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

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 30 days 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 30 days 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.