Background
Device underexpansion is associated with late adverse outcomes after bioresorbable vascular scaffold (BVS) implantation. This study, representing official IVUS
Conclusions
Unlike CoCr-EES, underexpansion was associated with greater negative remodeling and LLL in Absorb-BVS. This may in part account for the poorer outcomes of Absorb-BVS than CoCr-EES when under-expanded.
Methods
ABSORB Japan enrolled 148 patients (2:1 randomization) in the IVUS cohort. Serial IVUS was prescheduled at post-procedure and 3 years. Acute device expansion was evaluated with respect to the degree and uniformity of the implanted device.
Results
Overall, Absorb-BVS showed smaller and more nonuniform device expansion at post-procedure, compared with CoCr-EES, which was particularly prominent in small-vessel lesions. In serial analysis, Absorb-BVS showed unique associations of smaller device expansion (r = 0.40, p = 0.001) and more nonuniformity (r = 0.29, p = 0.007) at post-procedure with greater LLL at 3 years, primarily attributable to greater negative remodeling (r = 0.39, p = 0.006). In contrast, acute device expansion showed no relation with subsequent lumen change in CoCr-EES. In Absorb-BVS, ischemic-driven target lesion or vessel revascularization (ID-TLR or ID-TVR) at 3 years occurred more frequently in small- versus large-vessel lesions (12.5% vs. 0%, p = 0.04 for ID-TLR and 15.6% vs. 2.3%, p = 0.08 for ID-TVR). Conversely, Absorb BVS had no target lesion nor vessel failure, even in small-vessel lesions, when adequate device expansion was achieved at post-procedure. Conclusions: Unlike CoCr-EES, underexpansion was associated with greater negative remodeling and LLL in Absorb-BVS. This may in part account for the poorer outcomes of Absorb-BVS than CoCr-EES when under-expanded.