Background: Reverse redistribution (RR) is one of the abnormal scan patterns in myocardial perfusion scintigraphy using 201Tl. Its clinical significance is not known, however, it was reported to be commonly found in patients who had myocardial infarction and those who underwent revascularization. The objective of this study is to determine the prognostic value of reverse redistribution on stress Thallium-201 myocardial perfusion scintigraphy (MPS) among patients who underwent percutaneous coronary intervention (PCI).
Method: A prospective cohort study of 99 post-PCI patients who underwent MPS using T1-201 >3months after revascularization was done. The subjects were classified based on the scan finding of RR. Follow-up at 6-month interval was done to monitor for major adverse cardiac events (MACE).
Results: Ninety-nine subjects were included in this study, 19 (19%) of which had RR. Mean follow-up period for the event-free patients was 19 ± 8 months. MACE occurred in 30 (30%) of the subjects at a mean interval of 15 ± 8 months from the time of performance of MPS. Simple binary logistic regression was used to determine the association between RR and MACE. RR was not found to be a significant predictor of the occurrence of MACE (p-value = 0.217).
Conclusion: This study showed that RR on 201T1 MPS is not a significant predictor of future cardiac events among post-PCI patients. Post hoc findings favored attenuation artifact as a possible cause of RR in this study population. However, a larger sample size and a longer follow-up period is recommended to make a definite conclusion.