There was definitely deaths occurring due to EPO around 1990. As I remember the newspaper headlines, more than one young Dutch cyclist died at that time (was it even three? - the Dutch forum writers will know). One of them rode for TVM, as I remember it. And a bunch of Swedish XC runners died too, within few months. The EPO death would be to die in your sleep - the cardiac output is low at night, and the blood clots, obstructing the circulation in the lungs or heart. I have heard rumours of professional cyclists back then that would get up (alarm clock) at intervals during every night to exercise using the jumping rope in order to avoid clots. And of cyclists carrying Streptase (powerful clotbusting drug with potentially lethal/debilitating side effects) to use in case of a severe clot.