Prospective, Randomized, Multicenter Evaluation of a Polyethylene Terephthalate Micronet Mesh–Covered Stent (MGuard) in ST-Segment Elevation Myocardial Infarction: The MASTER Trial
This study sought to evaluate the potential utility of a novel polyethylene terephthalate micronet mesh–covered stent (MGuard) in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI).
Background
Suboptimal myocardial reperfusion after PCI in STEMI is common and results in increased infarct size and mortality. The MGuard is a novel thin-strut metal stent with a polyethylene terephthalate micronet covering designed to trap and exclude thrombus and friable atheromatous debris to prevent distal embolization.
Methods
A total of 433 patients with STEMI presenting within 12 h 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). The primary endpoint was the rate of complete (≥70%) ST-segment resolution measured 60 to 90 min post-procedure.
Results
Baseline characteristics were well matched between the groups. The primary endpoint of post-procedure complete ST-segment resolution was significantly improved in patients randomized to the MGuard stent compared with control patients (57.8% vs. 44.7%; difference: 13.2%; 95% confidence interval: 3.1% to 23.3%; p = 0.008). By core laboratory analysis, the MGuard stent compared with control stents also resulted in superior rates of Thrombolysis In Myocardial Infarction 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). 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 and control stent, respectively.
Conclusions
Among patients with acute STEMI undergoing emergent PCI, the MGuard micronet mesh–covered stent compared with conventional metal stents resulted in superior rates of epicardial coronary flow and complete ST-segment resolution. A larger randomized trial is warranted to determine whether these benefits result in reduced infarct size and/or improved clinical outcomes. (Safety and Efficacy Study of MGuard Stent After a Heart Attack [MASTER]; NCT01368471)
Key Words
embolic protection
myocardial infarction
reperfusion
Abbreviations and Acronyms
BMS
bare-metal stent(s)
CMRI
cardiac magnetic resonance imaging
DES
drug-eluting stent(s)
ECG
electrocardiogram
IPTE
intraprocedural thrombotic event
MVO
microvascular obstruction
PCI
percutaneous coronary intervention
PET
polyethylene terephthalate
STEMI
ST-segment elevation myocardial infarction
STR
ST-segment resolution
SVG
saphenous vein graft
TIMI
Thrombolysis In Myocardial Infarction
TLR
target lesion revascularization
TVR
target vessel revascularization
Cited by (0)
Dr. Stone is a consultant to Boston Scientific, Abbott Vascular, Medtronic, InspireMD, Atrium, Eli Lilly, and Daiichi Sankyo. Drs. Silber, Kornowski, Merkely and Dudek have received research grants from and/or are consultants to InspireMD. Mr. Bar is a full-time employee of InspireMD and owns options. Dr. Maehara has received research grant from Boston Scientific and lecture fees from St. Jude Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. A complete list of the study organization and participating sites and investigators from the MASTER (Safety and Efficacy Study of MGuard Stent After a Heart Attack) trial is provided in the Online Appendix.
