Prediction of cardiovascular outcomes with left atrial size: is volume superior to area or diameter?
OBJECTIVE
We sought to compare left atrial (LA) volume to LA area and diameter for the prediction of adverse cardiovascular outcomes.


BACKGROUND
The incremental value of LA volume compared with LA area or diameter as a cardiovascular risk marker has not been evaluated prospectively for patients with sinus rhythm or atrial fibrillation (AF).


METHODS
Left atrial size was assessed with biplane LA volume, four-chamber LA area, and M-mode dimension for 423 patients (mean age 71 +/- 8 years, 56% men) who were prospectively followed for development of first AF, congestive heart failure, stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death.


RESULTS
Of the 317 subjects in sinus rhythm at baseline, 62 had 90 new events during a mean follow-up of 3.5 +/- 2.3 years. All three LA size parameters were independently predictive of combined outcomes (all p < 0.0001). The overall performance for the prediction of cardiovascular events was greatest for LA volume (area under the receiver operator characteristic curve: indexed LA volume 0.71; LA area 0.64; LA diameter 0.59). A graded association between the degree of LA enlargement and risk of cardiovascular events was only evident for indexed LA volume. For subjects with AF, there was no association between LA size and cardiovascular events.


CONCLUSIONS
Left atrial volume is a more robust marker of cardiovascular events than LA area or diameter in subjects with sinus rhythm. The predictive utility of LA size for cardiovascular events in AF was poor, irrespective of the method of LA size quantitation.
Tsang
Teresa S M
TS
Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA. tsang.teresa@mayo.edu
Abhayaratna
Walter P
WP
Barnes
Marion E
ME
Miyasaka
Yoko
Y
Gersh
Bernard J
BJ
Bailey
Kent R
KR
Cha
Stephen S
SS
Seward
James B
JB
D000367:Age Factors; D000368:Aged; D001146:Arrhythmia, Sinus / Q000150:complications* / Q000473:pathology*; D001281:Atrial Fibrillation / Q000150:complications* / Q000473:pathology*; D002318:Cardiovascular Diseases / Q000209:etiology*; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors