Short-term changes in myocardial perfusion of the predominant donor vessel after percutaneous coronary intervention for chronic total occlusion.

Background: It remains unclear how rapidly the collateral circulation regresses after percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). This study aimed to investigate the short-term changes of myocardial perfusion in the predominant donor vessel after successful CTO PCI.

Methods: A total of 68 patients who underwent single-photon emission computerized tomography (SPECT) assessment before and within 24-72 hours after successful CTO PCI were retrospectively included into this study. The coronary flow reserve (CFR) in the CTO territory and the predominant donor vessel territory were analyzed.

Results: The average age of the included patients was 57.1±12.5 years old, and 88.2% were male. In the CTO territory, the CFR increased from 1.80±0.99 at baseline to 2.13±1.02 after PCI (P=0.018). In the predominant donor territory, the CFR at baseline did not significantly differ from that of after PCI (baseline: 2.12±1.09; after-PCI: 2.27±0.78; P=0.214). However, the change in CFR (ΔCFR) of the predominant donor territory was correlated with that in the CTO territory (P<0.001). The target vessel of CTO [left anterior descending artery (LAD) left circumflex artery (LCX); P=0.022] and diabetes mellitus (P=0.011) were other independent factors associated with ΔCFR in the predominant donor territory. In the those treated with CTO of the LAD, CFR in the predominant donor territory increased from 1.65±0.61 at baseline to 2.30±0.75 after PCI (P=0.003). In contrast, no significant ΔCFR was not observed in those treated with CTO of the LCX or right coronary artery (RCA).

Conclusions: The myocardial perfusion in the predominant donor territory was positively associated with that in the CTO territory. The myocardial perfusion in the predominant donor territory increased within a short-term period after CTO PCI, specifically in those patients with CTO of the LAD.