Abstract 10320: Left Atrial Strain is Associated With Atrial Fibrosis and MicroRNA-21 Expression in Cardiovascular Surgery Patients

• Published in: Circulation (New York, N.Y.) N.Y.), 2019-11, Vol.140 (Suppl_1 Suppl 1), p.A10320-A10320
• Main Authors: Hirose, Suguru, Nakajima, Toshiaki, Haruyama, Akiko, Kaneda, Hiroyuki, Obi, Syotarou, Nasuno, Takahisa, Inami, Shu, Shibasaki, Ikuko, Arikawa, Takuo, Sakuma, Satoshi, Toyoda, Shigeru, Nishimura, Masao, Fukuda, Hirotsugu, Abe, Shichirou, Inoue, Teruo
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.140.suppl_1.10320

IntroductionAtrial fibrosis plays an essential role in atrial remodeling and developing atrial fibrillation (Af). Left atrial strain (LAS) measured by two-dimensional speckle tracking (2DS) method has been reported to be a useful method to predict the degree of atrial fibrosis. On the other hand, small noncoding microRNAs are important mediators in many cardiac remodeling paradigms, and microRNA-21 (miR-21) has been suggested to be a crucial signaling molecule in atrial profibrillatory remodeling.HypothesisTo investigate the association of LAS, Af and atrial fibrotic remodeling by analyzing fibrosis-relating gene expression (collagen type 1 mRNA, and miR-21)MethodsConventional echocardiography and 2 DS method were performed in 117 patients (36 atrial fibrillation (Af) patients, 81 patients with sinus rhythm (SR), average age 69.7 years, 69 males) before cardiovascular surgery including cardiac valve replacement, and CABG. LAS was measured as systolic LA peak strain. The collagen type 1 mRNA and miR-21 expression were analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) in 39 cases in which left atrial tissues were removed from the appendage during surgery.ResultsLAS has a significant negative correlation with left atrial diameter (LAD), E/e ’and left atrial volume index (LAVI). LAS for patients with mitral valve replacement or repair was lower than LAS for patients with aortic valve replacement or TAVI and CABG, LAS was significantly lower in Af group, and LAD and LAVI were higher in Af group. LAS, but not LAD or LAVI, was negatively correlated with the expression level of collagen type 1 (r = -0.418, p = 0.015) and miR-21 (r = 0.471, p = 0.004). Similar findings were observed in patients with SR (18 patients), and LAS was an independent predictor of atrial miR-21 (β = -0.554, p = 0.004) and collagen type 1 (β = -0.736, p = 0.005) expression level even when corrected with age, gender and BMI.ConclusionsThe present study shows that LA strain is closely related to the degree of atrial collagen type 1 and miR-21 expression reflecting atrial fibrosis in cardiovascular surgery patients. LA strain is extremely useful as a marker for predicting the onset of atrial remodeling, atrial fibrosis and further atrial fibrillation.