SELECT IT.ITEM_CODE AS CODE,
CASE WHEN IT.ITEM_NAME<>IH.ITEM_NAME THEN IT.ITEM_NAME
    WHEN IH.ITEM_NAME IS NULL THEN IT.ITEM_NAME
    ELSE NULL 
    END AS NAME
FROM ITEM AS IT
LEFT OUTER JOIN  ITEM_HISTORY AS IH
ON IT.ITEM_CODE = IH.ITEM_CODE

ORDER BY IT.ITEM_CODE DESC;