Myocardial viability assessment in AMI by rest 201Tl/dipyridamole stress 99mTc MIBI/24 hour redistribution

초록

Objectives: We compared the diagnostic models for detecting myocardial viability in AMI by rest 201Tl(Tl)/dipyridamole stress 99mTc MIBI (MIBI)/24 hour redistribution Tl SPECT. Methods: In the acute phase (mean 3±1 days post-infarction), 23 pts (anterior MI: 12, inferior MI: 11 patients) underwent rest Tl and dipyridamole stress MIBI SPECT. In 14 patients having perfusion defects at rest, 24-hour redistribution SPECT were performed. Urokinase was intravenously administered in 11 patients. For 16 segments, Tl uptake was visually graded with 4 point scores from normal (0) to defect (3). Myocardial wall motion (WM) was graded with 4 point scores from normal (1) to akinesia (4). Myocardial WM was considered to improved when a segment showed more than 1 grade improvement in f/w echocardiography compared with the baseline value after delayed PTCA. The diagnostic models for detecting myocardial viability were defined as stress/rest reversibility (Rev), rest uptake (rest), and redistribution (Red). Among 75 akinetic segments, 57 (76%) were determined viable. Results: Positive predictive values of Rev, Rest, and Red were 88%(29/33), 92% (46/50), and 67%(14/21) respectively. Negative predictive values of Rev, Rest, and Red were 37% (14/38), 56% (14/25), 40%(6/15) respectively. Although, univariate logistic regression analysis revealed Rev(p=0.014). and Rest (p=0.0001) to be significant predictors, stepwise multivariate analysis found only the Rest to be a significant predictor (p=0.0147).Conclusion: Among diagnostic models of rest Tl/dipyridamole stress MIBI/ 24hour redistribution Tl SPECT for detecting myocardial viability in the acute phase of AMI, Tl rest perfusion was the only significant predictor.