NCT03084679

Characterization of Myocardial Interstitial Fibrosis and Cardiomyocyte Hypertrophy by Cardiac MRI in Heart Failure

Characterization of Myocardial Interstitial Fibrosis and Cardiomyocyte Hypertrophy by Cardiac MRI In Heart Failure: Implication on Early Remodeling and on the Transition to Heart Failure

• Status: Unknown
• Phase: N/A
• Study type: Interventional
• Enrollment: 90 (estimated)
• Sponsor: University of Campinas, Brazil · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The investigators hypothesised that novel MRI metrics derived from myocardium post-gadolinium T1 mapping analysis will improve the current knowledge about the role interstitial fibrosis and cardiomyocyte hypertrophy in the development of left ventricular (LV) remodelling and clinical Heart Failure (HF). The investigators believe that these recently described variables will be associated with prognostically important indices in HF development.

Detailed description

Cardiac hypertrophy is one of the earliest manifestations of myocardial disease, representing a modifiable, prognostic response to hemodynamic stimuli across physiologic (e.g., exercise) and pathologic states (e.g., hypertension, aortic stenosis). The extent of myocardial hypertrophy is determined by a combination of cardiomyocyte size and extracellular volume (ECV) expansion/interstitial fibrosis: while physiologic (exercise-induced) hypertrophy reflects mostly reversible cardiomyocyte hypertrophy, pathologic hypertrophy (e.g., in heart failure) is a combination of both interstitial fibrosis (potentially irreversible) and cardiomyocyte hypertrophy (reversible). Current methods to delineate the potential for LV reverse remodeling (e.g., natriuretic peptides and echocardiographic or clinical markers) detect primarily advanced disease, missing a critical opportunity to intervene and follow patients at an early disease phase where myocardial pathology may be reversible. Therefore, establishing novel, quantitative metrics of myocardial tissue phenotype that define a transition from hypertrophy to fibrosis, and then to irreversible LV remodeling/dysfunction may facilitate targeting therapies at a modifiable stage of disease in HF. The investigator's group has recently extended cardiac T1 mapping MRI techniques to quantify the intracellular lifetime of water (τic) serially as an index of cardiomyocyte diameter, validating this technique histologically in mouse models of pressure overload.

Conditions

• Heart Failure

Interventions

Type	Name	Description
OTHER	Aerobic exercise in treadmill	30-40min of aerobic exercise in treadmill. The aerobic intensity will be established by heart rate levels that corresponded to anaerobic threshold up to 10% below the respiratory compensation point obtained in the cardiopulmonary exercise test. This intensity corresponded to 60-72% peak V̇o2. During the exercise sessions, when a training effect will be observed, as indicated by a decrease by 8 to 10% in heart rate, the treadmill velocity or inclination will be increased to return to the target heart rate levels.
OTHER	Local strengthening exercises	15 min of local strengthening exercises will be performed in major muscle groups (legs, arms and trunk muscles): three series of each exercise, 12-15 repetitions.
OTHER	Stretching exercises	5-min stretching exercises will be performed in major muscle groups (legs, arms and trunk muscles)

Timeline

• Start date: 2017-11-01
• Primary completion: 2019-06-01
• Completion: 2020-07-01
• First posted: 2017-03-21
• Last updated: 2019-06-05

Locations

1 site across 1 country: Brazil