The Heart-Brain project is a randomized controlled trial designed to examine the effects of two different exercise programs of 12-week duration: 1) aerobic high intensity interval training (HIIT), and 2) aerobic HIIT plus resistance training, on brain health and other outcomes in coronary heart disease patients.

Patients with coronary heart disease (CHD) has higher risk of developing dementia, cognitive impairment, and mental disorders. There is, therefore, a need to identify effective and sustainable initiatives to avoid or attenuate cognitive and mental health declines in these patients, and in this context, physical exercise can play a major role. The overall objective of the present project is to investigate the effects of exercise on brain health outcomes in CHD patients. The Heart-Brain project is a single-blinded, exercise-based randomized controlled trial. We will run a three-arms trial with a waiting-list control group, and two intervention groups that will receive two different supervised exercise programs: 1) aerobic high intensity interval training (HIIT) and 2) a combination of aerobic HIIT plus resistance training. The study will be conducted in 90 patients with CHD who meet the eligibility criteria indicated below.

Inclusion Criteria:

1. Men and women aged between 50 and 75 years old, both inclusive (*Contingency plan: increase the range to 40-75 if we have difficulties to get the study sample)
2. Must have stable coronary heart disease (phase III), proven by invasive coronary angiography or CT with at least one coronary lesion > 50%.
3. Able to speak and read fluent Spanish.
4. Live in Granada city or surrounding areas (able to come to evaluations and exercise program)
5. Living in community during the study (i.e. independent home, non-assisted living facilities)
6. Ejection fraction ≥ 45%.
7. Functional grade I-II according to the New York Heart Association (NYHA) scale.
8. Sinus rhythm.
9. Stable optimal medical treatment (3 or more drugs at the determined by a cardiologist).
10. Physically inactive, considering: 1) not meeting the WHO recommendations in both the aerobic and strength part, and 2) not to be participating in a planned and structured exercise program at least 3 days per week and for more than 3 months. Both conditions must be met to be included. Note: going for a walk will not be considered an exclusion reason.
11. Classified as cognitively normal according to Stics-m

Exclusion Criteria:

1. Used of assisted walking devices.
2. Acute coronary syndrome in the last year, coronary surgery, or percutaneous intervention in the last 6 months.
3. Treatment for any type of cancer in the last 2 years.
4. Severe hospitalization in the intensive care unit in the last 6 months.
5. Current psychiatric diagnosis (visit to psychiatrist and drug treatment prescription in the last year), including major depression and history of psychiatric illness (schizophrenia, bipolar disorder, hallucinations).
6. Grade III obesity.
7. Diagnosis of neurological or cerebrovascular disorder (e.g. stroke).
8. Medical contraindication for inclusion in an exercise program.
9. Diabetes with uncontrolled glycemia.
10. Resting blood pressure > 180/110.
11. Chest pain with exertion or changes in the ST segment suggestive of severe ischemia during ergometry.
12. Severe inducible ischemia
13. Functional capacity in ergometry (<5 METS).
14. Obstructive left main artery disease (significant disease > 50%)
15. Unstable angina
16. Uncontrolled cardiac arrhythmia
17. Presence of metal implants (e.g., pacemaker or implantable cardioverter-defibrillator-ICD) not compatible with MRI (reported during the phone screening)
18. Paroxysmal or persistent atrial fibrillation with episodes in the last 6 months.
19. Moderate to severe pulmonary hypertension.
20. Acute endocarditis, myocarditis, or pericarditis.
21. Moderate to severe valve disease (grade 3-4)
22. Acute pulmonary embolism, or deep vein thrombosis.
23. Aortic dissection
24. High-grade heart block or complete left bundle branch block or altered basal electrocardiogram with difficulties to interpret in exercise testing.
25. Hypertrophic obstructive cardiomyopathy.
26. Retinopathy.
27. Severe autonomic or peripheral neuropathy.
28. Acute systemic illness or fever.
29. Acute or chronic renal failure (estimated glomerular filtration rate < 30 mL/min)
30. Pulmonary fibrosis or interstitial disease (respiratory failure or severe COPD confirmed by pneumological study).
31. Recent treatment for alcohol or substance abuse.
32. Claustrophobia.
33. Any surgery or medical intervention planned during the study period.
34. Plans to participate or current participation in other studies that might interferes with this study.
35. Current pregnancy or intention to get pregnant during the study period

The protocol, statistical analyses plan and data management plan will be share open access. Data files including IPD, and corresponding data dictionaries, will be shared under restricted access and upon reasonable request (contact FB Ortega) due to privacy issue and GDPR regulations. In principle, all collected IPD will be available for sharing under the "as open as possible, as closed as necessary" principle. The shared data files will be pseudonymized, only include participants who provided informed consent for sharing, and sharing is only possible when the data is used for research purposes regarding exercise, and cardiovascular and brain health. This is stated at the informed consent files that the participants signed when they agree to participate

The IPD data will be available 12 months after the primary outcome paper published. The data will be available 15 years after data collection.

The specific process of data access will be determined in a later stage, but in general the research team supports data sharing. Roughly, data will be available upon reasonable request to the PI (FB Ortega). The data requests must contain the purpose and aim of the research, but also specification of the data requested, and data analysis before data sharing. Data will only be shared for research purposes on exercise, cardiovascular and brain health. In addition, we will follow "as open as possible, as closed as necessary" principle, so depending on this principle we will decide whether the data could be shared. A data access committee will be installed to approve data requests.