Discharge antithrombotic strategies among patients with acute coronary syndrome previously on warfarin anticoagulation: Physician practice in the CRUSADE registry

Background: Patients experiencing acute coronary syndromes (ACS) with high-risk features frequently undergo percutaneous coronary intervention (PCI) with stent placement, prompting the requisite administration of aspirin and clopidogrel. The current management of ACS patients with a concomitant indication for warfarin anticoagulant therapy is a question of growing interest and clinical relevance. Methods: We analyzed discharge antithrombotic medication use among all patients with non-ST-segment elevation (NSTE) ACS enrolled in the Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA Guidelines (CRUSADE) initiative who were receiving warfarin at the time of hospital admission. Multivariable logistic regression was used to determine factors associated with a decision to discontinue warfarin at discharge. Results: Among 5673 patients with ACS previously on home warfarin, 1357 (24%) were not discharged on warfarin. In the subset of 1247 patients who underwent coronary stenting, 60% were prescribed triple anticoagulation therapy (aspirin, clopidogrel, and warfarin), 31% were given aspirin and clopidogrel without warfarin, and 3% received warfarin and aspirin without clopidogrel. Factors associated with a decision not to continue warfarin at the time of hospital discharge included in-hospital red blood cell transfusion, non-white race, prior stroke, and discharge clopidogrel use. The decision to continue warfarin at discharge correlated with perceived bleeding risk and was unaffected by patients' stroke risk. Conclusion: Physician practices vary with regard to the perceived optimal antithrombotic strategy at time of hospital discharge among patients with ACS with a concomitant indication for warfarin. Decisions are influenced primarily by other medication use and anticipated bleeding risk. Further research is needed to guide patient care based on the safety and efficacy of antiplatelet-anticoagulant combined pharmacotherapy.