Is It Safe To Take Bisoprolol Fumarate With Viagra?

I am 50 years old and while at work about 6 weeks ago I experience a mild heart attack that was fixed by placing two stints in my heart. Before that I was on two medication for high blood pressure and was taking viagra to help me with my ED. During my reanalysis of the new medication I was going to have to take because of my attack I asked if I could continue taking the viagra along with the new medication which included bisoprolol fumarate (beta blocker). I was told by the PA to be careful if I took both because it could cause a drop in my blood pressure. I decided not to use the viagra then and have changed my mind. Is it safe to use the viagra or not and if not what can i take for my ED.