High-efficiency SPECT MPI for detection of coronary artery disease defined by invasive coronary angiography

Objectives Recently, a novel camera system for high-efficiency (HE) SPECT myocardial perfusion imaging (MPI) (Spectrum-Dynamics, Israel) has been shown similar to conventional SPECT. However, the correlation between HE MPI and invasive coronary angiography (ICA) for the detection of coronary artery disease (CAD) has not been reported.

Methods We examined 83 consecutive patients with no known CAD who underwent ICA within three months of rest/stress HE MPI. The quantitative (Quant) magnitude of perfusion abnormality was assessed by the total perfusion deficit (TPD). Stress TPD ≥5% myocardium was defined as abnormal (abnl) scan. An abnl coronary territory was defined by >10% TPD in the segments ascribed to a given coronary artery (CA). MPI was visually categorized as normal/abnl.

Results The sensitivities (sens) of Quant MPI for detecting CAD defined as ≥50% and ≥70% diameter stenosis were 90% (44/49) and 91% (39/43). ROC areas for detecting CAD with ≥50% and ≥70% stenosis by stress TPD were 0.74±0.06 and 0.76±0.05 (both p<0.0001). The sens of visual MPI were 86% (42/49) and 86% (37/43) for ≥50% and ≥70% stenosis. By combined Quant and visual analyses, the sens and specificity (spec) for ≥50% stenosis were 80% (39/49) and 62% (21/34). By Quant analysis, the sens for individual vessels were 67% (20/30), 63% (12/19), and 72% (21/29), for ≥70% stenosis in left anterior descending CA, left circumflex CA and right CA, respectively, with respective spec of 72% (38/53), 70% (45/64), and 67% (36/54).

Conclusions This preliminary study shows that HE MPI correlates well with ICA for the presence of CAD.