Ozone Therapy in Refractory Ischemic Heart Disease.

Inclusion Criteria: * Adults with ischemic heart disease, Functional Class III-IV from the NYHA, with symptoms in spite of maximal conventional medical treatment and no suitable to further percutaneous or surgical procedures. * It should be required clinical diagnosis by the Cardiology Department and confirmation by cardiac catheterization with coronary angiography. * Ejection Fraction \< 40% * Patients who have signed and dated the study 's specific informed consent. * Before enrollment, women of childbearing potential should obtain a negative result in the serum or urine pregnancy test at the screening visit, and accept the use of appropriate contraceptive methods at least from the 14 days prior to the first dose of the study drug. up to 14 days after the last one. Exclusion Criteria: * Age \< 18 or \> 85 years old. * Severe valve disease and/or dynamic left ventricular outflow tract obstruction. * Pregnancy at the time of enrollment. * Limited walking ability due to neurologic or orthopedic impairments of the legs * Those who are incapable to fill in the scales used to measure the quality of life variables * Cerebral vascular accident (CVA or Transient Ischemic Attack (TIA) within the previous 3 months or carotid stenosis \> 80%. * Acute myocardial infarction (AMI), Percutaneous coronary intervention (PCI) or transmyocardial laser revascularization (TMR or PMR) within the previous 3 months. * Hemodynamically or clinically unstable patients. * Severe or limiting pulmonar…