Hospital Treatment Practices, 30-Day Hospital Readmissions, and Long-Term Prognosis in Patients Hospitalized with Acute Myocardial Infarction: A Dissertation

Abstract

Background: Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in the U.S. Acute myocardial infarction (AMI), with or without ST-segment elevation, is a common presentation of coronary heart disease and affected more than 800,000 American adults in 2010. The overall goal of this dissertation was to examine decade-long trends in the extent of delay in the receipt of a primary percutaneous coronary intervention (PCI) among patients hospitalized with ST-segment elevation myocardial infarction (STEMI), 30-day hospital readmission rates in patients having survived an AMI, and multiple decade long trends in 1-year post-hospital all-cause mortality, as well as factors associated with these outcomes, among patients hospitalized with AMI. Methods: Data from the Worcester Heart Attack Study, a population-based chronic disease surveillance project that has been carried out among adult residents of the Worcester, MA, metropolitan area, hospitalized with AMI on a biennial basis from 1975 through 2009 at all medical centers in central MA, were used for this dissertation. Results: Between 1999 and 2009, among patients hospitalized with STEMI, the likelihood of receiving a primary PCI within 90 minutes after emergency department arrival increased dramatically from 1999/2001 (11.6%) to 2007/2009 (70.5%). Between 1999 and 2009, among hospital survivors of an AMI, the 30-day all-cause rehospitalization rates decreased from 1999/2001 (20.3%) to 2007/2009 (16.7%). The overall cause-specific 30-day rehospitalization rates due to CVD, non-CVD, and AMI were 10.1%, 7.1%, and 1.8%, respectively, during the years under study. Between 1975 and 2009, among hospital survivors for a first AMI, the 1-year post-discharge mortality rates remained relatively stable from 1975-1984 (12.9%) to 1986-1997 (12.5%), but increased during 1999-2009 (15.8%). We identified several demographic, clinical and in-hospital treatment factors associated with an increased risk of failing to receive a primary PCI within 90 minutes after emergency department arrival, 30-day readmissions, and 1-year post-discharge mortality. Conclusions: Our findings can hopefully lead to the enhanced development of innovative, patient-centered, intervention strategies which can further improve the treatment and transitions of care, as well as short and long-term prognosis, of men and women hospitalized with AMI.