Hillary declined their offer because she feared a leak to the media would prove fatal to her presidential campaign. Instead, she has been secretly visiting the New York-Presbyterian Hospital, where she arrives through a private entrance out of public sight and where she can rely on her doctors not to speak to the media. Sources close to Hillary tell me that her doctors have discovered she suffers from arrhythmia (an abnormal heart beat) and a leaking heart valve. They have recommended that she consider having valve replacement surgery, but Hillary has refused because she does not want to risk the...