NEW YORK--(BUSINESS WIRE)--Fitch Ratings has assigned an 'A+' rating to the approximately $237,875,000 Massachusetts Development Finance Agency, revenue bonds, Lahey Health System Obligated Group Issue, series F (2015). In addition, Fitch has affirmed the 'A+' rating on the following debt issues: --$48,691,000 Massachusetts Health & Educational Facilities Authority (MA) (Lahey Clinic Medical Center Issue) revenue bonds series D; --$115,960,000 Massachusetts Health & Educational Faciliti