Characteristics and In-Hospital Outcomes of Patients With Non-ST-Segment Elevation Myocardial Infarction Undergoing an Invasive Strategy According to Hemoglobin Levels

The benefit of an invasive strategy in non-ST-segment elevation myocardial infarction (NSTEMI) was established from randomized trials that included few anemic patients. The aim of this study was to describe the characteristics, therapies, and mortality of patients with NSTEMIs who undergo an invasive strategy in relation to their admission hemoglobin levels. Data from 73,067 patients with NSTEMIs who underwent cardiac catheterization and who were captured by the Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With the Guidelines (ACTION-GWTG) were examined. Patients were divided into 3 hemoglobin groups on the basis of initial hemoglobin level: (1) <10 g/dl, (2) 10 to 12 g/dl, or (3) >12 g/dl. Patients with hemoglobin <10 g/dl had more co-morbidities and more 3-vessel coronary artery disease at catheterization compared with those with hemoglobin >12 g/dl (46.2% vs 33.9%, all p values <0.0001). They received fewer acute antithrombotic therapies, less often underwent revascularization (57.4% vs 74.1%), and had higher rates of red blood cell transfusion before catheterization (32.1% vs 0.3%, all p values <0.0001). After adjustment, in-hospital mortality was inversely associated with initial hemoglobin, with a 7% increase for each 1 g/dl decrease in hemoglobin lower than 15 g/dl (odds ratio 1.07, 95% confidence interval 1.02 to 1.11). In conclusion, in patients presenting with NSTEMIs and managed with an invasive strategy, a lower hemoglobin level is associated with more extensive coronary artery disease, less use of revascularization and evidence-based therapies, and increased mortality.