The objective of the MASTER trial was to demonstrate the superiority of the MGuardTM/MGuard Prime stent over commercially-approved bare-metal (BMS) or drug-eluting stents (DES) in achieving better myocardial reperfusion in primary angioplasty for the treatment of acute ST-elevation myocardial infarction (STEMI).


Study design

A total of 433 patients with STEMI presenting within 12 hours of symptom onset undergoing PCI were randomized at 50 sites in 9 countries to the MGuard (n=217) or commercially available bare metal or drug-eluting stents (n=216).



Baseline characteristics were well matched between the groups. Median age was 59 years and 24% of patients were female. The infarct vessel was the left anterior descending coronary artery in 40.2% of patients, the right coronary artery in 51.3%, and the left circumflex coronary artery in 8.3%. The primary endpoint of post-procedure complete STR was significantly improved in patients randomized to the MGuard stent compared to control (57.8% vs. 44.7%, difference [95%CI] = 13.2% [3.1, 23.3], P=0.008). In addition, the MGuard stent resulted in superior rates of TIMI-3 flow (91.7% vs. 82.9%, P=0.006) with comparable rates of myocardial blush grade 2 or 3 (83.9% vs. 84.7%, P=0.81) and cTFC (17.0 vs. 18.1, P=0.23). Mortality (0% vs. 1.9%, P=0.06) and major adverse cardiac events (1.8% vs. 2.3%, P=0.75) at 30 days were not significantly different between patients randomized to the MGuard stent vs. control, respectively. At 12 months, cardiac death and all-cause mortality were numerically lower in the MGuard stent compared to control ((1.0% vs. 3.3%, P=0.09, and 0.5% vs. 2.3%, P=0.10, respectively) TLR was higher in the MGuard arm (8.6% vs. 0.9%, P=0.0003).



Among patients with acute STEMI undergoing emergent PCI, MGuard resulted in superior rates of epicardial coronary flow and complete STR, with similar rates of 30 day MACE (1)



1. Stone GW, Abizaid A, Silber S, Dizon JM, Merkely B, et al. 2012. Prospective, Randomized, Multicenter Evaluation of a Polyethylene Terephthalate Micronet Mesh-Covered Stent (MGuard) in ST-Segment Elevation Myocardial Infarction: The MASTER Trial. J Am Coll Cardiol 60:1975-84