BACKGROUND AND OBJECTIVE:Shared decision making and advance planning in end-of-life decisions have become increasingly important aspects of the management of seriously ill patients. Here, we describe the use and timing of do-not-resuscitate (DNR) orders in patients hospitalized with acute myocardial infarction (AMI). STUDY DESIGN AND SETTING:The nonconcurrent prospective study population consisted of 4182 patients hospitalized with AMI in central Massachusetts in four annual periods between 2001 and 2007. RESULTS:One-quarter (25%) of patients had a DNR order written either prior to or during hospitalization. The frequency of DNR orders remained constant (24% in 2001; 26% in 2007). Among patients with DNR orders, there was a significant increase in orders written prior to hospitalization (2001: 9%; 2007: 55%). Older patients and those with a medical history of heart failure or myocardial infarction were more likely to have prior DNR orders than respective comparison groups. Patients with prior DNR orders were less likely to die 1 month after hospitalization than patients whose DNRs were written during hospitalization. CONCLUSION:Although the use of DNR orders in patients hospitalized with AMI was stable during the period under study, in more recent years, patients are increasingly being hospitalized with DNR orders already in place.