LONDON (Reuters) - AstraZeneca Plc faces a significant risk of losing U.S. patent protection on its top-selling heart drug Toprol XL, in a move that would hit near-term earnings, Deutsche Bank analysts said on Monday. Deutsche, which acts as broker to the company and rates the stock a "buy," estimates there is around a 40 percent chance AstraZeneca will lose a ruling on the drug, negating the need for a trial on February 13.
