Abstract P327: Device-Measured Sedentary Behavior and Risk of 1-Year Hospital Readmission After Suspected Acute Coronary Syndrome

Abstract

Background: Patients hospitalized with acute coronary syndrome (ACS) have an increased risk of a readmission during the first year after discharge; necessitating a need to identify modifiable therapeutic targets to improve outcomes. While moderate to vigorous physical activity (MVPA) has been a hallmark of secondary prevention efforts to prevent hospital readmission, sedentary behavior (SB) has emerged as a potentially unique and clinically important aspect of the physical activity profile. Yet, little is known regarding whether SB is associated with hospital readmission in ACS patients independent from or in addition to MVPA levels. Purpose: To examine the association between device-measured SB and risk of 1-year hospital readmission among patients evaluated for ACS, independent of MVPA. Methods: Patients (n=603, 47.8% female, 62.5±13.0 yrs) evaluated in the emergency department for ACS were fitted with a GENEActiv accelerometer in-hospital and were instructed to wear the device on their non-dominant wrist continuously in-hospital and for 30 days post-discharge. Hospital readmissions were ascertained by proactively searching medical records for any possible hospitalizations and by contacting participants or their closest contacts at 1- and 12-months follow-up; with supporting documentation secured from hospital medical records. Results: Over 1-year follow-up, 281 (46.6%) patients were readmitted. SB was associated with increased risk of 1-year hospital readmission after adjusting for socio-demographic factors, comorbidities, and disease severity indicators [HR per 1-hour per day increase in SB= 1.09, 95% CI: 1.01, 1.18]. The association remained significant after further adjusting for MVPA [HR per 1-hour per day increase in SB= 1.11, 95% CI: 1.02, 1.22]. In joint association analyses, high sedentary time in combination with low MVPA was associated with the greatest risk of 1-year hospital readmission in a fully adjusted model (HR: 2.18; 95%: CI: 1.44, 3.31) compared to the referent group (low SB/high MVPA). However, even among participants with higher levels of MVPA; high sedentary time was associated with a greater risk of 1-year re-hospitalization (HR: 1.54; 95% CI: 1.05, 2.27). For participants with low MVPA and low sedentary time, no significant association was observed (HR: 1.37; 95% CI: 0.84, 2.21). Conclusions: SB was associated with an increased risk of 1-year hospital readmission among patients evaluated for ACS. This increased risk was independent of MVPA and was not eliminated by high levels of MVPA. Implications of this study suggest that reducing SB should be considered as a modifiable therapeutic target in addition to MVPA to improve outcomes in ACS survivors.