Abstract
Objective: A high transient ischemic dilatation ratio (TID) for the left ventricle (LV) from a gated myocardial perfusion imaging (G-MPI) study is widely believed to be associated with significant coronary artery disease (CAD). We have investigated the relationship between TID and CAD for our male Saudi Arabian patient population.
Methods: In this retrospective study, all male Saudi Arabian patients who underwent a two-day G-MPI study using Tc99m MIBI during the year 2011 having a TID >= 1.20 were included. Quantitative perfusion and gated parameters were obtained using Cedar Sinai's AutoQuant software version 3.0, 2003, Means of summed stress scores, summed rest scores and summed difference scores (SSS, SRS, SDS, respectively), stress and rest ejection fraction (EF) were calculated. Visual interpretation was performed to classify the perfusion as normal, fixed, mixed (fixed and reversible defects), single reversible or multiple reversible defects. Coronary angiograms were assessed as normal with no CAD, single vessel, two-vessel or three-vessel disease. Correlations between the TID and other parameters were studied using analysis of variance (ANOVA) with IBM-SPSS version 20.
Results: A total of 52 male patients had a high TID of P1.20 (mean 1.30 0.13). Ten patients had a SSS of 0-3 and 16 were classified as normal by visual assessment. Stress EF (mean 50.4 +/- 12%) was lower than the rest EF (mean 56.6 +/- 12.8%) with the difference being statistically significant (Students paired t-test, p = 0.001).
Angiography results were available in 44 patients, 3 having a normal angiogram, 24 having three vessel disease, 7 having two vessel disease and 10 having one vessel disease. Five patients with normal perfusion and SSS = 0-3 had CADas seen on a coronary angiography. CADon coronary angiography showed a significant correlation with perfusion abnormalities as assessed by visual interpretation (p = 0.002). TID showed a significantly correlation with both perfusion abnormalities (p = 0.009), as assessed by visual interpretation, and with Summed difference scores, SDS (p = 0.000).
Conclusion: A high TID on G-MPI was a very sensitive indicator of significant CAD. In patients with normal perfusion and high TID further workup is warranted. (C) 2013 King Saud University. Production and hosting by Elsevier B.V. All rights reserved.