Adverse cardiovascular events in acute coronary syndrome with indications for anticoagulation

Objectives: Randomized acute coronary syndrome (ACS) trials testing various antithrombotic (AT) regimens have largely excluded patients with coexisting conditions and indications for anticoagulation (AC). The purpose of this study is to examine the 2-year clinical outcomes of patients with ACS with indication for AC due to venous thromboembolism (VTE) during hospitalization for the ACS event or a prior or new diagnosis of atrial fibrillation (AF) with a CHADS2 (Congestive heart failure; Hypertension; Age; Diabetes; previous ischemic Stroke) score ⩾2.

Methods: ACS patients with AC indication from 2004 to 2009 were identified (n = 619). A Cox proportional hazards model was used to examine the primary efficacy outcome of major adverse cardiovascular events (MACE) including all-cause death, myocardial infarction (MI) or stroke. The primary explanatory variable was at-discharge antithrombotic strategy [single antiplatelet ± AC, dual antiplatelet (DAP) ± AC or AC only; referent DAP + AC].

Results: A total of 261 (42.2%) patients had a MACE event. AT strategy was not a significant factor for MACE (all p > 0.09). The factors associated with MACE were high mortality risk score [hazard ratio (HR)=1.87, 95% confidence interval (CI): 1.39- 2.52; p < 0.001), prior MI (HR = 1.44, 95% CI: 1.03-2.01; p= 0.033) and presentation of ST elevation MI (HR = 2.70, 95% CI: 1.61-4.51; p < 0.001) or non-ST elevation MI (HR = 1.70, 95% CI: 1.15-2.49; p < 0.001) compared with angina.

Conclusions: In this real world observational study, the at-discharge AT strategy was not significantly associated with the 2-year risk of MACE. These findings do not negate the need for randomized trials to generate evidence-based approaches to management of this important population.