Left ventricular ejection fraction assessed from gated technetium-99m-sestamibi SPECT

Area of Science:

• Nuclear Cardiology
• Cardiovascular Imaging
• Radiopharmaceuticals

Background:

• Myocardial perfusion imaging with SPECT is established for assessing heart attack damage.
• Left ventricular ejection fraction (LVEF) is a critical prognostic indicator after myocardial infarction (MI).
• Current methods for LVEF assessment may require separate imaging studies.

Purpose of the Study:

• To evaluate the feasibility of measuring LVEF from gated 99mTc-sestamibi (MIBI) SPECT.
• To determine if gated MIBI SPECT can provide accurate LVEF values comparable to established methods.
• To assess the diagnostic and prognostic utility of LVEF derived from gated MIBI SPECT in MI patients.

Main Methods:

• 30 patients with recent MI underwent treadmill exercise with 99mTc-MIBI injection.
• ECG-gated SPECT imaging was performed 60 minutes post-injection.
• Left ventricular ejection fraction (LVEF) was calculated using Simpson's rule on end-diastolic and end-systolic frames, corrected for SPECT resolution.
• Results were compared with LVEF from gated 99mTc-blood-pool studies.

Main Results:

• LVEFs calculated from gated MIBI SPECT showed a linear correlation with gated blood-pool LVEF values (r=0.79-0.88).
• Interobserver and intraobserver variability for LVEF measurements were acceptable (r=0.75).
• Calculated LVEF values ranged from 0.21 to 0.73.

Conclusions:

• Resting LVEF can be accurately determined from gated MIBI SPECT in patients with MI.
• This method offers a valuable, integrated approach to assess myocardial perfusion, wall motion, and LVEF.
• Incorporating LVEF measurement into gated MIBI SPECT significantly enhances its diagnostic and prognostic value for MI patients.