Coffee and Caffeine FAQ

If your cardiologist says you need to drink decaf you need to drink decaf. End of story. There is no prep method that will have low or no caffeine in it. Espresso is similar in caffeine content to a cup of coffee but since it is in a smaller amount of liquid you actually feel the results faster.
As for perk pulling out more of the caffeine, that may be true but it's probably a few percent. Caffeine is fairly soluble in water so you will get your caffeine plus or minus a small amount regardless of prep method.