Serum fatty acid binding proteins as a potential biomarker in atrial fibrillation

Atrial fibrillation (AF) is a commonly occurring arrhythmia which significantly reduces patients' quality of life and substantially shortens life expectancy. Although long chain fatty acids (LCFAs) are the basic energy substrates for myocardial metabolism, their excess can result in lipotoxicity, which increases the risk of arrhythmia. Intracellularly, LCFAs are bound by fatty acid biding proteins (FABPs) and this results in low level of free LCFAs in the cytoplasm. Based on this principle, FABPs are considered "safeguards" against overwhelming accumulation of esterified into different bioactive lipid fractions (e.g. ceramide, diacylglycerols) LCFAs. So far, several FABPs have been discovered in humans. Currently, in relation to cardiovascular diseases heart-type fatty acid binding protein (H-FABP) and adipocyte fatty acid binding protein (A-FABP) play significant roles. Nowadays, A-FABP is of great interest for research related with obesity, diabetes and coexisting disorders including cardiovascular diseases. Concomitantly, H-FABP is already well-established marker in the early diagnosis of myocardial infarction. Moreover, FABPs were assigned as a potential biomarker of AF in patients with de novo diagnosed arrhythmia, chronic heart failure (CHF), and in patients undergoing cardiac surgery. Another group of studies where the concentrations of plasma FABPs were analyzed are patients subjected to electrical cardioversion (ECV) and radio-catheter ablation therapy (RFA). It is worth mentioning that, in addition to traditional anti-arrhythmic drugs (AADs) or ECV, ablation techniques are used with good effects. Even though the treatment of arrhythmias is constantly developing, the maintenance of the sinus rhythm (SR) is still a serious problem. Therefore, it is worth looking for a biomarker which is suitable for the patient's treatment qualifications as well as assessing its effectiveness. Thus, the aim of this work is to present current data on the clinical significance of FABPs in terms of the development and treatment of AF.