Magnesium-based Resorbable Scaffold Vs Permanent Metallic Sirolimus-Eluting Stent in Patients with ST-segment Elevation Myocardial Infarction: 3-Year Results of the MAGSTEMI Randomised Controlled Trial

BACKGROUND:The long-term safety and performance of magnesium-based bioresorbable scaffolds (MgBRS) in ST-segment-elevation myocardial infarction (STEMI) patients are uncertain.AIMS:The aim of this study was to report the 3-year clinical outcomes of the MAGSTEMI trial.METHODS:This investigator-driven, multicentre, randomised, single-blind, controlled trial randomised STEMI patients 1:1 to MgBRS or to permanent metallic sirolimus-eluting stents (SES) at 11 academic centres. The main secondary endpoints included device-oriented composite endpoints (DoCE) and patient-oriented composite endpoints (PoCE), their individual components, any bleeding, and device thrombosis rate. All endpoints were defined according to the Academic Research Consortium. Events were adjudicated by an independent committee.RESULTS:Three-year clinical follow-up was obtained in 142 (90.0%) patients. At 3-year follow-up, MgBRS were associated with a higher rate of DoCE than SES (13 [17.6%] vs 5 [6.6%], diff -11.0 [95% CI: -21.3 to -0.7]; p=0.038). This difference was driven by an increased incidence of DoCE within the first year of follow-up. In the landmark analysis, there was no difference between 1 and 3 years (0 [0.0%] vs 1 [1.4%]; p=1.000). The difference in the rate of DoCE was driven by a higher incidence of target lesion revascularisation (TLR) in the MgBRS group compared to SES (12 [16.2%] vs 4 [5.3%]; diff -10.9% [95% CI: -20.7 to -1.2]; p=0.030). The difference in TLR was observed during the first year, with no further differences observed between 1 and 3 years (0 [0.0%] vs 1 [1.4%]; p=1.000).CONCLUSIONS:At 3-year follow-up, MgBRS were associated with a higher rate of TLR, which was clustered within the first year, compared to SES.