Mild cognitive impairment predicts death and readmission within 30days of discharge for heart failure

Quan L Huynh; Kazuaki Negishi; Leigh Blizzard; Makoto Saito; Carmine G De Pasquale; James L Hare; Dominic Leung; Tony Stanton; Kristy Sanderson; Alison J Venn; Thomas H Marwick

doi:10.1016/j.ijcard.2016.07.074

Mild cognitive impairment predicts death and readmission within 30days of discharge for heart failure

Int J Cardiol. 2016 Oct 15:221:212-7. doi: 10.1016/j.ijcard.2016.07.074. Epub 2016 Jul 6.

Authors

Affiliations

¹ Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
² Cardiac Services, Flinders Medical Centre, South Australia, Australia.
³ Baker IDI Heart and Diabetes Research Institute, Melbourne, Australia.
⁴ Faculty of Medicine, University of New South Wales, Sydney, Australia.
⁵ School of Medicine, University of Queensland, Brisbane, Australia.
⁶ Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia; Baker IDI Heart and Diabetes Research Institute, Melbourne, Australia. Electronic address: Tom.Marwick@bakeridi.edu.au.

PMID: 27404677
DOI: 10.1016/j.ijcard.2016.07.074

Abstract

Background: Cognitive impairment is highly prevalent in heart failure (HF), and may be associated with short-term readmission. This study investigated the role of cognition, incremental to other clinical and non-clinical factors, independent of depression and anxiety, in predicting 30-day readmission or death in HF.

Methods: This study followed 565 patients from an Australia-wide HF longitudinal study. Cognitive function (MoCA score) together with standard clinical and non-clinical factors, mental health and 2D echocardiograms were collected before hospital discharge. The study outcomes were death and readmission within 30days of discharge. Logistic regression, Harrell's C-statistic, integrated discrimination improvement (IDI) and net reclassification index were used for analysis.

Results: Among 565 patients, 255 (45%) had at least mild cognitive impairment (MoCA≤22). Death (n=43, 8%) and readmission (n=122, 21%) within 30days of discharge were more likely to occur among patients with mild cognitive impairment (OR=2.00, p=0.001). MoCA score was also negatively associated with 30-day readmission or death (OR=0.91, p<0.001) independent of other risk factors. Adding MoCA score to an existing prediction model of 30-day readmission significantly improved discrimination (C-statistic=0.715 vs. 0.617, IDI estimate 0.077, p<0.001). From prediction models developed from our study, adding MoCA score (C-statistic=0.83) provided incremental value to that of standard clinical and non-clinical factors (C-statistic=0.76) and echocardiogram parameters (C-statistic=0.81) in predicting 30-day readmission or death. Reclassification analysis suggests that addition of MoCA score improved classification for a net of 12% of patients with 30-day readmission or death and of 6% of patients without (p=0.002).

Conclusions: Mild cognitive impairment predicts short-term outcomes in HF, independent of clinical and non-clinical factors.

Keywords: Cognitive function; Depression; Heart failure; Mortality; Rehospitalization.

MeSH terms

Aged
Australia / epidemiology
Cognitive Dysfunction* / diagnosis
Cognitive Dysfunction* / epidemiology
Cognitive Dysfunction* / physiopathology
Echocardiography / methods
Female
Heart Failure* / diagnosis
Heart Failure* / mortality
Heart Failure* / psychology
Heart Failure* / therapy
Humans
Intelligence Tests
Longitudinal Studies
Male
Middle Aged
Outcome Assessment, Health Care
Patient Discharge / statistics & numerical data
Patient Readmission / statistics & numerical data
Prognosis
Research Design
Risk Assessment / methods
Risk Factors