Left atrial volume and function in patients following ST elevation myocardial infarction and the association with clinical outcome: a cardiovascular magnetic resonance study.
OBJECTIVE
The left atrium (LA) transfers blood to the left ventricle in a complex manner. LA function is characterized by passive emptying (LA passive fraction), active emptying (LA ejection fraction), and total emptying (LA fractional change). Despite this complexity, the clinical relevance of the LA is based almost exclusively on LA maximal volume (LAmax), which may not glean the full prognostic potential. Cardiovascular magnetic resonance (CMR) is considered the most accurate method for studying LA function and size. The aim of the present study was to evaluate the prognostic importance of LA function in patients following ST elevation myocardial infarction (STEMI).


RESULTS
In 199 patients, a CMR scan was performed within 1-3 days after STEMI to measure LAmax and minimal volume (LAmin) and LA function. The incidence of death, re-infarction, stroke, and admission for heart failure [major adverse cardiac event (MACE)] were registered during the follow-up period [2.3 years (inter-quartile range: 2.0-2.5)]. A total of 40 patients (20%) met the clinical endpoint of MACE during follow-up. In a Cox regression analysis adjusting for known risk factors, LA fractional change remained independently associated with MACE [adjusted hazard ratio: 0.66 (95% confidence interval: 0.46-0.95)]. LAmax, LAmin, or LA passive fraction was not independently associated with MACE. Furthermore, LA fractional change provided incremental prognostic value to LAmax and other known predictors (Wald χ(2) 31.0 vs. 39.9, P= 0.016).


CONCLUSIONS
In STEMI patients, impaired LA fractional change is independently associated with outcome and provide incremental prognostic information to established predictors including LAmax.
Department of Cardiology, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen, Rigshospitalet, Denmark. Jacoblonborg@gmail.com
Jacob Thomsen
JT
Lønborg
Thomas
T
Engstrøm
Jacob Eifer
JE
Møller
Kiril A
KA
Ahtarovski
Henning
H
Kelbæk
Lene
L
Holmvang
Erik
E
Jørgensen
Steffen
S
Helqvist
Kari
K
Saunamäki
Helle
H
Søholm
Mads
M
Andersen
Anders B
AB
Mathiasen
Jørgen Tobias
JT
Kühl
Peter
P
Clemmensen
Lars
L
Køber
Niels
N
Vejlstrup
D000368:Aged; D000704:Analysis of Variance; D016279:Atrial Function, Left / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D006334:Heart Function Tests; D006801:Humans; D016014:Linear Models; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality; D009929:Organ Size; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology; D015996:Survival Rate