Which is safer: Cocaine of Heroin?

[Sk2005]

I've been using coke for about three months now. I use every day, but I
don't use that much. In short, I'm kinda tired of worrying about the
health effects. When I read about the dangers of coke use, I see the
words "cardiac arrest", "heart attack", and "stroke", which scares the
hell outta me. When I read about heroin, I see that the main dangers of
snorting the stuff are overdose and withdrawls. It seems that, If you
avoid these dangers (which is definately possible) then it's all good.
With coke there is no "guarantee". So, which drug do you think is safer
and why?"