99m tc-mibi stress gated-spect can obviate the need for conventional stress-rest spect imaging for the diagnosis of coronary artery disease

Abstract EN

Myocardial perfusion imaging is a commonly used procedure to diagnose coronary artery disease (CAD).

Based on the assumption that preserved wall thickening on the stress perfusion defect is most likely predictive of stress defect reversibility.

Conversely absent wall thickening is associated with fixed regional perfusion defect (scar or hibernating myocardium) Purpose: The purpose of this work is to test the predictive value of stress Gated SPECT with Tc-99m MIBI in diagnosing stress induced perfusion defect.

Further, we also aim at evaluating the clinical feasibility and limitation of Tc-99m MIBI stress Gated SPECT compared with the conventional protocol of stress rest SPECT imaging.

Patients and methods: This study included 109 patients referred for myocardial perfusion imaging for possible CAD or follow up of CAD.

Gated SPECT using Tc-99m MIBI or Myoview was used in all patients.

78 males and 31 females with mean age of 61 + -11.

63 % of patients were exposed to one day protocol and 37 % underwent two days protocol.

Results : A total of 2180 (109 x 20 segments each) were evaluated.

415 segments (19 %) showed stress perfusion defects, 305 out of them showed apparent wall thickening motion in G-SPECT study and the reminder 110 showed defects with no evidence of wall motion or wall thickening.

Among those 305 segments 284 showed reversible perfusion defects in the rest images with a predictive value of 95.5 %.

Out of the 110 stress induced perfusion defect segments with no wall thickening or wall motion, 71 segments demonstrated no reversibility in the rest image with negative predictive value of 64.5 %.

Conclusion : we concluded that stress Tc-99m MIBI G-SPECT may obviate the need to perform rest image with cost and time reduction to patients, physician and gamma camera time as well.

However, in absence of wall thickening and wall motion rest imaging must be performed to differentiate reversible ischaemia from infarctions in a stress induced perfusion defect.