Comparison of Epicardial Fat Volume between Patients with Normal Perfusion and Reversible Perfusion Abnormalities on Myocardial Perfusion Imaging.

PURPOSE OF THE STUDY

Our study purpose was to compare the epicardial fat volume (EFV) in myocardial perfusion imaging single photon emission computed tomography/computed tomography (MPI SPECT/CT) with normal and abnormal perfusion in patients with known or suspected coronary artery disease (CAD).

MATERIALS AND METHODS

one hundred and seventy-six patients (88 records with normal and 88 with reversible perfusion defects) underwent physical or adenosine stress with Tc-99m MIBI followed by SPECT and low-dose CT for attenuation correction. Rest MPI was done in patients showing perfusion defects on stress imaging. Software-based quantification of EFV was done by manually delineating pericardial contours with epicardial fat threshold set between -30 HU and -190 HU.

RESULTS

Median EFV in scans with normal perfusion was found to be 74.46 ml (32.92-211.51), and with reversible ischemia was 92.94 ml (43.70-207.53) with a median-summed difference score (SDS) of 5.00 (1.0-27). In 15 scans with reversible perfusion defects associated with infarcts in other segments, median EFV was 101.71 ml (63.03-156.46) with mean - SDS of 7.50 (standard deviation = 6.20). Scans with reversible perfusion defects demonstrated an increased EFV (median - 92.94 ml) when compared to scans with a normal perfusion (median = 74.64 ml) ( < 0.001).

CONCLUSION

Our results demonstrated an increased EFV in scans with presence of active reversible ischemia compared to that of normal perfusion on MPI ( < 0.001) suggesting potential role of cardiac SPECT/CT to evaluate EFV for risk stratification of suspected CAD.