Clinical impact of immediate invasive strategy in patients with non-ST-segment elevation myocardial infarction

Background Immediate invasive approach for non-ST-segment elevation myocardial infarction (NSTEMI) may permit treatment of the underlying plaque rupture as early as possible with subsequent reduction of death and myocardial infarction (MI). We sought to assess clinical impact of immediate percutaneous coronary intervention (PCI) for NSTEMI. Methods A total of 6134 NSTEMI patients undergoing PCI from the Korea Acute Myocardial Infarction Registry were divided into group 1 (immediate PCI within 4 h, n = 1132) and group 2 (non-immediate PCI after 4 h, n = 5002). Propensity-matched 12-month clinical outcome was compared. Results In all patients and propensity-matched cohort (n = 1131 in each group), group 1 had higher peak troponin level, higher rate of pre-PCI Thrombolysis In Myocardial Infarction (TIMI) grade 0 or 1, higher use of glycoprotein IIb/IIIa inhibitor, and lower use of unfractionated heparin and nitrates. In all patients, 12-month rates of MI and death/MI were higher in group 1. No differences were observed in 12-month death and major adverse cardiac events (MACE: composite of death, MI, target-vessel revascularization, and coronary artery bypass graft surgery). In propensity-matched cohort, no significant differences were observed in 12-month rates of death, MI, death/MI or MACE. However, group 1 had less major bleeding (0.8% vs. 3.0%, p = 0.024) and shorter hospital stay. Conclusions Immediate PCI for patients with NSTEMI was associated with lower pre-PCI culprit vessel patency and not with improved 12-month clinical outcome.