Inflammatory, renal, echocardiographic and epigenetic associations with prevalent permanent atrial fibrillation in patients with chronic heart failure: a cross-sectional study

Atrial fibrillation (AF) is a multifactorial condition potentially associated with inflammatory, morpho-structural, and epigenetic alterations. In recent years a growing body of evidence supported the role of inflammation in the initiation, maintenance and outcome of atrial fibrillation. We conducted a cross-sectional case-control study aimed at assessing possible associations between inflammatory cytokines, metabolic variables, epigenetic factors, and echocardiographic variables in patients with chronic heart failure (CHF) and permanent AF. We enrolled 82 consecutive patients with CHF and permanent AF and 82 consecutive patients with CHF and the similar cardiovascular comorbidity profile but with sinus rhythm and no known history of previous AF, consecutively admitted to the Internal Medicine with Stroke Care Ward of the "P. Giaccone" Hospital of Palermo January 2020 to May 2022. AF patients were significantly older and exhibited notable echocardiographic differences, including higher left atrial volume index (LAVI), reduced left atrial (LA) strain, increased relative wall thickness (RWT), and decreased ejection fraction (EF%). Renal function markers, such as estimated glomerular filtration rate (eGFR) and microalbuminuria, were also significantly different between groups. Inflammatory markers like C-reactive protein (CRP), interleukin 6 (IL6), interleukin 8 (IL8), and NT-proBNP were elevated in AF patients. No significant differences were observed for Monocyte Chemoattractant Protein-1 (MCP-1) and TNF-a. Sequential logistic regression analyses showed that LAVI, LA strain, microalbuminuria, albumin/creatinine ratio (ACr), and protein/creatinine ratio (PCr) remained significantly associated with prevalent permanent AF after sequential adjustment analyses including age and clinically relevant covariates. Correlation analysis in AF patients revealed associations between echocardiographic parameters, serum cytokines, and cardiac function indices. Notably, miRNA levels did not significantly differ between groups. These findings suggest significant associations between cardiac structure, renal function, inflammatory markers, and prevalent permanent AF.