Magnetic Resonance Technique in the Assessment of Exercise-induced Long- and Short-Term Changes in Cardiac Function and Morphology

Until now it has been assumed that regular endurance training has a positive influence on cardiac function and that the positive effect increases with increasing intensity. However, little is known about the effects of intense endurance stress on the heart. According to current knowledge repeated exposure to strenuous endurance activity may lead to minor but possibly irreversible damage to the heart with resultant scarring of the heart's muscle.

Within this study the investigators attempt to find out by different analytical methods - in particular magnetic resonance imaging (MRI) and ultrasound of the heart - to what extent the heart muscle is affected by long term intense endurance exercise and which changes in cardiac function and morphology can possibly be found. Therefore the investigators compare former national competitive endurance athletes with sedentary controls.

Study Overview

• Status: Completed
• Conditions: Myocardial Infarction; Myocardial Ischemia; Ventricular Remodeling; Myocardial Contraction; Ventricular Hypertrophy
• Intervention / Treatment: Other: repeated long term endurance exercise; Other: Other

Detailed Description

Background

Despite the well documented cardio-protective effects of aerobic exercise of moderate intensity, short- and long-term consequences of strenuous exercise are less clear. There is increasing evidence that maintaining a high cardiac workload over a prolonged duration may result in transient impairment of cardiac function. Recent studies have also reported a transient increase in cardiac biomarkers after prolonged strenuous exercise. While in patients with cardiac disease the presence of cardiac dysfunction and increased cardiac biomarkers generally reflects myocardial damage, the impact of these observations in athletes is ill defined. It is a matter of concern whether in athletes such findings simply reflect a reversible response or whether repetitive events may lead to an accumulative cardiac damage. Traditional echocardiographic methods used to determine potential cardiac changes in morphology or function are investigator-dependent and may be subject to interference by cardiac pre- and afterload. Cardiac magnetic resonance imaging provides an investigator-independent and objective method to quantify cardiac dimensions and function. Delayed contrast enhancement MR imaging is a highly reproducible cardiovascular magnetic resonance imaging technique to directly visualize myocardial edema, necrosis and fibrosis.

Objective

To use cardiac and delayed contrast enhancement magnetic resonance imaging in combination with echocardiographic methods to to assess whether athletes involved in prolonged strenuous exercise over years reveal persistent alterations of cardiac morphology and function.

Methods

Cardiac and delayed contrast enhancement magnetic resonance imaging will be used in combination with echocardiographic methods to investigate whether involvement in prolonged strenuous exercise over years leads to changes in cardiac function and morphology. Therefore we study and compare 15 veteran elite athletes and 15 sedentary controls. The use of cardiac MRI and delayed contrast enhancement magnetic resonance imaging techniques will be paralleled by echocardiographic and tissue Doppler measurements to allow comparative analyses of the two methods.

• Study Type: Observational
• Enrollment (Actual): 30

Contacts and Locations

Study Locations

• Switzerland
  • Bern, Switzerland, CH-3010
    • Dept. of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

• Sampling Method: Non-Probability Sample

Study Population

residents of Switzerland, either with history of national competitive endurance running (cases) or without history of endurance running (controls)

Description

Inclusion Criteria:

• Age 40-65y
• Healthy
• history of national competitive endurance running (cases)
• no history of endurance running (controls)

Exclusion Criteria

• Contraindication for MRI
• History of relevant cardiac disease (including cardiomyopathies)
• coronary heart disease
• coronary abnormalities
• cardiovascular risk factors
• History of any chronic disease
• drug abuse
• Arrhythmias which make adequate echocardiography unfeasible (such as atrial fibrillation or bundle-branch blocks)

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
1; 15 healthy male "veteran" runners (marathon, triathlon, orienteering) aged between 40 and 65 years with a history of competitive running at a national level during a period of at least 5 years, implicating normally a runner career with at least 50km per week over more than 10 years	Other: repeated long term endurance exercise; competitive running at a national level during a period of at least 5 years (i.e. approximately 50km per week over more than 10 years)
2; 15 healthy male volunteers, matched for age and bmi, without a history of competitive physical exercise (i.e. sedentary controls)	Other: Other; No history of endurance sports activity

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
cardiac fibrosis (area in cm^2) on late contrast enhanced MR images	at subject enrollment (cross-sectional design)

Secondary Outcome Measures

Outcome Measure	Time Frame
systolic/diastolic function and contractility measured by echocardiography	at subject enrollment (cross-sectional design)
various parameters of cardiac function and morphology assessed with MRI and echocardiography	at subject enrollment (cross-sectional design)
anthropometric data	at subject enrollment (cross-sectional design)
VO2max	at subject enrollment (cross-sectional design)
resting-ECG	at subject enrollment (cross-sectional design)
stress-ECG	at subject enrollment (cross-sectional design)
blood analyses	at subject enrollment (cross-sectional design)

Collaborators and Investigators

• Sponsor: University Hospital Inselspital, Berne
• Collaborators: Federal Office of Sports, Switzerland
• Investigators: Principal Investigator: Michael Ith, PhD, PhD/MD, Dept. of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern; Principal Investigator: Christoph Stettler, MD, Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Bern

Study record dates

Study Major Dates

• Study Start: January 1, 2011
• Primary Completion (Actual): May 1, 2012
• Study Completion (Actual): July 1, 2012

Study Registration Dates

• First Submitted: February 11, 2011
• First Submitted That Met QC Criteria: February 25, 2011
• First Posted (Estimate): February 28, 2011

Study Record Updates

• Last Update Posted (Estimate): May 15, 2013
• Last Update Submitted That Met QC Criteria: May 14, 2013
• Last Verified: May 1, 2013

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Necrosis; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Pathological Conditions, Anatomical; Myocardial Infarction; Infarction; Myocardial Ischemia; Ischemia; Hypertrophy; Ventricular Remodeling
• Other Study ID Numbers: KEK 005/010 B