Background: Post-stress ejection fraction (EF), end-dia-stolic (EDV) and en d-systolic (ESV) volumes by gated myocardial perfusion SPECT (MPS) are well val idated, reproducible and of prognostic significance. However, little is known ab out the impact of percutaneous coronary intervention (PCI) on left ventricular v olumes and remodeling. Methods: Thirty-eight patients who underwent MPS before and 6 months after PCI were evaluated. MPS were interpreted deriving summed stre ss(SSS), rest(SRS) and difference(SDS=SSS-SRS; extent of ischemia) scores. EF, EDV and ESV were generated by QGSTM. Pre-PCI MPS were compared to post-PCI MPS . Results: Single vessel disease was present in 63%of patients. PCI of one vess el was performed in 82%of patients. After 6 months, SSS (10.6±6.3 vs. 2.8±4.3 , p< 0.001) and SDS(8.2±5.6 vs. 1.4±2.3, p< 0.001) had improved; however, EF d id not change significantly(55±10 vs. 57±13, p=ns). Still, EDV(105±25 ml vs. 96±25 ml, p=0.006) and ESV(49±19 ml vs. 41±18 ml, p=0.001) were significantly reduced. Conclusion: Results of MPS documented the beneficial effect of PCI on symptoms and extent of ischemia. In addition, the findings showed a significant decrease in ESV and EDV after PCI as compared to pre-PCI findings which points to a positive effect on left ventricular remodeling even in the absence of signi ficant changes in EF. Background: Post-stress ejection fraction (EF), end-dia-stolic (EDV) and en d-systolic (ESV) volumes by gated myocardial perfusion SPECT (MPS) are well val idated, reproducible and of prognostic significance. However, little is known ab out the impact of percutaneous coronary intervention (PCI) on left ventricular voles and remodeling. Methods: Thirty-eight patients who underwent MPS before and 6 months after PCI were evaluated. MPS were interpreted deriving summed stre ss (SSS), Pre-PCI MPS were compared to post-PCI MPS. Results: Single vessel disease was present in 63 % of patients. PCI of one patient was performed in 82% of patients. After 6 months, SSS (10.6 ± 6.3 vs. 2.8 ± 4.3, p <0.001) and SDS (8.2 ± 5.6 vs. 1.4 ± 2.3, p < Still, EDV (105 ± 25 ml vs. 96 ± 25 ml, p = 0.006) and ESV (0,0.001) had no significant change (55 ± 10 vs. 57 ± 13, p = 49 ± 19 ml vs. 4 1 ± 18 ml, p = 0.001) were significantly reduced. Conclusion: MPS documented the beneficial effect of PCI on symptoms and extent of ischemia. In addition, the findings showed a significant decrease in ESV and EDV after PCI as compared to pre -PCI findings which points to a positive effect on left ventricular remodeling even in the absence of signi ficant changes in EF.