The 3-year outcomes from the COMPARE-ABSORB trial, a single blind, prospective randomized controlled trial comparing the Absorb bioresorbable vascular scaffold (BVS) to Xience drug-eluting stents in a population at high risk for restenosis were presented. Patients had to meet at least one of the inclusion criteria: medically treated diabetes, or multivessel disease with more than one de-novo target lesions and/or presence of at least one complex lesion (long lesion, small diameter vessel, total occlusion and/or bifurcation). This was the first trial involving specified implantation technique of BVS from the beginning of the trial, although these implantations requirements did change during the enrollment period.
1,670 patients (with a total of 2,547 lesions) at 45 sites in Europe were included in the study, which randomized patients 1:1 to Absorb vs. Xience. At 3 years, there was no significant difference in the rate of target lesion failure (TLF) between the Absorb and Xience arms (8.9% vs. 7.4%). There was also no difference in cardiac death or clinically indicated TLR. As demonstrated in earlier trials, the rate of target vessel MI and definite or probable stent thrombosis was higher in the BVS arm (5.2% vs. 3.3%), however, this difference was only observed in the first 30 days following implantation, which was noted in the 1-year landmark analysis. Between 30 days and 3 years, there was no difference in stent thrombosis rates between the two groups. Interestingly, intravascular imaging use was low in both arms (less than 25% IVUS or OCT use). Additionally, protocol changes were made approximately 1.5 years into the trial, including recommendations for prolongation of DAPT use and exclusions of vessels less than 2.5 mm. Patients in the BVS group were more often treated with DAPT for longer than 12 months. The prolonged DAPT is unlikely to have contributed to a reduction in overall TVR but could explain the plateau in BVS thrombosis rates and TVMI. Adjustments in the implantation technique during the trial likely also contributed to this plateau.