123I-mIBG SPECT Imaging

Inclusion Criteria: For all participants:

1. Male or female ≥ 18 years at study entry.

2. Able and willing to comply with the study procedures.

3. Written informed consent.

4. Female subjects must be post-menopausal, surgically sterilized or have negative serumbeta human chorionic gonadotropin pregnancy test at initial screening and maintaineffective contraceptive methods throughout the trial and for 30 days following the endof dosing. For participants with coronary artery disease and documented myocardial infarction:

5. Diagnosis of coronary artery disease (CAD) based on one or more of the following:documented myocardial infarction, significant obstructive CAD on invasive or computedtomography (CT) coronary angiography or abnormal stress perfusion study consistentwith ischemia or scar

6. LV ejection fraction >40% on non-invasive imaging or invasive LV angiography.

7. NYHA Class 0, I or II heart failure symptoms. For participants with nonischemic cardiomyopathy and LV ejection fraction between 30 and 40%:

8. Diagnosis of NYHA Class II - III heart failure. 6. No evidence of significantobstructive CAD on invasive coronary angiography or noninvasive stress imaging 7. RestingLV ejection fraction <40% on noninvasive imaging within 30 days of research cardiac MIBGimaging 8. Current stable treatment regimen of medications including a betablocker andeither an ACE inhibitor or ARB unless documented to be intolerant to these classes ofdrugs.

9. Clinically stable from at least 7 days prior to enrollment to the study to the time ofthe cardiac MIBG imaging. For control participants:

10. Low likelihood of CAD and a normal stress myocardial perfusion study or stressechocardiogram within 6 months of study entry.

11. No significant CAD: defined as stenosis >30% narrowing on invasive or CT coronaryangiography within 6 months of study entry.

Exclusion Criteria:

1. Previously received 123I-mIBG or 131I-mIBG.

2. Participation in any other investigational product or medical device study within 30days of enrollment.

3. History or suspicion of significant allergic reaction or anaphylaxis to iodine oriodinated imaging agents.

4. Poorly controlled hypertension (>180 mmHg systolic or >110 mmHg diastolic) based onmeasurements made during the preceding 6 months.

5. Use of medications for non-cardiac medical conditions that are known to interfere with 123I-mIBG uptake and these medications cannot be safely withheld for at least 24 hoursbefore study procedures.

6. Cardiac revascularization, insertion of an ICD or an acute myocardial infarctionwithin the past 30 days.

7. Serious non-cardiac medical condition associated with significant elevation of plasmacatecholamines including pheochromocytoma.

8. Claustrophobia or movement disorders that prevent the participant from lying still ina supine position for up to an hour at a time.

9. Renal insufficiency (serum creatinine >3.0 mg/dL or >265 mmol/L).

10. Diagnosis of or signs or symptoms of a neurologic disease such as Parkinson's disease,multiple systems atrophy or Parkinsonian syndromes, or other diseases known to affectthe sympathetic nervous system.

11. Breastfeeding or pregnancy.