2006 HSR&D National Meeting Abstract
3039 — The Prevalence and Outcomes of In-Hospital Acute Myocardial Infarction in the VHA
Maynard CC (Northwest Ctr for Outcomes Research in Older Adults)
Lowy E (Northwest Ctr for Outcomes Research in Older Adults)
Rumsfeld J (Denver VAMC)
Sales AE (Northwest Ctr for Outcomes Research in Older Adults)
Sun H (Northwest Ctr for Outcomes Research in Older Adults)
Kopjar B (Northwest Ctr for Outcomes Research in Older Adults)
Fleming B (Office of Quality and Performance)
Jesse R (Richmond VAMC)
Fihn SD (Northwest Ctr for Outcomes Research in Older Adults)
Most studies of the epidemiology and treatment of acute myocardial infarction (AMI) have focused on patients who have onset of symptoms in the community and then present to the hospital. There are patients whose symptoms of AMI begin after hospitalization for other medical conditions. The purpose of this study was to determine the prevalence of in-hospital AMI in a national sample of all AMI cases in VHA and compare characteristics, treatment, and outcomes according to whether individuals presented with AMI or had in-hospital AMI.
Using information collected as part of the VHA External Peer Review Program, we evaluated 7054 veterans who had a first documented AMI and were discharged from VHA medical centers between July 2003 and August 2004.
There were 792 (11%) patients who had AMI while hospitalized for other medical conditions. Respiratory, gastrointestinal, cancer, endocrine metabolic conditions, and injury accounted for 53% of the admitting diagnoses for these patients. Cardiovascular conditions, excluding AMI and angina, comprised 18% of admissions, and were mainly heart failure and cerebrovascular disease. Although similar in ethnicity, patients with in-hospital AMI were significantly older and had more chronic illnesses than patients who presented to the hospital with AMI, but had fewer cardiovascular risk factors. The odds of 30 day mortality were nearly 4 times greater (33% versus 12%) among the in-hospital group (odds ratio=3.6, 95% confidence interval=3.1-4.3). In-hospital AMI was significantly associated with 30-day mortality after adjustment for covariates using logistic regression (adjusted odds ratio=2.0, 95% confidence interval=1.7-2.4). The 95% confidence interval was unaltered by adjusting for the clustering of patients within medical center.
Although most attention has been paid to patients with AMI admitted via the community emergency medical system or through the emergency department, AMI occurring during hospitalization for other medical problems is an important clinical problem in VHA. Moreover, when comparing mortality for AMI across medical centers and systems of care, the distribution of in-hospital AMI should be considered.
The high mortality of in-hospital AMI in VHA mandates further study into the epidemiology and clinical outcomes of this problem and its prevalence in other health care systems.