Determination of culprit lesion in patients undergoing elective percutaneous coronary intervention by myocardial perfusion imaging.

UNLABELLED The aim of this study was to determine and localize culprit lesion by myocardial perfusion imaging (MPI) in cases of angiographically detected coronary narrowing >or= 75% of at least one coronary artery. MATERIAL AND METHODS One hundred and thirty-two (132) patients with angiographically detected significant coronary narrowing (>or= 75% luminal stenosis of at least one major coronary artery) were studied. All the patients submitted MPI (99m)Tc-MIBI, with pharmacologic dipyridamole stress protocol with concomitant low level bicycle exercise 50W (DipyEX). We measured relative uptake (99m)Tc-MIBI for each myocardial segment using short-axis myocardial tomogram study. A 5-point scoring system was used to assess the difference between uptake degree in stress and rest studies for the same segments, and we created two indices: Sum reversibility score (SRS), Index of sum reversibility score (ISRS). RESULTS A total of 396 vascular territories (2244 segments) were analyzed before elective percutaneous coronary intervention (ePCI). Overall sensitivity, specificity and accuracy using SRS were 90.2%, 87.5%, and 89.4%, with a positive predictive value of 94.1%. Overall sensitivity, specificity, and accuracy using ISRS were 94.4%, 90.6%, 93.2% and the positive predictive value was 95.7%. CONCLUSION DipyEX MPI with the two indices created, SRS and ISRS, significantly improves sensitivity, specificity and accuracy in the determination and localization of culprit lesions in patients undergoing elective PCI.