Long Noncoding RNA UCA1 Correlates With Electropathology in Patients With Atrial Fibrillation

Background: Perpetuation of atrial fibrillation (AF) is rooted in derailment of molecular proteostasis pathways that cause electrical conduction disorders that drive AF. Emerging evidence indicates a role for long noncoding RNAs (lncRNAs) in the pathophysiology of cardiac diseases, including AF. Objectives: In the present study, the authors explored the association between 3 cardiac lncRNAs and the degree of electropathology. Methods: Patients had paroxysmal AF (ParAF) (n = 59), persistent AF (PerAF) (n = 56), or normal sinus rhythm without a history of AF (SR) (n = 70). The relative expression levels of urothelial carcinoma–associated 1 (UCA1), OXCT1-AS1 (SARRAH), and the mitochondrial lncRNA uc022bqs.q (LIPCAR) were measured by means of quantitative reverse-transcription polymerase chain reaction in the right atrial appendage (RAA) or serum (or both). A selection of the patients was subjected to high-resolution epicardial mapping to evaluate electrophysiologic features during SR. Results: The expression levels of SARRAH and LIPCAR were decreased in RAAs of all AF patients compared with SR. Also, in RAAs, UCA1 levels significantly correlated with the percentage of conduction block and delay, and inversely with conduction velocity, indicating that UCA1 levels in RAA reflect the degree of electrophysiologic disorders. Moreover, in serum samples, SARRAH and UCA1 levels were increased in the total AF group and ParAF patients compared with SR. Conclusions: LncRNAs SARRAH and LIPCAR are reduced in RAA of AF patients, and UCA1 levels correlate with electrophysiologic conduction abnormalities. Thus, RAA UCA1 levels may aid staging of electropathology severity and act as a patient-tailored bioelectrical fingerprint.