Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . The cardiac , mediastinal , and hilar contours appear unchanged . The heart is mildly enlarged . The chest is mildly hyperinflated . Trace bilateral pleural effusions are suspected , but markedly decreased . There has also been resolution of fissural thickening . The lungs appear clear . Moderate degenerative changes and loss in height among several lower thoracic vertebral bodies appear unchanged . The bones appear demineralized .
    OUTPUT:
    
Stable mediastinal contours . No definite evidence for acute disease . Moderate hiatal hernia .