Clinical Trial Summary
Cardiovascular disease is the leading cause of death worldwide. It is becoming clearer that
heart failure (HF) is closely associated with body's metabolism. Even before the heart
becomes weaker, it responds to the stresses by changing the fuels it burns, which results in
a reduction in the heart's metabolic efficiency that worsens the heart's condition. Since the
heart burns so much fuel and consumes fats and carbohydrates along with other available
substrates, any changes in its metabolic efficiency could impact metabolism throughout the
body. Specifically, HF is characterized by limited flexibility in substrate utilization
leading to an overall energetic deficit. Such energetic deficit is associated with
progressive remodeling and alter cardiac hemodynamics. For example, obesity is a widely known
risk factor for cardiovascular disease likely lie in how the heart handles energy (substrate
utilization and energetics). One commonly recommended treatment for cardiovascular disease,
especially coronary artery disease (CAD) or congestive heart failure (CHF), is cardiac
rehabilitation. Cardiac rehabilitation for symptomatic cardiovascular disease has been shown
to promote a healthy lifestyle, improve physical health and reduce cardiovascular death iii
with an apparent dose-dependent response. Participation results in a reduced risk of
hospitalization and revascularization procedures, and improved functional status in
randomized controlled trials. Thus, cardiac rehabilitation is recommended for individuals
with symptomatic CAD or CHF by the American College of Cardiology and American Heart
Association. In addition, exercise training in preclinical animal models mirroring the
exercise component of cardiac rehabilitation routines have shown increased myocardial
regeneration and cardioprotective molecular effects ameliorating adverse myocardial
remodeling. Despite these benefits, there is vast heterogeneity in the efficiency of cardiac
rehabilitation on the individual level with large variances in improved exercise capacity and
cardiac function recovery. Personalization of cardiac rehabilitation necessitates a
non-invasive approach to monitor the direct beneficial effects on the heart and more ideally,
predict efficacy at baseline. Taken together, understanding how metabolic interventions
including bariatric surgery and cardiac rehabilitation change myocardial structure and
function is critical for the prevention, diagnosis and prognosis for patients with
cardiovascular diseases.
Advanced cardiovascular imaging using Magnetic Resonance Imaging (MRI) has proven to be
effective in providing gold standard myocardial tissue characterization. Our team has
developed novel cardiac MRI techniques that leverages endogenous tissue properties to reveal
a milieu of deep tissue phenotypes including myocardial inflammation, fibrosis, metabolism,
and microstructural defects. Among these phenotypes, myocardial microstructure has proven to
be most sensitive to early myocardial tissue damage and is predictive of myocardial
regeneration. In collaboration with cardiologists at Cleveland Clinic, the investigators aim
to study how myocardial microstructure revealed by cardiac MRI changes cardiovascular disease
patient population before and after metabolic interventions.
The primary clinical objective of the clinical study is to (1) determine cardiac
microstructural phenotypes by cardiac MRI in patients before and after cardiac
rehabilitation, or bariatric surgery, and their relationship to cardiac structure/function.
Aim 1: How does the heart's microstructure change before and after cardiac rehabilitation or
bariatric surgery? Is this linked to other prevalent macro structure and functional
abnormalities and how they change after each metabolic intervention (e.g., cardiac mass or
strain)?
Our hypothesis is that characteristic alterations in myocardial microstructure reflected in
non-contrast MRI are prevalent in symptomatic cardiovascular disease before and after the
respective interventions and may help early detection of cardiovascular disease.
The investigators have chosen a prospective longitudinal cohort design to test the hypothesis
that cardiac structure and function change significantly following cardiac rehabilitation or
bariatric surgery.
There are TWO arms of the study:
The study protocol for those undergoing cardiac rehabilitation will involve:
- Consent
- MRI at the beginning of 12 weeks of cardiac rehabilitation at Cleveland Clinic. Subjects
may opt to complete an MRI of the leg in addition to the cardiac MRI. Patients who opt
for both have the option to complete the scans at separate visits.
- Subjects will be scheduled for a 6 week scan if available; however, participation will
be optional
- MRI after 12 weeks of cardiac rehabilitation at the Cardiovascular Disease Prevention
Center at Cleveland Clinic. If subjects opted to complete both a cardiac scan and a leg
scan, the patients have the option to complete these at separate visits.
The study protocol for those who participate in bariatric surgery study:
- Consent
- MRI prior to the bariatric surgery.
- MRI within 12 months of surgery.
Optionally, if the subjects agree, the blood samples will be collected:
• Give blood sample for research purpose only. The blood draw is used to correlate the
clinical blood biomarkers to the cardiac MRI data to help us better understand and validate
the clinical utility of the novel cardiac MRI techniques. The blood draws should
approximately take 20 minutes. The blood draw will take place in the doctor's office or at
Mellen center private preparation by a registered nurse or approved technician. The blood
will be stored at Lerner freezers until needed for analysis and being analyzed for biomarkers
only for this study. It will not be used for future research in the Cleveland Clinic. Only
members of the research team will have access to the samples.
The study protocol for healthy volunteers will involve:
- Consent
- One MRI Scan
