What is a drug used in Congestive Heart Failure (CHF) that has shown
improvement of quality of life but not mortality?

You may be thinking of meloprolol CR/XL. Hjalmarson and colleagues in
the Journal of the American Medical Association volume 283 pages
1295-1302, 2000, showed that this beta blocker reduced all cause
mortality (not just from heart-related problems), hospitalizations for
any reason, and improved quality of life in patients with congestive
heart failure (CHF).  A directed exercise program can have positive
effects as well.

My father and mother both have congestive heart failure and both take
Proventil (Albuterol sulfate). It does not decrease the likliehood
that this chronic disease will ultimently contribute to their deaths
but it does significantly improve their quality of life. Let me know
if this answers your question.

Regards;
tutuzdad-ga