The SELEQT-HF (SELEnium and CoQ10 NuTrition for Heart Failure) Study Will Evaluate the Effect of Adding Selenium/and coQ10 on Top of Standard HF Therapy in Patients With HF and Will do so Using a Pragmatic, Registry Based Randomized Controlled Trial in the Netherlands.

The goal of this clinical trial is to learn whether taking selenium and coenzyme Q10 (CoQ10) can reduce HF related events and deaths related to cardiovascular disease. Researchers will compare selenium-CoQ10 supplements with a placebo to see if the supplements improve heart health and patient outcomes. Participants will: Receive either selenium-CoQ10 or placebo in addition to their usual heart failure treatment Attend standard clinical visits according to routine clinical care. The study will include 1,100 adults with chronic heart failure. Selenium and CoQ10 are natural nutrients with no known health risks. If effective, this supplement could provide a safe new way to improve outcomes for people with heart failure.