Brezhnev killed by stroke

You all know the story of the last years of the Sovjet union:
Brezhnev becomes very sick, is practically unable to do anything, but still lives for some years, constantly under drugs. He dies, his replacements Andropow and Chernenko too, after that we have Gorbachev, and the rest is history.

But WI Brezhnev was killed by a stroke while he was still able to lead the SU? Who would have followed, and how would history change?

If Andropov had come to power earlier he might have had enough time to save teh USSR. He was as aware of teh need for reform as Gorbachev but wasn't hampered by the latter's idealism.

Of course, if he dies early enough Kosygin's a more likely successor, another reformer, albeit perhaps not quite as potentially radical as Andropov.