Incidence, predictors, and outcomes of distal vessel expansion on follow-up intravascular ultrasound after recanalization of chronic total occlusions using new-generation drug-eluting stents: Data from the CTO-IVUS randomized trial

Objectives To evaluate the incidence, predictors, and outcomes of distal vessel expansion on intravascular ultrasound (IVUS) after recanalization of chronic total occlusion (CTO) particularly using new-generation drug-eluting stent (DES). Background The luminal changes of narrowed vessels distal to CTO segments after recanalization using new-generation DES have rarely been studied. Methods This substudy of the CTO-IVUS (Chronic Total Occlusion InterVention with drUg-eluting Stents) trial included a total of 69 new-generation DES-treated CTOs with serial matched IVUS analyses at index percutaneous coronary intervention (PCI) and at 1-year follow-up. The predictors of distal vessel expansion, any increase of lumen area at the distal reference (LAdistal ) on 1-year follow-up IVUS, were evaluated by multivariable binary logistic analyses. Results Distal vessel expansion was identified in 46 (67%). Independent determinants of distal vessel expansion were proximal CTO, a smaller LAdistal at the index PCI, a greater minimal stent area-to-LAdistal (MSA-to-LAdistal ) ratio, and a greater lumen area at the distal stent edge-to-LAdistal (LAedge -to-LAdistal ) ratio. The cut-off values of a MSA-to-LAdistal ratio and a LAedge -to-LAdistal ratio predicting the distal vessel expansion by receiver operating characteristic curve analysis were 1.0 and 1.1, respectively. During the median 5.1 years, rates of target vessel revascularization, cardiac death, and stent thrombosis were similar in the distal vessel-expanded and nonexpanded groups. Conclusion After opening CTO with new-generation DES, two-thirds of patients exhibited distal vessel expansion on 1-year follow-up IVUS. Expansion determinants were a proximal CTO, lower LAdistal , and larger stent areas relative to the LAdistal (modifiable procedural predictors).