Improved quantification and normal limits for myocardial perfusion stress-rest change.

UNLABELLED: We aimed to improve the quantification of myocardial perfusion stress-rest changes in myocardial perfusion SPECT (MPS) studies for the optimal automatic detection of ischemia and coronary artery disease (CAD).
METHODS: Rest-stress (99m)Tc MPS studies (997 cases; 651 consecutive cases with correlating angiography and 346 cases with less than 5% likelihood (low likelihood [LLK]) of CAD) were analyzed. Normal limits for stress-rest changes were derived from additional LLK patients (40 women, 40 men). We computed the global stress-rest change (C-SR) by integrating direct stress-rest changes for each polar map pixel. Additionally, stress-rest change and total perfusion deficit (TPD) at stress were combined in 1 variable (C-TPD) for the optimal detection of CAD.
RESULTS: The area under the receiver-operating-characteristic curve (AUC) for C-SR (0.92) was larger than that for stress TPD-rest TPD (0.88) for the identification of stenosis of 70% or more (P < 0.0001). AUC (0.94) and sensitivity (90%) for C-TPD were higher than those for stress TPD (0.91 and 83%, respectively) (P < 0.0001), whereas specificity remained the same (81%).
CONCLUSION: C-SR and C-TPD provide higher diagnostic performance than difference between stress and rest TPD or stress hypoperfusion analysis.