P2808Absorb bioresorbable scaffold vs. Xience metallic stent: outcomes in the AIDA trial stratified by SYNTAX score
Authors: Tijssen R Y G , Kraak R P , Van Dongen I M , Elias J , Hofma S H , Van Der Schaaf R J , Arkenbout E K , Weevers A P J D , Tijssen J G P , Piek J J , De Winter R J , Henriques J P , Wykrzykowska J J 
Published: October 2019

Abstract

Aims
Extent of coronary artery disease (CAD) may affect outcomes after percutaneous coronary intervention (PCI). In this pre-specified subgroup analysis of the AIDA trial we evaluated the impact of SXscore on clinical outcomes

Methods and results
AIDA was a multicenter trial comparing Absorb with Xience. SX score was assessed using the baseline diagnostic angiograms. Each coronary lesion with diameter stenosis ≥50% in vessels ≥1.5 mm was scored. All lesion scores were combined to provide the overall SXscore. The angiographic SXscore calculations were performed by core laboratory analysts who were blinded for clinical events (Cardialysis B.V., Rotterdam, The Netherlands). Clinical outcomes were subsequently stratified according to SXscore tertiles: SXlow (SXcore ≤8), SXmid (SXscore >8 and ≤15) and SXhigh (>15). The primary endpoint of this AIDA-trial substudy was target vessel failure (TVF), defined as a composite of cardiac death, target vessel myocardial infarction and target vessel revascularization.
The SXscore was prospectively calculated in 1661 of the 1845 patients (90%). The SXscore ranged from 1 to 57, with a mean±SD of 12.9±8.5 and a median of 11 (Q1-Q3 7–17). In this analysis the SXscore tertiles were defined as SXlow (SXcore ≤8) (n=589), SXmid (SXscore >8 and ≤15) (n=538), and SXhigh (>15) (n=534). Patients in the SXhigh group were older, had a more extensive medical history for previous revascularizations (both PCI and coronary artery bypass grafting), and were more likely to present with a ST-elevation myocardial infarction.
At 2 follow-up the Kaplan-Meier estimates of TVF for the overall AIDA study population was 15.5% in the SXhigh tertile, 10.4% in the SXmid tertile and 4.7% in the SXlow tertile (hazard ratio (HR) 3.53 95% CI 2.28–5.45; P<0.001). The event rate of the primary endpoint of TVF was numerically lower in Absorb when compared to Xience (3.7% versus 5.6%; HR 0.64; 95% CI 0.29 - 1.40; p=0.257) in the SXlow tertile. Patients treated with Absorb and a SXscore >8 had significantly higher event rates as compared to patients with a SXscore ≤8. The rates of TVF in the Absorb BVS population are 15.5% (SXhigh), 11.4% (SXmid), and 3.7% (SXlow), with a significant difference between the SXlow versus SXmid (HR 3.27; 95% CI 1.61–6.68; p=0.001) and SXlow versus SXhigh (HR 4.57; 95% CI 2.29–9.10; p<0.001).
Target Vessel Failure in Absorb BVS

Conclusions
This study demonstrates that implantation of the Absorb in patients with a SXscore ≤8 is associated with numerically lower TVF rates as compared to the Xience drug-eluting stent. The rate of scaffold thrombosis in this SXlow tertile, while still higher for Absorb, is more acceptable than in SXmid and SXhigh score tertiles. Higher SXscore (i.e. >8), both Sxmid and SXhigh, however, appears to be associated with markedly increased risk of device thrombosis, revascularization and myocardial infarction in patients treated with the Absorb.

Acknowledgement/Funding
The AIDA trial was financially supported by an unrestricted research grant from Abbott Vascular