The Effect of Ozone Treatment on Coronary Flow Reserve in Patients With Heart Failure Having Reduced Ejection Fraction

The goal of this clinical trial is to determine the effect of ozone treatment in heart failurte with reduced ejection fraction. The main questions it aims to answer are: Does ozone treatment have beneficial effects in heart failure patients? What medical problems do heart failure patients have when taking ozone treatment? Researchers will compare ozone treatment in patients with heart failure to ozone treatment in patients with no heart failure (control group) as well as before and after the ozone treatment in patients with heart failure to see if ozone works to treat heart failure. Participants will: Give blood samples Take 6-minute walk test Be perfomed Echocardiography with CFR (Coronary Flow Reserve) Take drug ABC or a placebo every day for 4 months Visit the clinic twice a week for ozone treatment for 2 months Give blood samples (after the ozone treatment) Take 6-minute walk test (after the ozone treatment) Be perfomed Echocardiography with CFR (Coronary Flow Reserve) (after the ozone treatment)