On Tuesday night’s edition of the Late Show with David Letterman, Emmy-winning Entourage star Jeremy Piven opened about his controversial exit from the Broadway play Speed the Plow last year.

Last week, an arbitrator ruled in Piven’s favor after he was sued by the producers of the David Mamet play after he left the production citing mercury poisoning from eating too much sushi. Jeremy insists he had to leave Plow after doctors warned him that he’d have a heart attack if he continued on Broadway in his condition.