International Study to Determine if AdreView Heart Function Scan Can be Used to Identify Patients With Mild or Moderate Heart Failure (HF) That Benefit From Implanted Medical Device

Inclusion Criteria

• •Participants \>=18 years of age at the time dated informed consent was obtained.
• •Female participants must be pre-menarchal, surgically sterile (had a documented bilateral oophorectomy and/or documented hysterectomy), postmenopausal (cessation of menses for more than 1 year), non-lactating, or, if of childbearing potential, a serum or urine pregnancy test with the results known prior to AdreView (Iobenguane I-123 Injection) administration) was negative.
• •Participants willing and able to comply with all study procedures and a signed and dated informed consent was obtained before any study-procedure was carried out.
• •Heart failure NYHA class II or III for symptoms, participants with ischemic or non-ischemic heart disease, eligible for ICD implantation as per each site's standard of practice.
• •Non-ischemic dilated cardiomyopathy or ischemic heart disease of at least 3 months duration receiving guideline-directed optimal medical therapy.
• •25%≤LVEF≤35%, performed within 3 months before or at time of enrollment, as measured by radionuclide ventriculography, or electrocardiogram \[ECG\]-gated SPECT myocardial perfusion imaging \[MPI\], or magnetic resonance imaging \[MR\], computed tomography \[CT\], or 3D or 2D echocardiography \[Simpson's or multidisc method only, M-mode echocardiography was not accepted\].
• •In case LVEF measurement was performed within 3 months before enrollment, measurement should be performed at least 40 days after a hospitalization for HF or acute coronary syndrome (including myocardial infarction), and to be valid, method of measurement should be in accordance with the protocol and the imaging exam should be made available to the Sponsor in digital format. In case several valid LVEF measurements are available, the closest to enrollment will be used for inclusion determination.
• •Clinically stable heart failure in the medical judgment of the investigator (i.e. no significant changes in medication, no worsening of symptoms, no unscheduled visits to the doctor's office) for the past 30 days and no hospitalization for heart failure or acute coronary syndrome (including myocardial infarction) in the past 40 days.
• •Reasonable expectation of meaningful survival for at least 1 year.