Kevin Smith was stoked about surviving a massive heart attack for at least one good reason ... he was dying -- in a manner of speaking -- to see "Avengers: Infinity War."
We got the famed director leaving the 'Late Show' studio Wednesday in NYC where he went into gnarly detail about what triggered the heart attack he suffered in February. As we reported, Kevin said the doctor told him he had 100% blockage in his "widow-maker" artery.
Check it out ... Kevin said the movie had some tense moments (don't worry, no spoilers here) but didn't kill him, thanks to his clean bill of health. Looking good, Kev!