FILE - In this July 3, 2012 file photo, Andres Manuel Lopez Obrador, presidential candidate for the Democratic Revolution Party (PRD), speaks during a news conference in Mexico City. The two-time Mexican presidential challenger has been hospitalized following a heart problem that required surgery. His spokesman Cesar Yanez said that Lopez Obrador is in good health after being admitted to a Mexico City hospital on Tuesday, Dec. 3, 2013. (AP Photo/Dario Lopez-Mills, File)