The following information was taken from the Bavarian Broadcasting Classic Website:
"Last week, Marcello Viotti, the former Chief Conductor of the Münchner Rundfunkorchester suffered a stroke. The 50-year old conductor had to undergo an operation for a blood clot in his carotid artery. Following this surgical intervention, his condition rapidly deteriorated to the point where there is serious doubt if his life can still be saved."
I will try to update Maestro Viotti's condition as information becomes available.