Non-alcoholic beverages and cardiomyopathy

My 45-year old boyfriend was diagnosed three months ago with idiopathic (but perhaps alcoholic) cardiomyopathy.  His cardiologist has recently given him the go-ahead to drink non-alcoholic wine and beer (alcohol content <.5%)  In what quantity/frequency could NA beverage consumption be harmful?  

He takes monopril, toprol xl and coumadin.  He'll have a MUGA in October to test his EF to determine if the treatment is working.  The heart cath revealed no blockages.  

Thanks for your help.

[CCF-M.D.-CRC]

Dear concerned,
I would think that one would need to drink large quantities of these beverages to reach the equilavent of one to two drinks which is what most doctors consider a moderate amount of alcohol intake.  If his doctor has given the OK for small amounts of alcohol then it would probably be OK to have 2 or 3 glasses of a non-alcoholic beverage a day.