Two-year clinical outcomes of patients treated with overlapping absorb scaffolds: An analysis of the ABSORB EXTEND single-arm study

BACKGROUND: Preclinical data showed that overlapping (OVP) scaffolds might result in delayed healing and strut coverage compared to nonOVP scaffold segments. Furthermore, OVP in patients could result in increased periprocedure myocardial infarction (MI) rate secondary to side branch occlusion; however, little is known whether this may have an impact on long-term clinical outcomes.

METHODS: ABSORB EXTEND is a prospective, single-arm, open-label clinical study in which 812 patients were enrolled at 56 sites. In this study, we compared the immediate and 2-year clinical outcomes of patients with OVP scaffolds (n = 115) to those of patients with nonOVP scaffolds (n = 697). The primary objective was the comparison of major adverse cardiac event (MACE) (cardiac death, MI and ischemic-driven target lesion revascularization [TLR]) and scaffold thrombosis (ST) rates up to 2 years.

RESULTS: Baseline clinical and angiographic characteristics were comparable between cohorts except for longer lesions in the OVP patients as expected (16.7 ± 7.3 vs. 11.6 ± 4.4 mm, P < 0.0001), higher lesion complexity (B2) and numerically smaller vessel size. In-hospital, there was a marked increase in MACE in the OVP cohort (7.0 vs. 0.9%, P = 0.002), exclusively driven by a higher rate of periprocedure MI (7.0 vs. 0.9%, P = 0.002). Long-term MACE did not significantly differ between groups (10.4% in the OVP cohort vs. 6.6% in the no-OVP group, P = 0.1) with comparable rates of cardiac death (0.9 vs. 1.2%, P = 1.0) and ischemia-driven TLR (1.7 vs. 2.5%, P = 1.0). Cumulative incidence of MI was higher in the OVP cohort (7.8 vs. 3.0%, P = 0.02). Of note, the rate of MI between hospital discharge and 2-year follow-up was lower in the OVP cohort (0.8 vs. 2.1%, P = 0.04). Cumulative incidence of definite/probable ST was relatively low and comparable between groups (1.8 vs. 1.5%, P = 0.7).

CONCLUSIONS: In this low-to-moderate complex population treated with the ABSORB scaffold the OVP group showed a higher incidence of periprocedure MI with no immediate or long-term increase in cardiac death, TLR or ST.