This study was designed to determine whether the treatment of patients with unstable angina pectoris or non-Q-wave myocardial infarction with a stent containing a protection net to prevent coronary microembolization affects the severity of biomarker release.The MGuard stent (InspireMD, Tel Aviv, Israel) was designed as a plaque/thrombus-trapping device, using a conventional bare metal stent covered with an ultrathin, flexible mesh net. We hypothesized that this stent would partly eliminate distal embolization and decrease subsequent troponin I (TnI) release.Forty-six acute coronary syndrome patients referred for percutaneous coronary intervention (PCI) were included and randomized in this study. Serum concentrations of TnI were measured prior to, as well as 24 and 48 hours after, the PCI procedure.Technical success was 95% and 100% in the MGuard group and non-MGuard group, respectively. A transient no-reflow phenomenon was observed in one interventional procedure in each group of patients (5% versus 4%; NS). Two patients (one in each group) died during the hospital stay. There was no statistically significant difference in median postprocedural TnI levels in either group.The results suggest that coronary stenting with a stent system containing a protection net to prevent coronary microembolization (eg the MGuard stent) in patients with acute coronary syndromes does not decrease procedural myocardial injury, as measured by TnI release. It seems likely that stenting with the MGuard stent is feasible, however, its safety should be verified in larger studies.