Hospital length of stay in patients with non-ST-segment elevation myocardial infarction

Abstract

Purpose: Substantial heterogeneity in hospital length of stay exists among patients admitted with non-ST-segment elevation myocardial infarction. Furthermore, little is known about the factors that impact length of stay.

Methods: We examined 39,107 non-ST-segment elevation myocardial infarction patients admitted to 351 Acute Coronary Treatment Intervention Outcomes Network Registry-Get With The Guidelines hospitals from January 1, 2007-March 31, 2009 who underwent cardiac catheterization and survived to discharge. Length of stay was categorized into 4 groups (≤2, 3-4, 5-7, and ≥8 days), where prolonged length of stay was defined as >4 days.

Results: The overall median (25(th), 75(th)) length of stay was 3 (2, 5) days. Patients with a length of stay of >2 days were older with more comorbidities, but were less likely to receive evidence-based therapies or percutaneous coronary intervention. Among the factors associated with prolonged length of stay >4 days were delay to cardiac catheterization >48 hours, heart failure or shock on admission, female sex, insurance type, and admission to the hospital on a Friday afternoon or evening. Hospital characteristics such as academic versus nonacademic or urban versus rural setting, were not associated with prolonged length of stay.

Conclusion: Patients with longer length of stay have more comorbidities and in-hospital complications, yet paradoxically, are less often treated with evidence-based medications and are less likely to receive percutaneous coronary intervention. Hospital admission on a Friday afternoon or evening and delays to catheterization appear to significantly impact length of stay. A better understanding of factors associated with length of stay in patients with non-ST-segment elevation myocardial infarction is needed to promote safe and early discharge in an era of increasingly restrictive health care resources.

Figure 1. Distribution of LOS

This figure displays the distribution of LOS in days as a percentage of the entire population studied.

Figure 2. Length of Stay based on Time to Catheterization and Occurrence of Complications

This figure displays the median LOS based on whether or not the patients had cardiac catheterization within three days of admission, or at least one complication. Regardless of the presence of complications, those who received cardiac catheterization after three days from admission had a longer hospital LOS.

Figure 3. Length of Stay based on ACTION Registry-GWTG Mortality Risk Score

There is a consistent trend of increased LOS with increased mortality risk, based on the ACTION Registry-GWTG mortality risk score.

Figure 4. Geographical Variation in Hospital Length of Stay

There are important variations in the lengths of stay based on geographical variations in the U.S. The Northeast has highest percentage of patients with LOS ≥5 days, while the West has the highest percentage of patients with LOS ≤2 days and the lowest percentage with LOS ≥5 days.