This is a prospective, multicenter, randomized, open-label, parallel-controlled Phase IIb study to investigate the diagnostic-prognostic utility of XTR003 Injection integrated with 18F-FDG as an exploratory clinical trial. A total of 40-60 patients will be enrolled and randomized into two study groups as: fasting XTR003/18F-FDG group and glucose-loaded group at a 1:1 ratio. Each group will receive resting myocardial perfusion imaging (MPI) combined with metabolic PET imaging to evaluate myocardial metabolic activity and myocardial viability. Segmental perfusion abnormality, metabolic activity and myocardial viability will be analyzed according to the standard approaches in Nuclear Cardiology. Regional and global left ventricular function will be assessed with cardiac MRI and echocardiography prior to and post the completion of full revascularization within 6-month time point. A repeated resting MPI will also be performed to assess the improvement of perfusion abnormality.

All study subjects will undergo 6 months follow-up for major adverse cardiac events (MACE).

Inclusion Criteria:

1. Aged 18 to 85 years, regardless of gender.
2. Diagnosed with ischemic cardiomyopathy (ICM).
3. significant coronary artery disease (CAD).
4. Left ventricular systolic dysfunction, with LVEF ranging from >20% to ≤40%
5. Assessed by a team of cardiac surgeons/operators as suitable for complete revascularization.
6. Capable of effective communication with the investigators, able to understand and comply with the clinical study requirements, voluntarily participate in the study, and provide written informed consent after being fully informed.

Exclusion Criteria:

1. Decompensated heart failure within 48 hours prior to enrollment.
2. Recent ST-segment elevation myocardial infarction (STEMI) within less than 4 weeks.
3. Left ventricular aneurysm.
4. Judged by the investigator as unable to complete PET examination.
5. Severe renal insufficiency.
6. Severe hepatic insufficiency.
7. Subjects with fever or active infectious diseases who are assessed by the investigator as unsuitable for study participation.
8. Pregnant or lactating women.
9. Contraindications to magnetic resonance imaging (MRI), such as claustrophobia or intracorporeal metallic implants.
10. Subjects with mental disorders or poor compliance.
11. Significant occupational exposure to ionizing radiation (e.g., exceeding 50 mSv per year) or exposure to radioactive substances/ionizing radiation for therapeutic or research purposes within the past 10 years.
12. Other circumstances deemed by the investigator as unsuitable for trial participation.