position.

  3. Cerebral blood flow regulation to exercise

    Time frame: Baseline and follow-up at 3-months

    Measured as the regression slope of cerebral blood flow per increase in cardiac output (L) during a staged submaximal exercise test to 75% of maximal heart rate.

  4. Cerebral ventricular and white matter hyperintensity volumes

    Time frame: Baseline and follow-up at 3-months

    Measured using MRPAGE and FLAIR MRI. Expressed as percentage of total intracranial volume

  5. Resting cerebral blood flow with MRI

    Time frame: Baseline and follow-up at 3-months

    Measured using arterial spin labelling MRI. Global cerebral blood flow will be expressed as the average of gray matter perfusion across all atlas regions.

Sponsors and collaborators

Lead sponsor

Mayo Clinic

Other

Registry information

Official study title

Cerebral Blood Flow Regulation and Cognitive Function in Adults With Cardiovascular Disease - Influence of Exercise Training and Intensity

Important dates

Study start
2021
Primary completion
2025
Study completion
2025
First posted
Aug 19, 2021
Registry last updated
May 29, 2025

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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