Association of pre-percutaneous coronary flow grade and clinical outcomes in patients with non-ST-segment elevation myocardial infarction: Data from the Korea Acute Myocardial Infarction Registry

Because of a paucity of published data, we compared the 2-year major clinical outcomes between pre-percutaneous coronary intervention (pre-PCI) thrombolysis in myocardial infarction (TIMI) flow grade 0/1 (pre-TIMI flow grade [pre-TIMI] 0/1) group and pre-PCI TIMI flow grade 2/3 (pre-TIMI 2/3) group in patients with non-ST-segment elevation myocardial infarction (NSTEMI) who underwent successful implantation of newer-generation drug-eluting stent. A total of 7506 NSTEMI patients were divided into 2 groups: pre-TIMI 0/1 group (n = 3157) and pre-TIMI 2/3 group (n = 4349). The primary outcome was major adverse cardiac events defined as all-cause death, recurrent myocardial infarction, or any repeat revascularization. The secondary outcome was stent thrombosis (ST). After propensity score-matched (PSM) analysis, 2 PSM groups (2473 pairs, n = 4946, C-statistic = 0.684) were generated. Major adverse cardiac events (hazard ration [HR], 1.294; 95% confidence interval [CI]: 1.065–1.572; P = .009), all-cause death (HR, 1.559, P = .003), cardiac death (HR: 1.641, P = .005), and all-cause death or MI (HR: 1.531, P = .001) rates were significantly higher in the pre-TIMI 0/1 group than in the pre-TIMI 2/3 group. Moreover, these differences were more prominent during the first 1 month after the index PCI. However, the cumulative incidences of recurrent myocardial infarction, any revascularization, and ST were similar between the 2 groups. Among a contemporary cohort of NSTEMI, these data suggest that the presence of a pre-PCI patency of the infarct-related artery showed better mortality reduction capacity than those with a lack of patency.