Predictors of bioresorbable scaffold failure in STEMI patients at 3 years follow-up

Background: Little data are available on the long-term outcomes of bioresorbable scaffold (BRS) in the setting of ST-segment elevation myocardial infarction (STEMI). The aim of this study is to investigate three-years outcomes and predictors of BRS failure in patients presenting with STEMI. Methods and results: Two prospective, single-arm registries were pooled. Incidence and predictors of clinical outcome were assessed with Kaplan-Meier and Cox regression analyses. From May-2012 to January-2015, 183 STEMI patients (58 ± 13 years, 77% males, 29% diabetics) who received a total of 256 BRS (1.4 ± 0.8 per patient) were included. 248 patients (65 ± 11 years, 74% males, 27% diabetics) treated for stable coronary artery disease (SCAD) served as control. 3-years follow-up was available in 386 (90%) patients. Device-oriented composite endpoint and scaffold thrombosis (ScT) rates were similar in the two groups (STEMI: 11.5% vs SCAD: 12.9%, P = 0.84; STEMI: 3.6% vs SCAD: 3.3%, P = 0.90). While early ScT was more frequent in SCAD patients, late/very late ScT was a feature of STEMI. While in STEMI patients the incidence of ScT was higher in vessels with RVD > 3.5 mm, a RVD < 2.5 mm was a predictor of events in stable patients. Similarly, BRS undersizing predicted events in STEMI patients, while oversizing was a predictor in stable ones. Finally, the incidence of ScT was reduced in both STEMI and stable patients (from 6.3% to 0% and from 5.80% to 0.9%) when an optimized implantation technique was used. Conclusions: The incidence of events for three years follow-up was similar in STEMI and SCAD patients, although different timing and features underlie ScT in the two groups.