Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . There is a prosthetic cardiac valve , likely an aortic valve replacement . Midline sternotomy wires and mediastinal clips are noted . The heart is within normal limits of size . No signs of pneumonia or CHF . No pleural effusion or pneumothorax . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
No acute findings in the chest . Aortic valve replacement surgery noted .