Does the apple watch actually save lives?

I have seen post on Reddit, videos, and ads from apple themselves that the Apple watch saves people's lives. I'm writing this to see if this isn't he case. I plan on switching to the iPhone mostly because of the Apple watch. I am overweight (286lb), I've been struggling to lose weight in two years and I have had issues with my chest for two years, but it was mostly due to GERD. I want an apple watch to monitor my heart more accurately. I don't have any underlying heart issues, but I have been having a growing anxiety of having a heart attack. I know the apple watch can't predict a heart attack, but looking at the info I've seen it can at least detect irregular rhythms in the heart.