Patterns of discharge antiplatelet therapy and late outcomes among 8,582 patients with bleeding during acute coronary syndrome: A pooled analysis from PURSUIT, PARAGON-A, PARAGON-B, and SYNERGY Mark Y. Chan, MBBS, MHS, FACC, a Jie L. Sun, MS, c Tracy Y. Wang, MD, MHS, c Renato D. Lopes, MD, MHS, PhD, c Marc E. Jolicoeur, MD, MHS, FACC, b,d Karen S. Pieper, MS, c Sunil V. Rao, MD, FACC, c,d L. Kristin Newby, MD, MHS, FACC, c,d Kenneth W. Mahaffey, MD, FACC, c,d Robert A. Harrington, MD, FACC, c,d and Eric D. Peterson, MD, MPH c,d Singapore, Singapore; Quebec, Canada; and Durham, NC Background Major bleeding during an acute coronary syndrome (ACS) is associated with increased late ischemic events. Patients with bleeding are often discharged without antiplatelet therapy (AT). The association between discharge AT use and late ischemic outcomes among ACS patients with bleeding is uncertain. Methods We examined discharge AT use among 8,582 ACS patients with in-hospital bleeding from a total of 26,451 patients enrolled in 4 randomized trials. After adjusting for the propensity to receive AT, we compared 6-month postdischarge outcomes between patients discharged with and those discharged without AT. Results Almost 1 in 10 patients with bleeding was discharged without AT (n = 826). Compared with those receiving discharge AT, those not receiving discharge AT had a higher risk of 6-month death, myocardial infarction, and stroke (14.3% vs 7.8%, propensity-adjusted hazard ratio [HR] = 1.36, 95% confidence interval = 1.01-1.85). Nonuse of AT at discharge was associated with worse outcomes among patients treated with percutaneous coronary intervention compared with those treated without it (adjusted HR = 4.22 vs 1.13, interaction P = .0003). Discharge monotherapy was associated with worse outcomes than dual AT among patients receiving stents (adjusted HR = 1.78, 95% CI = 1.04-3.03). Conclusions Bleeding occurred commonly among patients with ACS. AT was often not used in these patients at discharge, and lack of discharge AT was associated with an increased risk of 6-month ischemic events. These data raise the possibility that lack of AT use among patients with in-hospital bleeding may contribute to their excess risk of long-term ischemic outcomes. (Am Heart J 2010;160:1056-1064.e2.) Among patients hospitalized for acute coronary syn- drome (ACS), approximately 30% experience bleeding events of varying severity during hospitalization. 1-3 Major bleeding during an ACS is strongly associated with increased mortality and recurrent myocardial infarction (MI) up to 6 months after the initial bleeding event. 4-7 However, factors leading to the increased risk of future ischemic events in these patients are poorly understood. Antiplatelet therapy (AT) is often discontinued after bleeding, and many patients with bleeding are likely to be discharged without these agents. 8 Data on the association between the avoidance of discharge AT and late ischemic outcomes among ACS patients with bleeding are limited. We investigated the association between discharge AT and late clinical outcomes among ACS patients who had experienced bleeding during their index hospitalization. We hypothesized that among patients with bleeding, avoidance of discharge AT would be associated with higher risks of postdischarge ischemic outcomes com- pared with patients discharged on AT. We also sought to investigate whether this risk varied with the intensity of discharge AT and whether or not patients had undergone percutaneous coronary intervention (PCI) during their index hospitalization. Methods Data sources and study population We merged patient-level data from 4 phase III non–ST- elevation ACS clinical trials of antithrombotic therapy: Platelet From the a National University Heart Centre, Singapore, Singapore, b Montreal Heart Institute, Montreal, Quebec, Canada, c Duke Clinical Research Institute, Durham, NC, d Duke University Medical Center, Durham, NC. Submitted June 20, 2010; accepted September 5, 2010. Reprint requests: Mark Y. Chan, MBBS, MHS, FACC, National University Heart Centre, 1E, Kent Ridge Road, NUHS Tower Block, Level 9, Singapore, Singapore 119228. E-mail: mark_chan@nuhs.edu.sg 0002-8703/$ - see front matter © 2010, Mosby, Inc. All rights reserved. doi:10.1016/j.ahj.2010.09.001