Single-photon emission computed tomography for assessment of myocardial viability

Area of Science:

• Cardiology
• Nuclear Medicine
• Cardiovascular Imaging

Background:

• Left ventricular dysfunction in chronic coronary artery disease can stem from myocardial hibernation.
• Coronary revascularization improves outcomes if dysfunctional but viable myocardium is present.
• High-risk procedures necessitate careful patient selection for severe left ventricular dysfunction.

Purpose of the Study:

• To evaluate the role of myocardial viability assessment using SPECT in guiding revascularization decisions.
• To determine the proportion of patients with ischemic left ventricular dysfunction and viable myocardium.
• To identify patients unlikely to benefit from revascularization.

Main Methods:

• SPECT imaging protocols including thallium-201 (201Tl) rest-redistribution, technetium-99m (99mTc) viability tracers, and 18F-fluorodeoxyglucose (FDG) for metabolic assessment.
• Assessment of myocardial viability in patients with ischemic left ventricular dysfunction.
• Correlation of SPECT findings with potential benefits from coronary revascularization.

Main Results:

• Approximately 50% of patients with ischemic left ventricular dysfunction exhibit substantial dysfunctional but viable myocardium on SPECT.
• SPECT findings can identify patients who are candidates for coronary revascularization.
• Absence of myocardial viability indicates patients unlikely to benefit from high-risk interventions.

Conclusions:

• Myocardial viability assessment with SPECT is crucial for clinical decision-making in ischemic left ventricular dysfunction.
• SPECT facilitates selection of appropriate candidates for coronary revascularization, including percutaneous coronary intervention (PCI) and coronary bypass surgery.
• Identifying non-viable myocardium helps avoid unnecessary high-risk procedures and improve patient selection for revascularization.