title: Left atrial mechanics in patients with acute STEMI and secondary mitral regurgitation: A prospective pilot CMR feature tracking study.
abstract: OBJECTIVE
  Left atrium (LA) is an important biomarker of adverse cardiovascular outcomes and cerebrovascular events. This study aimed to evaluate LA myocardial deformation using cardiac magnetic resonance feature tracking (CMR-FT) in patients with acute ST-segment elevation myocardial infarction (STEMI) and secondary mitral regurgitation (MR). Additionally, to assess interobserver and intraobserver variability of the technique.
  
  
  METHODS
  Twenty patients with STEMI underwent CMR with a 1.5Tesla MRI scanner. According to the presence of MR patients were divided into two groups: MR(+) and MR(-). Total LA strain (ɛs), passive LA strain (ɛe), and active LA strain (ɛa) were obtained. Additionally, total, passive and active strain rates (SRs, SRe, and SRa) were calculated. To assess interobserver agreement data analysis was performed by second independent observer.
  
  
  RESULTS
  LA volumetric and functional parameters were similar in both groups. All LA strain values were significantly higher in patients with MR: ɛs(27.67±10.25 for MR(-) vs. 32.80±6.95 for MR(+); P=0.01), ɛe(15.29±7.30 for MR(-) vs. 19.22±6.04 for MR(+); P=0.01) and ɛa(12.38±4.23 for MR(-) vs. 14.44±5.19 for MR(+); P=0.03). Only SResignificantly increased in patients with MR (-0.57±0.24 for MR(-) vs. -0.70±0.20 for MR(+); P=0.01). All LA deformation parameters demonstrated high interobserver and intraobserver agreement.
  
  
  CONCLUSIONS
  Conventional volumetric and functional LA parameters do not detect early changes in LA performance in patients with STEMI and secondary MR. In contrast, LA reservoir, passive and active strain are significantly higher in patients with MR. Only peak early negative strain rate substantially increases during secondary MR. LA deformation parameters derived from conventional cine images using CMR-FT technique are highly reproducible.
authors.affiliation: Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania. Electronic address: tomas.lapinskas@lsmuni.lt.
authors.forename: Tomas
authors.initials: T
authors.lastname: Lapinskas
authors.affiliation: Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Paulius
authors.initials: P
authors.lastname: Bučius
authors.affiliation: Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Laura
authors.initials: L
authors.lastname: Urbonaitė
authors.affiliation: Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Agnieta
authors.initials: A
authors.lastname: Stabinskaitė
authors.affiliation: Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Živilė
authors.initials: Ž
authors.lastname: Valuckienė
authors.affiliation: Department of Internal Medicine II, University Clinic Giessen-Marburg, Giessen, Germany.
authors.forename: Lina
authors.initials: L
authors.lastname: Jankauskaitė
authors.affiliation: Department of Cardiac, Thoracic and Vascular Surgery, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania; Institute of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Rimantas
authors.initials: R
authors.lastname: Benetis
authors.affiliation: Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Remigijus
authors.initials: R
authors.lastname: Žaliūnas
mesh_terms: D000368:Aged; D016279:Atrial Function, Left; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015588:Observer Variation; D010865:Pilot Projects; D011446:Prospective Studies; D015203:Reproducibility of Results; D000072657:ST Elevation Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D018709:Statistics, Nonparametric; D013318:Stroke Volume
keywords: Cardiac magnetic resonance; Feature tracking; Left atrium; Myocardial deformation; Reproducibility