Abstract 16649: Recovery of Myocardial Perfusion After Percutaneous Coronary Intervention of Chronic Total Occlusions is Comparable to Non-Occlusive Lesions

Abstract

Background: The benefits of chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) are being questioned. The aim of this study was to assess the effects of CTO PCI on absolute myocardial perfusion, as compared to PCI of hemodynamically significant non-occlusive lesions. Methods: Consecutive patients with a preserved left ventricular ejection fraction (≥50%) and a CTO or non-CTO lesion, in whom [ 15 O]H 2 O positron emission tomography was performed prior and after successful PCI, were included. Change in quantitative (hyperemic) myocardial blood flow (MBF), coronary flow reserve (CFR) and perfusion defect size (in myocardial segments) were compared between CTOs and non-occlusive lesions. Results: Ninety-two patients with a CTO and 31 patients with a non-occlusive lesion were included. CTOs induced larger perfusion defect sizes (4.51±1.69 vs. 3.23±2.38 segments, p<0.01) with lower hyperemic MBF (1.30±0.37 vs. 1.58±0.62 mL·min -1 ·g -1 , p<0.01) and similarly impaired CFR (1.66±0.75 vs. 1.89±0.77, p=0.17) compared with non-occlusive lesions. After PCI both hyperemic MBF and CFR increased similarly between groups (p=0.57 and p=0.35) to normal ranges with higher hyperemic MBF values in non-CTO compared to CTO (2.89±0.94 vs. 2.48±0.73 mL·min -1 ·g -1 , p=0.03). Perfusion defect sizes decreased similarly after CTO PCI and non-CTO PCI (p=0.14), leading to small residual defect sizes in both groups (1.15±1.44 vs. 0.61±1.45 segments, p=0.054). Conclusions: Percutaneous revascularization of CTOs improves absolute myocardial perfusion similarly to PCI of hemodynamically significant non-occlusive lesions, leading to satisfying results. Myocardial perfusion findings are less favorable in patients with a CTO before and after PCI, suggesting a more advanced stage of coronary artery disease.