The clinical director of a home nursing agency in Waltham was found guilty for her role in a multimillion-dollar Medicare fraud scheme, the US attorney’s office said in a statement. Janice Troisi, 66, of Revere, was convicted in US District Court on Wednesday of conspiracy to commit health care fraud and 10 counts of health care fraud after she submitted more than $27 million in fraudulent claims to Medicare from the agency At Home VNA, the statement said. Medicare paid $20 million of these fraudulent claims from 2006 to 2012, the statement said. Galatis was sentenced to 92 months in prison in February. Troisi is scheduled to be sentenced in U.S. District Court on Nov. 10.