Determinants and prognostic value of left atrial volume in patients with dilated cardiomyopathy.
OBJECTIVE
We aimed to investigate the determinants of left atrial (LA) volume and its prognostic value in patients with dilated cardiomyopathy (DCM).


BACKGROUND
Enlargement of the LA is a marker of mortality in the general population. Patients with DCM are characterized by a wide range of LA sizes, but the clinical role of this observation has been played down.


METHODS
A complete echocardiographic Doppler examination was performed in 337 patients (age 60 +/- 13 years; 84% male) with the diagnosis of DCM. Left atrial maximal volume (LA(max)) was measured at left ventricular (LV) end systole (four-chamber view; area-length method). Left ventricular end-diastolic and end-systolic volumes (LVEDV and LVESV) and ejection fraction (EF) were also measured. Mitral regurgitation (MR) was graded using a 5-point scale. Mitral E-wave (E) and A-wave (A) velocities, as well as their ratio (E/A), were measured off-line.


RESULTS
Determinants of LA(max) were: atrial fibrillation (r = 0.34, p < 0.0001), LVEDV (r = 0.46, p < 0.0001), EF (r = 0.40, p < 0.0001), MR (r = 0.39, p < 0.0001), and E/A ratio (r = 0.36, p < 0.0001). During follow-up (41 +/- 29 months), 77 patients died and 12 underwent heart transplantation. Univariate Cox analysis showed that LA(max) (hazard ratio [HR] 1.01, 95% confidence interval [CI] 1.007-1.013, p < 0.0001), LVESV (HR 1.003, CI 1.001-1.005, p = 0.0003), E/A ratio (HR 1.6, CI 1.3-2.005, p < 0.0001), and MR (HR 1.21, CI 1.03-1.44, p = 0.02) were related to the outcome. On bivariate Cox analysis, LA(max) predicted the prognosis independently of each determinant. Patients with a larger LA volume (LA(max)/m(2) >68.5 ml/m(2)) had a risk ratio of 3.8 compared with those with a smaller LA volume.


CONCLUSIONS
In patients with DCM, LA volume is associated with LV remodeling, diastolic dysfunction, and the degree of MR. The maximal volume of the LA has an independent and incremental prognostic value, compared with all its determinants.
Rossi
Andrea
A
Dipartimento di Scienze Biomediche e Chirurgiche, Sezione di Cardiologia, Universita' di Verona, Verona, Italy. andrea.rossi@univr.it
Cicoira
Mariantonietta
M
Zanolla
Luisa
L
Sandrini
Rita
R
Golia
Giorgio
G
Zardini
Piero
P
Enriquez-Sarano
Maurice
M
D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012372:ROC Curve; D018608:Ultrasonography, Doppler; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D020257:Ventricular Remodeling