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:

- Patients ≥18 years of age at the time dated informed consent is obtained.

- Female patients 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) is negative.

- Patients willing and able to comply with all study procedures and a signed and dated
informed consent is obtained before any study-procedure is carried out.

- Heart failure NYHA class II or III for symptoms, patients 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 enrolment, 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 is not accepted].

In case LVEF measurement is performed within 3 months before enrolment, measurement should
be performed at least 40 days after a hospitalisation 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
enrolment 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 hospitalisation 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.

Exclusion Criteria:

- Patients with existing ICD or patient having an indication of ICD implantation for
secondary prevention of sudden cardiac death.

- Hospitalisation for HF or for acute coronary syndrome in the previous 40 days.

- Patients where a cardiac resynchronisation therapy (CRT) is planned or indicated.

- Other indication for placement of device (sustained ventricular tachycardia,
resuscitated sudden death, need for atrioventricular pacing).

- NYHA class I or class IV symptoms at the time of study entry.

- Patient with chronic renal insufficiency defined as serum creatinine ≥ 3 mg/dl (or ≥
265.2 µmol/L).

- American College of College-American Heart Association (ACC-AHA) class III or class IV
(unstable) angina.

- Known or suspected hypersensitivity/allergy to Iobenguane or to any of the excipients
an Adreview (Iobenguane I-131 injection).

- Patient who is pregnant or plans to become pregnant within 2 weeks after AdreView
(Iobenguane I-123 Injection) administration.

- Patient who has used any medication in the 2 weeks before AdreView (Iobenguane I-123
Injection) that could interfere with the test: e.g. but not limited to amitriptyline
or derivatives, imipramine or derivatives, other antidepressants or drugs known or
suspected to inhibit the norepinephrine transporter, antihypertensives that deplete
norepinephrine stores or inhibit reuptake, sympathomimetic amines or cocaine.

- Patients that have a medical condition that could interfere with the AdreView test
(e.g. but not limited to left ventricular assist device (LVAD), or prior heart
transplant).

- Patients who participated in a clinical study involving a drug or device within 30
days prior to study entry and patients participating in any other clinical study.

- Patients having serious non-cardiac medical condition associated with significant
elevation of plasma catecholamines, including pheochromocytoma.

- Patients with a clinical diagnosis of (or being treated for) Parkinson's disease or
Multiple System Atrophy.

- The patient has participated in a research study using ionizing radiation in the
previous 12 months.

- Patients previously randomized in this study.