Cardiac Rehab and Cerebral Blood Flow Study

NCT05012878 | Completed

• 1 other identifier: 20-010808
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Cardiovascular Diseases

Outcome Measures

Primary Outcomes (1)

• Cerebral blood flow regulation (as cerebrovascular reactivity)

  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.

  Baseline and follow-up at 3-months

Secondary Outcomes (1)

• Cognitive function

  Baseline and follow-up at 3-months

Other Outcomes (5)

• Cerebral blood flow regulation (as neurovascular coupling)

  Baseline and follow-up at 3-months

• Cerebral blood flow regulation (as autoregulation)

  Baseline and follow-up at 3-months

• Cerebral blood flow regulation to exercise

  Baseline and follow-up at 3-months

Study Arms (5)

Cardiac rehabilitation - High intensity interval training (HIIT)

EXPERIMENTAL

Patients attending cardiac rehabilitation randomized to HIIT.

Behavioral: Cardiac rehabilitation - high intensity interval training (HIIT)

Cardiac rehabilitation - Moderate intensity continuous training (MICT)

ACTIVE COMPARATOR

Patients attending cardiac rehabilitation randomized to MICT.

Behavioral: Cardiac rehabilitation - moderate intensity continuous training (MICT)

Cardiac rehabilitation - control

PLACEBO COMPARATOR

The control group (12 week period) will include participants who have declined cardiac rehabilitation.

Behavioral: Cardiac rehabilitation - control

Healthy control group

NO INTERVENTION

Healthy age-matched adults without cardiovascular disease, who will complete baseline assessments only. No intervention period.

Cardiac rehabilitation - observational

OTHER

This observational group will include patients who are completing an exercise-based cardiac rehabilitation program in line with standard care but are not part of the randomized exercise protocol groups (HIIT or MICT). Participants in this group will be combined with HIIT and MICT (as exercise-based cardiac rehabilitation group) for Aims 1b and 2b.

Behavioral: Cardiac rehabilitation - observational

Interventions

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.

Also known as: CR-HIIT

Cardiac rehabilitation - High intensity interval training (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.

Also known as: CR-MICT

Cardiac rehabilitation - Moderate intensity continuous training (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.

Also known as: CR-Control

Cardiac rehabilitation - 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.

Also known as: CR-Observational

Cardiac rehabilitation - observational

Eligibility Criteria

• Age: 40 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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).
• 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

You may not qualify if:

• 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).
• 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

Sponsors & Collaborators

• Mayo Clinic: lead

Study Sites (1)

Mayo Clinic in Rochester

Rochester, Minnesota, 55905, United States

Location

MeSH Terms

Conditions

Cardiovascular Diseases

Study Officials

• Bruce D Johnson, PhD

  Mayo Clinic

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Randomized control trial comparing two cardiac rehabilitation exercise groups: 1) high intensity interval training; and 2) moderate intensity continuous training. There will also be an observational control group who decline participation in cardiac rehabilitation, and an observational cardiac rehabilitation group who participate in cardiac rehabilitation but decline randomization. There is also a healthy control group without cardiovascular disease for baseline comparison only (no intervention).

Study Record Dates

• First Submitted: July 19, 2021
• First Posted: August 19, 2021
• Study Start: September 2, 2021
• Primary Completion: April 23, 2025
• Study Completion: April 23, 2025
• Last Updated: May 29, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)