Diagnostic value of early post exercise ~(99)Tc~m-MIBI ECG gated myocardial perfusion imaging in severe coronary artery disease

Objective To study and compare the diagnostic value in severe coronary artery disease (CAD) of 99 Tc m methoxyisobutylisonitrile (MIBI) electrocardiogram (ECG) gated early post exercise myocardial perfusion imaging (G MPI) with that of non ECG gated myocardial perfusion imaging (NG MPI). Methods Two hundred and fifteen suspected CAD patients had undergone G MPI and coronary artery angiography (CAG) within one month were enrolled and distributed into three vessel and non three vessel CAD groups according to CAG results (≥70%); the diagnostic values in severe CAD of G MPI and NG MPI were gained and compared to determine which one of the two protocols would be superior in identification of severe three vessel CAD. Results When the ≥70% diameter stenosis CAG was the diagnostic standard of severe CAD, the sensitivity of G MPI and NG MPI in the diagnosis of severe CAD were 95.3% (143/150) and 90.7% (136/150, χ 2=2.509, P =0 113), but when the comparison specifically pinpointed to severe three vessel CAD, there was significant difference between G MPI [100%(51/51)] and NG MPI [92.2% (47/51), χ 2=4.163, P =0.041]. Diagnostic specificity of G MPI was 80.0% and that of NG MPI was 72.3% ( χ 2=1.059, P =0.303). Conclusions The incremental diagnostic sensitivity of G MPI adding to the NG MPI in the diagnosis of severe CAD was mainly from the three vessel subgroup patients.Exercise stress G MPI has better diagnostic value in severe three vessel CAD patients than NG MPI.