PREDICTION OF FUNCTIONAL RECOVERY IN ACUTE MYOCARDIAL-INFARCTION - COMPARISON BETWEEN SESTAMIBI REVERSE REDISTRIBUTION AND SESTAMIBI BMIPP MISMATCH/

Background. It has been known that Tc 99m sestamibi/iodine 123 betamet hyliodophenylpentadecanoic (I-123-BMIPP) (sestamibi/BMIPP) mismatch is an indicator of viable myocardium in acute myocardial infarction (AMI ), We have reported that reverse redistribution of sestamibi in AMI in dicates the patency of infarct-related artery and a preserved left ven tricular function in the chronic stage. In this study we investigated the relationship between reverse redistribution of sestamibi and sesta mibi/BMIPP mismatch in patients with AMI. Methods. Twenty-three patien ts with AMI who received direct percutaneous transluminal coronary ang ioplasty underwent both BMIPP and sestamibi SPECT within 2 weeks after onset. Sestamibi images were obtained 1 hour (early) and 3 hours (del ayed) after injection of sestamibi, BMIPP imaging was carried out 30 m inutes after injection. The left ventricle was divided into 17 segment s, and regional myocardial uptakes of the tracers in each segment mere scored from 0 (normal) to 3 (no activity). A reverse redistribution p attern was defined as an increase of greater than or equal to 1 in the regional score at the delayed images. More reduced BMIPP uptake than sestamibi uptake in each segment was determined as sestamibi/BMIPP mis match. Contrast left ventriculography was performed soon after revascu larization and repeated 1 month later. Results, Of 15 patients with se stamibi reverse redistribution, sestamibi/BMIPP mismatch was observed in 14 patients (93%), whereas mismatch was seen in only one of seven p atients (14%) without reverse redistribution (p < 0.01), In patients w ith sestamibi reverse redistribution, regional scores of BMIPP agreed with those of early and delayed images of sestamibi in 51 segments (46 %) and in 92 segments (83%), respectively, In the chronic stage, both regional wall motion and left ventricular ejection fraction improved i n patients with sestamibi reverse redistribution (wall motion score: 6 .7 +/- 2.4 vs 2.7 +/- 2.1, p < 0.01; ejection fraction: 56% +/- 7% vs 64% +/- 8%, p < 0.01), but not in those without reverse redistribution . Conclusion. Both reverse redistribution of sestamibi and sestamibi/B MIPP mismatch reflect the recovery of left ventricular function and th us imply myocardial viability in AMI. Because the presence of reverse redistribution of sestamibi agreed with that of sestamibi/BMIPP mismat ch, additional BMIPP images can be replaced by the delayed images afte r a single injection of sestamibi.