Date of Award

January 2014

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Harlan M. Krumholz

Subject Area(s)



The treatment of patients with myocardial infarction was transformed by the introduction of intensive care units (ICUs), but we know little about how contemporary hospitals employ this resource-intensive setting and whether higher use is associated with better outcomes. We sought to determine the variation in the rates of ICU admission across hospitals for patients with myocardial infarction and whether these rates were associated with mortality or usage of critical care therapies. We hypothesized that large variations exist in rates of ICU use for these patients across hospitals, but that these differences would not be associated with in-hospital mortality. We identified 114,980 adult hospitalizations for acute myocardial infarction from 311 hospitals in the 2009-10 Premier database using codes from the International Classification of Diseases, Ninth Revision, Clinical Modification. Hospitals were stratified into quartiles by rates of ICU admission for patients with myocardial infarction. Across quartiles, we examined in-hospital risk-standardized mortality rates and usage rates of critical care therapies for these patients. Rates of ICU admission for patients with myocardial infarction varied markedly among hospitals (median 48%, IQR 35%-61%, range 0%-98%) and there was no association with in-hospital risk-standardized mortality rates (6% all quartiles; p=0.7). However, hospitals admitting more patients to the ICU were more likely to use critical care therapies overall (mechanical ventilation [from Quartile 1 with lowest rate of ICU use to Quartile 4 with highest rate: 13% to 16%], vasopressors/inotropes [17% to 21%], intra-aortic balloon pumps [4% to 7%], and pulmonary artery catheters [4% to 5%]; p for trend<0.05 in all comparisons). Rates of ICU admission for myocardial infarction vary substantially across hospitals and were not associated with differences in mortality, but were associated with greater use of critical care therapies.