Magnetic Resonance Technique in the Assessment of Exercise-induced Long- and Short-Term Changes in Cardiac Function and Morphology
Condition: Myocardial Ischemia; Myocardial Infarction; Ventricular Remodeling; Myocardial Contraction; Ventricular Hypertrophy
MeSH terms: Myocardial Infarction; Myocardial Ischemia; Infarction; Ischemia; Hypertrophy; Ventricular Remodeling
Study type: Observational

Summary: 
      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.
    

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.
    

Intervention name(s): repeated long term endurance exercise; Other
Intervention type(s): Other; Other
Intervention description(s): 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); No history of endurance sports activity
Observational model: Case-Control
Time perspective: Cross-Sectional
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)
      
Biospecimen description: 
      serum, plasma