As a result Cospito, who is in poor health after being on a hunger strike since October, will remain under the 41 bis regime in a protected ward of Milan's San Paolo hospital.
His lawyers said he suffered what they called 'transient cardiac arrest' last week.
The court refused to commute Cospito's term to house arrest or permanent custody in hospital.
It is the latest in a series of unsuccessful legal petitions against the 41 bis made by Cospito.
A court in the Sardinian city of Sassari on Monday also rejected a separate appeal for him to be put under house arrest.
The 41 bis is usually reserved for mafia convicts and the 55-year-old wants it to be abolished for all inmates.
ANSA
