Cognitive function in post-cardiac intensive care: patient characteristics and impact of multidisciplinary cardiac rehabilitation

New/worsening cognitive and physical impairments following critical care pose significant problems. Multidisciplinary cardiac rehabilitation (CR) can improve physical function after cardiac intensive care (CIC). This observational study aimed to evaluate cognitive function in patients participating in multidisciplinary CR and to identify correlates of impaired cognitive function after CIC. We analyzed 111 consecutive patients admitted to our comprehensive care ward at least 7 days after CIC and assessed factors associated with cognitive function using the Functional Independence Measure (FIM). Patients were stratified into two groups based on the median FIM-Cognitive scores: impaired (n = 56) and preserved cognition (n = 55) groups. Multiple logistic regression analysis identified age [odds ratio (OR) 1.06; 95% confidence interval (CI) 1.00–1.13; p = 0.042], Mini-Nutrition Assessment-Short Form (MNA-SF; OR 0.73; 95% CI 0.56–0.95; p = 0.017), and FIM-Physical scores (OR: 0.94; 95% CI 0.90–0.99; p = 0.012) as significant and independent factors associated with impaired cognition. The median length of hospital stay was 28 (interquartile range: 18, 43) days. The FIM-Cognitive and FIM-Physical scores significantly increased from admission to discharge [32.0 (27.0, 35.0) vs. 34.0 (29.0, 35.0) points; p < 0.001; 67.0 (53.0, 75.0) vs. 85.0 (73.5, 89.0) points; p < 0.001, respectively]. On subgroup analysis within the impaired cognition group, increased FIM-Cognitive scores positively and significantly correlated with increased FIM-Physical scores (ρ = 0.450; p = 0.001). Multiple linear regression analysis identified atrial fibrillation (AF; β = − 0.29; p = 0.016), ln(glycated hemoglobin; HbA1c) (β = 0.29; p = 0.018), and ln(high-sensitivity C-reactive protein; hs-CRP) (β = − 0.26; p = 0.034) as significant and independent factors correlated with increased FIM-Cognitive scores. In conclusion, advanced age, low MNA-SF score, and FIM-Physical score were independent factors associated with impaired cognition in post-CIC patients. Multidisciplinary CR improved both physical and cognitive functions, and AF, HbA1c, and hs-CRP were independent factors correlated with increased FIM-Cognitive score.