Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . Moderate cardiomegaly appears unchanged . The mediastinal and hilar contours appear stable . The pulmonary interstitium is slightly prominent , but this seems to be a background appearance without evidence for superimposed acute process . There is no pleural effusion or pneumothorax . No focal opacity is present . Mild degenerative changes are similar along the mid thoracic spine .
    OUTPUT:
    
No evidence of acute disease .