The American College of Cardiology/American Health Association guidelines recommend both an early invasive strategy and administration of antiplatelet/anticoagulant therapy for high-risk patients in the absence of contraindications. Little is known about adherence to guideline recommendations in patients with prior coronary artery bypass graft (CABG) surgery presenting with non–ST-segment elevation myocardial infarction (NSTEMI).

We analyzed 47,557 patients with NSTEMI in the 2007-2008 National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines. Treatment patterns were compared between patients with and without prior CABG surgery. Multivariable regression with generalized estimating equations evaluated the association between prior CABG and in-hospital outcomes.

In this study, 8,790 NSTEMI patients (18.5%) had a history of CABG surgery. Prior CABG surgery was associated with a significantly lower adjusted likelihood of early cardiac catheterization (adjusted odds ratio [OR] 0.88, 95% CI 0.83-0.92), higher rates of short-term clopidogrel use (adjusted OR 1.08, 95% CI 1.02-1.14), and comparable use of anticoagulant therapy (adjusted OR 0.96, 95% CI 0.88-1.04). Adjusted risks of bleeding and in-hospital mortality did not differ significantly between the 2 groups (adjusted ORs 1.00, 95% CI 0.92-1.11 and 0.99, 95% CI 0.87-1.11, respectively).

Patients with prior CABG surgery presenting with NSTEMI are often felt to be at high risk for adverse outcomes and therefore require aggressive treatment. Our study indicates that they are less likely to undergo guideline-recommended early cardiac catheterization but equally or more likely to receive guideline-recommended antiplatelet and anticoagulant therapy. This risk-treatment paradox, however, does not appear to negatively influence short-term clinical outcomes.