ABSORB EXTEND: BVS Safe Out to 3 Years
A bioresorbable vascular scaffold (BVS) yields low rates of MACE, repeat revascularization and scaffold thrombosis through 36 months, according to an interim analysis of the ABSORB EXTEND trial. The device elutes everolimus and absorbs into the body, leaving no permanent scaffold.
Previous 2-year results demonstrated a MACE rate of 6.7% and definite/probable scaffold thrombosis rate of 1.1% in the first 450 patients treated with the Absorb BVS (Abbott Vascular). Additionally, 3-year angiographic results from Cohort B demonstrated in-scaffold late loss of 0.29 mm.
The new analysis, presented at TCT 2014 by Pieter C. Smits, MD, PhD, of Maasstad Ziekenhuis, Rotterdam, the Netherlands, provides 36-month follow-up on the first 250 patients treated with the BVS. Overall, the analysis showed low rates of MACE, cardiac death, ischemia-driven target lesion revascularization (TLR) and other clinical outcomes (see Figure).
There were no instances of acute (0-1 day) or sub-acute (2-30 days) definite scaffold thrombosis; there was one case of late (31 days to 1 year) definite scaffold thrombosis, as well as one case of sub-acute probable thrombosis and one case of very late (>1 year) probable thrombosis. Overall, the rate of definite/probable scaffold thrombosis at 3 years was 1.2%.
Using propensity matching, the researchers compared 174 patients from ABSORB EXTEND with 290 patients in other trials who were treated with the everolimus-eluting Xience V stent (Abbott Vascular). There were no statistically significant differences between the BVS and Xience V at 36 months for MACE (HR 0.73; 95% CI 0.38-1.41), definite/probable scaffold thrombosis (HR 0.83; 95% CI 0.08-9.15), or MI (HR 1.06; 95% CI 0.41-2.73).
However, there was a hint of difference for target vessel failure (TVF) at 36 months, with rates of 14.2% in the XIENCE V group and 8.1% in the ABSORB EXTEND group (P=.0488), which Smits said requires further study. Furthermore, the analysis also found a significantly greater rate of angina in Xience V-treated patients in the SPIRIT IV trial compared with BVS-treated patients in ABSORB EXTEND, he added.
“Clinical data from the first 250 patients enrolled in ABSORB EXTEND demonstrate that the low rates of MACE, repeat revascularization and scaffold thrombosis seen at 12 and 24 months are sustained through 36 months,” Smits said.
Patients in ABSORB EXTEND could have up to two de novo lesions treated, located in separate native epicardial vessels; most patients (94%) had one target lesion. Device success was 98.5% and the clinical procedure success rate was 97.2%. Of the 250 patients (mean age 62 years), 74% were male; 29% had previous MI; 35% had unstable angina; and 25% had diabetes.
- Smits reports receiving lecture fees from Abbott Vascular and institutional grants from Abbott Vascular, Terumo Medical Corporation and St. Jude Medical.