Athenahealth Inc. said it expects its 2012 results will largely meet market expectations but 2013 earnings may fall short. The company, which provides electronic record and billing systems to medical industry clients, expects to earn up to $1 per share for the year, on an adjusted basis. It has also agreed to buy the Watertown office campus that serves as its headquarters from Harvard. Company executives said buying the property will allow them to expand in the future.