Trends, management, and outcomes of acute myocardial infarction hospitalizations with in-hospital-onset versus out-of-hospital onset: The aric study

BACKGROUND: Acute myocardial infarction (AMI) with in-hospital onset (AMI-IHO) has poor prognosis but is clinically underap-preciated. Whether its occurrence has changed over time is uncertain. METHODS AND RESULTS: Since 1987, the ARIC (Atherosclerosis Risk in Communities) study has conducted adjudicated surveillance of AMI hospitalizations in 4 US communities. Our analysis was limited to patients aged 35 to 74 years with symptomatic AMI. Patients with symptoms initiating after hospital arrival were considered AMI-IHO. A total of 26 678 weighted hospitalizations (14 276 unweighted hospitalizations) for symptomatic AMI were identified from 1995 to 2014, with 1137 (4%) classified as in-hospital onset. The population incidence rate of AMI-IHO increased in the 4 ARIC communities from 1995 through 2004 to 2005 through 2014 (12.7—16.9 events per 100 000 people; P for 20-year trend <0.0001), as did the proportion of AMI hospitalizations with in-hospital onset (3.7%–6.1%; P for 20-year trend =0.03). The 10-year proportions were stable for patients aged 35 to 64 years (3.0%–3.4%; P for 20-year trend =0.3) but increased for patients aged ≥65 years (4.6%–7.8%; P for 20-year trend =0.008; P for interaction by age group =0.04). AMI-IHO had a more severe clinical course with lower use of AMI therapies or invasive strategies and higher in-hospital (7% versus 3%), 28-day (19% versus 5%), and 1-year (29% versus 12%) mortality (P<0.0001 for all). CONCLUSIONS: In this population-based community surveillance, AMI-IHO increased from 2005 to 2014, particularly among older patients. Quality initiatives to improve recognition and management of AMI-IHO should be especially focused on hospitalized patients aged >65.