I don't disagree that diet is important in reducing heart disease (and a lot of other things besides) but I'd be very cautious before listening to someone who claims he has a "revolutionary" cure.

In the case of Caldwell Esselstyn, a quick Google search took me to my favourite skeptic blog: Science Based Medicine:

https://www.sciencebasedmedicine.org/bill-clintons-diet/

Get about halfway down. I remain skeptical!