What Causes Heart Attack In An Alcoholic Addict?

I give drug and alcohol counseling to a client who was a heroin user , who went on the Methadone program. Last weekend he advised me that he had suffered a stroke and was taken to ER and left the ER because he was afraid to stay. I his superiors advised him to return and find out what happened. He told me today it was confirmed he had a stroke. My question is what happens next?