Bioresorbable vascular scaffolds in coronary chronic total occlusions: clinical, vasomotor and optical coherence tomography findings at three-year follow-up (ABSORB-CTO study).

Aims: Percutaneous treatment of coronary chronic total occlusion (CTO) is associated with important arterial remodelling after successful recanalisation. Bioresorbable vascular scaffold (BVS) implantation in CTO has been shown to be feasible and can be of interest when the scaffold achieves complete bioresorption. We sought to evaluate the three-year results in terms of clinical events, serial imaging outcomes and vasomotion response in CTO lesions successfully treated with BVS.
Methods and Results: A total of 33 patients (35 CTO lesions) successfully treated with BVS were included in the ABSORB-CTO study. Clinical outcomes, quantitative coronary angiography (QCA) and optical coherence tomography (OCT) assessment were analysed at one- and three-year follow-up. Vasomotion examination was also performed at three years. At three years, cumulative target vessel reocclusion was observed in four lesions (11.4%). By QCA, the in-scaffold segment presented a lumen loss of 0.23±0.46 mm compared with the baseline procedure (p=0.001) and a lumen gain of 0.05±0.29 mm between one and three years (p=0.220). By OCT, the mean neointimal area stenosis progressed from 11.45% at 12 months to 17.10% at 36 months (p<0.001) and mean scaffold area increased continuously at 12 (+12%; p<0.001) and at 36 months (+14.85%; p=0.001). Late acquired incomplete scaffold apposition (LAISA) observed at 12 months in three patients was completely undetectable at three years. Most cases responded to endothelium-dependent vasomotor stimuli (69%). Vasoconstriction to acetylcholine was the predominant response (45%).
Conclusions: Successful recanalisation of coronary CTO with BVS implantation is associated with favourable clinical and imaging outcomes. Despite vessel motility restoration, successfully treated CTOs remain with signs of endothelial dysfunction.