Long-term changes in ischemic burden after chronic total occlusion percutaneous coronary intervention: a...

There is uncertainty of the benefit of percutaneous coronary intervention (PCI) for chronic coronary total occlusion (CTO). The study aimed to investigate potential long-term changes in ischemic burden in patients with CTO after PCI.

Patients who underwent CTO PCI with available records of ¹⁵O-H₂O positron emission tomography within 3 months prior to and at least 6 months after successful CTO PCI were retrospectively included. Data on perfusion defect size, hyperemic myocardial blood flow (MBF), and coronary flow reserve (CFR) within the CTO area before and after CTO PCI were extracted and compared for evaluating ischemic burden. The comparisons were also performed after stratifying by baseline perfusion defect sizes.

A total of 74 eligible patients were included with an average age of 62.0±7.5 years. Significant decrease in perfusion defect size (3 (2-4) versus 1 (0-2) segments, P<0.001) and significant increase in hyperemic MBF (1.32±0.39 versus 2.27±0.52 mL/min/g, P<0.001) and CFR (1.72±0.47 versus 2.73±0.73, P<0.001) were observed after CTO PCI when compared to that at baseline. When stratifying by baseline perfusion defect size, no significant differences were observed between groups in changes of hyperemic MBF (P=0.301) and CFR (P=0.850), but patients with larger perfusion defect size exhibited greater reduction in perfusion defect size (P<0.001).

CTO PCI relieved ischemic burden for at least 6 months, and patients with larger baseline perfusion defect size might benefit more from CTO PCI in terms of ischemic burden.