title: Left atrial expansion index predicts all-cause mortality and heart failure admissions in dyspnoea.
abstract: OBJECTIVE
  The power of left atrial (LA) parameters for predicting adverse events in relatively low-risk groups is not fully understood. This study investigated whether the LA expansion index predicts heart failure (HF) and all-cause mortality in subjects with dyspnoea.
  
  
  RESULTS
  Echocardiography was performed to identify causes of dypnoea in 1735 patients. The LA expansion index was calculated as (Volmax - Volmin) × 100%/Volmin, where Volmax was defined as the maximal LA volume and Volmin was defined as the minimal LA volume. The endpoints were 2-year frequencies of HF hospitalization and all-cause mortality. Over a median follow-up of 2.7 years, 91 participants reached endpoints. Rates of adverse events were exponentially proportional to the LA expansion index. For predicting adverse events, the LA expansion index was better than the maximal indexed LA volume and tissue Doppler parameters. Hospitalization for HF was independently associated with age, LVEF, pulmonary artery systolic pressure, LA expansion index, and history of prior HF. All-cause mortality was associated with age, pulmonary artery systolic pressure, and LA expansion index. Compared with the highest quartile of the LA expansion index, the lowest quartile had a 3.1-fold higher hazard of HF events and a 17.8-fold higher hazard of all-cause mortality.
  
  
  CONCLUSIONS
  The LA expansion index predicts adverse events in patients with dyspnoea. The prognostic power of the index exceeds that of other well-established echocardiographic parameters such as E/e' and maximal indexed LA volume. Trial registration NCT01171040.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
authors.forename: Shih-Hung
authors.initials: SH
authors.lastname: Hsiao
authors.forename: Kuan-Rau
authors.initials: KR
authors.lastname: Chiou
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016279:Atrial Function, Left / Q000502:physiology*; D004417:Dyspnea / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: All-cause mortality; Heart failure hospitalization; Left atrial expansion index; Maximal indexed left atrial volume