Coke is in a league of its own for cardiac hazard. Even Diego Maradonna eventually developed heart problems. At the same time E use is fairly standard, as Captain points out, while coke use ranges from the reasonably harmless (one line every other day) to the reckless (multi-shot IV sessions).
If you think in terms of chemistry, MDMA is an amp (that "MA" stands for "methamphetamine", remember). The attachment to that amp of a "M" group facilitates its crossing the blood-brain barrier, ie increases its effect on the CNS (as opposed to just pushing your blood pressure up).
In other words, you could say that in order to get the same high, more meth or amp is needed than MDMA.
It should also be remembered that MDMA is a "hotter" illegal drug than other amphetamine-related compounds. Therefore workers in the field will get kudos for coming up with "MDMA neurological damage" in their papers.
See "Harm Assessment" in Wikipedia:
http://en.wikipedia.org/wiki/MDMA#Harm_assessment
I particularly liked the following: "David Nutt, a former chairman of the UK Advisory Council on the Misuse of Drugs, stated in the Journal of Psychopharmacology in January 2009 that ecstasy use compared favorably with horse riding in terms of risk, with ecstasy leading to around 30 deaths a year in the UK compared to about 10 from horse riding, and "acute harm to person" occurring in approximately 1 in 10,000 episodes of ecstasy use compared to about 1 in 350 episodes of horse riding"