This is completely bullshit. Who sponsored this article? Viagara? Sounds like an infomercial rather than a news article. It doesn't give a single reason why. Any drug that diverts blood from the heart and brain can't be good for you.
Unless someone considers your penis is actually your heart, it's complete nonsense. It doesn't help blood flow to your heart. It only helps flood flow to the penis. If someone is having problems with their heart, they have bigger problems, and Viagara certainly won't cure them.