Longitudinal association of subclinical cardiac function with cognitive function

Abstract

Abstract Background Cognitive impairment and heart disease frequently co-exist due to shared disease processes and pathological mechanisms. The presence of one may lead to and/or worsen the other. This bidirectional relationship between cognitive impairment and heart disease acts as a vicious cycle that increases the burden of both diseases. Our previous findings have demonstrated that cognitive impairment is a strong predictor of post-discharge readmission or death in heart failure, second only to heart failure severity. However, whether heart failure and cognitive impairment has a causal relationship remains unknown. This study sought to determine the relationship between subclinical cardiac function and cognitive function. Methods This study included 1977 consecutive patients (62% men, aged 73±13 years) with heart failure ranging from stage A to C. These patients were followed up for 36 months. At both baseline and follow-up, subclinical cardiac function was measured by echocardiography, and cognitive function was measured using Montreal Cognitive Assessment (MOCA). Other measurements included blood biochemistry, comorbidities, physical measurements and questionnaires. Results Cognitive function was strongly associated with both readmission and death in patients with heart failure, particularly among those with stage C. Among patients with heart failure stage A or B, left atrial volume index (LAVI) and E/e’ were associated with a reduction of MOCA score and higher risks of newly developed cognitive impairment at 36-month follow-up (OR = 1.04 [95% CI:1.02-1.07] per 1ml/m2 LAVI, and OR = 1.07 [95% CI:1.01-1.15] per 1 unit E/e’). Patients with cognitive impairment have significantly enlarged left atrium, compared with those with normal cognition (p<0.001). While almost all (93%) of patients with consistent cognitive impairment from baseline to follow-up had an enlarged left atrium, 71% of those who became cognitively impaired at follow-up had an enlarged left atrium. Conclusions The longitudinal relationship between diastolic cardiac function and cognitive function suggests a causal pathway between these two. Assessment of cognitive function is recommended in patients with impaired cardiac function.