Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Stable , severe cardiomegaly with unchanged enlargement of the left atrial appendage . Hardware projecting over the left heart is unchanged and likely reflects prior mitral valve repair . Mediastinal and hilar contours are normal . Interval improvement in right basilar atelectasis . New , slight blunting of the right costophrenic angle likely reflects a small pleural effusion . No appreciable pneumothorax or pneumonia .
    OUTPUT:
    
New , small right pleural effusion .