BackgroundDespite guideline recommendations, a significant number of patients with non–ST elevation myocardial infarction (NSTEMI) do not receive dual antiplatelet therapy (DAPT) before angiography “pretreatment.” While there may be valid clinical reasons to not pretreat, such as concern for bleeding or multivessel disease warranting coronary artery bypass graft surgery, the degree of variability and factors associated with DAPT pretreatment are unknown.Methods and ResultsFrom the multicenter TRIUMPH registry, 1632 NSTEMI patients were not taking DAPT on admission and were included in the study cohort. Among the study patients, only 22% patients received DAPT pretreatment. A multivariable logistic regression model showed that race other than white or black (odds ratio [OR] 0.41, 95% CI 0.21–0.83), hemoglobin level (OR 1.18, 95% CI 1.08–1.29), patients’ bleeding risk (assessed with NCDR CathPCI Bleeding Risk Score) (OR 0.85, 95% CI 0.74–0.99), and severe left ventricular dysfunction (OR 0.3, 95% CI 0.13–0.65) were the main predictors of pretreatment with DAPT, whereas likelihood of needing coronary artery bypass graft surgery (GRACE prediction model) was not (OR 1.09, 95% CI 0.88–1.35). Median ORs were calculated to assess variability of receiving DAPT pretreatment across sites after adjustment for patient characteristics. Receiving DAPT pretreatment varied substantially across sites (range 0–100%, mean OR 3.94, P<0.0001).ConclusionsWhile deviating from guideline‐recommended DAPT pretreatment in patients with NSTEMI was associated with patient factors (eg, bleeding risk), marked variation was present across sites after accounting for patient‐level characteristics. This suggests that site‐level interventions are needed to improve concordance with current guidelines.