title: Left atrial passive emptying function during dobutamine stress MR imaging is a predictor of cardiac events in patients with suspected myocardial ischemia.
abstract: OBJECTIVE
  The aim of this study was to determine the prognostic value of assessing left atrial function during dobutamine stress testing.
  
  
  BACKGROUND
  Left ventricular diastolic dysfunction precedes systolic wall motion abnormalities in the ischemic cascade. Severity of left ventricular diastolic function during cardiac stress is not characterized well by current clinical imaging protocols but may be an important prognostic factor. We hypothesized that abnormal early left atrial emptying measured during dobutamine stress cardiac magnetic resonance will reflect these diastolic changes and may be associated with cardiovascular outcomes.
  
  
  METHODS
  We enrolled 122 consecutive patients referred for dobutamine stress cardiac magnetic resonance for suspected myocardial ischemia. Left atrial volumes were retrospectively measured by the biplane area-length method at left ventricular end-systole (VOL(max)) and before atrial contraction (VOL(bac)). Left atrial passive emptying fraction defined by (VOL(max) - VOL(bac)) × 100%/VOL(max) and the absolute percent increase in left atrial passive emptying fraction during dobutamine stress (ΔLAPEF) were quantified.
  
  
  RESULTS
  Twenty-nine major adverse cardiac events (MACE) occurred during follow-up (median 23 months). By Kaplan-Meier analysis, patients with ΔLAPEF <10.8 (median) experienced higher incidence of MACE than did patients with a ΔLAPEF >10.8 (p = 0.004). By univariable analysis, ΔLAPEF was strongly associated with MACE (unadjusted hazard ratio for every 10% decrease = 1.56, p < 0.005). By multivariable analysis, every 10% decrease in ΔLAPEF carried a 57% increase in MACE, after adjustment to presence of myocardial ischemia and infarction.
  
  
  CONCLUSIONS
  Reduced augmentation of left atrial passive emptying fraction during dobutamine stress demonstrated strong association with MACE. We speculate that reduced left atrial passive emptying reserve during inotropic stress may represent underlying diastolic dysfunction and warrants further investigation.
authors.affiliation: Department of Medicine, Brigham and Women’s Hospital, Boston, MA, USA.
authors.forename: Afshin
authors.initials: A
authors.lastname: Farzaneh-Far
authors.forename: Vignendra
authors.initials: V
authors.lastname: Ariyarajah
authors.forename: Chetan
authors.initials: C
authors.lastname: Shenoy
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Dorval
authors.forename: Matthew
authors.initials: M
authors.lastname: Kaminski
authors.forename: Zelmira
authors.initials: Z
authors.lastname: Curillova
authors.forename: Henry
authors.initials: H
authors.lastname: Wu
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Brown
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Kwong
mesh_terms: D000368:Aged; D016279:Atrial Function, Left; D001900:Boston; D002316:Cardiotonic Agents; D004280:Dobutamine; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012044:Regression Analysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine