It varies from one person to another. If you already have a weaker heart naturally, steroids will can be the trigger. There would have to be serious studies on a large group to determine the effect.
I think it's safe to say that serious users of anabolics will have more heart/liver/kidney problems. But they have a lifestyle surrounding it that also contributes most of the time: rec. drugs (cocaine, meth, pain killers, opiates), high intake of protein is bad for your arteries,extreme dieting is tough on your organs, diuretics, being extremely overweight during offseason,...