Impact of mild cognitive impairment on unplanned readmission in patients with coronary artery disease.

Aims: To investigate the effect of mild cognitive impairment (MCI) on unplanned readmission in patients with coronary artery disease (CAD).

Methods And Results: From 2132 CAD patients, MCI was estimated with the Japanese version of the Montreal Cognitive Assessment (MoCA-J) in 243 non-dementia patients who met the study criteria. The primary outcome was unplanned hospital readmission after discharge. The incidence of MCI in this cohort was 33.3%, and 51 patients (21.0%) had unplanned readmission during a mean follow-up period of 418.6 ± 203.5 days. After adjusting for the covariates, MCI (hazard ratio, 2.28; 95% confidence interval: 1.09-4.76; P = 0.03) was independently associated with unplanned readmission in the multivariable Cox proportional hazard regression analysis. In the Kaplan-Meier analysis, the cumulative incidence of unplanned readmission for the MCI group was significantly higher than that for the non-MCI group (log-rank test, P < 0.001). Even after exclusion of the patients readmitted within 30 days of discharge, the main results did not change (log-rank test, P < 0.001).

Conclusion: Mild cognitive impairment was independently associated with unplanned readmission after adjustment for many independent variables in CAD patients. In addition to its short-term effects, the adverse effects of MCI had a persistent, long-term impact on CAD patients. Assessment of cognitive function should be conducted by health professionals prior to hospital discharge and during follow-up. To prevent readmission of CAD patients, it will be necessary to support solutions to the problems that inhibit secondary prevention behaviours based on the assessment of the patients' cognitive function.