Association of Permanent Atrial Fibrillation with Cognitive Impairment in Stroke-Censored Patients from Western Romania: A Cross-Sectional Study

Background/Objectives: Cognitive impairment is highly prevalent in atrial fibrillation (AF) and frequently occurs in the absence of overt stroke, implicating non-embolic mechanisms. We hypothesized that atrial remodeling and impaired cerebral hemodynamics are associated with mild cognitive impairment (MCI) in permanent AF. Methods: In this cross-sectional study, 252 stroke-free patients with permanent AF receiving direct oral anticoagulants (DOACs) underwent transthoracic echocardiography and transcranial Doppler (TCD) assessment of middle cerebral artery flow. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) were analyzed. Multivariable logistic regression identified factors independently associated with MCI, and receiver operating characteristic (ROC) curves evaluated discriminative performance. Results: MCI was present in 40% of patients (101/252). AF-MCI patients were older and showed greater left atrial remodeling, reflected by increased left atrial diameter and left atrial volume index (LAVI) (both p ≤ 0.001), without differences in left ventricular systolic function. TCD demonstrated reduced EDV and increased RI in the MCI group (all p ≤ 0.01), whereas PSV showed minimal differences. In multivariable analysis, age, LAVI, and average RI were independently associated with MCI. Age showed excellent discrimination (AUC 0.858), whereas maximum RI demonstrated moderate discrimination (AUC 0.645; p < 0.001 for comparison). Conclusions: In stroke-censored permanent atrial fibrillation, cognitive impairment was associated with atrial remodeling and impaired diastolic cerebral perfusion, consistent with a potential contribution of chronic hypoperfusion and increased microvascular resistance. Combined echocardiographic and cerebral hemodynamic assessment may help characterize hemodynamic patterns associated with cognitive impairment in AF.