The influence of pressure injury risk on the association between left ventricular ejection fraction and all-cause mortality in patients with acute myocardial infarction 80 years or older.

Abstract

We aimed to investigate whether the pressure injury risk mediates the association of left ventricular ejection fraction (LVEF) with all-cause death in patients with acute myocardial infarction (AMI) aged 80 years or older. This retrospective cohort study included 677 patients with AMI aged 80 years or older from a tertiary-level hospital. Pressure injury risk was assessed using the Braden scale at admission, and three risk groups (low/minimal, intermediate, high) were defined according to the overall score of six different variables. LVEF was measured during the index hospitalization for AMI. All-cause death after hospital discharge was the primary outcome. Over a median follow-up period of 1,176 d (interquartile range [IQR], 722-1,900 d), 226 (33.4%) patients died. Multivariate Cox regression analysis showed that reduced LVEF was associated with an increased risk of all-cause death only in the high-risk group of pressure injury (adjusted hazard ratios [HR]=1.81, 95% confidence interval [CI]: 1.03-3.20; P=0.040), but not in the low/minimal- (adjusted HR=1.29, 95%CI: 0.80-2.11; P=0.299) or intermediate-risk groups (adjusted HR=1.14, 95%CI: 0.65-2.02; P=0.651). Significant interactions were detected between pressure injury risk and LVEF (adjusted P=0.003). The cubic spline with hazard ratio plot revealed a distinct shaped curve relation between LVEF and all-cause death among different pressure injury risk groups. In older patients with AMI, the risk of pressure injury mediated the association between LVEF and all-cause death. The classification of older patients for both therapy and prognosis assessment appears to be improved by the incorporation of pressure injury risk assessment into AMI care management.