title: Left atrial dimension and traditional cardiovascular risk factors predict 20-year clinical cardiovascular events in young healthy adults: the CARDIA study.
abstract: OBJECTIVE
  We investigated whether the addition of left atrial (LA) size determined by echocardiography improves cardiovascular risk prediction in young adults over and above the clinically established Framingham 10-year global CV risk score (FRS).
  
  
  RESULTS
  We included white and black CARDIA participants who had echocardiograms in Year-5 examination (1990-91). The combined endpoint after 20 years was incident fatal or non-fatal cardiovascular disease: myocardial infarction, heart failure, cerebrovascular disease, peripheral artery disease, and atrial fibrillation/flutter. Echocardiography-derived M-mode LA diameter (LAD; n = 4082; 149 events) and 2D four-chamber LA area (LAA; n = 2412; 77 events) were then indexed by height or body surface area (BSA). We used Cox regression, areas under the receiver operating characteristic curves (AUC), and net reclassification improvement (NRI) to assess the prediction power of LA size when added to calculated FRS or FRS covariates. The LAD and LAA cohorts had similar characteristics; mean LAD/height was 2.1 ± 0.3 mm/m and LAA/height 9.3 ± 2.0 mm(2)/m. After indexing by height and adjusting for FRS covariates, hazard ratios were 1.31 (95% CI 1.12, 1.60) and 1.43 (95% CI 1.13, 1.80) for LAD and LAA, respectively; AUC was 0.77 for LAD and 0.78 for LAA. When LAD and LAA were indexed to BSA, the results were similar but slightly inferior. Both LAD and LAA showed modest reclassification ability, with non-significant NRIs.
  
  
  CONCLUSIONS
  LA size measurements independently predict clinical outcomes. However, it only improves discrimination over clinical parameters modestly without altering risk classification. Indexing LA size by height is at least as robust as by BSA. Further research is needed to assess subgroups of young adults who may benefit from LA size information in risk stratification.
authors.affiliation: Department of Cardiology/Cardiovascular Imaging, Johns Hopkins University, 600 N. Wolfe Street/Blalock 524, Baltimore, MD 21287-0409, USA Universidade Federal do Vale do São Francisco, Petrolina, PE, Brazil.
authors.forename: Anderson C
authors.initials: AC
authors.lastname: Armstrong
authors.affiliation: Northwestern University, Chicago, IL, USA.
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.affiliation: Kaiser Permanente, Oakland, CA, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sidney
authors.affiliation: Northwestern University, Chicago, IL, USA.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Colangelo
authors.affiliation: Department of Cardiology/Cardiovascular Imaging, Johns Hopkins University, 600 N. Wolfe Street/Blalock 524, Baltimore, MD 21287-0409, USA.
authors.forename: Satoru
authors.initials: S
authors.lastname: Kishi
authors.affiliation: Department of Cardiology/Cardiovascular Imaging, Johns Hopkins University, 600 N. Wolfe Street/Blalock 524, Baltimore, MD 21287-0409, USA.
authors.forename: Bharath
authors.initials: B
authors.lastname: Ambale-Venkatesh
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Arynchyn
authors.affiliation: University of Minnesota, Minneapolis, MN, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Jacobs
authors.affiliation: Escola Bahiana de Medicina, Salvador, BA, Brazil.
authors.forename: Luís C L
authors.initials: LC
authors.lastname: Correia
authors.affiliation: Nemours Cardiac Center, Wilmington, DE, USA.
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Gidding
authors.affiliation: Department of Cardiology/Cardiovascular Imaging, Johns Hopkins University, 600 N. Wolfe Street/Blalock 524, Baltimore, MD 21287-0409, USA jlima@jhmi.edu.
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D008297:Male; D009929:Organ Size; D011237:Predictive Value of Tests; D018570:Risk Assessment; D014481:United States / Q000453:epidemiology
keywords: Cardiovascular events; Echocardiography; Left atrial size; Young adults