PROGNOSTIC VALUE OF PERSISTENT TL-201 DEFECTS THAT BECOME REVERSIBLE AFTER REINJECTION IN PATIENTS WITH CHRONIC MYOCARDIAL-INFARCTION

Background. The presence of defects at stress-redistribution thallium- 201 scintigraphy is related to a higher risk of cardiac events, Howeve r, the prognostic value of defects that become reversible after reinje ction is not known, In this study we evaluated the prognostic contribu tion of stress-redistribution-reinjection with special regard to 3-hou r fixed defects that become reversible after reinjection. Methods and Results. We studied 122 patients with chronic myocardial infarction (> 2 months) and suspected or known residual ischemia, with stress-redist ribution-reinjection planar scintigraphy, Thallium scans were analyzed by three observers (three segments per view, 5-point score) and class ified as normal, fixed, and reversible, The lung/heart ratio was also calculated, At a median follow-up of 47 months, 10 patients had hard e vents (four deaths and six myocardial infarctions) (group I), 12 patie nts had unstable angina (group II), 12 patients underwent planned coro nary artery bypass grafting or percutaneous transluminal coronary angi oplasty (group III), and 86 patients had no events (group IV), The pre sence of fixed defects that became reversible after reinjection did no t identify patients at higher risk, The number of reversible defects a t 3 hours was significantly higher only in patients who underwent reva scularization, Unstable angina was not predicted by any scintigraphic pattern, The variables that were statistically related to hard events by univariate analysis mere increased lung uptake, reversible cavity d ilation, and the number of fixed defects that remained fixed after rei njection, By Cox multivariate analysis, the strongest predictor of har d events was the presence of more than three fixed defects that remain ed fixed after reinjection as a marker of irreversible myocardial dama ge, Conclusions, (TI)-T-201 reinjection is a useful approach for not o nly detecting viable myocardium but also risk stratification in patien ts with chronic myocardial infarction.