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.

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.

Eligibility Criteria:
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)